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Pathogen reduction in septic tank sludge through vermicomposting using Eisenia fetida
Abstract
This study evaluated the potential of earthworms (Eisenia fetida) to remove pathogens from the sludge from septic tanks. Three earthworm population densities, equivalent to 1, 2, and 2.5kgm(-2), were tested for pathogen removal from sludge. The experimental phase lasted 60days, starting from the initial earthworm inoculation. After 60days, it was found that earthworms reduced concentrations of fecal coliforms, Salmonella spp., and helminth ova to permissible levels (<1000MPN/g, <3MPN/g, and <1viable ova/g on a dry weight basis, respectively) in accordance with Official Mexican Standard of environmental protection (NOM-004-SEMARNAT-2002) (SEMARNAT, 2002). Thus, sludge treatment with earthworms generated Class A biosolids, useful for forest, agricultural, and soil improvement.
... A diverse range of feed stocks can be incorporated into the process and providing certain parameters are maintained, this is a cost effective and fairly rapid treatment compared to standard composting. In previous studies, vermicomposting has been shown to enhance mineralisation of nitrogen [8] and phosphorus [9], stabilise organic matter, reduce or even eliminate pathogens [10][11][12] and produce a chemically and biologically enriched material [13]. ...
... Though septic tank waste is an excellent source of carbon and nitrogen, it can contain high levels of ammonia which is toxic to worms. Therefore a short period of precomposting was necessary to eliminate this potential [10]. The length of the pre-composting phase was determined by exposing earthworms to daily sub samples of the treatments and measuring mortality over a 24 hour period. ...
... waste and well acclimatised. Rodríguez-Canché et al. [10] reported complete removal of Helminth ova after 60 days of vermicomposting from sewage sludge with an initial native concentration of 12.5 ova/g dry wt., which were almost 2 orders of magnitude lower than ours. ...
... Thus, vermicompost is deemed as a microbial fertilizer mostly applied to agricultural lands (Sharma and Garg, 2018) and aquacultural operations (Godara et al., 2015a(Godara et al., , 2015b. Vermicomposting for recycling sewage sludge has also been successfully demonstrated by several studies (Yasir et al., 2009;Rodríguez-Canché et al., 2010;Xing, et al., 2012;Fu et al., 2015;Fernández-Gómez et al., 2015;Villar et al., 2016). In addition, previous studies also found that human pathogenic bacteria present in the sludge could be significantly reduced after vermicomposting, in contrast to usual composting methods (Rodríguez-Canché et al., 2010;Godara et al., 2015c;Soobhany et al., 2017). ...
... Vermicomposting for recycling sewage sludge has also been successfully demonstrated by several studies (Yasir et al., 2009;Rodríguez-Canché et al., 2010;Xing, et al., 2012;Fu et al., 2015;Fernández-Gómez et al., 2015;Villar et al., 2016). In addition, previous studies also found that human pathogenic bacteria present in the sludge could be significantly reduced after vermicomposting, in contrast to usual composting methods (Rodríguez-Canché et al., 2010;Godara et al., 2015c;Soobhany et al., 2017). However, to the best of our knowledge, only a few attempts have been made to investigate the effects of earthworms on the fate of ARGs during sludge vermicomposting. ...
... It is worthy to note that Flavobacteriales, Campylobacterales and Spirochaetales enriched human pathogenic bacterial species, which also took along diverse ARGs (tetX, tetG and tetO) in control system as compared to vermicomposting system. The ability of earthworms to effectively decrease pathogenic bacterial abundance has been documented by several studies (Rodríguez-Canché et al., 2010;Soobhany et al., 2017). This could be mainly due to the excretion of fibrinolytic enzymes and antibacterial substances from earthworms, which have negative effects against the pathogenic bacteria (Li et al., 2011). ...
Diverse antibiotic resistance genes (ARGs) present in sewage sludge are difficult to be eliminated using conventional sludge treatment processes. To date, little remains known on the fate of the ARGs during vermi-composting of sludge. This study aimed to investigate the effect of earthworms on the fate of tetracycline and fluoroquinolone resistance genes, and integrons during vermicomposting of sewage sludge through contrasting two systems of sludge stabilization with and without earthworms. Compared to the control without earthworms, vermicomposting significantly (p < 0.05) decreased the abundances of tetracycline and fluoroquinolone resistance genes and int1, with complete removal for parC. Variations in ARGs were associated with environmental factors, horizontal gene transfer, bacterial community composition, and earthworms during vermicomposting. In addition, earthworms strongly affected the possible host bacteria encoding ARGs and Int1, abating the patho-genic bacteria in vermicomposting product. These results imply that vermicomposting could effectively reduce tetracycline and fluoroquinolone resistance genes in the sludge.
... Thus, vermicompost is deemed as a microbial fertilizer mostly applied to agricultural lands (Sharma and Garg, 2018) and aquacultural operations (Godara et al., 2015a(Godara et al., , 2015b. Vermicomposting for recycling sewage sludge has also been successfully demonstrated by several studies (Yasir et al., 2009;Rodríguez-Canché et al., 2010;Xing, et al., 2012;Fu et al., 2015;Fernández-Gómez et al., 2015;Villar et al., 2016). In addition, previous studies also found that human pathogenic bacteria present in the sludge could be significantly reduced after vermicomposting, in contrast to usual composting methods (Rodríguez-Canché et al., 2010;Godara et al., 2015c;Soobhany et al., 2017). ...
... Vermicomposting for recycling sewage sludge has also been successfully demonstrated by several studies (Yasir et al., 2009;Rodríguez-Canché et al., 2010;Xing, et al., 2012;Fu et al., 2015;Fernández-Gómez et al., 2015;Villar et al., 2016). In addition, previous studies also found that human pathogenic bacteria present in the sludge could be significantly reduced after vermicomposting, in contrast to usual composting methods (Rodríguez-Canché et al., 2010;Godara et al., 2015c;Soobhany et al., 2017). However, to the best of our knowledge, only a few attempts have been made to investigate the effects of earthworms on the fate of ARGs during sludge vermicomposting. ...
... It is worthy to note that Flavobacteriales, Campylobacterales and Spirochaetales enriched human pathogenic bacterial species, which also took along diverse ARGs (tetX, tetG and tetO) in control system as compared to vermicomposting system. The ability of earthworms to effectively decrease pathogenic bacterial abundance has been documented by several studies (Rodríguez-Canché et al., 2010;Soobhany et al., 2017). This could be mainly due to the excretion of fibrinolytic enzymes and antibacterial substances from earthworms, which have negative effects against the pathogenic bacteria (Li et al., 2011). ...
... Several studies indicated that vermicomposting was a reliable process for pathogen destruction in human waste and animal manure, as indicated by the fecal indicator bacteria (Escherichia coli, Salmonella spp. and enterococci) (Eastman et al. 2001;Hill and Baldwin 2012;Rodríguez-Canché et al. 2010). However, the method of fecal indicator bacteria showed the poor correlation with pathogens, especially the pathogens from non-fecal sources . ...
... Gómez-Brandón et al. (2011) reported that earthworms could alter the physical and chemical status of organic wastes significantly and that this modification led to a significant change in bacterial communities in vermicomposting. Moreover, earthworms could change the bacterial composition through stimulating or feeding specific taxa (Rodríguez-Canché et al. 2010;Wang et al. 2015). Therefore, it could be assumed that microbial community was directly or indirectly affected by earthworm activities. ...
... This result might suggest that vermicomposting had the potential to remove human pathogens from the sludge and animal manure. Although several studies reported that vermicomposting could reduce the total coliforms in animal manure and septic tank sludge to the safe levels (Monroy et al. 2009;Rodríguez-Canché et al. 2010 (a) (b) (c) Fig. 6 The bacterial pathogen identified at species level and their relative abundance in initial mixture (a), the end products of vermicomposting (b), and the control treatment (c) ...
This study aims to reveal the effects of earthworms (Eisenia fetida) on bacterial profiles during the vermicomposting process of sewage sludge and cattle dung with the high-throughput sequencing technology. The earthworms could accelerate organic degradation and improve the stabilization process. Moreover, the addition of earthworms not only affected the bacterial numbers, but also increased the bacterial community diversity. The activity of earthworms had significant effects on the bacterial community structure as the bacterial community was clearly different between the vermicomposting and the control treatment. Furthermore, the earthworms affected the physical and chemical properties of substrates, thus promoting the growth of some microorganisms, such as Flavobacteria, Acidbacteria, and Planctomycetes. Earthworms largely inhibited the growth of various human pathogenic bacteria. In summary, earthworms significantly affected the bacterial community in vermicomposting and it could be applied as an authentically effective technique for the stabilization of organic wastes.
... However, long duration and fre- quent turning of material for dissipation of heat and maintaining the aerobic condition during composting result in loss of nutri- ents (Hait and Tare, 2011b). On the other hand, vermicompost- ing is a mesophilic waste bio-oxidation and stabilization process where earthworms and diverse microbial communities jointly process organic wastes under the aerobic condition to produce nutrient-rich and pathogen-free vermicompost (Domínguez, 2004;Rodríguez-Canché et al., 2010;Hait and Tare, 2011a). Unlike composting, vermicomposting is a mesophilic process (<35°C) during which organic wastes do not undergo thermo- philic stabilization that eliminates pathogens. ...
... Unlike composting, vermicomposting is a mesophilic process (<35°C) during which organic wastes do not undergo thermo- philic stabilization that eliminates pathogens. However, patho- gen removal is not ensured, since the temperature is always in the mesophilic range, although some studies have provided evidence of suppression of pathogens ( Eastman et al., 2001;ContrerasRamos et al., 2005;Monroy et al., 2008Monroy et al., , 2009Bhargava, 2009a, 2009b;Rodríguez-Canché et al., 2010;Yadav et al., 2010Yadav et al., , 2011Yadav et al., , 2012Aira et al., 2011;Tare, 2011a, 2011b;Kumar and Shweta, 2011;Hill and Baldwin, 2012). Furthermore, vermicomposting is a better option than composting, as it results in a homogeneous product with better quality in terms of desirable aesthetics, reduced levels of patho- genic microbes, and more available plant nutrients (ContrerasRamos et al., 2004;Hait and Tare, 2012). ...
... The pathogenic contents of organic wastes during vermistabilization must be reduced to a safe level com- plying with the prevailing pathogens standards to prevent health risks. Nevertheless, the fate of pathogens during vermistabiliza- tion of various organic wastes has been investigated, following a range of experimental approaches from many laboratory-scale vermireactors to a few pilot-and full-scale studies, to show a significant reduction (>90%, in general) in human pathogen content (Eastman et al., 2001;Contreras-Ramos et al., 2005;Monroy et al., 2008Monroy et al., , 2009Bhargava, 2009a, 2009b;Rodríguez-Canché et al., 2010;Yadav et al., 2010Yadav et al., , 2011Yadav et al., , 2012Aira et al., 2011;Hait and Tare, 2011aKumar and Shweta, 2011;Hill and Baldwin, 2012). However, little effort has been made to summarize the various plau- sible mechanisms and factors responsible for human pathogen reduction during the process. ...
Management of both municipal and industrial organic wastes remains a major threat to biota and the environment due to the presence of pathogens in abundance. Vermicomposting employing earthworms is increasingly gaining attention as a sustainable and ecofriendly technique to transform and sanitize a variety of organic wastes into nutrient‐rich biofertilizer. Although considerable research has been undertaken to show that vermicomposting can significantly reduce pathogenic contents, there is little effort to summarize the various mechanisms responsible for it. With the aim to assess the fate of pathogens during vermicomposting of various organic wastes, this article provides a comprehensive summary on the occurrence of pathogens in a variety of wastes vis‐à‐vis pathogens standards, the efficacy of the process for pathogen reduction, and current knowledge of the plausible mechanisms involved. It is evident from the present study that earthworms and endosymbiotic microbes during vermicomposting tend to eliminate pathogens by enhancing enzymatic activities in both gut‐ and cast‐associated processes. Pathogen reduction during vermicomposting can be plausibly attributed to direct actions like microbial inhibition due to intestinal enzymatic action, and secretion of coelomic fluids with antibacterial properties, as well as indirect actions like stimulation of endemic microbes leading to competition and antagonism, and aeration by burrowing activity. Further, the pathogen reduction during vermicomposting is largely selective, and earthworms exert a differential effect according to the earthworm species and whether the pathogen considered is Gram‐positive or ‐negative, owing to its cell wall composition. However, further research is necessary to understand the exact mechanisms involved for pathogen reduction during vermistabilization of municipal and industrial organic wastes.
Core Ideas
Vermicomposting using earthworms effectively sanitizes various organic wastes.
Pathogen removal during this process is linked to direct and indirect earthworm actions.
Pathogen reduction during vermicomposting is largely selective.
Earthworms differentially affect pathogens, depending on bacteria being either G+ or G −.
... As per Yadav and Garg, acceptable pH range for the vermicomposting process is between 5.5 and 8 [58,59]; while Ali et al. have pointed out that a neutral pH is adequate for the proper development of worms, although they may survive in a range of 4.5 to 9 [10]. Humidity percentages during this process were maintained within the 50% to 80% range in all four mixtures, this is adequate for vermicomposting according to multiple authors who have indicated an ideal range of between 50% and 90% [10,[60][61][62][63][64]. Figure 9 shows OM behavior during the vermicomposting process, initial values of 87% were observed in CR and M1 and 85% and 86% in M2 and M3 respectively. These values are close to the 80.54% reported in the vermicomposting process of corn straw substrate [16]. ...
... These values are close to the 80.54% reported in the vermicomposting process of corn straw substrate [16]. Humidity percentages during this process were maintained within the 50% to 80% range in all four mixtures, this is adequate for vermicomposting according to multiple authors who have indicated an ideal range of between 50% and 90% [10,[60][61][62][63][64]. Figure 9 shows OM behavior during the vermicomposting process, initial values of 87% were observed in CR and M1 and 85% and 86% in M2 and M3 respectively. These values are close to the 80.54% reported in the vermicomposting process of corn straw substrate [16]. ...
As vermicomposting has become a viable alternative for the valorization of organic waste; the objectives of this research were to (1) assess the feasibility of said process for corn cob waste (corn cobs and corn husks) and (2) evaluate the operation conditions for the biodegradation of different mixtures with load material (LM). LM did not include animal excreta as a nitrogen source, a practice widely used in a range of studies. The experiment consisted of an initial phase of pre-composting in order to obtain a partially stabilized substrate. Subsequently, four separate mixtures were made consisting of corn cob waste mixed with consistent load material (LM) containing vegetable waste and eggshells (CR, M1, M2, M3) to obtain a balance substrate able to facilitate degradation using Eisenia fetida earthworms. The following parameters were analyzed during the control process: temperature, pH, humidity, organic material (OM), total organic carbon (TOC), total nitrogen (TN) and carbon/nitrogen (C/N) ratio. The analysis of the final values of the stabilized mixtures showed that vermicomposting is indeed a feasible alternative for the degradation of corn cob waste for use as a soil improver.
... Moreover, the gut of earthworms carries a certain content of HPB, which may enhance the environmental risk of HPB in vermicompost (Roubalová et al., 2019). Surprisingly, most studies indicated that the reduction percentage of HPB could exceed 85% for total coliforms, 93% for fecal coliforms, and 99% for fecal enterococci during sludge vermicomposting (Rodríguez-Canché et al., 2010;Hénault-Ethier et al., 2016;Soobhany, 2018;Lv et al., 2018). Furthermore, their removal rate in response to vermicomposting was higher than that of composting (Soobhany, 2018;Lv et al., 2018). ...
... Despite the lower HPB abundance in sludge vermicompost than in control, it was still higher than in initial sludge. This finding contrasts with earlier studies where vermicomposting could decrease the HPB in bio-solid wastes, such as sludge (Rodríguez-Canché et al., 2010;Lv et al., 2018), pig slurry (Monroy et al., 2009), toilet waste (Hill and Baldwin, 2012), and organic municipal solid waste (Soobhany, 2018). The first reason can likely be ascribed to a change of environmental parameters and the regulation of microbial community by earthworm activity in the vermicomposting system, which is particularly the case for competitive or antagonistic species (Swati and Hait, 2018;Lv et al., 2018). ...
This study used a metagenomic approach to investigate the effects of earthworms on ARGs and HPB during the vermicomposting of dewatered sludge. Results showed that 139 types of ARGs were found in sludge vermi-compost, affiliated to 30 classes. Compared with the control, the total abundance of ARGs in sludge vermi-compost decreased by 41.5%. Moreover, the types and sequences of plasmids and integrons were also decreased by vermicomposting. Proteobacteria and Actinobacteria were the most dominant hosts of ARGs in sludge ver-micompost. In addition, earthworms reduced the total HPB abundance and modified their diversity, thus leading to higher abundance of Enterobacteriaceae in sludge vermicompost. However, the sludge vermicompost was still ARG and HPB enriched, indicating a remaining environmental risk for agricultural purpose. The observed change of microbial community and the reduction of mobile genetic elements caused by earthworm activity are the main reasons for the alleviation of ARG pollution during vermicomposting.
... Moreover, the gut of earthworms carries a certain content of HPB, which may enhance the environmental risk of HPB in vermicompost (Roubalová et al., 2019). Surprisingly, most studies indicated that the reduction percentage of HPB could exceed 85% for total coliforms, 93% for fecal coliforms, and 99% for fecal enterococci during sludge vermicomposting (Rodríguez-Canché et al., 2010;Hénault-Ethier et al., 2016;Soobhany, 2018;Lv et al., 2018). Furthermore, their removal rate in response to vermicomposting was higher than that of composting (Soobhany, 2018;Lv et al., 2018). ...
... Despite the lower HPB abundance in sludge vermicompost than in control, it was still higher than in initial sludge. This finding contrasts with earlier studies where vermicomposting could decrease the HPB in bio-solid wastes, such as sludge (Rodríguez-Canché et al., 2010;Lv et al., 2018), pig slurry (Monroy et al., 2009), toilet waste (Hill and Baldwin, 2012), and organic municipal solid waste (Soobhany, 2018). The first reason can likely be ascribed to a change of environmental parameters and the regulation of microbial community by earthworm activity in the vermicomposting system, which is particularly the case for competitive or antagonistic species (Swati and Hait, 2018;Lv et al., 2018). ...
This study used a metagenomic approach to investigate the effects of earthworms on ARGs and HPB during the vermicomposting of dewatered sludge. Results showed that 139 types of ARGs were found in sludge vermicompost, affiliated to 30 classes. Compared with the control, the total abundance of ARGs in sludge vermicompost decreased by 41.5%. Moreover, the types and sequences of plasmids and integrons were also decreased by vermicomposting. Proteobacteria and Actinobacteria were the most dominant hosts of ARGs in sludge vermicompost. In addition, earthworms reduced the total HPB abundance and modified their diversity, thus leading to higher abundance of Enterobacteriaceae in sludge vermicompost. However, the sludge vermicompost was still ARG and HPB enriched, indicating a remaining environmental risk for agricultural purpose. The observed change of microbial community and the reduction of mobile genetic elements caused by earthworm activity are the main reasons for the alleviation of ARG pollution during vermicomposting.
... Essentially, they are referred to as a 'sludge digester' [62]. The sludge is softened by the secretion excreted in the mouth of earthworms when it is discharged to the esophagus [63]. In the esophagus, the softened sludge components are neutralized by calcium (excreted by the inner walls of esophagus) and then passed on to the gizzard for further action. ...
... In the muscular gizzard, it is finely Control [34] ground (with the aid of stones) into small particles to a size of 2-4 µm and passed on to the intestine for enzymatic digestion. The gizzard and the intestine are regarded as a 'bioreactor' [63]. In the intestine, the ground and pulped sludge components are decomposed by proteases, lipases, amylases, cellulase, and chitinase. ...
The aim of the present work was to present a review of about 103 recently published studies into the use of earthworms and aquatic worms for reducing the sludge produced by wastewater treatment plants. Also, there will be a discussion of the use of sludge reduction by aquatic and earth worms, aspects that need attention, changes in the characteristics of these worms, the effect of environmental factors on sludge reduction by aquatic worms and earth worms, new perspectives, and the operational problems involved. Sludge is an unavoidable, hazardous, and odorous substance formed in conventional water and wastewater treatment plants. The previous research showed that the treatment and disposal of the excess sludge accounts for more than 40–60% of the total operational costs in wastewater treatment plants. This denotes the necessity of a costly treatment process. A biological technology for processing waste sludge is waste sludge reduction by worms (innovative technology). These worms are of two types: earthworms (vermicomposting) or aquatic worms. Sludge reduction by earthworms is a promising and relatively common technology, especially in small-scale communities in developing countries. Studies showed that 20–40% of sludge is converted into worm biomass. The effectiveness of vermicomposting fertilizers in improving soil fertility is 30–40% higher than that of chemical fertilizers. It is a low-cost technology system for the processing or treatment of organic waste. It is concluded the aquatic and the earth worms can reduce the different types of municipal waste sludge. Sludge reduction by earthworms and aquatic worms are promising and relatively common technologies, especially in small-scale communities in developing countries.
... The growth rate of earthworms has been related to the moisture level in the vermicomposting system [122]. An optimum moisture range between 50 and 80% has been considered for efficient vermicomposting [123]; however, up to 90% of moisture level has also been considered efficient for vermicomposting process [120]. ...
... The density of earthworms is influenced by several factors including initial substrate quality and quantity, temperature, moisture, and soil structure and texture [21,[128][129][130]. The copulation frequency of earthworms is high at low population density, whereas it decreases when the density approaches the carrying capacity of the substrate [122]. It has been reported that the stocking density of 1.60 kg worms/m 2 is optimum for vermicomposting [107]. ...
Generation of the huge amount of solid waste around the globe is a major ecological and technical problem. Vermicomposting may be the viable option to handle solid waste in an environmentally friendly way. This review provides a general overview of viability of vermicomposting processes as an ecofriendly approach. The integrated approach of composting and vermicomposting processes provides better results. Further, to optimize the process of vermicomposting, codigestion of organic wastes provides better opportunity for both microorganisms and earthworms to convert the organic fraction of solid waste under controlled environmental conditions. Feeding, stocking density, pH, C/N ratio, temperature, and moisture, by inference, seem to be the critical factors that influence the vermicomposting process. Furthermore, the end product of vermicomposting, the nutrient-rich compost, could be used for biogas production. Hence, the management of solid waste and energy production can be achieved at the same time with no further costs. © 2015 American Institute of Chemical Engineers Environ Prog, 2015
... Though vermicomposting, a mesophilic process, provides favorable conditions for HPBs growth, it is reported that HPBs growth generally reduced the growth percentage of HPBs during sludge vermicomposting. For instance, reduction percentages for total coliforms 85%, for fecal coliform 93%, for fecal enterococci 99% are reported, and the reduction rate is also higher in vermicomposting in comparison to conventional composting (Rodriguez-Canche et al., 2010;Henault-Ethier et al., 2016., Soobhany, 2018Lv et al., 2018). A previous study also reported that vermicomposting Fig. 2 Illustration of the role of earthworms-associated microbes in ecological consequences. ...
Management of organic waste is a burning concern in the modern world. Among all the conventional and advanced methods, composting is one of the most popular and sustainable methods for waste management. Organic wastes such as food materials, vegetable residues, fodder, sludge, animal dung, eggshell, agricultural wastes are used for composting procedures. Vermicomposting is also a natural way to recycle the organic wastes where the wastes are degraded by different species of earthworms and associated microbes such as bacteria, fungi, actinomycetes and produce nutrient-rich vermicast and vermiwash, which are used as manure in agricultural fields. The gut of the earthworm is the original bioreactor of vermicomposting. The gut microflora, their mutualistic relationship with the earthworm and the associated soil microbes, and their interaction are the key factors behind the composting process. These mutualistic relationships, their different metabolism, enzymes, and enzymatic reactions have immense importance for vermicomposting. Earthworm also has a very mutualistic relationship with microbes. The microbial enzyme helps in digesting the organic litter that the earthworm consumes. They also act as an agent for nutrient solubilization and nitrogen fixation, which make the vermicast more nutrient-rich. Suppression of plant pathogenic microbes is also carried out by these beneficial microbes. The present chapter focuses on the different groups of popularly used earthworms in vermicomposting, their interactive relationships with microbes as well as the dynamics of the gut microbes. The overall content might help us to understand the possible role of gut microflora of earthworms on the quality of organic waste recycling and look toward a future roadmap for better and healthier possibilities for sustainable agriculture; hence better food security and safe
... Though vermicomposting, a mesophilic process, provides favorable conditions for HPBs growth, it is reported that HPBs growth generally reduced the growth percentage of HPBs during sludge vermicomposting. For instance, reduction percentages for total coliforms 85%, for fecal coliform 93%, for fecal enterococci 99% are reported, and the reduction rate is also higher in vermicomposting in comparison to conventional composting (Rodriguez-Canche et al., 2010;Henault-Ethier et al., 2016Lv et al., 2018). A previous study also reported that vermicomposting also reduces HPBs in toilet waste (Hill and Baldwin, 2012), municipal solid waste , pig slurry (Monroy et al., 2009), and bio waste (Lv et al., 2018). ...
This chapter provides comprehensive information on organic waste pathogen reduction using insect larvae, mechanisms of pathogen suppression during entomocomposting, and the contribution of insect frass fertilizer to improving soil fertility and crop productivity in an environmentally sound, socially just, climate-resilient, and cost-effective manner. Finally, we provide concluding remarks and key recommendations on sustainable utilization of entomocomposting for waste management and fertilizer production. This knowledge will guide investors, entrepreneurs, and farmers who wish to use insects for waste recycling, environmental cleanup, and fertilizer generation to achieve sustainable development goals.
... This material outperforms compost in soil fertility improvement due to its high nitrogen content and humified organic matter and aids nutrient mineralization by stimulating soil microbial growth and activity (Wang et al., 2018). However, most studies recommend partial stabilization of the substrate prior to vermicomposting since the earthworm needs time to acclimatize to the fresh waste (Pottipati et al., 2021;Rodríguez-Canché et al., 2010;Varma and Kalamdhad, 2016). Further, it is common practice to use vermicomposting to remediation soil and organic matter contaminated with high levels of HMs (Sun et al., 2020). ...
The present study investigated the stabilization of fresh sewage sludge through a dual-stage biodegradation process; rotary drum composting in series with vermicomposting. After thermophilic exposure in a rotary drum composter, the partially degraded feedstock was separated into S1 without vermiculture, S2 and S3 with Eudrilus eugeniae and Eisenia fetida vermi-monocultures, respectively. The S3-derived vermicompost exhibited an 80% and 88% reduction in CO2 and ammonium-nitrogen evolution rates, respectively, demonstrating the expedient stabilization of sludge. The robust, more than 85% seed germination index supported S2 and S3 derived vermicompost viability. A significant decrease in heavy metals was evinced with S2 and S3-derived vermicompost; the S1-derived end product exhibited higher Zn, Cr, and Pb levels in the absence of vermicomposting. Furthermore, soil amended with 20% vermicompost from S3 displayed 50% more plant growth than S1. Thus, the optimized thermophilic-mesophilic dual-biodegradation technique stabilizes sewage sludge quickly, has a lot of potential in sludge management facilities around the world, and produces a marketable end product.
... If the vermicomposting process operates properly, pathogen will be reduced significantly. Rodríguez-Canché et al. [56] observed significant helminth egg removal in a vermicomposting process of faecal sludge. After 60 days of vermicomposting faecal coliforms, Salmonella spp., and helminth ova quantity reduced to < 1000 MPN/g, < 3 MPN/g, < 1 viable ova/g on a dry weight basis, respectively. ...
Population growth and urbanization have encouraged the entire world to revamp the sanitation system safely through a proper Faecal Sludge Management (FSM) value chain. Faecal Sludge (FS) is a mixture of human excreta in partially digested and semisolid form, mainly collected from onsite sanitation facilities and usually is discharged into open drains and water bodies. Hence, a well-planned FSM is required to ensure safe collection, transportation, treatment, and disposal of onsite collected excreta to make a pollution free environment. The present review paper analyzed various treatment technologies available for FS along with their end products. An overview of the current global situation on FSM, basic design of a Faecal Sludge Treatment Plant (FSTP), waste treatment mechanism and end use of treatment products are also discussed. This study observed that the solid portion of the FS is used as manure, soil conditioner and energy producer whereas the liquid part is used for the purpose of gardening, car-washing, and road-washing.
... Vermicomposting has been proposed as a low-cost technology for rural communities to stabilize sewage sludge for use as a soil amendment. This is because vermicomposting can reduce pathogens and organic contaminants while generating a valuable product rich in plant nutrients (Rodriguez-Canche et al. 2010;Yadav et al. 2010). Vermicomposts have low C:N ratios, high porosity and high water-holding capacity (e.g. ...
Purpose
The impact of vermicompost on tree-soil systems is not yet fully understood. This study aimed to comparatively investigate the effects of chemical fertilizer, compost and vermicompost on soil enzymatic activities, seedling mycorrhizal colonization, growth and nutrition of one exotic tree species (radiata pine, Pinus radiata D. Don) and two native tree species (mānuka, Leptospermum scoparium and tōtara, Podocarpus totara).
Methods
A 12-month-long pot trial was set up in the glasshouse with a factorial design of three tree species (radiata pine, tōtara and manuka) by six treatments, including T1-control, T2-chemical fertilizer, T3-HS compost, T4-HS vermicompost, T5-LS vermicompost and T6-CM vermicompost. We assessed the main effects and interactions of treatment and species on soil chemical and biological properties, plant growth and nutritional responses.
Results
Compared to the untreated control (T1), application of vermicomposts (T4-T6) and compost (T3) significantly improved soil chemical properties and enzymatic activities, and increased total seedling dry weight by 160–260%, shoot concentrations of nitrogen (N) by 54–97% and phosphorus (P) by 61–91%. Vermicomposts were comparable to diammonium phosphate (DAP) applied at 133 kg N ha⁻¹ (T2) in stimulating the growth of native species (mānuka and tōtara) without negative impact on mycorrhizal colonization, with T5 being better than DAP (T2) in promoting mānuka growth. However, application of vermicompost alone was less effective than DAP in stimulating the exotic radiata pine growth. Overall, soil activities of dehydrogenase, urease, acid phosphatase and invertase were significantly and positively correlated to total C and N and exchangeable Ca and Mg.
Conclusion
The increased growth of three tree species after application of vermicomposts was mainly related to improved N and P nutrition associated with enhanced root growth and soil enzymatic activities. Our findings imply that the vermicomposting products from septic tank waste could be a promising alternative to inorganic fertilizers in land application or greenhouse potting media of native tree species.
... Namely, organic wastes, such as animal byproducts that can be vermicomposted and used as fertilizers, may contain pathogenic microorganisms [83][84][85]. Roubalova et al. [83] observed the reduction of pathogens such as Escherichia coli, Enterococcus spp., and thermotolerant coliform bacteria in grape marc during vermicomposting. There are several possible ways by which earthworms contribute to the reduction of pathogens including bacteria, fungi and many others. ...
Industrialization and urbanization have led to an increased accumulation of waste materials that are transformed into a nutrient-rich and high-quality product called vermicompost by the vermicomposting process. Vermicomposting is an ecofriendly and economically favorable biotechnological process that involves the interaction of earthworms and microorganisms. Due to the importance of this process and its great potential in dealing with the consequences of waste accumulation, this review aims to provide key insights as well as highlight knowledge gaps. It is emphasized that there is a great challenge in understanding and clarifying the mechanisms involved in the vermicomposting process. The optimization of the factors affecting the possible application of vermicompost is crucial for obtaining the final product. Information on the composition of bacterial communities, amount of vermicompost, effect on heavy metal content, plant pathogens, diseases and organic waste selection is here recognized as currently the most important issues to be addressed. By answering these knowledge gaps, it is possible to enable wider utilization of vermicompost products.
... [11] Rodríguez-Canché et al. utilized the vermicomposting process in a study with the aim of eliminating pathogens in septic tank sludge, and results showed that pathogen count had reduced drastically. [30] In a study conducted by Aira et al. on the reduction of pathogens in cow manure, results showed that fecal coliform had not reduced to the standard EPA level which is consistent with the results of the present study. [31] Edwards et al. reported that using the vermicomposting process, the number of fecal coliforms reduced drastically after 7 days. ...
Aim: Although vermicomposting is rich in nutrients, the virulent microbes and pathogens present in it may be a threat to human health and the environment. Therefore, the objective of this study is to investigate the microbial quality of produced vermicompost, including fecal coliform and parasitic eggs, at a pilot scale, and compare it to present standards. Materials and Methods: Three various reactors containing decomposable domestic waste (T1), cow manure (T2), and dewatered sludge (T3) were used to produce vermicompost using Eisenia fetida. According to the standard methods, fecal coliforms, parasitic eggs, and some of the treatment characteristics including organic carbons, nitrogen, temperature, humidity, pH, electrical conductivity and metals were evaluated during the 56-day operation period. Results: According to the results, the number of fecal coliforms in treatments of T1, T2 and T3 reduced from 2.5 × 104, 6 × 105 and 15 × 106 to 1000, 1500 and 1500 MPN/g dw, respectively. All parasite eggs reached zero after the 3rd week. At the end of the study, the average of organic carbon in T1, T2, and T3 were 35.4 ± 6%, 50.7 ± 5%, and 58.4 ± 7%, respectively. This value for total nitrogen were 0.9 ± 0.2%, 1.8 ± 0.7%, and 4.2 ± 1.2%, respectively. Conclusion: Results showed that the worm E. fetida has a great ability to reduce pathogens without the need for an increase in temperature. Furthermore, it can be concluded that vermicompost can improve the quality of compost in 8 weeks. The vermicomposting process can also greatly destroy the fecal coliforms and all parasite eggs.
... communities of sewage sludge, fresh earthworm casts and vermicompost were largely composed by their own or exclusive ASVs(Fig. 5, Supplementary Tables S4, S5).Several studies have found important levels of reduction of microbial human pathogens during vermicomposting of sewage sludge[27][28][29] and animal manures ...
Wastewater treatment plants produce hundreds of million tons of sewage sludge every year all over the world. Vermicomposting is well established worldwide and has been successful at processing sewage sludge, which can contribute to alleviate the severe environmental problems caused by its disposal. Here, we utilized 16S and ITS rRNA high-throughput sequencing to characterize bacterial and fungal community composition and structure during the gut- and cast-associated processes (GAP and CAP, respectively) of vermicomposting of sewage sludge. Bacterial and fungal communities of earthworm casts were mainly composed of microbial taxa not found in the sewage sludge; thus most of the bacterial (96%) and fungal (91%) taxa in the sewage sludge were eliminated during vermicomposting, mainly through the GAP. Upon completion of GAP and during CAP, modified microbial communities undergo a succession process leading to more diverse microbiotas than those found in sewage sludge. Consequently, bacterial and fungal community composition changed significantly during vermicomposting. Vermicomposting of sewage resulted in a stable and rich microbial community with potential biostimulant properties that may aid plant growth. Our results support the use of vermicompost derived from sewage sludge for sustainable agricultural practices, if heavy metals or other pollutants are under legislation limits or adequately treated.
... Biosólidos de tanque séptico Reducción de patógenos Rodríguez-Canche, et al., 2010 Lodos de planta de tratamiento de aguas residuales de un rastro Tratamiento de lodos residuales Vicencio-De la Rosa, et al., 2011 Lixiviado de digestor de biogás mezclado con residuos de trigo, caña de azúcar y salvado Tratamiento del lixiviado y producción de vermicomposta Suthar, 2010) e. Operación y mantenimiento Para asegurar una operación exitosa y sustentable del sistema de humedales se debe contar con un Plan de Operación y Mantenimiento a fin de identificar claramente las acciones de mantenimiento requeridas y su frecuencia. El plan de mantenimiento debe incluir un esquema debidamente etiquetado donde se muestre el tren de tratamiento completo, todas las estructuras existentes, las áreas abiertas, los registros, los cuerpos de agua y el tipo de planta sembrada. ...
Al noroeste de México, en el Estado de Baja California, se instaló un sistema de humedales construidos de tipo sub-superficial para el tratamiento parcial del agua residual del Centro de Ingeniería y Tecnología de la Universidad Autónoma de Baja California, como parte de un plan piloto para incentivar la aplicación de tecnologías alternativas a las plantas de tratamiento comerciales en comunidades rurales. El sistema consta de dos celdas, flujos vertical y horizontal, y es precedido por un tanque séptico y un sedimentador para disminuir sólidos y carga orgánica. Asimismo, utiliza plantas acuáticas y un medio filtrante para fijar y retener los contaminantes utilizando procesos naturales y un funcionamiento hidráulico por gravedad. Finalmente, las pruebas fisicoquímicas de calidad de agua realizadas por un laboratorio certificado, demuestran una alta eficiencia, 70%, de tratamiento en remoción del contaminante Demanda Bioquímica de Oxígeno.
... Several studies have found important levels of reduction of microbial human pathogens during vermicomposting of sewage sludge [27][28][29] and animal manures 30,31 . We have found that earthworm activity, mainly during the gut-associated processes, is a critical factor leading to the rapid reduction of pathogens during vermicomposting. ...
Wastewater treatment plants produce hundreds of million tons of sewage sludge every year all over the world. Vermicomposting is well established worldwide and has been successful in processing sewage sludge, which can contribute to alleviate the severe environmental problems caused by their disposal. Here, we utilized 16S and ITS rRNA high-throughput sequencing to characterize bacterial and fungal community composition and structure during the gut- and cast-associated processes (GAP and CAP, respectively) of vermicomposting of sewage sludge. Bacterial and fungal community composition and diversity changed significantly during both vermicomposting processes. Most of the bacterial and fungal taxa in the sewage sludge were eliminated during vermicomposting, mainly through the GAP. Vermicomposting of sewage resulted in a stable and rich microbial community with potential biostimulant properties that may aid plant growth. Our results support the use of vermicompost derived from sewage sludge for sustainable agricultural practices.
... Vermicomposting has a bundle of advantages over all the other waste management methods i.e. this process can be carried out indoors as well as outdoors, allowing whole year round composting (Rodríguez et al., 2010). This process allows obtaining organic nutrients sources for the crops in less time, which are nutritionally, physically and biochemically efficient as compared to other composts (Yadav et al., 2010). ...
Solid waste management is a serious ecological problem in Saudi Arabia due to rapid industrialization, population growth and urbanization. Recycling and sorting are in their infancy in Saudi Arabia and huge amounts of mixed household and industrial wastes are still dumped without any pre-treatment. Solid waste management techniques such as incineration, pyrolysis and gasification have high investment costs. Composting and vermicomposting of solid organic waste have been considered as an economically viable and sustainable waste management technologies. However, wastes often contain pollutants, such as heavy metals that are toxic to decomposer micro-organisms. Thus, heavy metals are a challenge for the successful biological treatments. Waste may also contain a mixture of organic pollutants that certain microbes, such as micro-algae are known to degrade. The present review paper focuses on understanding the role of vermicomposting as a management tool in mitigating solid organic wastes. It is noteworthy to mention that the microbes also play a pivotal role in the degradation process, wherein the enzymes secreted during the process aid in decomposition of complex molecules into simpler compounds. Also, the extracellular polymeric substance secreted by the earthworm under metal stress serves a source of nutrient for the bacteria to flourish. Henceforth the goal of discussion in present review shows the way forward in using vermicomposting as a novel approach in dealing with solid organic waste.
... Edwards and Lofty (1977) clearly point out that moisture content is an essential factor affecting the growth and reproduction of earthworms. It has been discovered that the suitable moisture range for E. fetida is between 60 and 90%, with the fastest growth rate at 80-90%, but low moisture content often delays their sexual development (Domínguez and Edwards 2004;Rodríguez-Canché et al. 2010). Also, Yadav and Garg (2011) indicate that the ideal humidity for vermicomposting is between 60-80%, and too much water can result in the culling of worms due to creating an anaerobic environment. ...
The present study aimed to explore the effect of a range of moisture content levels, including 65%, 72%, and 78%, on physicochemical properties and microfauna communities during vermicomposting of municipal sludge. As a result, death of perishable microfauna together with the degradation of organic matter was the dominant response in all groups in the early period of vermicomposting, while the effects of moisture content levels on various physiochemical parameters did not appear until the mid-later period. After the treatment with 78% moisture content, the content of mineral nitrogen was 1.186 g/kg in the sludge, with a 9.36 × 10³ ind./g of microfauna quantity and 663.01 g of earthworm biomass. The values of these three measurements in 78% group were significantly higher than other two groups (p < 0.05), indicating that the effects of 78% moisture content were more pronounced for promoting nitrogen mineralization as well as microfauna and earthworms growth during vermicomposting. Specifically, testate amoebae were strongly associated with nitrification process, while nematodes were related to ammonification and phosphorus mineralization, of which testate amoebae had great potential of being bioindicators during vermicomposting of municipal sludge.
... (Elissen et al. 2006). Among this, the biological approaches have received considerable attention as a sustainable way for the treatment of sewage sludge (Rodríguez-Canché et al. 2010;Wang et al. 2011). Composting undergoes biochemical and microbial reactions for converting sludge into a valueadded product as fertilizer (Abbasi et al. 2019;Cai et al. 2012;Li et al. 2014;Sadef et al. 2014;Villasenor et al. 2011). ...
Composting process of sewage sludge requires a preprocessing step in order to prepare the appropriate mixture of dewatered sludge (Xs) with amendment (Xa), bulking agent (Xb), and/or recycled materials (Xr). This research aimed to develop a novel mathematical model for finding an optimal mixture ratio of dewatered sludge with the aforementioned influencing elements on co-composting process. Seven feasible scenarios were presented and the best one was selected in viewpoint of technical and economic perspectives. The optimum mixture was prepared and its quality was evaluated in the terms of physical, chemical, and microbial characteristics. The optimum mixture was loaded in an aerated static pile composting reactor in order to evaluate the quality of the final compost product. If the test results were not in compliance with the USEPA standards, the model was iteratively modified to fulfill the desired objective. The model was validated using the experimental results. The mixture of Xs:Xa:Xb:Xr with a weight ratio 7.4:1.0:1.4:2.3 allowed optimal moisture content (59.8 ± 0.5%), organic matter (80.0 ± 2.6%), dry matter (40.2 ± 0.6%), C/N ratio (28.0 ± 1.6), and free air space (> 30%) across the composting pile. The final product of compost met the heavy metal and microbial requirements for land application. It can be concluded this mathematical model is a promising method for selecting the optimal amount and type of materials for preparing the initial mixture of co-composting process.
... For example, manure and SS comprise a variety of PB including fecal coliforms and fecal streptococcus as a consequence of leaching in ground water was investigated (Gerba and Smith, 2005;Lalander et al., 2019). In line with the environmental point of view, when these PB like fecal coliforms and Escherichia coli were transmitted in to soil, via manure and SS diffusion with water bodies from main point reservoir, thus, these PB rapidly grow, proliferate, reproduce, and travel toward to ground water for up to two months and cause serious negative impact on the non-target environments as well as influence to human and animal health in certain case (Rodriguez-Canché et al., 2010;Pandey et al., 2016). ...
This study aim was to investigate the influence of black soldier fly larvae (BSFL) Hermetia illucens L. (Diptera: Stratiomyidae) on pathogenic bacteria (PB) survival in the chicken manure (CM), pig manure (PM), cow manure (COM) and sewage sludge (SS) compost. Three kinds of manure [chicken (T2), pig (T4) and cow (T6)] and SS (T8) were inoculated with BSFL (1.2:7 ratio on fresh weight basis) and without BSFL (T1, T3, T5 and T7) was used as control and experiment lasted for 9 days. The results indicated that BSFL amendment 90–93% of PB abundances (RAs) was significantly mitigate in CM and COM (T2 and T6), and 86–88% in PM and SS compost. However, relatively greater abundance of PB was recorded in the T4 and T8 treatments. Most of the PB belong to Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes phylum and their community composition varied from phylum to species levels among the all treatments. The PB composition was significantly altered by BSFL amendment and also important role play to enhance in compost quality. Interestingly, Bacillus and Clostridium were significantly very less abundant present in BSFL applied treatments, but considerably higher population of these bacterial genus and its associated species were identifies from control or without BSFL applied treatments. Overall, without BSFL blended-all three kinds of manure-composts have comparatively greater PB abundance than with BSFL applied treatments, as the PB species Listeria_monocytogenes_FSL_R2–503, Staphylococcus_aureus_M0406, Bacillus_anthracis, Listeria_ivanovii, Staphylococcus_aureus_C0673, Salmonella Bacillus_cereus_VD115, Mycobacterium_tuberculosis_FJ05194 and Pseudomonas_aeruginosa has relatively greater RAs, followed by Bartonella_bacilliformis_Ver075; Bordetella_pertussis_2356847; Brucella_melitensis_ADMAS-G1; Klebsiella_pneumoniae_LCT-KP182 and Corynebacterium_jeikeium_K411 respectively. Thus, chicken manure composting with BSFL addition is efficient technology for the organic waste recycling and conversion of sanitized matured compost with significantly less abundance of pathogenic bacteria.
... This is due to that fact that these systems do not create thermophilic conditions or chemical inhibitors necessary to result in pathogen reduction. There have been some studies indicating that vermicomposting can reduce fecal coliforms (Rodríguez-Canché et al., 2010), however, since other studies contradict these finding (Monroy et al., 2009), we have chosen to conservatively score vermicomposting as no improvement in hygienic quality of the product. Further treatment of the end-product from these systems would be necessary for safe reuse. ...
The aim of this study is to present a structured approach for comparing possible nutrient-recovery fecal sludge (FS) treatment systems in order to support transparent decision-making. The approach uses a multi-dimensional sustainability assessment of treatment technologies for nutrient recovery from FS, using a typical case of Kampala City, Uganda. A synthesized list of 22 treatment technologies was prepared from literature. This list included wastewater treatment technologies, which could be adapted to treat fecal sludge, and established fecal sludge treatment technologies that are available or potentially applicable in Kampala. Based on the local situation, the list was reduced to eight possible options, which were carried forward into a multi-dimensional sustainability assessment that incorporated input of stakeholders. The technologies included in the final assessment were optimization of the existing system, lactic acid fermentation (LAF), composting, vermicomposting, Black-Soldier Fly (BSF) composting, ammonia treatment, alkaline stabilization and solar drying. Optimization of the existing system performed well against the set criteria and is a recommended short-term solution. This will require e.g., adding narrower screens to remove more trash from the incoming sludge and respecting storage times prior to selling the sludge. To maximize the agricultural value of the recovered product, while respecting the need for safe reuse, a combination of technologies becomes relevant; the use of a combination of BSF, and subsequent ammonia or alkaline treatment of the remaining organic fraction would allow for maximized safe nutrient recovery and can be the aim for long-term sanitation planning in Kampala. The results of this process provide supporting information for a discussion of trade-offs between stakeholder groups as part of a decision-making process within a larger planning context.
... Wastes suitable for vermicomposting can be of various origins, ranging from agricultural and horticultural wastes to farmyard manures, food waste and sewage sludge. Importantly, the process facilitates more efficient and sustainable waste management, which may otherwise pose threats to our living environment [28][29][30][31][32]. Vermicomposting helps to reduce the incidence of human pathogens in organic waste, including faecal coliforms, Salmonella species, enteric viruses and helminths [28,29,[33][34][35]. Indeed, vermicomposting has been considered a scalable, futuristic, and sustainable way to manage urban waste [17,21,36], most directly by reducing landfill input through lowering waste bulk density and bypassing many of the challenges associated with handling raw organic wastes [14]. ...
This chapter focuses on the scientific discoveries pertaining to the characteristics and plant growth biostimulating properties of vermicomposts. Vermicomposting is an efficient process of converting organic wastes into valuable humus‐like soil amending substances with good mineral nutrient content. Wastes suitable for vermicomposting can be of various origins, ranging from agricultural and horticultural wastes to farmyard manures, food waste and sewage sludge. Although different vermicomposts vary in their mineral nutrient content, the process of vermicomposting consistently results in a product with greater content of bioavailable nutrients than the source organic waste material. In addition to their mineral nutrient content, the microbial properties of vermicomposts provide significant plant growth stimulating capability. The biostimulatory efficacy of vermicompost is likely to be attributed to the plant growth promoting substances which include humus, phytohormones and other possible unidentified novel substances. Auxins are important class of phytohormones that play crucial roles in regulating various plant growth processes.
... Whereas, soil biofilters are incapable of reducing the sludge or sludge formation and thus results in failure of the system, mainly due to the biofilm formation and deposition of suspended particles (Arora et al., 2014b;Dhadse et al., 2010;Li et al., 2009). Rodriguez-canche et al. (2010) have reported that vermifilter not only helps in reduction and stabilization of sludge, it also proves beneficial in terms of pathogen reduction and aesthetic environment. It is also reported that the earthworm microorganism interaction is an important factor for sludge reduction and stabilization rather than their feeding (Li et al., 2014). ...
The high water demand along with constant rise of the aquatic pollution has led to the treatment and reuse of the wastewater produced from the breweries. With the aim to treat effluent from breweries, many attempts have already been undertaken and some of the attempts showed very appealing results. However, the existing technologies have its own set of limitations, predominantly; high energy consumption, expensive capital and maintenance cost, requirements of skilled man power and generation of harmful by-products. After an intensive survey and analysis of literature, vermifilters (VFs) were recognized as a promising alternative for the treatment of brewery wastewaters. However, the incomplete nutrient removal (phosphates and nitrates), frequent clogging and the unavailability of any mechanistic tool to design a vermifiltration based treatment plants were the biggest bottlenecks in its implementation for treating brewery wastewaters. Owing to the above, a study was carried out with a number of developments in the conventional vermifilter that is relevant to address all the above concerns.
In the present study, an attempt has been made to develop a vermifilter coupled with adsorption with the objective of facilitating the simultaneous organic degradation, nitrification, denitrification and adsorption to achieve enhanced organics and nutrient removal from brewery wastewater. On the basis of the functionality, the developed reactor can be divided into two units. One is the earthworm housed soil column, while, the other one is a packed bed column of dolochar. The flow through these units is designed to be curvilinear, subsurface and horizontal. At the hydraulic loading rate (HLR) of 1.8 m3/m2-d, organic loading rate (OLR) of 3.38 kgCOD/m3-d, the average removal efficiencies from the VF having earthworm density (EWD) of 10000 was 96.241±0.545% for chemical oxygen demand (COD), 85.6±2.29% for ammonium nitrogen (NH4+-N), 21.56±3.8% for total nitrogen (TN), 61.31±3.06% for phosphate phosphorous (PO43--P) and 43.29±4.32% for total phosphorous (TP). The nitrate nitrogen (NO3-- N) generation was also observed to be in parity with the NH4+-N conversion from the system, while the effluent dissolved oxygen (DO) ranged between 1.5-2.1 mg/L. The results suggest that the treatment of pollutants in terms of organics and nutrients in this hybrid vermifilter was considerably more than the conventional vermifilters as well as soil biofilters. Varying OLR has an impact over the vermifiltration, as it affected the nitrogen removal and the effluent DO negatively. However, there was no change in phosphate removal due to the absence of biological phosphorous removal. The optimization of the vermifilters revealed that the lifespan of the system and the organics removal may be maximized if the system is run on an influent COD of 3701 mg/L, EWD of 9475 earthworms/m3 and HLR of 1.84 m3/m2-d. The COD removals and decrease in hydraulic conductivities from the experiments performed with both synthetic and real wastewater were in good agreement with the RSM model predicted values. The study also revealed that high OLR activates a higher number of microbial sites, in turn causing a higher degree of clogging. However, the introduction of earthworms and increase in EWD reduces the clogging rate significantly along with enhanced treatment performance. The COD removal index (CRI) was developed using hydraulic retention time (HRT), influent COD and earthworm density (EWD), and it was seen to have a good correlation with the experimentally obtained COD removals from the developed vermifilter. Additionally, the validation of the developed CRI with the literature harvested data suggests suitability of the CRI index in designing and scaling up of the vermifiltration based treatment plant for other types of wastewater also. The results of this research depict that the newly developed vermifiltration coupled with adsorption may turn out to be a significant step towards sustainable natural treatment system ensuring the safe disposal of effluents coming out from the breweries.
... Moreover, manure-derived compost contains a number of pathogenic microbes including bacteria, fungi and yeast, which normally originate from the food, feed and excretory liquid or solid materials of livestock. Regardless of the many studies that have been performed on composting or vermicomposting of various organic wastes, as well as the evaluation of the pathogenic bacterial load in compost [12,13], many scientists have identified bacterial pathogens even after the biooxidative phase of composting, despite the fact that temperatures higher than 60 ⁰C were applied for at least 4 days [14][15][16]. Furthermore, the standard compost maturity and quality parameters have been recommended by the Chinese government, and it is confirmed that these recommendations will form new national legislation to improve the compost applicability for organic farming [17,18]. ...
The aim was to evaluate pathogenic bacteria (PB) survival during the composting of chicken manure (CM) amended with five different dosages of clay compared to CM without clay-applied treatment. The results showed that 85–87% of PB relative abundances (RAs) were significantly reduced in lower dosages of applied clay (T2 and T3). However, the maximum survival of PB was noticed in the T6 and T5 treatments, but most of the PB belong to Firmicutes, Actinobacteria and Proteobacteria phylum and their derivative bacterial species. The changes in PB during the composting were not only strongly influenced by clay amendment but also significantly associated with the succession of bacterial species in compost. Bacillus, Clostridium, Mycobacterium and Klebsiella were the dominant spore-forming bacteria identified in higher dosages of clay (i.e., T4, T5 and T6) treatments, but very low abundance of these bacterial genus and its species were recovered from lower dosages of clay (T2 and T3)-applied treatments. Overall, without clay, amended-CM-derived compost contained a relatively higher PB abundance than other treatments, as the anaerobic bacterial species Clostridium_difficile_AA1, Vibrio_cholerae, and Acinetobacter_calcoaceticus had relatively greater RAs, followed by Klebsiella_oxytoca_10-5248, Paenibacillus_Bacillus_cereus and Bartonella_quintana_RM-11. Thus, CM composting with 4% clay amendment is considered a useful method for the efficient recycling of CM, as this process produced sanitized compost with less survival of PB.
... Some gut bacteria of earthworms possess antimycobacterial ( Fiolka et al. 2010) and anti-Can- dida albicans ( Fiolka et al. 2012) activity, so vermicomposting earthworms may be Fig. 1 Profile of microbial communities in four soil samples and composition of microorganisms isolated from intestines of earthworms living in corresponding soils. Values represent relative abundance of microorganisms used for the reduction of pathogens in septic tank sludge ( Rodriguez-Canche et al. 2010). All animals exist in close relationship with microorganisms that play an essential role in the normal development and tissue physiology of hosts. ...
Earthworms live in microbial-rich habitats populated with various bacteria, fungi, protozoa, and other organisms. Thus, soil represents an environment with high antigenic pressure, and earthworms have developed potent defense mechanisms. Besides the abundant microbiota, earthworms are also highly influenced by various types of organic and inorganic pollutants and by the nanoparticles that reach the soil system. These contaminants affect earthworm physiology and their ability to reproduce, grow, and survive. As a result, earthworms are well suited for the monitoring soil contamination.
... Wastes suitable for vermicomposting can be of various origins, ranging from agricultural and horticultural wastes to farmyard manures, food waste and sewage sludge. Importantly, the process facilitates more efficient and sustainable waste management, which may otherwise pose threats to our living environment [28][29][30][31][32]. Vermicomposting helps to reduce the incidence of human pathogens in organic waste, including faecal coliforms, Salmonella species, enteric viruses and helminths [28,29,[33][34][35]. Indeed, vermicomposting has been considered a scalable, futuristic, and sustainable way to manage urban waste [17,21,36], most directly by reducing landfill input through lowering waste bulk density and bypassing many of the challenges associated with handling raw organic wastes [14]. ...
... Contreras-Ramos et al. (2005) reported that the numbers of human pathogens in vermicompost was greatly reduced, an effect obtained in traditional composting due to rise in temperature. The survival of pathogenic organisms such as Salmonella, Shigella, fecal coliform, and helminth eggs was eliminated after vermicomposting of sewage sludge and human feces, proving that these pathogens were completely digested as they passed through the gut of earthworms (Rodriguez-Canche et al., 2010;Yadav et al., 2010). The reduction of pathogen numbers has been correlated to the release of coelomic fluids by the earthworms during vermicomposting, as it possesses antibacterial properties and kills pathogens (Sinha et al., 2002). ...
... The destruction in Salmonella spp. after vermicomposting processes of the food waste, paper waste and yard waste from OFMSW was in accord with previous research on sewage sludge by Eisenia fetida ( Rodriguez-Canch e et al., 2010) which suggested a consistent anti-microbial response on gramnegative bacteria from the gizzard through the intestinal tract of the earthworms. Interestingly, the OFMSW composts and vermicomposts were in acceptable level as specify by MS 164 (2010) which recommend Salmonella spp. ...
The use of composts or vermicomposts derived from organic fraction of Municipal Solid Waste (OFMSW) brought about certain disagreement in terms of high level of bacterial pathogens, thereby surpassing the legal restrictions. This preliminary study was undertaken to compare the evolution of pathogenic bacteria on OFMSW compost against vermicompost (generated by Eudrilus eugeniae) with promises of achieving sanitation goals. Analysis to quality data showed that OFMSW vermicomposting caused a moderately higher reduction in total coliforms in contrast to composting. E. coli in OFMSW composts was found to be in the range of 4.72-4.96 log10 CFU g-1 whilst on a clear contrary, E. coli was undetectable in the final vermicomposts (6.01-6.14 logs of reduction) which might be explained by the involvement of the digestive processes in worms’ guts. Both OFMSW composts and vermicomposts generated Salmonella-free products which were acceptable for agricultural usage and soil improvement. In comparison to compost, the analysis of this research indicated that earthworm activity can effectively destroy bacterial pathogenic load in OFMSW vermicomposts. But still, this study necessitates extra research in order to comprehend the factors that direct pathogenic bacteria in vermicomposting and earthworm-free decomposition systems.
... Whereas, geo-microbial filters are incapable of reducing the sludge or sludge formation and thus result in failure of the system, mainly due to the biofilm formation and deposition of suspended particles (Arora et al., 2014b;Dhadse et al., 2010;Li et al., 2009). Rodriguez-Canche et al. (2010) have reported that vermifilter not only helps in reduction and stabilization of sludge, it also proves beneficial in terms of pathogen reduction and for maintaining hygienic and aesthetic environment. Researchers have also reported that earthworm microorganism interactions are more important factor for sludge reduction and stabilization rather than their feeding (Li et al., 2014). ...
With global population explosion, the available water resources are slowly being polluted due to the excessive human interference. To encounter this, it is the need of this hour to find out sustainable pollution remediating technologies to meet the stringent discharge standards for domestic as well as industrial wastewaters. In addition, those techniques should have the capabilities for effective implementation even in developing countries. Based on the available literatures, one such technique, named vermifilter, has been identified which takes care of almost all the sustainable and economical criteria for its effective implementation even in developing countries. The aim of this meta-analysis is to provide a comprehensive review on assessment mechanisms involved, factors affecting the process and performance of vermifiltration under different scenarios. The present review envisages the current state of the knowledge regarding physical, chemical and biological aspects related to the treatment mechanisms and effective functioning of earthworms. This review has also proposed several suggestive plans on its application at any proposed site.
... Several authors observed a decline in populations of pathogenic Salmonella spp. during vermicomposting of sewage sludge by E. fetida (Mitchell, 1978;Cardoso, 2002;Bajsa et al., 2005;Rodriguez-Canché et al., 2010), human waste by E. fetida (Lalander et al., 2013), pineapple wastes by E. eugeniae (Mainoo et al., 2009), biosolides by E. fetida (Eastman et al., 2001;Contreras-Ramos et al., 2005) and other organic wastes (Kumar and Shweta, 2011). It was found in an earlier study made by Brown and Mitchell (1981) that E. fetida decreased Salmonella spp. ...
Waste management strategies for organic residues, such as composting and vermicomposting, have been implemented in some developed and developing countries to solve the problem of organic solid waste (OSW). Yet, these biological treatment technologies do not always result in good quality compost or vermicompost with regards to sanitation capacity owing to the presence of bacterial pathogenic substances in objectionable concentrations. The presence of pathogens in soil conditioners poses a potential health hazard and their occurrence is of particular significance in composts and/or vermicomposts produced from organic materials. Past and present researches demonstrated a high-degree of agreement that various pathogens survive after the composting of certain OSW but whether similar changes in bacterial pathogenic loads arise during vermitechnology has not been thoroughly elucidated. This review garners information regarding the status of various pathogenic bacteria which survived or diffused after the composting process compared to the status of these pathogens after the vermicomposting of OSW with the aim of achieving sanitation goals. This work is also indispensable for the specification of compost quality guidelines concerning pathogen loads which would be specific to treatment technology. It was hypothesized that vermicomposting process for OSW can be efficacious in sustaining the existence of pathogenic organisms most specifically; human pathogens under safety levels. In summary, earthworms can be regarded as a way of obliterating pathogenic bacteria from OSW in a manner equivalent to earthworm gut transit mechanism which classifies vermicomposting as a promising sanitation technique in comparison to composting processes.
... However, a few studies on composting of source-separated faeces claimed that a sufficiently high temperature for pathogen destruction is difficult to achieve (Bjorklund 2002;Niwagaba et al. 2009). Similarly, in vermicomposting, some studies have provided evidence of suppression of pathogens (Monroy et al. 2008;Rodriguez-Canche et al. 2010;Eastman et al. 2001), while others (Bowman et al. 2006;Hill et al. 2013) demonstrated the insignificant effect of vermicomposting in reducing Ascaris summ ova as compared to composting without worms. The effectiveness of vermicomposting for pathogen destruction was still remaining unclear due to conflicting information in the literature (Hill et al. 2013); the present scenario thus, calls for further exploration. ...
Background
Composting is one of the integrated waste management strategies used for the recycling of organic wastes into a useful product. Composting methods vary in duration of decomposition and potency of stability, maturity and sanitation. This study was aimed to investigate the comparative effectiveness of four different methods of composting viz. windrow composting (WC), Vermicomposting (VC), pit composting (PC) and combined windrow and vermicomposting (WVC) on the stabilization, maturation and sanitization of mixtures of municipal solid organic waste and dried faecal sludge.
Methods
The composting treatments were arranged in a completely randomized block design with three replications. The changes in physico-chemical and biological characteristics of the compost were examined at 20 days interval for 100 days using standard laboratory procedures. The analysis of variance was performed using SAS software and the significant differences were determined using Fisher’s LSD test at P ≤ 0.05 level.
Results
The evolution of composting temperature, pH, EC, NH4+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{NH}}_{ 4}^{ + }$$\end{document}, NO3-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{NO}}_{ 3}^{ - }$$\end{document}, NH4+\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{NH}}_{ 4}^{ + }$$\end{document}:NO3-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{NO}}_{ 3}^{ - }$$\end{document} ratio, OC, C:N ratio and total volatile solids varied significantly among the composting methods and with composting time. The evolution of total nitrogen and germination index also varied significantly (P ≤ 0.001) with time, but their variation among the composting methods was not significant (P > 0.05). Except for PC, all other methods of composting satisfied all the indices for stability/maturity of compost at the 60th day of sampling; whereas PC achieved the critical limit values for most of the indices at the 80th day. A highly significant differences (P ≤ 0.001) were noted among the composting methods with regard to their effectiveness in eliminating pathogens (faecal coliforms and helminth eggs). The WVC method was most efficient in eliminating the pathogens complying with WHO’s standard.
Conclusion
Turned windrow composting and composting involving earthworms hastened the biodegradation process of organic wastes and result in the production of stable compost earlier than the traditional pit method of composting. The WVC method is most efficient in keeping the pathogens below the threshold level. Thus, elimination of pathogens from composts being a critical consideration, this study would recommend this method for composting organic wastes involving human excreta.
... Temperatures above 45°C are essential in order to remove pathogens from compost (Velasco-Velasco et al., 2011). However, literature shows the effectiveness of vermicomposting at eradicating pathogens (Edwards et al., 2011;Rodríguez-Canché et al., 2010). Precomposting prior to vermicomposting could be the solution to removing pathogens and weed seeds from vermicomposting (Wang et al., 2014), however N loss and GHG emissions during pre-composting need further investigation because higher N losses and GHG emissions might occur during the pre-composting stage (Velasco-Velasco et al., 2011). ...
Thermophilic composting produces a significant amount of greenhouse gases. The objectives of this study were (i) to evaluate the effectiveness of vermicomposting to reduce nitrogen losses and greenhouse gases emissions compared to thermophilic composting, and (ii) to determine the effect of different variables (i.e. carbon:nitrogen ratio, earthworm density, moisture content and carbon quality) on greenhouse gases emissions and earthworm growth during vermicomposting. The results showed that vermicomposting significantly reduced nitrogen loss by 10–20% compared to thermophilic composting. Vermicomposting decreased nitrous oxide emissions by 25–36% and methane emissions by 22–26%. A higher earthworm density increased carbon dioxide emissions by 3–14%, but decreased methane emissions by 10–35%. Earthworm density had a marginal effect on nitrous oxide emissions. Vermicomposting decreased nitrous oxide emissions by 40% with higher moisture and by 23% with lower moisture. Vermicomposting also decreased methane emissions by 32% and 16% with higher and lower moistures respectively. This study showed that the addition of labile carbon sources increased carbon dioxide and methane emissions and earthworm growth, but did not affect nitrous oxide emissions. In conclusion, vermicomposting is effective at reducing nitrogen losses and greenhouse gas emissions from composting. Therefore, vermicomposting could represent an option for reducing greenhouse gas emissions from composting, particularly in developing countries where the existing technical solutions are expensive and difficult to implement.
... Earthworms can increase the mineralization rate of soil and fresh OM in a short term (Speratti and Whalen 2008;Bernard et al. 2012). Several studies ascribed the phenomenon to the ability of earthworms to fragment manure substrates, increase the contact between OM and microorganisms, alter soil properties and so on (Jouquet et al. 2010;Rodríguez-Canché et al. 2010;Ros et al. 2010;Naveed et al. 2014). However, longterm treatment with earthworms can promote the OC storage. ...
Purpose
Application of functional organisms in soil organic amendments has the potential to accelerate organic matter decomposition and stimulate C cycling. In this study, a short-term (a year) field experiment was conducted to investigate the collaborative effects of earthworms and phosphate-solubilizing bacteria on C accumulation in pig manure-amended soil.
Materials and methods
A field experiment was conducted with six treatments established. The first three treatments, including control (CK), pig manure (Pm), and pig manure + slurry (Pm + S), were set up to evaluate the influences of pig manure on soil C accumulation. The other three treatments, including manure + slurry + earthworms (Te), manure + slurry + phosphate-solubilizing bacteria (Tb), and manure + slurry + earthworms + bacteria (T(e + b)), were set up to investigate the collaborative effects of functional organisms on soil C cycling. The Pm + S treatment was chosen as the control (T) for this purpose.
Results and discussion
The results showed that the soil C pools did not increase significantly under the manure treatment. In contrast, an integrated application of manure, slurry, earthworms, and bacteria significantly increased the various C fractions, such as SOC and humin, indicating a rapid and positive effect of earthworms and bacteria on C accumulation. Besides, C sequestration by the integrated application was as high as 1.35 Mg C ha−1 soil, half of which was stabilized.
Conclusions
The T(e + b) was an efficient strategy to sequestrate and stabilize SOC in arid hillside soils. The bacteria increased the labile OC, especially microbial biomass C, while the earthworms were apparently essential for the increase in stable OC.
... During vermicomposting, the earthworm body is reported to act as a bio-filter that can purify and also disinfect and detoxify solid wastes (Kumar and Kumar, 2011). Not only making the compost of high nutrient rich, vermicomposting has also proved to more efficient in removing pathogens, as they are eliminated as soon entering the food chain of earthworms (Canche et al., 2010;Arunugam et al., 2004;Ramos et al., 2005). Epigeic species including Eisenia fetida, Eudrilus eugeniae and Perionyx excavates have greater potential in decomposing organic waste and animal manure due to its humus consuming and surface dwelling nature (Hartenstein et al., 1979;Abbasi and Ramasamy, 1999;Kale et al., 1982). ...
Composting is nowadays evolving as a highly technical process for
processing organic waste separately replacing landfilling along with municipal
solid waste. Vegetable waste with high organic content can be composted to
produce nutrient rich material that can work as soil conditioner instead of
dumping in open landfills. Various studies reveal that due to high organic
content of vegetable waste it increases leachability, thereby contaminating the
groundwater and increasing greenhouse gas emissions on open dumping. Since
the nitrogen and carbon rich materials are layered in an optimal balanced
composition in composting, microbes decompose the material faster to produce
high quality compost with nutrient value. Vegetable waste rich in organic
nitrogen can be easily mineralised by compost microorganisms to form NH4
and NO3, thereby successfully incorporating them in the compost. Depending
on the source of organic waste, composting methodology can be selected for
the efficient degradation and better compost quality. In the present study, it has
been reviewed about the composting methodologies practiced for organic waste
providing the optimised parameters for improving the processes.
... Li et al. (2009) reported that earthworm technology showed efficient reduction of COD, BOD 5, NH 3 -N and SS despite the fluctuations of hydraulic loading rate (HLR) and organic input. Rodriguez-Canche et al. (2010) evaluated the potential of earthworms (Eisenia fetida) for the removal of bacteria (Fecal coliforms) and pathogens (Salmonella) from the sludge of septic tank and found that due to the presence of these earthworms species concentrations of fecal coliforms and Salmonella reduced to permissible limit (<1000 MPN/g and <3 MPN/g) on a dry weight basis, respectively, and the resulting compost achieved class A biosolids standards. ...
Performance evaluation of vermireactors (Trials T1, T2, T3) for co-treatment of organic fractions of
municipal solid waste (OFMSW) and sewage was conducted on three different earthworm species such as
Eisenia fetida, Perionyx excavatus, and Perionyx sansibaricus. The results were compared with control
reactor (T4) (without earthworms) for 120 days. Sewage was applied at hydraulic loading rate of 1 m3/m2/
day, and earthworm biomass of 500 mg per 2 kg of organic waste was used for the treatment purpose. A
significant gain in earthworm biomass was noted, and maximum growth was observed in T1 followed by
T2 than T3. The treatment process due to earthworms causes removal of total organic carbon (65–75%),
CODtot (85–86%), BOD5 (84–87%), ammonia nitrogen (45–59%), and coliforms (99.9%), but increase in
nitrate nitrogen (172.5–186.7%) and total phosphorous (161–201%) subsequently in treated effluent and
nutrient enhancement in solid waste samples was observed. Scanning electron micrographs revealed the
final products (vermicompost) exhibited a distinct physical appearance than initial solid waste samples
characterized by predominantly spherical cell-like structure and significantly lower number of
filamentous bacteria. Moreover, it can be concluded that these three earthworm species are suitable
for onsite co-treatment of OFMSW and municipal sewage.
Relationship Between Microbes and Environment for Sustainable Ecosystem Services, Volume One: Microbial Products for Sustainable Ecosystem Services promotes advances in sustainable solutions, value-added products, and fundamental research in microbes and the environment. Topics include advanced and recent discoveries in the use of microbes for sustainable development. Users will find reference information ranging from the description of various microbial applications for sustainability in different aspects of food, energy, the environment and social development. Volume One includes the direct and indirect role of bacteria, fungi, actinomycetes, viruses, mycoplasma and protozoans in the development of products contributing towards sustainable. The book provides a holistic approach to the most recent advances in the application of various microbes as a biotechnological tool for a vast range of sustainable applications, modern practices, exploring futuristic strategies to harness its full potential.
India is an agriculture-driven economy and this sector roughly contributes to 30% of the national GDP. However, with ever-increasing population, demand for agricultural resources has also started increasing. Currently, agriculture accounts for 80% of the country's freshwater withdrawals and more than 90% of its consumptive use. Over the years, this has depleted the ground and surface water drastically, especially in some urban areas. In this situation of water scarcity, farmers have to look for alternative ways to grow crops efficiently. Wastewater reuse is now being explored as a potential resource because the practice helps decrease water use pressure and moderates water pollution. However, wastewater is a rich source of all the essential components required for the comprehensive growth of crop plants only if it is properly treated. Otherwise, it may cause fatal physiological and chromosomal disorders. The recommended parameters should be checked before the use of treated wastewater so that it does not affect the soil ecosystem, habitat of the organisms prevailing around or the food chain. Vermitechnolgy is a green engineering approach and is considered as one of the most reliable decentralized technology for wastewater treatment. It is based on a bio-conversion process of earthworms interacting with microorganisms and is practically maintenance-free, does not produce sludge and foul odor, consumes less energy and gives treated vermiwash and vermicompost as nutrient-rich end products. Its operation is simple, economical and energy-efficient thus, proving to be very beneficial at rural and agricultural levels. The present chapter aims to review the use of this innovative technology for solving the problem of agricultural water depletion through thorough application-based evaluation in various fields and also understands the holistic effects on soil ecosystem and crop productivity.
A culture-independent DNA metabarcoding analysis of the bacterial communities was carried out throughout a complete vermicomposting cycle of municipal solid waste material using the earthworm Eisenia fetida. 16S rRNA amplicons from the initial material (0 days), an intermediate (42 days), and a final stage (84 days) were sequenced in an Illumina NGS platform and compared. A steady increase in community diversity was observed corresponding to a 2.5-fold higher taxa richness and correspondingly risen values of the Shannon and Simpson ecological indexes and the evenness parameter. A total of 49665 operational taxonomic units (OTUs) were counted. From the qualitative standpoint, a clear successional shift was observed with an initial community dominated by putatively plant-associated groups belonging to the Rhizobiales order within the Alphaproteobacteria class, regressively leaving the scores of relative abundance (RA) to the Firmicutes phylum and in particular to the Bacilli. Vermistabilization of municipal solid waste (MSW) increased (P < 0.001) the TKN and total P content in the final vermicompost, while pH, TOC, and C/N ratio declined (P < 0.001) in the process. Likewise, a progressive decrease was noticed in β-glucosidase, acid phosphatase, and urease activity while protease and dehydrogenase showed a slight increase, followed by a steep fall. A strong positive correlation was observed among the canonical functions of physico-chemical attributes and enzyme activities. The canonical correspondence analysis (CCA) revealed that significant families did not change on the temporal scale; however, their abundance was influenced by the abiotic environmental factors. In comparison to prior studies on vermicomposting that used different earthworm species (Eisenia andrei) and different substrates (lignified plant residues), results reflect a considerable degree of substrate specificity for the earthworm species used. The results offer clues to optimize the vermistabilization of MSW along with its potential use in agriculture, to foster improved levels of the circular economy.
Garbage enzyme is made from fruit and vegetable wastes. Apple peel, dragon peel and eggplant peel are selected as to ferment for 6 months. The product has many active enzymes and microbiology flora. To research the effect of garbage enzyme to improve soil nutrient, self-made garbage enzyme is diluted in the ratio of 1:800 and irrigated to soil of flowerpot. Soil is irrigated by dilution once in two days for four weeks. Total nitrogen and organic matter are detected once per week. Test method of total nitrogen and organic matter is respectively Kjeldahl method and potassium dichromate method. Total nitrogen and organic matter background are respectively 1.61 g/kg and 24.32 g/kg. The results illustrate that garbage enzyme gradually increase soil total nitrogen and organic matter with the increase irrigation time. Soil sample’s total nitrogen of apple peel, dragon peel and eggplant begin to increase gradually and respectively peaked at 3.17 g/kg, 4.13 g/kg and 4.27 g/kg after 4 weeks irrigation. The content of total nitrogen is classified as the first level (>0.20 g/kg). After 4 weeks irrigation of dilution of garbage enzyme made from eggplant peel, the sample’s organic matter begins to increase gradually and peaked at 49.33 g/kg after 4 weeks. The content of organic matter is higher than background (24.32g/kg) and classified as the first level (>40 g/kg).
In Burkina Faso, faecal sludge is mostly discharged into the environment untreated, with associated public health risks. Thus, sanitation technology that efficiently treats Blackwater (BW) in-situ is urgently required. This paper reports the design and testing of a proposed worm-based toilet (wormlet). The presence of E.eugeniae (EE) is found to reduce the total accumulated BW by a maximum of 61.74%. Over five to ten weeks, 1 kg of BW (dry portion) can be processed to 0.49–0.61 kg of vermicast by the EE. The wormlet effluent is of superior quality, as the log 10 removal efficiency of the bedding and filter matrix reached 7.45 and 5.85 for E. coli and faecal coliform, respectively. Helminth egg removal was found to be 97% within the 75-cm depth. Average organics and nutrient removal efficiencies are 99–100% for total solids and total suspended solids; 99% and 98% for the biochemical and chemical oxygen demand, respectively. Removal efficiencies between 97 and 99% were found for NH4⁺, NO3⁻, NO2⁻, and PO4³⁻. A 100% turbidity removal was found in the systems containing charcoal. Thus, the wormlet appears to be superior for in-situ BW treatment, generating sub-products that can be reused or safely discarded.
Based on the theoretical knowledge of vermicomposting, a project was realized for the construction of a three-chamber domestic wooden vermicomposter, in which aerobic degradation of three types of animal excrements (cow, pig, dog) using the earthworm Eisenia andrei was carried out. Before laying the individual excrements to the compost batch, the appropriate input samples were taken for the microbiological examination of the biopathogens. After six months, final samples of the final substrate were taken to determine whether proper compost sanitization took place during the vermicomposting process; according to valid legislation, the bacteria Escherichia coli, Enterocococcus sp. and Salmonella sp. were identified as indicator micro-organisms. After the evaluation of the performed laboratory analyses, it was proved that the use of earthworm bioactivity resulted in elimination or at least significant reduction of the concentrations of these bacterial strains in the final vermicompost samples.
PurposeMicrobial pathogens can lead to health problems and disease transmission. Present study aimed to evaluate the microbial quality and quantity of vermicompost production and to compare to the current Iranian standards to protect public health and environmental concerns. Method
This is a pilot-scale experimental study conducted in the Public Health laboratory of Shahid Sadoughi University of Medical Sciences. The samples included organic municipal solid waste, cow manure and wastewater treatment plant sludge which are used for vermicompost production. The samples are mixed as cow manure–organic waste and cow manure–sewage sludge in two reactors. Microbial tests such as fecal coliforms (FC) and parasite egg (Ascaris) were carried out during start, processing and curing time with duplication analysis in 56 days. Totally, a number of 128 samples was analyzed. Analyses were conducted according to standard methods. Data analysis was conducted through one-way ANOVA and Duncan tests. ResultsThe results showed a significant reduction in number of FCs in cow manure–organic waste so that the number of 350,000 MPN/g in the raw sample decreased to 800 MPN/g within 8-week period, also FC in the case of cow manure–sewage sludge was achieved to 2400 from 6,500,000 MPN/g. In two cocomposting cases, the parasite eggs were completely removed in the second week. Conclusion
The results showed vermicomposting as a feasible method to convert waste into fertilizer humus in agriculture which also enables to achieve Iranian class A compost standard.
RESUMEN Los sistemas de tratamiento de aguas residuales generan un subproducto llamado lodo residual. Existe una disyuntiva entre su tratamiento y disposición final, debido a su contenido de organismos patógenos y parásitos. Por lo tanto, su estabilización para disponerlos al ambiente es prioritaria, además su aplicación al suelo aporta nutrimentos esenciales y mejora sus propiedades físicas y químicas. El trabajo tuvo como objetivo evaluar la eficiencia del lombricompostaje para la estabilización del lodo residual crudo de acuerdo a la NOM-004-SEMARNAT-2002. Los lodos residuales de una planta de tratamiento de aguas residuales municipales, fueron caracterizados mediante parámetros microbiológicos, parasitológicos y físico-químicos. El efecto de la actividad de la lombriz (Eisenia spp.) sobre los lodos residuales, se evaluó mediante un diseño experimental con cuatro tratamientos y tres repeticiones cada uno: T1 (Lodo residual crudo), T2 (Lodo residual + lombrices), T3 (Lodo residual + composta + lombrices) y T4 (Lodo residual + materia vegetal fresca + lombrices). Los resultados fisicoquímicos del lodo crudo y de los diferentes tratamientos demostraron que tienen un alto potencial como fertilizantes orgánicos. Los resultados de cuenta viable de microorganismos manifestaron un importante incremento de UFC/g en los tratamientos, demostrando una relación entre la estimulación de las lombrices inoculadas y la actividad microbiana. Los tratamientos donde se inóculo materia vegetal fresca y composta resultaron ser más eficientes en la remoción de huevos de helmintos y coliformes fecales, sin embargo no fue así para la eliminación de Salmonella. INTRODUCCIÓN Cualquier actividad humana que requiere de agua genera residuos líquidos conocidos como aguas residuales, están clasificadas de acuerdo a su origen en industrial, agrícola-ganadera y doméstica. Estas aguas residuales deben de ser tratadas para poder reincorporarse parcial o totalmente. Del tratamiento de aguas residuales se generan residuos remanentes llamados lodos residuales, de acuerdo con la NORMA OFICIAL MEXICANA, NOM 004-1 SEMARNAT-2002, son sólidos con una cantidad variable de humedad, provenientes de las plantas potabilizadoras y de tratamientos de aguas residuales, que no han sido sometidos a procesos de estabilización. Moeller et al. (2000), señalan que su composición depende de las características del agua residual y del proceso de tratamiento utilizado en la planta que lo depura. Las aguas de origen doméstico contienen alta carga microbiana, se encuentran diferentes microorganismos que están presentes en el intestino del hombre, llamados "flora intestinal normal" y los microorganismos patógenos que en el intestino producen enfermedades de diferentes tipos (Ortiz-Hernández 1994). Por esta razón deben considerarse según la Ley General para la Prevención y Gestión Integral de los Residuos y la NOM-052-SEMARNAT-1993 como un residuo peligroso del tipo Biológico-infeccioso. Ésta legislación define a un agente infeccioso como "un microorganismo capaz de causar una enfermedad y cuya presencia en un residuo lo hace peligroso" por lo que se necesita realizar un proceso de estabilización, para poder manejarlo, utilizarlo o depositarlo. Al lodo residual estabilizado la NOM 004-SEMARNAT-2002 lo define como un biosólido.
A field experiment tested the feasibility of vermicomposting as a method for elimi- nating human pathogens to obtain United States Environmental Protection Agency (USEPA) Class A stabilization in domestic wastewater residuals (biosolids). The ex- perimental site was at the City of Ocoee's Wastewater Treatment Facility in Ocoee, Florida, and Class B biosolids were used as the earthworm substrate. Two windrows of biosolids 6 m long were heavily inoculated with four human-pathogen indicators, fecal coliforms, Salmonella spp., enteric viruses and helminth ova. The test row was seeded with earthworms, Eisenia fetida. The quantity of E. fetida was calculated at a 1:1.5 wet weight earthworm biomass to biosolids ratio and the earthworms allowed time to consume the biosolids and stabilize the biosolids. The test indicated that all of the pathogen indicators in the test row were decreased more than in the control row within 144 hours. The test row samples showed a 6.4-log reduction in fecal coliforms compared with the control row, which only had a 1.6-log reduction. The test row sam- ples showed an 8.6-log reduction in Salmonella spp., while the control row had a 4.9- log reduction. The test row samples showed a 4.6-log reduction in enteric viruses while the control only had a 1.8-log reduction. The test row samples had a 1.9-log re- duction in helminth ova while the control row only had a 0.6-log reduction. Dr. Jim Smith, Senior Environmental Engineer and Pathogen Equivalency Commission (PEC) Chair, for the USEPA, indicated by personal communications, that a three- to four-fold reduction in indicator organisms would be sufficient to warrant serious con- sideration of vermicomposting as an effective stabilization methodology (Smith 1997). These results in conjunction with pilot project results strongly indicate that ver- micomposting could be used as an alternative method for Class A biosolids stabi- lization. This was obtained statistically by vermicomposting.
SummaryThe growth, fecundity, and mortality of the epigeic earthworm Eisenia fetida, in a range of different wastes were studied for more than one year in the laboratory. Separated, pre-composted, and fresh cattle manure solids, fresh pig manure solids of different levels of maturity (nursery young, growing-finish, and sow pigs), and fruit and vegetable wastes from a supermarket were offered to the earthworms as substrates. The growth, fecundity and mortality of E. fetida were monitored for 23 weeks until the earthworms stopped producing cocoons. The surviving adult earthworms in each substrate were separated into two population groups. The first group was cultured without any further substrate additions (batch cultures), using the earthworm casts as bedding. The second group was cultured in their casts with new substrates added regularly (continuous cultures). The second and third new substrate changes were after intervals of 22 and 15 weeks respectively. E. fetida could not survive in fresh cattle solids, fresh young pig solids, fruit wastes, and vegetable wastes. The growth of E. fetida in growing-finish pig solids and sow pig solids was faster than in either separated cattle solids or pre-composted cattle solids. Most earthworms produced cocoons again when the second substrate was added. The rate of growth of E. fetida was slower and the cocoon and hatchling production was lower after adding the third substrate. Some E. fetida could survive without any new substrate addition up to 60 weeks.
Paper mills have severe problem in disposing effluent or semisolid sludge despite repeated recycling. It requires treatment prior to disposal of sludge. In recent years biological treatment methods received much attention and considered as efficient low-cost treatment. One such method is vermiculture treatment. The present study was carried out to dispose the paper mill sludge biologically using 2 exotic species (Eudrilus eugineae and Eiseniafoetida) and an indigenous species (Lampito mauritii) of earthworm. The paper mill sludge in various concentration 25%,50% and 75% were subjected to vermitub treatment for a period of 60 days. During the period of study data were collected on reproductive strategies of earthworm and chemical analysis of wastes before and after treatment. Results obtained indicate that 25% concentration of sludge was ideal and of the three worms used Eiseniafoetida proved to be the best worm for biomanagement.
Unlabelled:
In Mexico 31% of the treatment plants have a flow less than 60 l/s. This study offers a simple and economical alternative through vermicomposting to resolve the management of sewage sludge and water hyacinth for these small treatment plants. This study was developed with laboratory and pilot scale systems. In the laboratory Eisenia foetida survival was quantified. They were fed three doses of sludge and water hyacinth and different percentages of humidity were applied. The production of worm cocoons was quantified as biomass production and the reduction in the TV/STS ratio as an indicator of stability. To install the pilot system the mixture with the highest cocoon production was chosen. In the pilot test the effect of the worm population density on the waste degradation was observed, the experiment was divided into five modules, four with densities from 2.5 to 15 kg/m2 and one module without worms that served as a blank test.
Results:
the best mixture was 70% sewage sludge and 30% water hyacinth, with 80% humidity and an average production of 298 cocoons/kg of vermicompost. There were no significant differences in the TVS/TS reduction between the different modules with worms, but in the blank test module there was no reduction. The Type A vermicompost obtained, with non-restricted use, 900 fecal coliforms NMP/g, 0.0 helminth ova/g, highly organic (60% M.O.), high concentration of total nitrogen (2.5%), phosphorus (0.96%) and cationic exchange capacity (60.2 meq/100 g), which indicates that soil fertility would increase if used in agriculture.
The importance of biological processes in the management of organic wastes has been widely recognized and this Chapter deals with one of the most efficient methods for converting solid organic materials into environmentally-friendly and valuable products. Vermicomposting is an accelerated process of bio-oxidation and stabilization of organic wastes involving interactions between earthworms and microorganisms.
Earthworms, the main characters of this process, are described briefly, showing how these animals can be important organic waste decomposers and converters. The different earthworm species that are suitable for vermicomposting have quite different requirements for their optimal development, growth and productivity in organic wastes and we review the life cycles of these species and the general requirements of ideal vermicomposting earthworm species. Vermicomposting is a complex biological and ecological process and to illustrate some of the important physical, chemical and biological transformations occurring during it, we present a case study.
Although earthworms are critical for the process, in vermicomposting, complex interactions between the organic matter, microorganisms, earthworms and other soil invertebrates result in the fragmentation, bio-oxidation and stabilization of organic matter. The vermicomposting system sustains complex food webs, and at the same time, modifies different chemical forms of several nutrient elements into inorganic compounds readily available to plants, which are important for nutrient dynamics.
The suitabilty of cow slurry as a substrate for vermicomposting by Eisenia fetida was investigated. Particular attention was given to the effects of the earthworm on the decomposition and stabilization of the slurry, and to the interactions between E. fetida and the microflora of the substrate. -from Authors
Vermicomposting technique for agricultural solid waste treatment uses earthworm species which need soil as habitat. However little work has been done for its application in community solid waste management. In the present studies an exotic species of earthworm - Eudrilus Eugeniae (African Night Crawler) - was used in treatment of organic part of community solid waste (produced from populous city of Madras, India). The species does not need soil substratum, thereby reducing reactor volumes to around 60%. Bench scale reactor studies were performed on the organic solid waste, under controlled optimum environmental conditions (temperature: 20 °C-30 °C, moisture content: 48-52%), with variable vermi-loading (4.5-10.5 kg/m 3). Characteristics of solid waste and process progress were monitored through conventional and additional parameters (BOD, COD). Studies yield kinetic rate constants of vermicomposting process (with respect to BOD/COD), useful for rational approach to vermicomposting reactor design.
The effect of different residual bulking agents (paper, cardboard, grass clippings, pine needles, sawdust and food wastes) in mixtures with sewage sludge (1:1 dry weight) on the growth and reproduction of Eisenia andrei, Bouché 1972 was studied in smallscale laboratory experiments with batches of sixty earthworms. The maximum weight achieved and the highest growth rate were attained in the mixture with food waste (755±18 mg and 18.6±0.6 mg day−1 respectively) whereas the smallest size and the lowest growth rate was achieved in the mixture of sewage sludge with sawdust (572±18 mg and 11±0.7 mg day−1 respectively). The earthworms showed much higher reproductive rates in the paper and cardboard mixtures (2.82±0.39 and 3.19±0.30 cocoons earthworm−1 week−1 respectively) compared to the control with sewage sludge alone (0.05±0.01 cocoons earthworm−1 week−1).
Significant reductions in total mass of feedlot cattle manure were obtained by the intensive activity of earthworms. The process yielded two products: residual vermicompost, and an increase in earthworm biomass. Various modes of manure application were made to a prepared bedding (or support material), the most successful being a surface (vertical) application which resulted in a reduction of 30% of the initial manure (dry) mass and the production of live earthworms to 4.9% of the initial manure mass (dry weight). The increase in earthworm biomass represented extraction of, respectively 7, 18, 7 and 2% of initial total C, N, S and P from the manure. The production of vermicompost from manure resulted in a pH shift toward neutral, a reduction in electrical conductivity, large increases in oxidation potential, and significant reductions in water-soluble chemical species which constitute possible environmental contaminants.
In India, millions of tones of livestock excreta are produced. Our study explores the potential of an epigeic earthworm Eisenia foetida to compost different livestock excreta (cow, buffalo, horse, donkey, sheep, goat and camel) into value added product (vermicompost)
at the laboratory scale. Vermicomposting resulted in lowering of pH, electrical conductivity, potassium and C:N ratio and
increase in nitrogen and phosphorus contents. Total K was lower in the final cast than in the initial feed. C:N ratios of
the vermicomposts ranged from 16.2 ± 2.17 to 75.4 ± 6.84. Microbial activity measured as dehydrogenase activity in buffalo,
donkey and camel wastes increased with time up to day 90. But in sheep and goat wastes, maximum dehydrogenase activity was
recorded on day 60 and decreased thereafter. The cocoons and hatchlings production by Eisenia foetida in different excreta were also investigated. The greatest number and biomass of hatchlings was recorded in horse excreta
followed by cow, goat and sheep excreta. Thus, cow, horse, sheep and goat excreta show potential as good substrates in vermicomposting
using Eisenia foetida, although further research is required to explore the feasibility of use of buffalo, donkey and camel excreta in combination
with cow/sheep/goat excreta.
The double-pronged problem of quantity, and disposal of waste streams from a myriad of industries, is becoming increasingly acute, the world over. The use of earthworms as a waste treatment technique for such wastes is gaining popularity. This method is commonly known as vermicomposting. Compared to conventional microbial composting, vermicomposting produces a product that is more or less homogenous, with desirable aesthetics, with reduced levels of contaminants and tends to hold more nutrients over a longer period, without impacting the environment. Like in other related waste treatment techniques, certain parameters need to be established for the design of efficient and economical vermicomposting systems. Specifically, the focus of this study was to investigate and establish an optimal stocking density and an optimal feeding rate for the vermicomposting of biosolids, with paper mulch provided as bedding. A stocking density of 1.60 kg-worms/m2 (0.33 lb-worms/ft2) and a feeding rate of 1.25 kg-feed/kg-worm/day resulted in the highest bioconversion of the substrate into earthworm biomass. The best vermicompost was obtained at the same stocking density and a feeding rate of 0.75 kg-feed/kg-worm/day.
The biochemical changes in fresh cow manure caused by the earthworm Eisenia andrei (Bouché) were measured over a period of four months, under controlled laboratory conditions. Earthworms were introduced into each of four plastic containers (0.4 × 0.27 × 0.15 m) containing fresh cow manure (2500 g), and four containers containing manure but without earthworms served as controls. Earthworms reduced the pH and decreased the moisture content in the manure. The C:N ratio of the manure with or without earthworms decreased progressively from 36 to 21. The ash and total nitrogen contents increased greatly for a few weeks after the introduction of earthworms, reflecting a rapid breakdown of carbon compounds and mineralization of nitrogen by the earthworms. CO2 evolution decreased rapidly (44%) one week after the introduction of earthworms, and continued at a lower rate throughout the 17 weeks (51% reduction as compared to 22% without earthworms), indicating increasing stability of the organic matter. Earthworms reduced microbial biomass early in the process, but enhanced nitrogen mineralization and increased the rates of conversion of ammonium-nitrogen into nitrate. The major general effect of earthworms on the organic wastes was to accelerate the maturation of the organic wastes as demonstrated by enhanced growth of lettuce and tomato seedlings.
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