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Toxic Waste From Leather Industries
... The leather processing industry is an ancient manufacturing sector that converts raw hide into processed leather goods including footwear, bags, garments etc. (Sivaram and Barik, 2019). It has a current global worth of about 271.21 billion dollars in 2021, consistently increasing for the past five years (Hira et al., 2022;Statista, 2021). ...
... From an environmental engineer's point of view, the tannery industry is a storehouse of complex wastes which require varied treatment methods for complete detoxification. Apart from the solid (flesh, hair, skin trimmings etc) and liquid (bodily fluids) wastes from the hides, the wastes from tannery industries also include a mixture of chemicals used in the various processes (Sivaram and Barik, 2019). One metric tonne of raw hide gets converted into only 200 kg of leather in useable form. ...
... One metric tonne of raw hide gets converted into only 200 kg of leather in useable form. Of the total waste produced, about 120 kg is untanned trimmings, 70-230 kg is untanned fleshings, 115 kg is tanned splits, 100 kg is shavings & trimmings, 32 kg is dyeing/finishing wastes, 2 kg is buffing dust, 150 kg is suspended solids and 20 kg constitute other chemicals (Dowlath et al., 2021;Sivaram and Barik, 2019). The discharged effluents from tannery industries are said to contain heavy metals, sodium chloride, sodium sulphate, organic & inorganic substances including eggs of parasitic organisms, biologically oxidizable material, and organic suspended matter apart from other wastes (Khan et al., 2022;Zhang et al., 2022aZhang et al., , 2022bZhang et al., , 2022c. ...
In the recent times, more attention is on industrial waste management due to the unaffordable space for dump yards and landfills and the increased charges for waste dumping. Even though the vegan revolution and plant-based meat products are booming, the traditional slaughterhouses and the wastes produced by them continue to be a concern. Waste valorisation is an established procedure striving to create a closed chain process in industries where there is no refuse. Although a highly polluting industry, slaughterhouse industry wastes have been recycled to economically viable leather since ancient times. However, the tannery industry is causing pollution in par with or even more than the slaughterhouses. Effective management of the liquid and solid wastes from the tannery is of utmost concern because of its toxicity. The hazardous wastes generated enter the food chain, causing long term impacts in the ecosystem. Several leather waste transformation processes are widely used in the industries, and they are yielding good products of economic value. However careful exploration into the processes and products of waste valorisation are often ignored as long as the transformed waste product is of higher value than the waste. The most efficient and environmentally friendly waste management technique should convert the refuse into a value-added utilization without any toxic leftovers. Zero waste concept is an extension of the zero liquid discharge concept, where the solid waste is also treated and reused to such an extent that there is no residue to be sent to the landfill. This review initially presents the existing methods for the de-toxification of tannery wastes and examines the possibility of solid waste management within the tannery industry to attain zero waste discharge.
... These compounds often result in impairment of the kidneys, lungs, urinary, liver, and genital systems, as well as causing conjunctivitis and skin irritation. Their concentrations in the plasma and bloodstream are measured to detect their high levels [48]. Chromium, namely in the form of Cr 6+ , is present in significant quantities within the effluent generated by the leather sector. ...
... During the concluding phase of manufacturing, tanneries use biocides as a means of inhibiting the proliferation of microflora. Allergy or irritation to the skin may be induced by these substances, while high dosages may result in symptoms such as migraine or vertigo [48]. At the moment, the generation of energy is a major producer of greenhouse gasses, whereas recycling of materials and energy occurs at relatively low levels. ...
The leather processing industry produces a significant quantity of waste materials, which can be treated in a manner that is consistent with the concepts underlying the circular economy. This article provides an overview of ways to recycle substances or energy from tannery waste, such as thermal, biological, chemical and other procedures. These approaches have the potential to facilitate the recovery and recycling of a diverse range of recyclable chemical substances like chromium, fats, gelatin vitamins, hydrolysate and minerals, biomass, and microbial waste products for use in other manufacturing operations. All the methods related to leather waste valorization have been discussed in this study to illustrate the recent development in techniques and processes of leather waste. The incorporation of the concept of circular economy has also been depicted. The premise of the circular economy model is that any waste product from the leather industry may be recycled and utilized again in the leather-producing process or in other related sectors. This study demonstrates that the circular economy approach to leather production offers chances for collaboration and innovation across several industries. Collaboration among organizations may lead to the discovery of innovative methods to minimize waste, enhance productivity, and extract value from resources that would otherwise be disposed of. The overview also addresses the state of waste legislation today and how it affects the environment. Technologies for sustainable and intelligent valuation allow for high recycling levels without negatively impacting the natural environment. PROGRESE RECENTE PRIVIND METODELE ECOLOGICE DE VALORIZARE A DEȘEURILOR DE PIELE CA MIJLOC DE PROMOVARE A ECONOMIEI CIRCULARE: O REVIZUIRE CUPRINZĂTOARE REZUMAT. Industria de prelucrare a pielii produce o cantitate semnificativă de deșeuri, care pot fi tratate în concordanță cu conceptele care stau la baza economiei circulare. Acest articol oferă o privire de ansamblu asupra modalităților de reciclare a energiei sau a substanțelor din deșeurile de tăbăcărie, prin procese termice, biologice, chimice și alte procese. Aceste abordări au potențialul de a facilita recuperarea și reciclarea unei game diverse de substanțe chimice reciclabile, cum ar fi cromul, grăsimile, vitaminele din gelatină, hidrolizatul și mineralele, biomasa și deșeurile microbiene pentru utilizare în alte operațiuni de producție. În acest studiu s-au discutat toate metodele legate de valorificarea deșeurilor pentru a ilustra progresele recente privind tehnicile și procesele de gestionare a deșeurilor de piele. De asemenea, a fost descrisă încorporarea conceptului de economie circulară. Premisa modelului economiei circulare este că orice produs rezidual din industria pielăriei poate fi reciclat și utilizat din nou în procesul de producție a pielii sau în alte sectoare conexe. Acest studiu demonstrează că abordarea producției de piele în termeni de economie circulară oferă șanse de colaborare și inovare în mai multe industrii. Colaborarea între organizații poate duce la descoperirea unor metode inovatoare pentru a reduce la minimum risipa, a spori productivitatea și a extrage valoare din resursele care altfel ar fi eliminate. Prezentarea generală abordează, de asemenea, starea legislației actuale privind deșeurile și modul în care acestea afectează mediul. Tehnologiile pentru valorizarea durabilă și inteligentă a deșeurilor permit niveluri ridicate de reciclare fără a avea un impact negativ asupra mediului natural. CUVINTE CHEIE: tăbăcărie, deșeuri, valorificare, durabilitate, crom DÉVELOPPEMENTS RÉCENTS DANS LES MÉTHODES RESPECTUEUSES DE L'ENVIRONNEMENT POUR LA VALORISATION DES DÉCHETS DE CUIR COMME MOYEN DE PROMOUVOIR L'ÉCONOMIE CIRCULAIRE : UN BILAN COMPLET RÉSUMÉ. L'industrie de transformation du cuir produit une quantité importante de déchets qui peuvent être traités d'une manière cohérente avec les concepts qui sous-tendent l'économie circulaire. Cet article donne un aperçu des moyens de recycler les substances ou l'énergie des déchets des tanneries, telles que les procédures thermiques, biologiques, chimiques et autres. Ces approches ont le potentiel de faciliter la récupération et le recyclage d'une gamme diversifiée de substances chimiques recyclables comme le chrome, les graisses, les vitamines de la gélatine, les hydrolysats et les minéraux, la biomasse et les déchets microbiens pour une utilisation dans d'autres opérations de fabrication. Toutes les méthodes liées à la valorisation des déchets de cuir ont été abordées dans cette étude pour illustrer l'évolution récente des techniques et procédés de gestion des déchets de cuir. On a décrit également l'intégration du concept d'économie circulaire. Le principe du modèle d'économie circulaire est que tout déchet de l'industrie du cuir peut être recyclé et réutilisé dans le processus de production du cuir ou dans d'autres secteurs connexes. Cette étude démontre que l'approche de l'économie circulaire dans la production du cuir offre des opportunités de collaboration et d'innovation entre plusieurs secteurs. La collaboration entre les organisations peut conduire à la découverte de méthodes innovantes pour minimiser les déchets, améliorer la productivité et extraire de la valeur de ressources qui autrement seraient éliminées. L'aperçu aborde également l'état actuel de la législation relative aux déchets et la manière dont elle affecte l'environnement. Les technologies de valorisation durable et intelligente permettent des niveaux de recyclage élevés sans impact négatif sur l'environnement naturel.
... During the entire tanning operation, a huge amount of pollutant water is discharged. The pollutant load for each operation and the amount of water consumed for each step are presented in Table 3 (Dixit et al., 2015;Sivaram et al., 2019). ...
... Pollutant load released and water consumption during the chrome tanning process Source:Dixit et al, (2015),Sivaram et al. (2019) ...
Industrial activities are paramount to sustaining the economy in a rapidly developing nation and global powerhouse like India. Leather industries are important in the country’s economic map due to the high revenue and employment generation opportunities. Several of these industries contribute largely to environmental pollution. The pollution of the environment is mainly caused by improper disposal of the tannery effluents that are highly rich in hexavalent chromium, a potent human carcinogen. Hexavalent chromium imparts toxic effects on the biotic components, which include plants, animals, and humans. The review portrays the current status of the Indian leather tanning sector and its impact on the Indian economy. The process of chromium tanning and its adverse effects on the environmental biotic components have been briefly discussed. Phytoremediation of these effluents using suitable hyperaccumulating plants has been suggested as an eco-friendly and cost-effective approach for the sustainable restoration of the polluted environment. The mechanism behind the remediation approach and the factors influencing it have been detailed. The manuscript briefly discusses some important advancements in the field of phytoremediation and emerging technologies and concludes by emphasizing further research for sustainable management of tannery wastes.
... The hazardous materials produced can cause pollution to the surrounding environment, inappropriate waste treatment can hinder the industry towards sustainable growth [3]. In the process water and pollutants are discharged in very large quantities, in the pre tanning and tanning process produces almost 90% of the total pollution from leather tanning, the environment is polluted by the discharge of chemicals which have a negative impact on the ecological function of water [4]. Then solid waste that is simply thrown away and pollutes the environment will become a threat to the ecology and water around the tanning factory [4] . ...
... In the process water and pollutants are discharged in very large quantities, in the pre tanning and tanning process produces almost 90% of the total pollution from leather tanning, the environment is polluted by the discharge of chemicals which have a negative impact on the ecological function of water [4]. Then solid waste that is simply thrown away and pollutes the environment will become a threat to the ecology and water around the tanning factory [4] . Even though the leather processing industry is one of the most important industries at this time, the pollution produced from this industry is very large, so it is very necessary to pay attention to how to reduce the negative impact of the waste produced [5]. ...
The leather processing industry always experiences growth every year. However, at the stage of processing leather to become raw material for a product, it produces a lot of solid waste containing hazardous materials used during the process. The resulting hazardous materials can cause pollution to the surrounding environment. Hence, there needs to be a solution to handle this solid waste, so that it does not pollute the surrounding environment. Magot Black Soldier Fly (BSF) cultivation training is a technique that can be used as a solution to process solid waste from the leather tanning industry so that it has high selling value. In a study, BSF cultivation shows circular economic results and future opportunities for investors, which will lead to increased demand. The cultivation of BSF as an alternative for processing waste into organic fertilizer and animal feed is a promising technology. It is worth inoculating, especially in countries that have low incomes with expensive fertilizer and animal feed costs. BSF maggot cultivation training was conducted for MSME players in the Sukaregang leather industry in the Garut district. The results of the evaluation were that 99% of the training activity participants felt that the training provided was very targeted and the material provided was appropriate, and easy to understand. So it can be concluded that the training provided is appropriate and beneficial for leather industry MSMEs, whoever participates. Keywords: BSF, economic empowerment, leather industry
... In general, leather production is divided into three main stages: the preparation stage, the tanning stage, and the finishing/crusting stage (Sivaram and Barik 2019). In the preparation stage, animal leather is prepared through several processes to prepare the skin appropriately for the tanning process. ...
... At the tanning stage, the raw leather is processed into more stable leather that does not rot easily. Finally, the last stage involves crusting and coloring the leather to be ready for use according to its intended purpose (Dixit et al. 2015;Sivaram and Barik 2019;Battig et al. 2021). This stage of leather production requires the use of large amounts of water, approximately 24.8-33.5 m 3 /t hide, and will certainly disrupt the water ecosystem and surrounding water needs, which can cause water scarcity (Chowdhury et al. 2015;de Aquim et al. 2019;Kumar et al. 2021). ...
Purpose
Mycelium-based leather is a leather-like material composed of filamentous, branched, and fibrous vegetative parts of fungi, specifically fungal mycelium. This study aimed to assess the production process of mycelium-based leather in Indonesia, especially in the Mylea™ manufacturing process, by considering its environmental impact through a life cycle assessment.
Method
The scope of the study starts from the cradle where mycelium is cultivated to the gate of the leather process. A functional unit of 1 m² natural Mylea™ grade A was used as a reference. The inventory of mycelia as foreground data was gathered from the Indonesian factory with supporting data taken from relevant literature. The infrastructure is not included within the system boundaries. The ISO 14040 and 14044 standards were followed during the analysis. This study used the software OpenLCA 2.02 to carry out the impact assessment and used the Ecoinvent database v3.8. The life cycle impact assessment (LCIA) was carried out using the CML-IA baseline method with 11 impact categories. A sensitivity and uncertainty analysis were conducted to evaluate the environmental impact.
Results
The finishing process is the main contributor to all the environmental impact categories. The LCIA results revealed that 1 m² of natural Mylea™ grade A produces 57.15 kg of CO2 eq. Energy usage in the form of electricity consumption is the major cause, contributing 46.53 kg of CO2 eq to the total carbon footprint, followed by cotton at 6.67 kg of CO2 eq and (ethylene–vinyl acetate) EVA glue at 1.03 kg of CO2 eq. The finishing process, which uses cotton fabric, emerged as the primary environmental hotspot, contributing significantly to most impact categories, such as terrestrial ecotoxicity potential (TEP), abiotic depletion potential (ADP), and global warming potential (GWP100a). Alternative energy scenarios, including hydropower and solar energy, were examined, revealing their potential to reduce the environmental impact.
Conclusion
The environmental impacts of mycelium-based leather production were identified in 11 categories. According to the findings, the most critical input parameter is the use of electricity sources. Therefore, several alternative energy sources, such as hydropower and solar photovoltaics, have been proposed to reduce environmental impacts.
... However, the study evaluated the impact without following a life cycle approach, but referring to assessments based on Effective Concentration (EC 50 ) or Lethal Concentration (LC 50 ). Similar outcomes have been obtained by (Sivaram and Barik, 2019), who identified that both the manufacturing waste and the solid waste derived by EoL a potentially responsible for the increasing toxicity impacts, especially in the case of involvement of heavy metals and chromium, in particular. ...
... Combined with the use of biocides, synthetic dyes, aluminum salts, etc., the tanning industry today poses a severe environmental burden for many countries especially in the Third World by exploiting the natural mineral resources and polluting the delicate environment. Worldwide, the disposal of toxic used waste products forms a significant challenge to societies and governments (e.g., described by Dixit et al. 2015;Sivaram and Barik 2019;Syed et al. 2010). ...
Tanning is among the most polluting industries in the world. Industrial-produced hides and skins are fully or pre-tanned with highly polluting chromium salts. The purpose of the study was to gain new knowledge about Iron Age tanning methods to clarify whether sustainable tanning methods can be developed based on this. Fur skin capes, uncovered in Jutland bogs, from Baunsø Mose (20-220 AD), Borremose I (365-116 BC), Huldremose I (1-174 AD) and Vindum Mose (386-203 BC) were analysed by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Gas Chromatography-Mass Spectrometry (GC-MS) and morphological assessment of the skin fibres to identify tanning substances and material condition. Analyses were supplemented with source studies of previous visual assessment of the capes and measured shrinkage temperature of leather and skins excavated from bogs. Our results show that only the samples from Baunsø Mose, Borremose I and Huldremose I contain vegetable tannins. Furthermore, Baunsø Mose contains cow fat and Borremose I, Huldremose I and Vindum sheep fat. All contain indications of the presence of aluminum and iron compounds. The samples are decomposed to varying extents. Remnants from conservation were detected on Huldremose I, Baunsø Mose and Vindum Mose.
... Sulfur compounds found in effluents originate from organic matter, primarily hair, as well as from processing chemicals such as surfactants, unhairing agents like sodium sulfide (Na2S), sulfates, and sulfides. Hydrogen sulfide (H2S) poses a risk due to its toxic and corrosive properties, necessitating appropriate management and treatment strategies [10,11]. As a response to these challenges, researchers have turned to bio-based dehairing agents, such as enzymes derived from Carica Papaya. ...
Enzyme-based leather dehairing has become widely recognized as a more environmentally friendly alternative to conventional chemical processes. In recent decades, the demand for plant-based enzymes has grown, leading to the need to improve catalytic efficiency and meet industrial requirements through advanced extraction and isolation techniques. Therefore, the objective of this study was to extract plant papain enzyme from Carica papaya and evaluate their potential as a dehairing agent in the leather industry. The experimental study was conducted in a laboratory setting from July to August 2023. Carica papaya samples were collected from various locations in Arba Minch town. Papain enzyme was extracted from Carica papaya by grinding it in a blender with extraction media such as distilled water and 50 mM phosphate buffers. The optimization of proteolytic activity was performed using the response surface method and Box-Behnken Design (BBD), considering parameters like pH, temperature, and reaction time. The optimized conditions for temperature, pH, and reaction time were found to be 55°C, 7.5, and 38.5 minutes, respectively, resulting in an optimum protease activity of 32 U/ml. The crude protease enzyme derived from papaya was successfully used to dehair goat hides at 25°C for 16 hours without the addition of Na2S. Microscopic analysis revealed hides that were free of epidermis and hair, with clean pores and no significant damage to the grain surface. In conclusion, the papain enzyme derived from Carica papaya can be a valuable tool for implementing cleaner technologies in tanneries, particularly for lime and sulphide-free dehairing processes.
... The tanning process necessitates the use of various chemicals, including sodium chloride, ammonium chloride, sulphate, and chromium (Hashmi et al., 2017). Regrettably, this intricate procedure results in the generation of solid, liquid, and gaseous waste, releasing toxic chemicals with considerable environmental repercussions (Sivaram & Barik, 2019). This not only poses health risks for tannery workers but also exposes them to potential hazards associated with carcinogenic compounds (Hashmi et al., 2017). ...
... The tanning process necessitates the use of various chemicals, including sodium chloride, ammonium chloride, sulphate, and chromium (Hashmi et al., 2017). Regrettably, this intricate procedure results in the generation of solid, liquid, and gaseous waste, releasing toxic chemicals with considerable environmental repercussions (Sivaram & Barik, 2019). This not only poses health risks for tannery workers but also exposes them to potential hazards associated with carcinogenic compounds (Hashmi et al., 2017). ...
La industria textil, un sector clave de la economía global, enfrenta importantes desafíos para lograr la sostenibilidad a largo plazo debido a su impacto ambiental.
... It has been analysed that, there is an element that is swimmable and liquid waste in water, Microbial approach can also kill this germ. In this assessment plan of tannery industry of India, Microbial approach worked as a "Volatile Organic Compounds" (Sivaram & Barik, 2019) [41] . It has been outlined that, it used to reduce all types of emission in water such as toxic chemicals. ...
Tannery wastewater is highly dangerous and it also creates a huge negative impact on entire environment. In order to reduce the toxicity of elements in wastewater, it is highly required to implement microbial approach for treatment of wastewater. In this part of the research, research background research rational, aim, objectives and research question have created to identify the major core factors of this research. Additionally, membrane separation process and bio inhibition process also has described to decrease the negative impact of toxic elements in wastewater from tannery industry. It has been found from this research that wastewater from tannery industry is making a huge problem in environmental system. Degradation of values can demolish equilibrium of the ecosystem and creates different problems in society and human health. Thus, treating this wastewater is required to mitigate these issues and provide a suitable infrastructure for everyone. Bioassay helps to treat concentration effects in tissue and cells. On the other hand, coagulation and pre-polymerized coagulants help to reduce harmful components in wastewater that comes from tannery industrial products. In this paper review of tannery industry of India, different procedures are discussed such as process of biodegradable treatment in this industry. As a propagation plan, wastewater treatment needs to be implemented in this industry, bio-assay and microbial approach is a major plan to purify wastewater of this industry.
... Only 20% of the raw materials are utilized in creating finished leather products, while the rest is transformed into waste that could potentially damage the environment and impact human health.(Fibres, Textiles and Clothing | ITC, 2022) (Sivaram & Barik, 2019). The leather industry is struggling. ...
In this review, we are going to discuss the ecological, environmental, and social impact of the leather industry and the potential for sustainability within it. The process of transforming animal hide into leather involves the use of harsh chemicals, which can have significant negative impacts on the environment and ecosystem, both directly and indirectly. While many alternative methods for producing leather have been developed, the impact of leather production has yet to be fully overcome. This is because leather is still in high demand, and the alternatives are not yet able to fully replace traditional leather production methods. However, with increasing knowledge and awareness of the environmental and social impacts of the leather industry, more and more people are becoming concerned about the livelihoods of those impacted by the industry. There is a growing demand for more sustainable and ethical practices within the industry. To address this demand, alternative ways of producing leather are gaining popularity. For example, fruit leather is one potential alternative that is gaining attention due to its environmentally friendly production process. These alternatives have the potential to reduce the impact of the leather industry on the environment and create a more sustainable and ethical industry. Due to nature of material increase in demand with alternate ways has gained popularity like fruit leather.
... Large amounts of lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni), and other toxic chemicals and metals are found in the effluents released and waste dumped by the tannery industry (Bhuiyan et al. 2010). Even while Bangladesh's 180 million square feet of leather production annually is crucial to the country's economy, the country's tannery industries are also a major contributor to environmental damage (Paul et al. 2013;Chen et al. 2020;Sivaram and Barik 2019). The discharge of effluent and dumping of solid wastes is a persistent problem in the Bangladeshi leather industry (Rasul et al. 2006). ...
The shifting of tannery industries from Hazaribagh to Savar adjacent to Dhaleshwari River might have inevitable adverse impacts, especially the heavy metal contamination of both terrestrial and aquatic ecosystems. The study was carried out to investigate the concentrations of four heavy metals in the soil, water, and plant samples collected from around Dhaleshwari River adjacent to the Bangladesh Small & Cottage Industries Corporation Tannery Industrial Estate, Dhaka. This study revealed that average concentrations of cadmium and chromium in soil exceeded the maximum permissible limit of World Health Organization (1996) and average concentrations of lead, cadmium, and chromium in water exceeded the maximum permissible limit of World Health Organization (2011) and Environmental Conservation Rules (1997). The average concentrations of lead, cadmium, and chromium in the roots and shoots of both Eichhornia crassipes and Cynodon dactylon exceeded the maximum permissible limit of Food and Agriculture Organization/ World Health Organization (2016). Ecological risk assessment using indices model for soil pollution indicated that soil is mostly contaminated with cadmium and chromium which can pose strong ecological risk Health risk assessment using indices model for water pollution revealed the high degree of contamination and unacceptable non-carcinogenic risk and carcinogenic risk for adults as well as children through ingestion of water. Average bioconcentration factor and bioaccumulation factor were higher in Eichhornia crassipes than Cynodon dactylon for lead, cadmium, and chromium. Average translocation factor was also higher in Eichhornia crassipes for all the metals except cadmium. It is suggested remedial and mitigation measures be instituted to control environmental degradation of the newly established Tannery Industrial Estate.
... The management and reuse of wastes as secondary raw materials for a sustainable circular economy aims at retaining resources within value chains, reducing negative environmental impacts (Das et al., 2019;Bongers and Casas, 2022). Despite the development of cleaner technologies (Rosu et al., 2018;China et al., 2020), leather tanning still represents a potentially pollution-intensive industry (Dixit et al., 2015;Laurenti et al., 2016), generating substantial quantities of hazardous non-renewable waste by-products (Sivaram and Barik, 2019;Tasca and Puccini, 2019). In particular, the chromium salts (usually basic Cr(III) sulfate), used as tanning agent in over 80% of the world's leather production, produce a tannery sludge with Cr excess, yielding potential negative environmental impacts when wastes are improperly treated and disposed (Mella et al., 2015;Famielec, 2020). ...
... The water used in the chrome tanning process pollutes water resources, as in many counties they are discharged directly into waterways. Discarding natural leather products at end of life can produce substantial amount of methane gas [97]. The use of BC leather is eco-friendly as it is free from the toxic chemicals used during processing and is free from the problems of land allocation for pastures and stockyards, where land is scarce in many countries. ...
The fashion and textile manufacturing sectors are increasingly focusing on innovative raw materials that are renewable and biodegradable. Such materials not only mitigate environmental impacts but also prevent resource depletion. Bacterial cellulose (BC) has emerged as a prime candidate, derivable from a variety of natural ingredients such as tea and coffee in addition to a sugar source in presence of the bacterial microorganisms. Numerous studies have established the potential of BC in future fashion, and some brands have already started to utilise BC as a sustainable raw material. The applications of BC ranges from basic clothing and accessories to wearable electronics. This paper discusses the scope of BC in fashion and textiles, positioning it as a sustainable alternative to conventional materials. We present a comprehensive scoping review, covering the unique properties of BC, the factors influencing its production, and its applications in textile, clothing, and footwear over the past decade. The advantages of BC in fashion are manifold: zero-waste manufacturing, reliance on renewable sources, diminished environmental pollution, and biodegradability. Furthermore, the use of BC aligns with United Nations Sustainable Development Goals 6, 7, 12, 13 and 15. However, there exist challenges pertaining to production costs, scalability, and quality, in addition to the imperative of harnessing food waste streams instead of contending for human food resources. Addressing these challenges is vital to cement BC’s position as a pivotal sustainable material in future fashion.
... The tanning industry is considered one of the most important industries due to its economic, employment, and export potential. However, it is worth noting the leather industry generates approximately 600,000 tonnes of solid waste per year worldwide [1,2]. Uncontaminated or slightly contaminated waste fractions produced before the tanning process could be recovered in other industrial sectors such as the production of gelatine, sausage casings, yarns, sponges, artificial leather, adhesives, cosmetics, and technical fats for animal feed [3][4][5][6][7]. ...
Chrome tanned leather shavings (CTLS) are considered one of the more difficult wastes to manage in the tanning industry. At the same time, this waste is an important source of good quality collagen. The few methods described in the literature for the valorization of these wastes usually require pre-treatment or activation. In this study, an attempt was made to see if raw chrome tanned leather shavings (CTLS) could be modified to obtain secondary raw materials with new physical properties. Glutaraldehyde, glycerol, EDCs, pectin, and tannins were selected for modification of the CTLS. The effectiveness of the processes carried out was confirmed by FTIR analysis of the materials obtained. Changes in the intensity of the characteristic collagen peak (amide I, amide II, and amide III) and changes in the position of the bands in the 1200–1000 cm⁻¹ region were observed in the recorded spectra. The modifications introduced confirmed changes in the physical properties of samples M1–M5, including an increase in bulk density from 0.15 to 0.59 g cm⁻³, and improved tensile strength is some cases. The elemental content results of the samples tested showed the resulting modified CTLS were free of Cd, Hg, Pb, and Cr(VI). It was also confirmed tanning waste contained significant amounts of various valuable elements. The research also included preliminary tests to assess the environmental impact of the modified materials. In a phytotoxicity test conducted on modified CTLS, M1 with pectins showed the highest root stimulation (105%), while samples with glutaraldehyde and unmodified CTLS showed significant root inhibition (75%, 74%). Other samples showed moderate plant toxicity and seed germination was not significantly affected.
... Treated skin containers created from camel, pig, or young goat skins have historically been used for water, milk, and wine because they are flexible, lighter in weight, and non-breakable. Flour and sugar were also packaged in Treated skin cases and pouches, but the use of leather in most processed food applications has now ended [27]. ...
... The production of leather entails the intricate processing of raw animal skin and hides through a tanning process, necessitating the use of diverse chemicals, such as sodium chloride, ammonium chloride, sulphate, and chromium [5]. Unfortunately, this tanning procedure generates solid, liquid, and gaseous waste, along with the emission of toxic chemicals, leading to significant environmental repercussions [6]. Moreover, these processes expose workers in tanneries to potential health risks associated with carcinogenic compounds [5]. ...
In response to the growing focus on sustainability and ethical practices, there is an increasing interest in developing sustainable coated textiles with agri-food by-products as alternatives to traditional animal leather. This transition not only addresses ethical concerns but also contributes to waste reduction within the agri-food industry, fostering a more circular and sustainable approach. The coffee silverskin (CS), a by-product of the coffee processing industry, is gaining significant attention for its potential in sustainable resource optimization and value creation. This study explores the versatility of coffee silverskin as a sustainable coating material for textiles. The innovative exploration of CS as a bio-based coating material involves different residue treatment procedures and formulations to assess its suitability for coatings. The use of planetary ball milling as a pre-treatment method has resulted in a homogeneous deconstruction of the integument, yielding a uniform and soft coating. In conclusion, this study represents a significant step towards sustainable coated textiles as an ethical alternative to animal leather. By harnessing the potential of coffee silverskin, the textile industry can contribute to a more sustainable and responsible future.
... The total heavy-metal concentration was reduced by one-third and TDS, BOD, and COD by about half. Elsewhere, similar reductions (45-60%) of tannery effluents have been reported [38,39]. These reductions are not enough to satisfy the environmental regulations. ...
Simple Summary
Several large tanneries operate in Saudi Arabia. The tanneries produce more than 15,000 pieces of leather per day and 200 metric tons of wastewater per day. Leather manufacturing is a highly polluting activity throughout the world, and in many places, it is not known how efficient the wastewater treatments in the factories are. This was found to be the case in Saudi Arabia, where we revealed insufficient treatments in all four of the factories that we studied. We propose here an additional biological treatment using a bacterial–fungal consortium. Bacteria and fungi were isolated from tannery wastewaters, and their collagenase and gelatinase activities were measured to discover their potential to clean tannery wastewater. Different single bacteria and fungi and their consortia were used in the experiment to find the most suitable species for the treatment. The treatment appeared to be efficient, reducing almost all parameters to below the environmental regulation limit for wastewater discharge to the environment in Saudi Arabia.
Abstract
Environmental pollutants such as toxic heavy metals and oxygen-demanding solids are generated by leather manufacturing. In most tanneries, wastewaters are treated with physico-chemical methods but overly high levels of pollutants remain in surface waters. The efficiency of tanning wastewater treatment with conventional techniques was evaluated in four tanneries in Saudi Arabia. It was observed that the wastewaters contained high amounts of pollutants, needing further treatment. We isolated microorganisms from the wastewaters and carried out experiments to treat the effluents with different bacteria, fungi, and their consortia. We hypothesized that a consortium of microorganisms is more efficient than the single microorganisms in the consortium. The efficiency of five single bacterial and five fungal species from different genera was tested. In a consortium experiment, the efficiency of nine bacterial–fungal consortia was studied. The bacterium Corynebacterium glutamicum and the fungus Acremonium sp. were the most efficient in the single-microbe treatment. In the consortium treatment, the consortium of these two was the most efficient at treating the effluent. The factory wastewater treatment reduced total dissolved solids (TDS) from 1885 mg/L to 880 mg/L. C. glutamicum treatment reduced TDS to 150 mg/L and Acremonium sp. to 140 mg/L. The consortium of these two reduced TDS further to 80 mg/L. Moreover, the factory treatment reduced BOD from 943 mg/L to 440 mg/L, C. glutamicum to 75 mg/L, and Acremonium sp. 70 mg/L. The consortium reduced BOD further to 20 mg/L. The total heavy-metal concentration (Cd, Cr, Cu, Mn, and Pb) was reduced by the factory treatment from 43 μg/L to 26 μg/L and by the consortium to 0.2 μg/L. The collagen concentration that was studied using hydroxyproline assay decreased from 120 mg/L to 39 mg/L. It was shown that the consortium of the bacterium C. glutamicum and the fungus Acremonium sp. was more efficient in reducing the pollutants than the single species. The consortium reduced almost all parameters to below the environmental regulation limit for wastewater discharge to the environment in Saudi Arabia. The consortium should be studied further as an additional treatment to the existing conventional tannery wastewater treatments.
... Chemicals in leather industry effluent include ammonium salts, calcium salts, phenol, chromium, nitrogen, sulfides, solvents, surfactants, acids, and metallo-organic dyes; natural or synthetic tanning agents; sulfonated oils, and salts. Pre-tanning and tanning operations account for roughly 90% of total leather industry pollution (Sivaram & Barik 2019). The pre-tanning operation causes pH differences, which raises the chemical oxygen demand (COD), total dissolved solids (TDS), chlorides, and sulfates in tannery wastewater. ...
... Chemicals in leather industry effluent include ammonium salts, calcium salts, phenol, chromium, nitrogen, sulfides, solvents, surfactants, acids, and metallo-organic dyes; natural or synthetic tanning agents; sulfonated oils, and salts. Pre-tanning and tanning operations account for roughly 90% of total leather industry pollution (Sivaram & Barik 2019). The pre-tanning operation causes pH differences, which raises the chemical oxygen demand (COD), total dissolved solids (TDS), chlorides, and sulfates in tannery wastewater. ...
Globally organic wastes are generated from fruits, vegetables, and their peels. It is mostly decomposed in landfills or by composting methods. Food processing industries, vegetable markets, and restaurants produce a huge amount of organic waste daily, generally disposed of in the environment or composted. Producing an eco-enzyme from organic kitchen waste was an innovative solution for domestic waste pollution. It is an enzyme solution obtained from an organic waste substance that contains organic acids, enzymes, and mineral salts. It is produced by performing a simple batch fermentation that involves a mixture of brown sugar, fruit or vegetable waste, and water in the ratio of 1:3:10. Two types of the eco-enzyme were produced by a fermentation process using vegetable and fruit peels for about 90 days involving Saccharomyces cerevisiae. The ultimate liquid or enzyme obtained was brown. Eco-enzyme 1 from (Cucurbita maxima) contained hydrolytic enzymes like amylase and lipase. The microbial diversity was observed, and bacteria like Yersinia sp., Bacillus sp., and fungi like Trichoderma sp. and Penicillium sp. No enzymes and microorganisms were observed in Eco-enzyme 2 (Citron). Eco-enzyme 1 with 50% dilution effectively reduced various parameters like BOD, COD, TDS, Nitrate, Nitrite, and Ammonium in the effluent. Also, it promoted plant growth within 10 days compared to the control. Therefore, the present study outlines how the eco-enzyme could be used to treat industrial effluent cost-effectively and environmentally friendly.
... El cuero procesado tiene un sinfín de aplicaciones en todas las actividades humanas gracias a sus propiedades físicas y químicas. El proceso de curtiembre se puede simplificar en varias etapas como se muestra en la Figura 3. Todas las etapas generan residuos, los cuales, dependiendo de la cantidad y composición química se convertirán en un problema de mayor o menor impacto para el ecosistema (Sivaram & Barik, 2019), (Hinojosa & Saldaña, 2020). ...
Las curtiembres son industrias muy contaminantes que liberan compuestos peligrosos, como el cromo, en sus efluentes sólidos y líquidos y gases derivados de la descomposición orgánica en sus efluentes gaseosos, los cuales se liberan al medio ambiente. Según lo que se ha encontrado en bibliografía se puede notar que todos los vertidos sólidos van a parar a los vertederos; mientras, que los efluentes líquidos son tratados, hasta cumplir normas ambientales locales y luego son eliminados en los ríos más cercanos. Es indispensable que se desarrollen tecnologías ecosostenibles e innovadoras para el manejo y eliminación de estos desechos. Pero como el wet-blue es tan estable químicamente, el desarrollo de nuevas tecnologías de reciclaje y/o reúso estos residuos de curtiembres se está convirtiendo en un gran desafío para los investigadores. En la actualidad, los encargados de estudiar estos residuos han empezado a utilizar estos desechos para producir nuevos materiales que simulen las cualidades del cuero o tecnologías que permitan extraer colágeno del wet-blue de la forma más económica. Existen varios trabajos sobre la gestión de residuos de cuero y los que se han utilizado para elaborar este resumen, informan de manera concisa los procesos que se utilizan para reutilizar y/o reciclar el wet-blue. Esta revisión informa por primera vez el estado del arte de las estrategias relacionadas con la recuperación y valorización de estos residuos de cuero y la obtención de colágeno hidrolizado a partir de ellos. En la sección de conclusiones, los autores brindan implicaciones prácticas para la industria con relación al reciclaje del wet-blue.
... From the different processes, industrial waste is generated, and its toxicity and amount released depend on the industrial processes (Altaf et al., 2008). In recent years, the leather industry has been shown to be the most polluting industry considering its adverse environmental effect (Sivaram and Barik, 2019). The main wastes from the tannery industry are chrome shavings, buffing dust, and tannery sludge that is produced at different stages of the leather industry (Guan et al., 2019). ...
In the leather industry, tannery sludge is produced in large volume. This study investigated the thermal degradation behavior of tannery sludge using thermogravimetric analysis (TGA). The experiments were carried out in an inert atmosphere using nitrogen gas at varied heating rates of 5, 10, 20, and 40 °C/min in the temperature range of 30-900 °C. For the kinetic parameters calculation, three different models, Friedman, Kissinger-Akahira-Sunose (KAS) and the Ozawa-Flynn-Wall (OFW), were employed. The average activation energy Ea obtained from Friedman method, KAS, and the OFW were 130.9 kJ mol-1, 143.14 kJ mol-1, and 147.19 kJ mol-1 respectively. Along with that experiment of pyrolysis was accomplished in fixed bed reactor at temperature of 400 °C. Biochar produced has a yield of about 71%. The analysis of gas chromatography-mass spectroscopy shows the different chemical compounds present in the bio-oil containing hydrocarbons (alkanes and alkenes), oxygen containing compounds (alcohols, aldehyde, ketones, esters carboxylic acids and the esters) and the nitrogen containing compounds. The kinetic assessment was complemented by frequency distribution of activation energy model (DAEM). In the pyrolysis of tannery sludge six pseudo-components were found to be involved. Furthermore, artificial neural network (ANN) was used to predict the activation energy from conversion, temperature, and the heating rate data. MLP-3-11-1 described well the conversion behavior of tannery sludge pyrolysis.
... This sector contributes to the economy of some nations; however, its process generates large volumes of wastewater that pollute the environment. The waste generated by the leather industry can be categorized into two distinct kinds: solid waste and wastewater composed of volatile organic compounds (VOCs) and harmful chemicals [9][10][11]. The most important element in tanning is chrome, the use of which has become essential in the tanning industry owing to the high leather quality standards to be achieved. ...
The effluents generated by the tannery industry have a high content of chromium and other toxic elements, representing a potential threat to ecosystems. An eco-friendly alternative to treat these effluents is the use of microorganisms, such as fungi, with the capacity to biosorb heavy metals. The present work aims to determine the effect of the molasses concentration, pH variation, and time on the removal of total chromium using the filamentous fungus Trichoderma spp. An experimental design was adopted using pH (4 and 6), concentrations of molasses (0.5 and 1%), and time (8 and 12 days) as independent variables. The Trichoderma inoculum was constant in all the treatments. The different treatments were evaluated after 0, 8, and 12 days by taking 50 mL of sample from each bioreactor. The chromium concentration was subsequently determined in each sample. The results show that treatment 3 (1% molasses and pH 4) showed higher chromium removal after both 8 and 12 days. The concentrations of total chromium decreased from 665 mg/mL to values of 568 mg/mL by day 8 and 486 mg/mL by day 12. These values are, however, still above the maximum threshold imposed by Peruvian law regarding the discharge of non-domestic effluents into the sewage system. The results show that Trichoderma spp. can increasingly remove chromium from the effluent with longer incubation periods. However, future studies are necessary to determine the mechanisms of chromium biosorption by the fungus and the influence of other physicochemical parameters.
... The discharge of huge amounts of effluents containing dyes by industries such as textile, pulp and paper, leather tanning, cosmetic, and food technology poses a serious threat to the environment because of the toxic nature of these compounds to humans and aquatic life (Al-Tohamy et al., 2022;Ben Slama et al., 2021;Kahraman & Şimşek, 2020;Pereira & Alves, 2012;Şimşek, 2023;Sivaram & Barik, 2019). Different techniques have been used to remove synthetic dyes from wastewater such as adsorption (Bingol et al., 2010;Erdem et al., 2019;Mittal et al., 2012;Pourfaraj et al., 2017), ion exchange (Leszczyńska & Hubicki, 2009;Marin et al., 2019), biological treatment (Alghazeer et al., 2019;Asgher et al., 2016;Rathi & Kumar, 2022;Sarkar et al., 2017), photocatalytic degradation (Rauf et al., 2011;Wang et al., 2017;Yeber et al., 2010), wet catalytic oxidation (Bi et al., 2009;Kondru et al., 2009;Qiu et al., 2005), Fenton oxidation (Dutta et al., 2015;Meriç et al., 2003;Tekbaş et al., 2008), anodic oxidation (Gutierrez & Crespi, 1999;Hamad et al., 2018;He et al., 2018), and ozone oxidation (Faouzi et al., 2006;Leeuwen et al., 2009;Shu & Huang, 1995). ...
Removal of brilliant yellow azo dye from wastewater by electrocoagulation was carried out using a cell with Al helical coil whose external surface acts as an anode, and its internal surface acts potentially as a cooler to control the cell temperature. This is important in the case of large-scale cells which use high currents and low electrolyte conductivity where accumulated heat decreases the rate of electrocoagulation. The helical coil anode was enclosed between two Al cylindrical screen cathodes. Variables studied were current density, initial dye concentration, solution pH, solution temperature, NaCl concentration, and magnetic stirring rate. Most of the variables were found to have opposing effects on the % dye removal. Under the optimum conditions, a maximum of 92% dye removal was obtained in 90 min using a current density of 3 mA/cm², pH 5–6, an initial dye concentration ranging from 10 to 75 ppm, and NaCl concentration of 30 g/L. Electrical energy consumption ranged from 3.258 to 313.3 kW∙h/kg of dye removed depending on the operating conditions.
... The leather industry employs waste from the food industry to produce diverse products, such as garments, footwear, upholstery, etc. However, these operations use a significant amount of chemicals and water, producing huge amounts of solid and liquid waste and leading to a negative effect on the environment [1]. To decrease environmental impact, new technologies are being developed; these can be classified into two main groups: ...
Due to their variety, specific activity, and mild reaction conditions, enzymes have a wide application in beam house processes such as soaking, dehairing, bating, and de-greasing. Recently, due to improvements in biotechnology, re-bating after chroming has received increased attention. The aim of this work was to investigate the application of enzyme preparation in the re-bating process and its effect on the semifinished and finished product, as well as its influence on post-tanning operations. The enzymatic treatment of chromed semifinished leather (wet blue) led to a higher shrinkage temperature (1–6 °C), greater water vapour absorption (0.3–5.5%), better chromium compounds exhaustion during re-chroming (4–21%), and better dye penetration. Moreover, collagen was affected during the enzymatic process; the results showed a greater concentration influence in the operation compared to the process time. On the other hand, no effect on the physical and mechanical properties and fat-liquoring process was observed. Overall, these results indicate that some properties and processes are improved; however, before use for re-bating, every enzyme should be carefully investigated.
... Leather industry is one of the manufacturing industries that produce an incredible amount of goods like footwear, bags, garments, gloves, and other articles for millions of consumers around the world every day (Sivaram, 2019). The industry uses hides and skins, which are the by-products of meat processing as a main raw However, the leather industry development in Ethiopia has faced an unprecedented challenge (CSA, 2017;Koleros and Attfiled, 2017). ...
Leather industries in countries with a large raw material base, such as Ethiopia, could contribute significantly to meeting future global demand for leather and leather goods. So far, Ethiopia's leather industry has begun producing leather shoes, jackets, and elegant gloves, which are sold in many developed countries through world-class branded distributors. However, shortage of raw materials has become a major constraint for the industry even if the volume of raw material production is greater than the design capacity of the industry. Therefore, the aim of this study was to investigate the complete process of raw material supply, i.e., starting from the point of production until it reaches the boundaries of tanneries and reveal how the process affects cost, quality, and availability of raw materials. Data were collected through surveys, observations, focus group discussions, and questionnaire. After modeling the existing raw material supplying process and conducting both qualitative and quantitative analysis, this study found that: (i) the existing process fails to collect about 45% of the total available raw material, (ii) the raw material price increases by five-fold when it reaches the tanneries, (iii) it takes 3 to 4 more steps than the standard of reaching raw material to the industry, and (iv) there is a lack of quality control throughout the entire process.. In conclusion, the existing process of raw material supply is a real challenge for the industry. Different interventions suggested by this study could improve the existing conditions.
... The pharmaceutical industry is the primary commercial use for sulphate. Industrial waste and atmospheric deposition also contribute to sulphate contamination of water [37]. Sulphates concentration in the drinking water of the region ranged from 33.4 mg/L to 106.2 mg/L with an average value of 64.78 mg/L (Table 3); (Figure 2 (f)), which lies below the WHO desirable limits ( Table 2). ...
The issue of water quality is becoming ever more serious as freshwater resources are severely degraded across the world. Water quality in rivers, streams, lakes, and subterranean aquifers is deteriorating, posing a threat to human life and ecological sustainability. A proper study of the physico-chemical properties of the water samples provide insight into the quality of life in a specific region, as poor water quality not only affects the aquatic life but the surrounding ecosystem as well. In the present study, 30 different water samples were collected from different regions of district Mardan and they were analyzed for their physico-chemical properties such as pH, total suspended solids, conductivity, total dissolved solids, nitrates concentration, sulphates concentration, chlorides concentration, dissolved oxygen, and biochemical oxygen demand. The results of the analysis show that most of the parameters have significantly higher values than the WHO permissible limits. From the analysis of water samples, the researchers have been able to designate the study area with poor water quality and to propose future advice for sustaining the water quality in the region.
Available methods of wastewater treatment of tanneries require improvement to ensure the desired efficiency of purification and regeneration of valuable components contained in the waste process solutions. The purpose of this study was to provide a comprehensive coagulation-flocculation treatment of liquid waste from tanneries using mathematical modelling methods. The study conducted experimental investigation of the effectiveness of coagulants – aluminium sulphate and iron (III) chloride – and flocculants: polyhexamethylene guanidine hydroxychloride and its acetate, as well as reagent P228. The effect of pH on the coagulation process was examined. The efficiency of the coagulation process was evaluated by an integral indicator - the degree of purification, which was determined considering the turbidity and optical density of the purified water samples. The study presented the findings on coagulation and flocculation effects that occur during the purification of samples of tannery waste process solutions after the filling-fattening and dyeing processes. The studied samples are characterised by high concentrations of sulphates (over 9,000 mg/dm3) and chlorides (over 1,500 mg/dm3), an increased content of suspended solids (over 843 mg/dm3) and metal ions: chromium (III), iron, and aluminium. According to the findings of the study, the aluminium-based coagulant is more efficient than the iron-based coagulant. Among the flocculants, polyhexamethylene guanidine hydroxychloride is the most effective, while the pH value should be 10. The results of experimental studies were used to obtain a mathematical model that described the coagulation process with a sufficient degree of accuracy. The results of mathematical modelling can be used to calculate the optimum parameters of the coagulation process.
Introduction. Despite the positive trends in the field of industrial and consumer waste management, issues related to the legal regulation of activities to eliminate objects of accumulated damage to the environment and its relationship with activities to eliminate unauthorized landfills remain unresolved. A separate and important problematic aspect is the assignment of waste to a certain hazard class and their subsequent accounting and neutralization. The study aims to consider the established practice of using sanitary-epidemiological and environmental legislation in the management of industrial and consumer waste, including in assessing their toxicity. Materials and methods. The authors conducted the study using an information and analytical method for analyzing regulatory documentation and scientific publications from the databases Elibrary, Scopus, Web of Science, PubMed, Techexpert, Consultant, etc. They also compared the topical issues of assessing the toxicity of production and consumption waste and identified the specifics of the methodology for calculating the amount of damage as a result of unauthorized waste disposal. Results. It has been established that one of the optimal solutions in the issue of assessing the hazard class of waste may be to bring the criteria for their classification according to the degree of toxicity to uniformity, as well as the development of a single document carried out by institutions regardless of departmental subordination. Studies conducted to determine the amount of damage as a result of unauthorized disposal of production and consumption waste and to establish the hazard class of waste must comply with the requirements of uniformity of measurements and accreditation in the national system, respectively. To correctly calculate the amount of harm, you need to use the value of the mass of waste with the same hazard class. The availability of separate documents in sanitary-epidemiological and environmental legislation can significantly affect the calculation of the amount of harm due to various methods of determining the hazard class of waste, as well as the timeliness of identifying the long-term impact of waste on the environment and public health. Limitations. The study is limited to the analysis of law enforcement practice in the field of waste management, as well as the results of research in domestic and international literature. The analysis will allow researchers to consider non-obvious and controversial issues in the planning of activities. Conclusion. Updating documents on the establishment of the hazard class of waste should be carried out considering law enforcement practice. The absence of duality in compliance with the established requirements in both the field of environmental and sanitary-epidemiological legislation can be a guarantee of the reliability and truthfulness of research. This will allow you to make the right management decisions. Ethics. The study does not require the submission of the conclusion of the biomedical ethics committee.
“Planet Prosperity: Achieving Sustainable Business Growth” is a comprehensive book that highlights the importance of sustainability for modern businesses. An effort has been made to consolidate the recent trends and practices with respect to integrating sustainability concepts into business operations. Provide strategic insights into aligning business practices with global environmental goals, enhancing competitive advantage through sustainable operations, and optimizing resource utilization. Integrating sustainable practices into business operations is crucial for ensuring long-term success. By committing to sustainability, businesses not only contribute to the well-being of the planet but also create a competitive advantage and build a resilient future.
The tanning industry, a significant contributor to global leather production, faces critical challenges in wastewater management due to the hazardous pollutants generated during processing. Zero liquid discharge (ZLD) systems present a sustainable solution by efficiently treating and reusing wastewater while minimizing environmental impact. This study aims to explore the successful implementation of ZLD in the tannery industry, considering its economic and environmental benefits. Through a comprehensive review of literature and case studies, this research assesses the factors contributing to ZLD success, potential barriers to widespread adoption, and future advancements in technology. Methodologies include analyzing existing ZLD implementations, evaluating cost analyses, and investigating potential advancements in ZLD technologies. Results demonstrate that while ZLD offers significant advantages in water conservation, resource recovery, and environmental protection, challenges such as high installation costs and technical complexities hinder widespread adoption. Addressing these challenges requires concerted efforts from stakeholders, including tannery owners, regulatory bodies, and technology providers. Future directions suggest the need for ongoing research and development to enhance ZLD efficiency and cost-effectiveness. By embracing ZLD systems, tanneries can achieve sustainable wastewater management, conserve water resources, and meet environmental standards, thereby advancing towards an environmentally conscious and socially responsible business approach.
The leather and footwear industry in Kenya has been in existence for over a century, dominated mainly by small and medium scale tanneries and producers of leather products. Over the years the industry’s transformation has undergone several metamorphosis and upheavals along its development. There is interest in developing eco-friendly tanning processes, specifically those based on organic processes. As a consequence, the emerging scope for vegetable tanning provides an encouraging prospectus for the leather industry in Kenya. In this paper, an attempt is made to summarize closely related aspects of the Kenyan leather industry with a bias on the vegetable tanning sector. It highlights the historical perspective of vegetable tanning in Kenya, current trends, product development and its merit in socio-economic impact, sustainable production.
Water pollution caused by various industrial effluents has been increasing on a tremendous scale due to rapid industrialization. One of the blooming and revenue-generating industries is the tannery industry with an annual turnover of around 7.8 billion euros. However, the tannery industry uses various toxic heavy metals (e.g., chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), etc.) in the leather tanning process and also generates various kinds of wastes, such as proteins, lime, hair, salts, acids, dyes, tannins, oils, etc. Sludge produced from the physical-chemical treatments of tannery wastes are called tannery sludge (TS), a type of solid waste. Cr salts are extensively used as tanning agents to give leather good mechanical and hydrothermal resistance. The third-most hazardous and carcinogenic substance, namely, hexavalent chromium, is present in tannery sludge. Such hazardous tannery sludge are disposed into the environment, thus causing both water and soil pollution. The rapid growth of industrialization and urbanization has increased the amount of toxic wastewater disposed by various industries into water bodies and environments, with ~80% of the wastewater containing harmful chemicals, e.g., heavy metals, carcinogenic dyes, etc. Numerous types of health hazards are caused by the consumption of polluted water. The World Health Organization (WHO) has reported that ~25% of health diseases are triggered by pollution (soil, air, and water pollution). This chapter provides detailed information on the emerging contaminants of tannery sludge and their environmental impact and health hazards, a discussion on their management as well as challenges and future perspectives, and a chapter summary as conclusion.
Desalination of seawater, brackish water, and reclaimed water is becoming increasingly prevalent worldwide to supplement and diversify fresh water supplies. However, particularly for industrial wastewater, the need for environment-friendly and economically viable alternatives for concentrate management is the major impediment to deploying large-scale desalination. This review covers various strategies and technologies for managing reverse osmosis concentrate (ROC) and also includes their disposal, treatment, and potential applications. Developing energy-efficient, economical, and ecologically sound ROC management systems is essential if desalination and wastewater treatment are being implemented for a sustainable water future, particularly for industrial wastewater. The limitations and benefits of various concentrate management strategies are examined in this review. Moreover, it explores the potential of innovative technologies in reducing concentrate volume, enhancing water recovery, eliminating organic pollutants, and extracting valuable resources. This review critically discusses concentrate management approaches and technologies, including disposal, treatment, and reuse, including new technologies for reducing concentrate volume, boosting water recovery, eliminating organic contaminants, recovering valuable commodities, and minimizing energy consumption.
The leather industry generates $150 billion USD annually. The industry that processes animal hides or skins for finished leather goods generates a lot more solid waste than its main output, leather. The current ineffective disposal of these solid wastes (via open dumping, incineration, and landfilling) results in pollution, which obstructs the industry’s path to sustainable expansion. Interestingly, recycling waste into usable form seems like a potential option. Leather biomass contains collagen, keratin, and fat and can be used to produce sustainable bioproducts and replace petroleum-based materials. This chapter provides an extensive perspective on the effective reutilization of diverse forms of leather waste (keratin waste, untanned/fleshing waste, chrome-tanned waste, and tannery waste sludge) that are generated at various stages of processing the leather. However, there is still a sizable difference between the stated targets for sustainable leather technology and the levels that have been reached, despite ongoing research efforts. The chapter concludes that solid waste, which is generated from the tannery industry, is a gold mine that can be immediately used to make money while closing the loop.
The tannery is a well-established, age-old industry that has been substantially industrialized across all nations over time and contributes significantly to the global economy, but it also offers a serious threat to the environment due to its high water and more than 250 chemicals, including polychlorinated biphenyl, chromium, sulfides, nitrates, and others, are utilized in the process, which results in the production of effluent with a high concentration of pollutants into the ecosystem. The ecosystem is severely impacted by a large-scale discharge of inadequately handled solid tannery waste (STW), which contaminates the soil, surface water, and groundwater resources and poses serious risks to human and animal health. Proteinaceous untanned and tanned waste make up STW, which must be properly treated for disposal in an environmentally friendly manner. Over the years, a number of strategies have been created STW should be reduced and recycled to produce renewable energy (biogas and biohydrogen), biofuels (biodiesel and briquettes), building materials, fertilizers, commercial items (adsorbents, animal feeds, proteins, fats, and enzymes), biodegradable packaging and non-packaging materials, and biodegradable packaging and non-packaging materials. In this book chapter, we will emphasize the utilization of solid tannery waste (STW) as useful construction material. A brief review of both traditional and modern methods for treating tannery industry effluent also covered the role of nanotechnology in the tannery industry. We can protect the ecology, aquatic wildlife, and human health by turning the problem created by solid tannery waste into a possibility, paving the path for a healthier and more sustainable future.
The Upflow Anaerobic Sludge Blanket reactor is a viable high-rate anaerobic digestion design for the treatment
of different wastewater with low to high solubility. This can also be used for the treatment of solid wastes with
less HRT. In this study, the performance evaluation of a lab-scale UASB reactor was carried out for different
hydraulic retention times of 24, 21, 18, 15 and 12 h for obtaining the best HRT for tannery fleshings. The gas
production varied between 3.7 – 4.5 L with a methane content of 64.31 – 67.72%. It was observed that the
maximum gas production was at 18 h HRT and this optimized condition was applied to the pilot-scale UASB
reactor. The performance evaluation of the pilot-scale UASB reactor was carried out with an HRT of 18 h. The gas
production of 450 ± 50 L, the maximum specific gas production of 0.274m3/kg of VS destroyed and 0.239m3/
kg of TS destroyed was obtained and the maximum biogas productivity of 0.495 L was observed at 18 h HRT with
the highest methane content of 67.86%. The payback period of the pilot scale reactor is 3.2 years.
Phenol, a toxic and carcinogenic compound found in industrial effluent, poses a severe threat to the
environment and aquatic life. Conventional methods such as physio-chemical techniques have limitations in
efficiency, cost, and sustainability, leading to the development of advanced hybrid approaches like the Moving
Bed Biofilm Reactor (MBBR) to treat phenols.
Review method: In this study, we aimed at an in-depth review of MBBR for the remediation of phenolic wastewater
at an industrial scale. The review uses a methodology that involves a comparative analysis of various
conventional methods, including activated sludge process (ASP), sequencing batch biofilm reactor (SBBR),
Fluidized Bed Biofilm Rector (FBBR), and trickling filter (TF) with MBBR, to determine their efficacy in phenol
degradation. In this context, a thorough bibliometric assay of MBBR is carried out to understand the recent
publication trends. The study also examines the impact of different types and shapes of bio-carriers and their
filling ratios on phenol biodegradation.
Significant finding: The present work demonstrates the feasibility of using an aerobic MBBR along with a Fentonlike
system (advanced oxidation processes) to treat phenolic effluent LCCA is discussed for selected treatment
methods for assessing the sustainability aspects. In light of recent advancements, future research endeavors
should prioritize the refinement and optimization of MBBR systems to strengthen their efficiency and sustainability,
thus paving the way for a greener and cleaner future.
Статтю присвячено дослідженням особливостей мікроструктури огарку від відходів виробництва шкіряної промисловості. Це необхідно для використання отриманого матеріалу як хромвмісної сировини для виробництва легуючих добавок шляхом алюмотермічної плавки. Для досягнення цієї мети був застосований комплекс новітніх методів досліджень з використанням растрової електронної мікроскопії з рентгенівським мікроаналізом для визначення хімічного складу цільових ділянок поверхні зразків. Визначено, що мікроструктура огарку розупорядкована пориста та складалася з відокремлених частинок різної форми і розмірів. Оксидна природа переважної кількості компонентів підтверджується виявленням кисню в ділянках аналізу в межах 14,04—25,12 %мас. В досліджених ділянках вміст хрому знаходився на відносно високому рівні — від 59,49 %мас. до 74,64 %мас. Із тугоплавких елементів також був присутній ванадій у кількості 0,18—0,29 %мас. Вміст заліза коливався в межах 0,41—0,62 %мас. Разом з цим в огарку було виявлено деякий вміст супутніх домішок Ca, Mg, Al, Na, Si, Cl, Mn, K, а також S та P — в кількості 0,55—1,52 %мас. та 0,12—0,21 %мас. відповідно. Це дозволило зробити ряд важливих практичних висновків, що отриманий продукт для подальшого ефективного використання в якості легуючої хромвмісної добавки потребує застосування алюмотермічної рафінувальної плавки. При цьому огарок від відходів шкіряного виробництва можна додавати замість частини хромвмісного рудного концентрату при виплавці ферохрому. Одночасно з переробкою і поверненням у виробництво техногенних відходів від шкіряного виробництва забезпечується підвищення рівня безпеки та гігієни праці, зниження екологічної напруженості промислово розвинених областей, зменшення забруднення навколишнього середовища і підвищення безпеки життєдіяльності.
Volatile organic compounds (VOCs) are gases that are emitted into the air from products or processes and are major components of air pollution that significantly deteriorate air quality and seriously affect human health. Different types of metals, metal oxides, mixed‐metal oxides, polymers, activated carbons, zeolites, metal‐organic frameworks (MOFs) and mixed‐matrixed materials have been developed and used as adsorbent or catalyst for diversified VOCs detection, removal, and destruction. In this comprehensive review, we first discuss the general classification of VOCs removal materials and processes and outline the historical development of bifunctional and cooperative adsorbent‐catalyst materials for the removal of VOCs from air. Subsequently, particular attention is devoted to design of strategies for cooperative adsorbent‐catalyst materials, along with detailed discussions on the latest advances on these bifunctional materials, reaction mechanisms, long‐term stability, and regeneration for VOCs removal processes. Finally, challenges and future opportunities for the environmental implementation of these bifunctional materials are identified and outlined with the intent of providing insightful guidance on the design and fabrication of more efficient materials and systems for VOCs removal in the future.
Pyrolysis in an inert atmosphere is a widely applied route to convert tannery wastes into reusable materials. In the present study, the Cr(III) conversion into the toxic hexavalent form in the pyrolyzed tannery waste referred to as KEU was investigated. Ageing experiments and leaching tests demonstrated that the Cr(III)–Cr(VI) inter-conversion occurs in the presence of air at ambient temperature, enhanced by wet environmental conditions. Microstructural analysis revealed that the Cr-primary mineral assemblage formed during pyrolysis (Cr-bearing srebrodolskite and Cr-magnetite spinel) destabilized upon spray water cooling in the last stage of the process. In the evolution from the higher to the lower temperature mineralogy, Cr is incorporated into newly formed CrOOH flakes which likely react in air forming extractable Cr(VI) species. This property transforms KEU from an inert waste to a hazardous material when exposed to ordinary ambient conditions.
The leather industry is one of the oldest industries around the world and produces many different types of leather and leather goods. These products are incredibly popular among millions of people across the world for fashion and function. The leather manufacturing sector has been contributing more than $100 billion to the global markets. However, it is considered a major source of pollution with over 80% of the raw material going to waste. It produces toxic waste, environmental pollution, and greenhouse gas emissions. The main factors in greenhouse effects include energy consumption, wastewater, and solid waste. The emission of greenhouse gases (GHG) through industrial processes is a crucial problem for the environment. This chapter will provide a condensed review of relevant literature on leather manufacturing and the direction forward to achieving net zero. The importance of leather and its products, its contribution to the economic global markets, manufacturing processes, environmental pollution, net zero, and the role of mathematics for net zero have been discussed.
Worldwide, road traffic crash is a significant public health issue due to increasing number of injuries and fatalities. In recent time in Nigeria, FRSC released an annual report on road traffic crash for 2021. However, little is known about the variation in the accident cases, involved persons and direct consequences, and how each differ based on quarter to quarter analysis. In this study, we addressed these issues with a view to mitigating human and property losses in the country. Secondary data on accident cases, people involved, the injured and deaths were obtained from the Federal Road Safety Corps (FRSC). Five different hypotheses were tested using one-way ANOVA. The findings for the first hypothesis showed a statistically significant variation in annual RTC cases, people involved and direct consequences. Findings for the second, fourth and fifth hypotheses showed no statistically significant variation in RTC cases, the injured and deaths across the different quarters of the year while that of the third hypothesis indicated a statistically significant variation in the people involved in RTC across the different quarters of the year. It is concluded that accident cases, number of involved persons and direct
consequences are different during the study period while for the quarter by quarter analysis, the number of people involved in accident during travel might be determinable by season, but no seasonality effect is evident in RTC cases, the number of injured people and the number of deaths.
Water is a crucial elemental contributor for all sectors; however, the agricultural sector alone accounts for 70% of the world's total water withdrawal. The anthropogenic activity from various industries including agriculture, textiles, plastics, leather, and defence has resulted in the release of contaminants into water systems, resulting harm to the ecosystem and biotic community. Algae-based organic pollutant removal uses several methods, such as biosorption, bioaccumulation, biotransformation, and biodegradation. The adsorption of methylene blue by algal species Chlamydomonas sp. showed a maximum adsorption capacity of 2744.5 mg/g with 96.13% removal efficiency; on the other hand, Isochrysis galbana demonstrated a maximum of 707 µg/g nonylphenol accumulation in the cell with 77% removal efficiency indicating the potential of algal systems as efficient retrieval system for organic contaminants. This paper is a compilation of detailed information about biosorption, bioaccumulation, biotransformation, biodegradation, and their mechanism, along with the genetic alteration of algal biomass. Where the genetic engineering and mutations on algae can be advantageously utilized for the enhancement of removal efficiency without any secondary toxicity.
Recent advances have been recorded in the tanning industry with biotechnology in principle playing a very important role through related applied research. This review paper demonstrates that a previously tagged tanning sector as the most hazardous can be resolved through adoption of cleaner technologies, waste management and remedial measures that can be put in place. Pollution is depicted stepwise along the leather processing phases with a selected xenobiotic and contaminants identified such as Sodium chloride, Chromium, Sulphates, Chlorinated phenolics etc. As an interventionist strategy, biological tools using novel techniques of investigation are shown including the aquatic ecosystems. Remedial methods using known threshold in an identified tannery in Kenya is used to comprehend how to scale down the pollutants eventually. However it is recognised that though phytoremediation potential exist, it will require a combination of several other recently developed methods to provide a much firmer basis of controlling pollution loads related to the tanning Industry.
The leather tanning industry is perceived as responsible of a significant consume of natural resources and output of wastes
such as high concentration of organics, salts and heavy metals such as chromium, both in solid and liquid form as a result.
Now as ever the future of tanneries strongly depends on the increase of their awareness that a sustainable industry for the
future means embracing a forward-looking philosophy of the leather making process through optimal resource management within
the tannery. This study reports the characterization of some chemicals used in a large tanning district area in terms of COD,
BOD, aromaticity (UV280) and double bond (UV254) absorbance measurements, toxicity on fresh and saline water as well as terrestrial species, GC-MS scanning. The study provides
a consistent set of information on tannin-associated concentration-related trends and suggests novel criteria in defining
control quality for evaluating environmental impact of leather tanning industry.
The environmental impact of the tanning industry is generally significant with outputs of wastes, i.e. high concentrations of organics, salts and heavy metals (chromium compounds), both in solid and liquid form, as a result. In order to bring the tanning industry more in line with present environmental thinking, various methods have been devised to reduce impacts.The underlying study proposes a modification of the method for unhairing–liming of hides where the unhairing–liming liquids are reused several times after being recharged by reduced quantities of chemicals. The study, therefore, aims at reducing both the economic and environmental costs of the unhairing–liming process.Experiments were carried out at lab scale with a simulation apparatus designed for the purpose. Life cycle assessment was used to evaluate the net environmental benefits of the modified method. The present value approach was used to evaluate the economic feasibility of the modified method. The quality of the produced leather was assessed by experts from the tanning sector (tanners).On the environmental level, the modified method reduced the environmental impact of the process by 24%, COD was reduced by 50% as well as sulfide which was reduced by 73% when the process water was recycled four times.The modified method requires some investment in new equipment and is a little more labor intensive as compared with the conventional method but does permit for savings in water up to 58% and chemicals up to 28% as well as wastewater treatment cost which was reduced by 58%. The modified method allowed for four times reuse of the unhairing–liming liquor without visibly affecting the quality of the final product of leather.It was concluded that both the economic and the environmental costs of the unhairing–liming process were reduced relative to the same of the conventional method.
Lead is a ubiquitous toxicant that causes tremor and cerebellar damage. Essential tremor (ET) is a highly prevalent neurologic disease associated with cerebellar involvement. Although environmental toxicants may play a role in ET etiology and their identification is a critical step in disease prevention, these toxicants have received little attention. Our objective was to test the hypothesis that ET is associated with lead exposure. Therefore, blood lead (BPb) concentrations were measured and a lifetime occupational history was assessed in ET patients and in controls. We frequency matched 100 ET patients and 143 controls on age, sex, and ethnicity. BPb concentrations were analyzed using graphite furnace atomic absorption spectrophotometry. A lifetime occupational history was reviewed by an industrial hygienist. BPb concentrations were higher in ET patients than in controls (mean +/- SD, 3.3 +/- 2.4 and 2.6 +/- 1.6 microg/dL, respectively; median, 2.7 and 2.3 microg/dL; p = 0.038). In a logistic regression model, BPb concentration was associated with diagnosis [control vs. ET patient, odds ratio (OR) per unit increase = 1.21; 95% confidence interval (CI), 1.05-1.39; p = 0.007]. BPb concentration was associated with diagnosis (OR per unit increase = 1.19; 95% CI, 1.03-1.37; p = 0.02) after adjusting for potential confounders. Prevalence of lifetime occupational lead exposure was similar in ET patients and controls. We report an association between BPb concentration and ET. Determining whether this association is due to increased exposure to lead or a difference in lead kinetics in ET patients requires further investigation.
This study examines the possibility of using pelletized leather tannery wastes (LTW) in the co-combustion process with hardwood pellets (HP). The experiments were carried out in a small-scale combustion reactor and were followed by thermogravimetric analysis (TGA) of fuels in the nitrogen and air atmosphere. The experimental investigation has indicated that the leather tannery wastes can be an interesting fuel with a relatively high heating value (HHV), at the level of 16 MJ/kg, and the volatile content of about 68%. Thermal decomposition of the leather tannery sample occurs at temperatures ranging between 220 and 420 °C, with the maximum of intensity at 320 °C. The experimental results indicated that the averaged maximum temperatures obtained during the combustion reached similar values for all samples, which indicates that doping wood pellets with leather waste pellets does not have a significant impact on the temperature characteristics of the combustion process. However, decreasing the amount of hardwood pellets in the mixture reduces the bulk density of the fuel bed and the combustion front velocity. The emission of nitrogen oxides for combusting blends is twice as high as for combustion of pure HP, which is related to higher nitrogen content in leather waste as well as higher ash content.
A mixture of aquo complexes of chromium (III) is used for tanning. These complexes vary in their nature and reactivity to the protein. The present investigation deals with the understanding of the nature of the chromium(III) complexes present in spent chrome tanning solutions. An ion exchange chromatography technique has been employed for the isolation of the various complexes from fresh and spent tanning solutions. These studies indicated the presence of low affinity species to the extent of 45% of the total chromium in the spent solution. The low affinity chromium(III) complex was characterised by UV-visible spectroscopy, charge per atom, charge per species, degree of polymerisation and hydroxyl per chromium and has been established to be a cyclic tetrapositive tetrameric species with unusual reactivity.
The idea of "sustainability" has become one of the major topics in industry and politics and probably represents one of the mega-trends of the early 21st Century. Due to outdated processes and methods applied in the leather industry, the waste products and the significant amounts of process water used oppose more and more legislation and the concept of sustainability. Examples are very well known, e.g. organic sludges with sulfides, chrome, salts, residues of surfactants like Nonylphenolethoxylates (NPE), poor biodegradable tannins and fats - the list is long and we are aware that these problems can only be tackled stepwise. Last year we reported about a more "sustainable" surfactant for the substitution of NPE's. Today we want to discuss a whole new concept, which especially addresses new legislation in Europe. It states that by the middle of 2005 chrome shavings and other organic wastes can no longer be dumped in landfill-sites.
Severe restrictions imposed by the pollution control authorities on the disposal of chromium, total dissolved solids and chlorides in tannery effluents have forced the tanners to look for low-waste, high exhaust chrome tanning salts. An improved chrome syntan with more than 90% uptake of chrome has been developed. The new product serves both as tanning and retanning agent and can be applied directly to delimed pelts thus eliminating the conventional pickling stage in the leather processing. This modified process helps to reduce the chemical oxygen demand (COD), total dissolved solids (TDS) and chlorides in the spent tan liquor by 51, 81 and 99%, respectively. The product offers full, soft leathers having shrinkage temperature comparable to conventional chrome tanned skins. Since the developed product is highly reactive, it saves time and reduces the water requirement when compared to the conventional chrome tanning method. Thus the novel product/process developed not only has advantages in reducing pollution loads but also seems to be techno-economically viable.
The occurrence of foam on a transboundary river close to the Austrian-Hungarian border was a constant strain to Austria's political relationship with Hungary. A one-year monitoring programme linked the instream foam mainly to the effluent of three Austrian tanning factories in the catchment of the river. As all tanneries are equipped with wastewater treatment technology in accordance with the best available technique, an amendment of the Austrian Edict on wastewater emissions for tanneries was necessary to implement foam-abatement measures. The changes in the Edict included the introduction of surface tension as an emission parameter for foam causing substances together with appropriate emission standards to reduce the resulting instream foam formation.
An attempt has been made to develop a method for processing leathers in a narrow range of pH viz., 4.0-8.0. A process for dehairing at a pH of around 8.0 has been explored. This has been achieved by employing a commerical enzyme in combination with small quantities of sodium sulphide. A method for applying the dehairing formulation on the grain side was established. Hair removal was shown to be complete using scanning electron microscopy (SEM) and cystine content analysis. Potential grain damage by the enzyme formulation was avoided through process control measures and the effectiveness of such methods was established by investigation by scanning electron micrographs. Strength and bulk properties of the experimental leathers appear to show some improvement as compared to the leathers made using conventional processes. The process enjoys an environmental benefit by significantly reducing the COD load in the effluent. Improved chrome content in the grain surface of the butt region adds an additional benefit to the dehairing process developed.
There is a growing demand for the formaldehyde-free leathers in global leather market due to increasing awareness towards
eco-labelling. The first part of this work described the optimisation of formaldehyde-free syntans in their applications as
single syntans in making leathers with desired properties. In this work the use of formaldehyde-free syntans in combination
to produce leathers with desired properties has been attempted. Three combination-retanning systems have been chosen using
formaldehyde-free resin, acrylic and protein syntans. The performance of leathers in terms of bulk and strength properties
is shown to be comparable or even better for all the combination-retanning systems chosen compared to the control system.
In particular, Experiment “C” (resin syntan 3%, acrylic syntan 4% and protein syntan 2%) provides leathers with improved bulk,
strength and colour properties as well as reduced COD and TS loads, besides not having free formaldehyde. Scanning electron
microscopic study reveals that the extent of filling in all the three combination-retanning systems is similar.
The problem of water pollution acquires greater relevance in the context of a developing agrarian economy like Pakistan. Even though, the leather industry is a leading economic sector in Pakistan, there is an increasing environmental concern regarding tanneries because they produce large amounts of potentially toxic wastewater containing both trivalent and hexavalent chromium, which are equally hazardous for human population, aquaculture and agricultural activities in the area. Therefore, we defined the scope of the present study as to employ different bioassays to determine the eco-toxic potential of tannery effluent wastewater (TW) and its chromium based components, i.e., potassium dichromate (K2Cr2O7) and chromium sulfate Cr2(SO4)3. Particle-induced X-ray emission (PIXE) analysis of TW was carried out to determine the concentration of chromium in TW and then equal concentrations of hexavalent (K2Cr2O7) and trivalent chromium Cr2(SO4)3 were obtained for this study. Cytotoxicity assay, artemia bioassay and phytotoxicity assay was utilized to investigate the eco-toxicological potential of different concentrations of TW, K2Cr2O7 and Cr2(SO4)3. All the dilutions of TW, K2Cr2O7 and Cr2(SO4)3 presented concentration dependent cytotoxic effects in these assays. The data clearly represents that among all three tested materials, different dilutions of K2Cr2O7 caused significantly more damage (P < 0.001) to vero cell, brine shrimp and germination of maize seeds. Interestingly, the overall toxicity effects of TW treated groups were subsequent to K2Cr2O7 treated group. Based on biological evidences presented in this article, it is concluded that hexavalent chromium (K2Cr2O7) and TW has got significant eco-damaging potential clearly elaborating that environmental burden in district Kasur is numerous and high levels of chromium is posing a considerable risk to the human population, aquaculture and agricultural industry that can obliterate ecosystem surrounding the tanneries.
In the present study, green and sustainable method or eco-friendly approaches to tanning process based on unnatural D-amino acids (D-AA)-aldehyde (Ald) as a substitute for chrome-free tanning has been attempted. The distribution of optically active D-AA in tanned leather, the hydrothermal stability, the mechanical properties and resistance to collagenolytic activity of tanned leather, the evaluation of eco-friendly characteristics were investigated. Scanning electron microscopic (SEM) and Atomic force microscopic (AFM) analyses indicate the surface morphology and roughness, respectively, of the tanned leather collagen matrix. Shrinkage and Differential scanning calorimetric (DSC) analyses shows that the shrinkage temperature (T(s)) and denaturation temperature (T(d)) of tanned leather are related to the content of D-AA+Ald present in the leather matrix. It has been found that the T(s) of D-AA tanned leather is more than that of Ald tanned leather and also more or less equal to chrome tanned leather. Environmental impact assessment (EIA) shows that the developed process results in significant reduction in total solids content (TSC) and improves better biodegradability of organic compound present in the effluent compared to chrome tanning.
Biomethanation is a process by which organic material is microbiologically converted under anaerobic conditions to biogas. Three main physiological groups of microorganisms are involved: fermenting bacteria, organic acid oxidizing bacteria, and methanogenic archaea. Microorganisms degrade organic matter via cascades of biochemical conversions to methane and carbon dioxide. Syntrophic relationships between hydrogen producers (acetogens) and hydrogen scavengers (homoacetogens, hydrogenotrophic methanogens, etc.) are critical to the process. Determination of practical and theoretical methane potential is very important for design for optimal process design, configuration, and effective evaluation of economic feasibility. A wide variety of process applications for biomethanation of wastewaters, slurries, and solid waste have been developed. They utilize different reactor types (fully mixed, plug-flow, biofilm, UASB, etc.) and process conditions (retention times, loading rates, temperatures, etc.) in order to maximize the energy output from the waste and also to decrease retention time and enhance process stability. Biomethanation has strong potential for the production of energy from organic residues and wastes. It will help to reduce the use of fossil fuels and thus reduce CO(2) emission.
Influence of ultrasound (US) on various unit operations in leather processing has been studied with the aim to improve the process efficiency, quality, reduce process time and achieve near-zero discharge levels in effluent streams as a cleaner option. Effect of US on substrate (skin/leather) matrix as well as substances used in different unit operations have been studied and found to be useful in the processing. Absorption of US energy by leather in process vessel at different distances from US source has been measured and found to be significant. Effect of particle-size of different substances due to sonication indicates positive influence on the diffusion through the matrix. Our experimental results suggest that US effect is better realized for the cases with pronounced diffusion hindrance. Influence of US on bioprocessing of leather has been studied and found beneficial. Attempts have also been made to improve the US aided processing using external aids. Operating US in pulse mode operation could be useful in order to reduce the electrical energy consumption. Use of US has also been studied in the preparation of leather auxiliaries involving mass-transfer resistance. Preliminary cost analysis carried out for ultrasound-assisted leather-dyeing process indicates scale-up possibility. Therefore, US application provide improvement in process efficiency as well as making cleaner production methods feasible. Hence, overall results suggest that use of US in leather industry is imminent and potential viable option in near future.
The effects of Metanil yellow, Orange II and their blend on hepatic xenobiotic metabolizing enzymes were compared. Parenteral administration of Metanil yellow and Orange II to rats at a dose of 80 mg/kg body weight for 3 days caused a significant induction of ethoxyresorufin-O-deethylase (40-190%), aniline hydroxylase (27-92%), aryl hydrocarbon hydroxylase (50-62%) and aminopyrine N-demethylase (42-49%) activities. Metanil yellow and Orange II brought about a substantial increase in cytosolic quinone reductase (34-82%) and glutathione S-transferase (23-43%) activities and significant depletion of glutathione levels with a concomitant increase in lipid peroxide formation. A blend (1:1) of Metanil yellow and Orange II showed a synergistic or additive effect on these hepatic parameters, suggesting that the addition of these two prohibited dyes together in foodstuffs may give rise to more toxic effects than are produced by each dye individually.
The interaction of three types of chromium(III) complexes, [Cr(salen) (H2O2]+, [Cr(en)3]3+, and [Cr(EDTA) (H2O)]- with AGP has been investigated. [Cr(salen) (H2O2]+, [Cr(en)3]3+ and [Cr(EDTA) (H2O]- bind to Human alpha1-acid glycoprotein with a protein:metal ratio of 1:8, 1:6, and 1:4, respectively. The binding constant, K(b) was estimated to be 1.37 +/- 0.12 x 10(5) M(-1), 1.089 +/- 0.05 x 10(5) M(-1) and 5.3 +/- 0.05 x 10(4) M(-1) for [Cr(salen) (H2O2]+, [Cr(en)3]3+, and [Cr(EDTA) (H2O)]-, respectively. [Cr(en)3]3+ has been found to induce structural transition of AGP from the native twisted beta sheet to a more compact alpha-helix. The complexes, [Cr(salen) (H2O2]+ and [Cr(EDTA) (H2O]-, in the presence of H2O2, have been found to bring about nonspecific cleavage of AGP, whereas [Cr(en)3]3+ does not bring about any protein damage. Treatment of [Cr(salen) (H2O)2]+-protein adduct with iodosyl benzene on the other hand led to site specific cleavage of the protein. These results clearly demonstrate that protein damage brought about by chromium(III) complexes depends on the nature of the coordinated ligand, nature of the metal complex, and the nature of the oxidant.
This paper describes the derivation of aquatic life water quality criteria for formaldehyde, developed in accordance with United States Environmental Protection Agency's (USEPA's) Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses. The initial step in deriving water quality criteria was to conduct an extensive literature search to assemble available acute and chronic toxicity data for formaldehyde. The literature search identified a large amount of information on acute toxicity of formaldehyde to fish and aquatic invertebrates. These acute data were evaluated with respect to data quality, and poor quality or uncertain data were excluded from the data base. The resulting data base met the USEPA requirements for criteria derivation by having data for at least one species in at least eight different taxonomic families. One shortcoming of the literature-derived data base, however, was that few studies involved analytical confirmation of nominal formaldehyde concentrations and reported toxicity endpoints. Also, there were relatively few data on chronic toxicity. The acute toxicity data set consisted of data for 12 species of fish, 3 species of amphibians, and 11 species of invertebrates. These data were sufficient, according to USEPA guidelines, to calculate a final acute value (FAV) of 9.15 mg/l, and an acute aquatic life water quality criterion (one-half the FAV) of 4.58 mg/l. A final acute-chronic ratio (ACR) was calculated using available chronic toxicity data and USEPA-recommended conservative default assumptions to account for missing data. Using the FAV and the final ACR (5.69), the final chronic aquatic life water quality criterion was determined to be 1.61 mg/l.
A 2-generation reproductive toxicity study of tributyltin chloride (TBTCl) was conducted in male rats using dietary concentrations of 5, 25, and 125 ppm TBTCl to evaluate its effect on sexual development and the reproductive system. F1 males were killed on postnatal day 119 and F2 males were killed on postnatal day 91. TBTCl affected the male reproductive system of rats. The weights of the testis and epididymis were decreased and homogenization-resistant spermatid and sperm count were reduced mainly in the 125 ppm TBTCl group. Histopathologic changes were also observed in the testis of this group and included vacuolization of the seminiferous epithelium, spermatid retention, and delayed spermiation. However, the changes were minimal in nature. The weight of the ventral prostate was decreased to 84% of the control value in the 125 ppm group in the F1 generation and decreased to 84 and 69% of the control value in the 25 ppm and 125 ppm TBTCl groups, respectively, in the F2 generation. The serum 17beta-estradiol concentration was also decreased to 55% of the control value in the 125 ppm group in the F1 generation and decreased to 78 and 57% of the control value in the 25 ppm and 125 ppm TBTCl groups, respectively, in the F2 generation. However, the serum concentrations of luteinizing hormone (LH) and testosterone were not decreased in these groups. These changes corresponded with those caused by aromatase inhibition and therefore TBTCl might be a weak aromatase inhibitor in male rats.
The comparative toxicities of selected phenols to higher plants Cucumis sativus were measured and the negative logarithm molar concentration of the root elongation median inhibition (IRC50) were derived. Quantitative structure-activity relationships (QSARs) were developed to explore the toxicity influencing factors and for predictive purpose. The toxicity data, fell into two classes: polar narcosis and bio-reactive. For polar narcotic phenols, a highly significant two-parameter QSAR based on 1-octanol/water partition coefficient (logKow) and energy of the lowest unoccupied orbital (E(lumo)) was derived (IRC50 = 0.77 log Kow - 0.39E(lumo) + 2.36 n = 22 r2 = 0.89). The five bio-reactive chemicals proved to show elevated toxicity due to their typical substructure involved diverse reactive mechanisms. In an effort to model all chemicals, a robust multiple-variable QSAR combining logKow, E(lumo) and Qmax, the most negative net atomic charge, was developed (IRC50 = 0.65 logKow - 0.72E(lumo) + 0.23Qmax + 2.81 n = 27 r2 = 0.94), indicating that hydrophobicity, electrophilicity and hydrogen bond interaction contribute mainly to the phytotoxicity. The toxicological data was compared with Tetrahymena pyriformis 2-d population growth inhibition toxicity (IGC50) and excellent interspecies correlations were observed both for the polar narcotics and for five reactive chemicals (for polar narcotics: IRC50 = 0.95IGC50 + 1.07 n = 16 r2 = 0.89; for bio-reactive chemicals: IRC50 = 0.98IGC50 + 2.19 n = 5 r2 = 0.97; and for all: IRC50 = 0.93IGC50 + 1.63 n = 21 r2 = 0.87). This suggested that T pyriformis toxicity could serve as a surrogate of C. sativus toxicity for phenols and interspecies correlation also could be established for reactive chemicals.
While attempting to find a suitable crosslinking reagent for biopolymers, a naturally occurring proanthocyanidin (PA) obtained from grape seeds was selected to fix biological tissues. The cytotoxicity and crosslinking rate, reflected by the in vitro and in vivo degradation of fixed matrices has been studied. The shrinkage temperature of the fixed bovine pericardium increased from 66 to 86 degrees C. A cytotoxicity assay using fibroblast cultures revealed that PA is approximately 120 times less toxic than glutaraldehyde (GA), a currently used tissue stabilizer. In vitro degradation studies showed that fixed tissue was resistant to digestion by bacterial collagenase. Crosslinks between PA and tissues can be stabilized by decreasing the dielectric constant of the solution during storage. After subcutaneous implantation for periods ranging between 3 and 6 weeks, we found no apparent degradation of the GA- or PA-fixed tissues, whereas fresh tissue controls rapidly disintegrated. Beyond 6 weeks PA crosslinks began to degrade. More fibroblasts migrated and proliferated inside the PA-fixed implants compared with GA counterparts. Tissues crosslinked with PA manifested an enhanced collagen expression and deposition and did not calcify after implantation. GA, on the other hand, even after thorough rinsing continued to be cytotoxic, inhibited collagen synthesis and encouraged dystrophic calcification. Collagen matrices crosslinked with PA are expected to be of value in the design of matrices that will encourage cell ingrowth and proliferation, which are temporary in nature, and that are intended to regenerate or replace missing tissues, which can delay the biogradation of collagen. As such they should be of significant value in the emerging field of tissue engineering.
Leather processing generates huge amounts of both solid and liquid wastes. The management of solid wastes, especially tanned leather waste, is a challenging problem faced by tanners. Hence, studies on biodegradability of leather become imperative. In this present work, biodegradability of untanned, chrome tanned and vegetable tanned leather under anaerobic conditions has been addressed. Two different sources of anaerobes have been used for this purpose. The effect of detanning as a pretreatment method before subjecting the leather to biodegradation has also been studied. It has been found that vegetable tanned leather leads to more gas production than chrome tanned leather. Mixed anaerobic isolates when employed as an inoculum are able to degrade the soluble organics of vegetable tanned material and thus exhibit an increased level of gas production during the initial days, compared to the results of the treatments that received the anaerobic sludge. With chrome tanned materials, there was not much change in the volume of the gas produced from the two different sources. It has been found that detanning tends to improve the biodegradability of both types of leathers.
Apoptosis is an active process induced by a variety of physiological and external stimuli, in which elimination of damaged cells are effected through a genetically controlled process. In this study, we have examined the mechanism of chromium(III) [Cr(III)]-induced cytotoxicity with respect to its relationship to oxidative stress. Morphology, flow cytometry, and DNA fragmentation studies show that tris-(1,10-phenanthroline)chromium(III) [Cr(III)-phen], tris-(2,2'-bipyridyl)chromium(III) [Cr(III)-bpy], trans-diaqua[1,2-bis(salicylideneamino)ethanechromium(III)] [Cr(III)-salen], and trans-diaqua[1,3-bis(salicylideneamino)propanechromium(III)] [Cr(III)-salprn] induced apoptosis of lymphocytes. Pentaammineaquachromium(III) [Cr(III)-hpa] does not induce apoptosis. Apoptosis induced by these complexes involves the generation of reactive oxygen species (ROS) as seen by increased fluorescence of dichloroflourescein (DCF) observed through flow cytometry. Pretreatment of lymphocytes with antioxidants completely abrogate apoptosis. Cr(III) treatment also increased the expression and activation of Src-family tyrosine kinases viz. p56lck, p59fyn, and p53/56lyn, as seen by immunoblotting and immune complex kinase assay. PP2, a selective Src-family tyrosine kinase inhibitor, abolishes apoptosis, indicating that Src-family tyrosine kinases are directly involved in eliciting apoptosis. Interestingly, a one-to-one correlation between the expression of Src-family tyrosine kinases and ROS is observed, since antioxidants pretreatment inhibits the expression and the activation of these kinases. These results further indicate that Cr(III)-induced apoptosis is mediated through production of ROS, which in turn activates the Src-family tyrosine kinases. The increased activation of Src-family tyrosine kinases may be a mechanism involved in apoptosis of lymphocytes elicited by various other physiological stimuli that exploit ROS as a second messenger.
In this paper, the authors deal with the problem of processing various types of waste generated by leather industry, with special emphasis to chrome-tanned waste. The agent that makes this waste potentially hazardous is hexavalent chromium. Its compounds can have negative effects on human health and some CrVI salts are considered carcinogens. The authors present the risks of spontaneous oxidization of CrIII to CrVI in the open-air dumps as well as the possible risks of wearing bad quality shoes, in which the chromium content is not controlled. There are several ways of handling primary leather waste, but no satisfactory technology has been developed for the secondary waste (manipulation waste, e.g. leather scraps and used leather products). In this contribution, a new three-step hybrid technology of processing manipulation waste is presented and tested under laboratory, pilot-scale and industrial conditions. The filtrate can be used as a good quality NPK fertilizer. The solid product, titanium-chromium sludge, can serve as an inorganic pigment in glass and ceramic industry. Further, the authors propose selective collection of used leather products (e.g. old shoes), the hydrolysable parts of which can be also processed by the new hybrid technology.
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