No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Biological Colour Removal of Pulp and Paper Mill Wastewaters
Abstract
The pulp and paper mill effluent is highly coloured. The main contribution to the colour in the effluent comes from the chlorolignin compounds which are discharged from the bleaching step of the manufacturing process. These compounds being non-degradable, by chemical and conventional biological methods, pose problems in the removal of colour. Several methods—physical, chemical and biological—have been attempted for the removal of colour from pulp and paper mill effluents. Physical and chemical methods of colour removal, as per the technology available so far, are quite expensive and less efficient and none is viable practically. Biological colour removal process seems to be attractive since, in addition to colour and chemical oxygen demand, it also reduces biological oxygen demand and low molecular weight chlorolignins. This article reviews the current research on the use of biotechnological methods to remove colour from pulp and paper mill wastewater. The progress made and the further scope are also discussed.
... One problem regarding wastewater streams that have originated from wood/lignocellulosic processing is the persistent colour of the treated effluent [9][10][11][12]. Additionally, there is a concern regarding further yellowing of the treated wastewater that may occur and intensify beyond the point of discharge, even after prolonged time periods. ...
... Components of biorefinery effluents that are believed responsible for the colour include residual cellulose, hemicelluloses, lignin, pulping process chemicals and microorganism from the wastewater stream. Oxidative reactions of these components may result in coloured degradation products, usually containing carbonyl (C]O) groups and carbon-carbon double bonds (C]C) [10,13,14]. Among those, lignin residues have often been linked to effluent colour development [15,16]; however, evidence is scarce, and even more scarce concerning the governing mechanisms. ...
... Lignin reactions were identified as the major cause of photo yellowing [33,34]. Therefore, lignin and depolymerised lignin derivatives are hypothesised to be responsible for the colour development in pulp and paper mills wastewater even long after treatment [10]. ...
... Some of these studies have optimized the operating conditions for effluent treatment [23][24][25]. Biological treatment methods involved the use of fungi, bacteria, algae and enzymes [26] as a single step treatment or in combination with other physical and chemical methods [27][28][29]. The biological treatment studies have confined themselves to the evaluation of microorganism, basic mechanism behind treatment and changes in the effluent after treatment. ...
... Microorganism showing good production of these enzymes have the potency to treat effluent. Biological treatment systems are particularly attractive, since in addition to colour they also reduce the BOD and COD of the effluent [26]. ...
... Reducing this colour before the effluents are discharged into natural water is an important goal. Other toxic contaminants of pulp and paper mill industry are chlorinated compounds [41,26]. Physical and chemical methods undertaken to study colour removal from the effluent is not found to be costeffective technology. ...
... Review articles by Pokhrel and Viraraghavan (2004), Zhao et al. (2014), and Kamali and Khodaparast (2015) provide background for different types of treatment facilities. Bajpai and Bajpai (1994) reviewed strategies for the removal of color from P&P mill wastewater. Various articles have focused on the performance and "best available technology" for treating P&P mill wastewater in different regions (Lescot and Jappinen 1994;Hammar and Rydholm 1972;Gehm 1973;Rajvaidya and Markandey 1998;European Commission 2001;Demel et al. 2003;Tiku et al. 2007;Menezes et al. 2010;Zhu et al. 2012;BREF 2015). ...
... Indeed, the appearance of "black liquor," the spent alkaline solution left over after kraft pulping, can be attributed to such compounds. As noted by Bajpai and Bajpai (1994), highly colored compounds in typical pulping and bleaching wastewaters often are resistant to biodegradation and removal during treatment operations. The sources and types of colored compounds that develop during pulping and papermaking have been reviewed (NCASI 2011). ...
... The sources and types of colored compounds that develop during pulping and papermaking have been reviewed (NCASI 2011). Measures to remove color from the effluent of P&P mills have been reviewed and reported (Bajpai and Bajpai 1994;Garg and Tripathi 2011;Garg et al. 2012). Langergraber et al. (2004) discussed the evaluation of color in such wastewater by instrumental methods. ...
The pulp and paper (P&P) industry worldwide has achieved substantial progress in treating both process water and wastewater, thus limiting the discharge of pollutants to receiving waters. This review covers a variety of wastewater treatment methods, which provide P&P companies with cost-effective ways to limit the release of biological or chemical oxygen demand, toxicity, solids, color, and other indicators of pollutant load. Conventional wastewater treatment systems, often comprising primary clarification followed by activated sludge processes, have been widely implemented in the P&P industry. Higher levels of pollutant removal can be achieved by supplementary treatments, which can include anaerobic biological stages, advanced oxidation processes, bioreactors, and membrane filtration technologies. Improvements in the performance of wastewater treatment operations often can be achieved by effective measurement technologies and by strategic addition of agents including coagulants, flocculants, filter aids, and optimized fungal or bacterial cultures. In addition, P&P mills can implement upstream process changes, including dissolved-air-flotation (DAF) systems, filtration save-alls, and kidney-like operations to purify process waters, thus reducing the load of pollutants and the volume of effluent being discharged to end-of-pipe wastewater treatment plants.
... The effluent from CE unit recorded the pH value of 9.84 which is a little higher than WHO prescribed tolerance limit of pH value i.e. 6 to 9 for the paper industry effluent [29]. Colour of effluents or wastewaters depends on concentration of lignin which come up due to the presence of low and high molecular weight chlorinated organic compound produced during different processing stages like pulping, bleaching and alkali extraction as the lignin degradation products [30,31].The colour of the effluent from all the four processing stages measured in PCU showed considerable variation ranging from 481.44±0.58 to 3936.16±5.76 PCU. ...
... In this experiment, the effect of ferric chloride, lime, and alum on COD, BOD, TS, TDS, TSS, Color, AOX and turbidity at each stage of effluent was studied with respect to different amount of chemical doses (100, 300, 500 ppm), pH (~7), revolution (50, 100 and 150 rpm) and retention time intervals (30,80, and 130 min). A stock solution of 10g/L of ferric chloride, alum and lime was prepared and different doses of 100, 300 and 500 ppm respectively were taken out from this stock solution. ...
Discharge of a large amount of wastewater as effluent from pulp and paper industries in the surrounding streams result in serious health and environmental problems. These large quantities of effluents need to be treated after characterization prior to their disposal. Physicochemical characteristics of effluents from an agro-based paper mill located in Uttar Pradesh state of India were analyzed in terms of pH, colour, TS, TDS, TSS, turbidity, BOD, COD and AOX. The results found markedly higher values of all physicochemical parameters of effluents from various processing units of the paper mill than the permissible limit thus necessitating appropriate treatment prior to their discharge in the environment. In the present paper several types of coagulant viz. Ferric chloride, lime, alum and Ferric chloride with polyacrylamide (PAM) have been examined for their effectiveness of reducing the chemical load of the effluent.
... It is also possible to mix enzymes together with special microbes, which normally do not have high enzyme activity, and remove recalcitrant and harmless compounds from wastewater. The use of novel enzymes and rDNA technology in sludge and wastewater treatment will also be discussed (Pratima et al, 1994) ...
... The waste water of paper recycling contains also particles which have to be filtrated. Rests of plastics, metal parts (paper clips, etc.) other waste have to be removed (Pratima et al, 1994) ...
Environmental Pollution is a Major hazard facing the World Today and there is Increase Awarenes of the fact that a Clean Environment is Necessary for Smooth Fluences on Society and the Environment not only in Term of benefits but also in Risks and Hazards. This Book is aimed at summarizing the possible ways of Remediating Pollution Arising from Chemical Industries. Since the Need for a better life has made it impossible to avoid pollution due to the world increase in population.
... One of the significant problem is the persistent dark brown color in the released effluent from waste water treatment facilities of which the major contributors are lignin and its derivatives, such as chlorolignin, discharged from the pulp bleaching process. 3 Black liquor which originates from the chemical pulping stage contains lignin, carbohydrates, organic acids, sulfur compounds, phenolic compounds, terpenes and resin. 1 The bleaching agents used in pulp and paper industries are chlorine, alkali, hypochlorite and hydrogen peroxide. The use of chlorine based chemicals in the bleaching process generates chlorophenol compounds which are completely resistant to microbial attack and remain as recalcitrants [3] . ...
... 3 Black liquor which originates from the chemical pulping stage contains lignin, carbohydrates, organic acids, sulfur compounds, phenolic compounds, terpenes and resin. 1 The bleaching agents used in pulp and paper industries are chlorine, alkali, hypochlorite and hydrogen peroxide. The use of chlorine based chemicals in the bleaching process generates chlorophenol compounds which are completely resistant to microbial attack and remain as recalcitrants [3] . The pollution load in terms of biological oxygen demand (BOD) from small paper mills is 2.5 times higher than that of large paper mills, which employ the soda recovery process The release of bleach plant waste into the receiving waters which contains high adsorable organic halogen (AOX) has become one of the major environmental problems for the pulp and paper industry. ...
Fifty six samples were collected from Western Ghats area, of Tamilnadu and Karnataka, South India. The collected fungi were isolated and identified based on the key provided previously. Phanerochaete chrysosporium-787 was obtained from Microbial Type Culture Collection, (MTCC) Chandigarh, India and was used as the reference fungus. The fungi were screened for their ligninolytic activity based on their ability to oxidize dyes, poly R-478 and remazol brilliant blue, to degrade native lignin and further confirmation was done by the liberation of ethylene from KTBA (2-keto-4-thiomethyl butyric acid). The color removals in 57 samples were in the range of 11.5 to 38.4% in poly-R dye and 11.1 to 72.0 % in remazol brilliant blue. The mycelial growth rates were in the range of 1.24 to 3.67 mg/day and percent degradation of lignin was found to be in the range 20.4 to 68.8. The ligninolytic activity of the fungi were further confirmed by their ability to release ethylene from KTBA and the results were found to be in the range of 1.210 to 3.121 ppm. From the above screening results three best white rot fungi Polyporus hirsutus, Daedalea flavida, Phellinus sp were selected for bioremediation of pulp and paper mill effluents on laboratory scale and pilot scale. On the laboratory scale a maximum decolourization of 62.2 % was achieved by Phellinus sp on 10th day of treatment. Inorganic chloride 820mg/l (189.7 %,) was liberated by Phellinus sp on the 10th day of treatment. The chemical oxygen demand (COD) was also reduced to 3010 mg/l (42.1%) by Phellinus sp. In pilot scale, a maximum decolourization of 66.2% was achieved by Polyporus hirsutus on 10 th day, inorganic chloride 582mg/l (105%) was liberated on the 10th day by Phellinus sp and the chemical oxygen demand (COD) was reduced to 3260mg/l corresponding to 37.3 % by polyporus hirsutus. These results suggest that Polyporus hirsutus and Phellinus sp are efficient for the treatment of pulp and paper industry effluent.
... Even though the effluents' color appears less harmful, it was discovered that color in pulping effluent is more than just an aesthetic issue [6]. The chemicals that cause the effluent's color absorb light, affecting photosynthesis directly, and they also reduce visibility, reducing microorganisms' chances of feeding or reproducing [5,12,13]. Therefore, several strategies and methods were proposed to decolorize and detoxify P & P effluents [14,15]. ...
Wheat straws are a globally abundant agro-waste that may play a critical role in the global transition from single-use plastics to green materials as an inexpensive and renewable raw material. Vast amounts of wastewater are produced during the technological process of wheat straw-cellulose/hemicellulose conversion. In this context, this work focuses on wastewater decolorization via activated carbon adsorption. A set of carefully planned experiments enabled the identification of a model that described the relationship between the system’s outputs and parameters. While process optimization is frequently connected with identifying process parameters that improve efficiency, this work employed a multi-objective optimization approach from both a technological and economic aspect. Nondominated sorting genetic algorithm versions II and III—NSGA-II and NSGA-III algorithms—were applied. As objectives, maximum efficiency and minimum cost per experiment were followed in different scenarios using pseudoweights and trade-off metrics. When optimizing only the efficiency, the results indicated a 95.54% decolorization yield, costing 0.1228 Euro/experiment, and when considering both the efficiency and cost, different solutions were obtained. The lowest cost was 0.0619, with a 74.42% decolorization. These findings indicate that incorporating an economic perspective into the optimization procedure can improve cost estimation and facilitate managerial decision-making.
... During the ozonation treatment, it was observed that the color of the wastewater was completely removed after 5 min. The main reason is that the color of the biological effluent of RPPW is mainly provided by lignin and lignin derivatives (Bajpai and Bajpai 1994). Ozonation can effectively destroy its color structure. ...
Recycled paper pulping wastewater (RPPW) will cause serious environmental problems due to the high loads of dissolved organic matter (DOM) and toxic components. In the present work, the degradation of DOM in the biologically treated RPPWs (cardboard wastewater (CW) and corrugated container wastewater (CCW)) by a combined coagulation and ozonation process was investigated. The optimal chemical oxygen demand (COD) removal of CW reached 73.64% at aluminum sulfate (Al2(SO4)3) dosage of 800 mg/l, aeration aperture of 10 μm, pH of 9, hydrogen peroxide (H2O2) dosage of 100 mg/l, and reaction time of 70 min. The optimal COD removal of CCW reached 55.76% at a poly-aluminum chloride (PAC) dosage of 700 mg/l, H2O2 dosage of 140 mg/l, and reaction time of 50 min. This study provided some insights into the change of DOM during the combined treatment through the use of UV–Vis spectroscopy and excitation-emission matrix spectroscopy (EEM). PAC and Al2(SO4)3 removed high molecular weight organic such as lignin and lignin-derived compounds to improve the biodegradability of the wastewater. Ozone oxidized high molecular weight organic with complex functional groups to low molecular weight organic with simple functional groups and even mineralization, and this phenomenon resulted in the COD of ozonation effluent significantly reduced. Thus, the results presented in this study support the application of the combined coagulation and ozonation process in treating RPPW.
Graphical abstract
... Laccase, lignin peroxidase, and MnP are the most important enzymes, which are used for color reduction of bleaching effluents from pulp and paper mill. In another approach, a mixture of enzymes and microbes can be mixed together to remove recalcitrant and injurious compounds from wastewater (Bajpai and Bajpai 1994). ...
... The aerobic bacteria' oxygen needs are met by distributed aerators or a shaft mechanical aeration system. According to Bajpai and Bajpai (Bajpai and Bajpai, 1994), the removal of AOX ranges from 15 to 65%, while the elimination of specific chlorinated organics such as chlorinated phenols, catechols, guaiacols, and vanillins can range from 20 to 100%. The ASP that treats wastewater from paper mills appears to be particularly prone to thickening. ...
Paper mills generate large quantities of wastewater and sludge waste depending on the type of paper making processes employed. This poses several problems regarding wastewater treatment, discharge, and sludge disposal. Whenever wastewater is generated, it should be treated in wastewater treatment plants prior to being released to the environment since it can be polluting and dangerous. A study was conducted at Star Paper Mills Ltd. Saharanpur, UP to demonstrate the existing and advanced technologies for wastewater treatment. The mill uses woody raw materials such as eucalyptus, poplar, and veener chips to manufacture a wide range of industrial and cultural grade papers, such as absorbent kraft, maplitho, azure lay, and copier. We observed that the most common excess back water is from paper machines, bleach plant effluent, floor cleaning, and other sources of wastewater. High chemical oxygen demand (COD), biochemical oxygen demand (BOD), and low biodegradability are all characteristics of pulp and paper wastewater. Approximately 85–90% of the fresh water utilized is wasted. We examined the wastewater collected and evaluated from the paper mill by Central Pulp and Paper Research Institute (CPPRI). The Effluent treatment plant (ETP) at Star Paper Mills Ltd. is sufficient to facilitate satisfactory removal of suspended matter in clarifiers and oxidation of biodegradable organic matter in aeration tank. As a matter of fact, if the ETP is operated under optimal conditions, the aeration capacity is sufficient to effectively treat even higher BOD loads than the existing load.
... This finding suggests that an HRT from 24 to 72 h insignificantly affected tanninlignin removal in the dark brown CIE. Tannin-lignin compounds have complex molecules with a high molecular weight and are persistent towards degradation due to the presence of carbon-to-carbon linkage of biphenyl type and other linkages in the molecule [33]. The degradation of tannin-lignin has also been studied in pulp and paper wastewater using granular sludge technology, where the removal decreased at high concentrations [34]. ...
The coffee processing industry produces toxic and low biodegradable effluent, which can pollute water bodies. A pre-treatment study on coffee effluent using a dual-media biofilm reactor (DM-BR) containing sand and Hexafilter (HEX) was conducted alongside a control biofilm reactor (C-BR) containing sand media. The novelty of this study lies in the use of dual media in biofilm reactor (DM-BR) for real coffee effluent treatment, where these processes were used individually in previous studies. The performance of DM-BR and C-BR in treating coffee effluent were investigated at different hydraulic retention times (HRTs), 24, 48 and 72 h, and the degrading bacteria were identified. Both biofilm reactors were inoculated with a recycled paper mill-activated sludge and accli-matised for 97 days. The DM-BR displayed the highest removal of chemical oxygen demand (COD) and NH4 +-N at 47% and 38%, respectively, within 48 h of HRT, whereas colour and tannin-lignin reached maximum average removal of 21% and 29%, respectively, at 24 h of HRT. The combination of sand and HEX media in a system showed COD and NH4 +-N removal improvement at 48 h of HRT and encouraged a variety of bacterial species growth. Bacterial characterisation analysis revealed Proteobacteria to be dominant.
... The resinous and phenolic compound also imparts color in the waste water. In the pulp and paper industry with a soda recovery facility, waste water discharged with an average of 350 L for the production of 1 kg of paper and 40-50 g lignin per kg of bleached paper is produced (Bajpai and Bajpai, 1994). Lignin is the main constituent that is responsible for color imparting in the pulp and paper industry (Chakradhar and Shrivastava, 2004). ...
The pulp and paper industry consumes a huge amount of water and releases more polluted and colored wastewater every year. Many conventional techniques are used in the treatment of paper industry wastewater. However, for color removal from paper mill effluent, there is no proven method so far, on an industrial scale. Due to high energy input and high cost, there is an urgent need to find out a new technique that must be sustainable, economical, and environment friendly. Various methods have been investigated on bench scale and pilot scale also but no proven method for color removal on an industrial scale. The paper provides an overview of the color removal techniques from different sources of pulp and paper mill wastewater discharged by various industries. The review described various components involved in various processes for color removal from paper mill waste water. The present works focus on processes like chemical, chemical/physical, biological, physicochemical, and electrochemical applied in color removal from paper mill wastewater. The present review gives key information on the effectiveness, use, betterment, and limitations of numerous methods of treatment targeted at color removal from paper mill wastewater using various techniques still under evolution.
... Biological treatment to remove the contaminant is the best and most efficient known method for the reduction of toxic effects of effluent from Kraft mills (Thakur 2004), while the chemical and physical methods are on treatment track, due to cost inefficiency and residual effects. Biological treatment method involves the use of microbes such as algae, bacteria, fungi, and enzymes (Bajpai and Bajpai 1994) as a single step treatment or in the combination with chemical and physical approaches (Afzal et al. 2008;Balcıoğlu et al. 2007;Pedroza et al. 2007). ...
Over the past few decades, the rapid development of agriculture and industries has resulted in contamination of the environment by diverse pollutants, including heavy metals, polychlorinated biphenyls, plastics, and various agrochemicals. Their presence in the environment is of great concern due to their toxicity and non-biodegradable nature. Their interaction with each other and coexistence in the environment greatly influence and threaten the ecological environment and human health. Furthermore, the presence of these pollutants affects the soil quality and fertility. Physicochemical techniques are used to remediate such environments, but they are less effective and demand high costs of operation. Bioremediation is an efficient, widespread, cost-effective, and eco-friendly cleanup tool. The use of microorganisms has received significant attention as an efficient biotechnological strategy to decontaminate the environment. Bioremediation through microorganisms appears to be an economically viable and efficient approach because it poses the lowest risk to the environment. This technique utilizes the metabolic potential of microorganisms to clean up contaminated environments. Many microbial genera have been known to be involved in bioremediation, including Alcaligenes, Arthrobacter, Aspergillus, Bacillus, Burkholderia, Mucor, Penicillium, Pseudomonas, Stenotrophomonas, Talaromyces, and Trichoderma. Archaea, including Natrialba and Haloferax, from extreme environments have also been reported as potent bioresources for biological remediation. Thus, utilizing microbes for managing environmental pollution is promising technology, and, in fact, the microbes provide a useful podium that can be used for an enhanced bioremediation model of diverse environmental pollutants.
... The highest pH value of effluents from CE unit may be due to the addition of alkali at this stage for the precipitation of total solids which produces hydroxyl ions in water thereby raising the pH of effluent making it alkaline in nature [12]. The effluent from CE unit recorded the pH value of 9.8 which is slightly higher than WHO prescribed tolerance limit of pH value for the paper industry effluent as 6 to 9 [13].Colour of effluents or wastewaters depend on concentration of lignin which come up due to the presence of low and high molecular weight chlorinated organic compound produced during different processing stages like pulping, bleaching and alkali extraction as the lignin degradation products [14][15][16]. The colour of the effluent from all the four processing stages measured in PCU showed considerable variation ranging from 410±0.060 to 2802±1.15 ...
The pulp and paper industries discharge a large amount of effluent as wastewater in the surrounding streams thereby causing serious health and environmental problems. These large quantities of effluents need to be treated after characterization prior to their disposal. Physicochemical characteristics of effluents from an agro-based paper mill located in Uttarakhand state of India were analyzed in terms of pH, colour, TS, TDS, TSS, turbidity, BOD, COD, and AOX. The results demonstrated markedly higher values
of all physicochemical parameters of effluents from various processing units of the paper mill than the permissible limit thus necessitating appropriate treatment prior to their discharge in the environment. In the present paper several types of coagulant viz. Ferric chloride, lime, alum and Ferric chloride with polyacrylamide (PAM) have been examined for their effectiveness of reducing the chemical load of the effluent.
... The advantage of using chlorine is simply that it is cheap and effective. In the chlorination stage chlorine in first dissolved in the water and it produces both hydrochloric acid and hypochlorous acid (Bajpai and Bajpai, 1994.) During chlorination, wood component (lignin and some carbohydrates) are structurally modified, degraded, and chlorinated. ...
Pulp and paper industries discharge enormous amount of wastewaters containing recalcitrant pollutants into the environment. However, due to stringent environmental legislation the effluent needs to be treated before final discharge in compliance of the norms and standards laid by regulatory bodies. In fact, the volume and pollution load of the generated wastewater depends upon processes involved in the production, type of raw materials, chemicals used, types of paper products and the degree of water recovery. Therefore, the treatment protocols need to be industry specific. In consideration of fact, the work was aimed to characterize bleached effluent generated from selected agro-based pulp and paper mills and to evolve chemical and tertiary treatments for reuse of wastewater in the process and pre treatment of combined effluent/post treatment of effluent to reduce the pollution load and improve the ETP performance. Two agro-based pulp and paper mills one each in the states of Uttar Pradesh and Uttarakhand, India designated as Mill 'A' and Mill 'B' respectively were selected for the study. Effluent samples from different streams i.e. chlorination, extraction, combined bleach plant and primary clarifier inlet were collected and separately evaluated for physicochemical characteristics including colour, pH, turbidity, COD, BOD, TS, TSS, TDS and AOX as per APHA and CPPA standard methods which indicated the extent and degree of pollution in the effluents at each stage of both the Mills. Further, in view of the fact that use of chemical pre-treatment not only reduce the pollution loads but also helps mills in improving ETP performance, attempt was made to evaluate the pollution reduction efficiency of different chemicals separately and in combination for treatment of various polluted effluent streams. Also, treatment of chemically treated effluents with activated charcoal was considered essential and accordingly treatment conditions including dose (ppm) and retention time (min) were worked out. Results of studies the indicated a significant reduction in COD with all the chemical treatments with an average > 80% reduction; however, alum was found to be the most effective followed by ferric chloride considering overall conditions of the two mills. Activated charcoal treatment despite being efficient may not be a feasible treatment option for the Mills owing to its high cost. In terms of colour reduction, the combined chemical treatment with FeCl3+PAM was found to be the most effective followed by the lime. Furthermore, alum was found to be the most effective in reducing the chlorinated organic halides (AOX) where reduction was more than 90% followed by FeCl3+ PAM.
The studies concluded that the effluent discharged from both the paper industries need to be treated effectively before discharging to receiving water bodies because of high pollution loads as prescribed by the standards of regulatory agency of India. Based on the results obtained it is revealed that the chemicals like ferric chloride, lime ,alum ,ferric chloride with PAM and activated charcoal are found effective for treatment of effluent to reduce COD, color and AOX which are one of the main environmental regulatory parameters. However combination of Alum and lime was found to be the most effective and economic for the mills under the study. Activated charcoal was also found most effective to reduce color, AOX and COD from effluent. Use of these chemicals as pre treatment steps not only reduce the pollution loads, but will also help paper mills in reducing the operating cost of subsequent activated sludge process and to meet the discharge standards. The optimized effluent treatment conditions as evolved through the study for both the agro-based paper mills could successfully used in prediction of their toxicity and effective management and will also help in formulation of proper strategies to counter the pollution load borne by paper mill effluents prior to their disposal into the environment.
... The TSS of the high organic load effluent (HE) was 10 mg L -1 , showing an adequate efficiency of the secondary clarifiers. Considering that the biological effluent treatment decomposes biodegradable organic matter and toxic components (Hubbe et al. 2016) and does not remove recalcitrant organic material, there was a residual COD, color and TDS of 360 mg L -1 , 575 CU and 1900 mg L -1 , respectively, in the HE originated mainly from wood organic matter (Bajpai and Bajpai 1994). The high color originates from the lignin of wood degraded during the pulping and bleaching processes, with high aromatic content and unsaturated structures (Hubbe et al. 2016), in addition to hemicelluloses, resins, fatty acids, tannins, phenols, among others (Pokhrel and Viraraghavan 2004). ...
The bleaching plant of a kraft pulp mill is the sector that consumes water and generates effluent with the highest volume. Water recycling is an attractive option to reduce water consumption and effluent generation. This study evaluated the technical feasibility of using treated effluent as washing water in the bleaching stages. The bleaching sequence was simulated in the laboratory using four types of washing water: deionized water, whitewater, low organic load effluent, and high organic load effluent. To achieve 90% ISO pulp brightness, the ClO2 consumption increased from 8.1 kg ClO2 odt-1 when using water to 13.8 and 16.3 kgClO2 odt-1 for the low and high organic effluents. Physical and optical tests of the hand-sheet papers did not show any statistical difference between various washing waters. The filtrates showed values that did not burden the efficiency of the effluent treatment plant. It was possible to use effluent in the bleaching stages, considering that the filtrates and the produced paper complied with the quality standards.
... Colour of effluents or wastewaters depend on concentration of lignin which come up due to the presence of low and high molecular weight chlorinated organic compound produced during different processing stages like pulping, bleaching and alkali extraction as the lignin degradation products [30,31]. The colour of the effluent from all the four processing stages measured in PCU showed considerable variation ranging from 481.44±0.58 to 3936.16±5.76 ...
Discharge of large amount of wastewater as effluent from pulp and paper industries in the surrounding streams result in serious health and environmental problems. These large quantities of effluents need to be characterized for evolving proper treatment strategy prior to their disposal. Physicochemical characteristics of effluents from an agro-based paper mills located in Uttar Pradesh state of India were analyzed in terms of pH, colour, TS, TDS, TSS, turbidity, BOD, COD, and AOX. The effluent samples collected from different processing units of the paper mill varied considerably across the discharge streams. The mean values pH, colour, TS, TDS, TSS, turbidity, BOD, COD, and AOX ranged from 1.82±0.03 to 9.84±0.06, 481.44±0.58 to 3936.16±5.76 PCU, 1718.49±0.65 to 4252.29±4.46 ppm, 1518.27±2.65 to 3032.14±3.32 ppm, 200.22±2.01 to 1220.15±3.15 ppm, 113.23±1.46 to 481.22±2.61 NTU, 355.65±3.50 to 1342.22±3.50 ppm, 881.52±3.19 to 2710.12±4.52 ppm, and 15.75±0.51 to 38.35±0.21 ppm respectively. The results demonstrated markedly higher values of all physicochemical parameters of effluents from various processing units of the paper mill than the permissible limit thus necessitating appropriate treatment prior to their discharge in the environment.
... Colour of effluents or wastewaters depend on concentration of lignin which come up due to the presence of low and high molecular weight chlorinated organic compound produced during different processing stages like pulping, bleaching and alkali extraction as the lignin degradation products [14][15][16]. The colour of the effluent from all the four processing stages measured in PCU showed considerable variation ranging from 410±0.060 to 2802±1.15 ...
The pulp and paper industries discharge of a large amount of effluent as wastewater in the surrounding streams thereby causing serious health and environmental problems. These large quantities of effluents need to be characterized for evolving proper treatment strategy prior to their disposal. Physicochemical characteristics of effluents from agro-based paper mills located in Uttarakhand state of India were analyzed in terms of pH, colour, TS, TDS, TSS, turbidity, BOD, COD, and AOX. The effluent samples collected from different processing units of the paper mill varied considerably across the discharge streams. The mean values pH, colour, TS, TDS, TSS, turbidity, BOD, COD, and AOX were found in the range of 2.559.8±0.05, 4102802 PCU, 1980.652785.79 ppm, 1650.672470.35 ppm, 315.44401.35 ppm, 73.22349.37 NTU, 170.32670.42, 705.522000.55 ppm, and 14.9840.82 respectively. The result shows that all the studied physicochemical parameters of effluents at different processing units of the mill are higher than the permissible standards that need proper treatment for their safe disposal.
... High COD lev els in the dis charges of tex tile mills in di cate the pres ence of con t a m i nants which ul ti mately pro duce detri men tal ef fect on aquatic life ( Dawkar et al., 2010 ). The mi croor gan isms hav ing biore me di a tion po ten tial are im por tant agents for de col oriza tion and re duc tion of BOD and COD of the in dus trial wastes ( Bajpai and Bajpai, 1994 ). Our study shows signif i cant re duc tion in COD val ues, there fore dis play ing the po ten tial of mi crobes in the biore me di a tion of ef flu ent pol luted with dyes and other nox ious com pounds. ...
Textile effluent is one of the major sources of land and water pollution due to the presence of dyes in addition to other contaminants. The lands receiving these toxic effluents have become deprived of a number of species of natural flora. Competency of indigenous bacterial strains to degrade the dyestuffs present in textile wastewater was evaluated. Decolourization by the bacterial strains was found to be 36%, 66% and 89% for B. cereus, B. thurningienis and B. licheniformis, respectively. The comparative analysis showed that COD reduced to 80% by B. cereus, 82% by B. thuringiensis and 93% by B. licheniformis whereas BOD reduced to 61% by B. cereus, 65% by B. thuringiensis and 69% by B. licheniformis. TS, TDS, TVS and TSS contents reduced to 34%, 89%, 21%, 9% by B. cereus, 36%, 98%, 30%, 41% by B. thuringiensis and 43%, 99%, 43% and 49% by B. licheniformis. Seed germination and growth of Triticum eastivum was used as an indicator to study the phytotoxic effects of textile mill effluents. Plants grown with treated effluent showed maximum growth of plumule and radical and such properties may be helpful to develop alternatives for the management of dyeing wastewater. Maximum tolerance index and minimum relative toxicity and percentage phytotoxicity was found with bioremidiated textile industrial effluent. This study showed the effectiveness of biological pretreatment involving appropriate microorganisms. Bioremediation, no doubt, is an inexpensive and environment friendly approach for eradication of toxic effects caused by dyes and ultimately the conservation of natural flora.
... O tratamento biológico é responsável pela degradação da matéria orgânica biodegradável e componentes tóxicos (Hubbe et al., 2016). Porém, essa sequência de tratamento não tem a capacidade de remover a matéria orgânica recalcitrante (não biodegradável), proveniente, sobretudo, da madeira, o que faz com que os valores de DQO, cor e SDT sejam relativamente altos (360 mg L -1 , 575 uC e 1900 mg L -1 , respectivamente) (Bajpai & Bajpai, 1994). A cor elevada é originada da própria lignina da madeira degradada durante o processo de polpação e branqueamento, que possui elevado conteúdo aromático e estruturas insaturadas (Hubbe et al., 2016), além da presença de hemiceluloses, resinas, ácidos graxos, taninos, fenóis, entre outros (Pokhrel & Viraraghavan, 2004). ...
O branqueamento é o estágio da produção de polpa celulósica kraft que gera maior carga hídrica poluente e muitas fábricas têm buscado minimizar ou até mesmo eliminar a quantidade de efluente gerado. O fechamento de circuitos d´água vislumbra-se como uma opção atrativa para a redução do consumo de água e da geração de efluentes. O objetivo do presente trabalho foi avaliar a viabilidade técnica de utilizar efluentes tratados como água de lavagem nos estágios do branqueamento. A sequência Dht(EP)DP de branqueamento foi simulada em laboratório utilizando três tipos de água de lavagem: a) água deionizada, b) água branca (AB) da máquina de secagem e c) efluente de alta carga orgânica (EAC) tratado biologicamente por um processo de lodos ativados. Para alcançar alvura da polpa de 90% ISO, o consumo de ClO2 da sequência completa de branqueamento foi de 8,1, 8,0 e 13,8 kgClO2 tas-1 ao utilizar água deionizada, AB e EAC, respectivamente. A viscosidade, n° kappa e o teor de ácido hexenurônico da polpa branqueada com EAC diminuíram em relação à polpa branqueada com água deionizada. Os testes físicos e ópticos dos papéis confeccionados não demonstraram alterações estatísticas significativas com a mudança do tipo de água utilizada para lavagem. Os filtrados dos estágios Dht e EP apresentaram valores de condutividade elétrica, cor, turbidez, DQO, SDT e teor de Ca, Fe, K, Na e Cu maiores para os branqueamentos realizados com efluente em relação às referências (água deionizada e AB). Não obstante, sua qualidade não compromete a eficiência da Estação de Tratamento de Efluentes (ETE). Conclui-se que foi possível utilizar efluente na lavagem dos estágios de branqueamento, uma vez que as qualidades dos filtrados gerados, da polpa branqueada e dos papéis confeccionados foram satisfatórias, havendo, contudo, um incremento no consumo de reagentes ao longo da sequência e, consequentemente, um aumento do custo de produção de polpa celulósica.
... Laccase, lignin peroxidase, and MnP are the most important enzymes, which are used for color reduction of bleaching effluents from pulp and paper mill. In another approach, a mixture of enzymes and microbes can be mixed together to remove recalcitrant and injurious compounds from wastewater (Bajpai and Bajpai 1994). ...
The traditional pulp- and papermaking processes involve huge quantity of water, energy, and chemicals. In today's scenario, due to increasing environmental and economic concerns associated with traditional processes, papermakers are hard pressed to introduce eco-friendly processes for the reduction in energy consumption and toxic chemicals. Therefore, microbial enzymes may augment various pulp and paper processes with less effort and better results including savings in electricity, water, and harsh chemicals, thereby reducing environmental impacts. Currently, the most promising areas for enzyme applications in pulp and paper industry are amylase for the starch modification in surface sizing; xylanase as well as mannanase for pulp bleaching and deinking of recycled pulp; cellulase for pulp refining, pulp drainage improvement, and deinking of recycled pulp; and lignin-degrading enzymes for pulp bleaching, wastewater treatment, etc. Some applications have already been commercialized; however, the majority of the potential applications are still in the pilot or lab scale. Therefore, this chapter covers the prospects and developments of different enzymes applied in various areas in pulp and paper industry including current research on laboratory, pilot, and mill scales.
... In particular, the color in the effluent is called "the true color" because it is caused by the degradation of organisms and the yield of the metamorphic process of life which is high stable and difficult to decompose and separate by filtration [15]. In addition, traditional biological and chemical treatment processes was not effective to remove organic substance which degrades in water [16], [17]. This research uses 3 types of fly ash which are the remaining of industrial heating process such as Bagasse fly ash, Rice husk ash and Lignite fly ash. ...
Color removal from pulp and paper mill wastewater by using fly ash was one of the effective and low-cost methodologies to improve the quality of the wastewater. The fly ash had the capability to remove various organic pollutants, such as Lignin, Tannins, Humic, and Fulvic, from wastewater. These organic pollutants contribute to the color intensity of industrial effluent. The research examined the removal capability of fly ash including Bagasse fly ash, Rice husk ash and Lignite fly ash. The samplings were analyzed in the laboratory for color removal capability. The test was divided into 3 steps as follows: Step 1 the comparison of color removal efficiency by using 3 types of fly ashes; Bagasse fly ash, Lignite fly ash and Rice Husk ash. Step 2: Analyzing the functional group of fly ashes before and after color removal by using the Fourier Transform Infrared Spectroscopy (FT-IR) to determine the adsorption mechanism and other influencing factors. Step 3: Color removal efficiency by sand filter experiment. The results showed that; Step 1: Bagasse fly ash, Rice husk ash and Lignite fly ash were effective in color removal of 94.2, 74.8 and 71.8 percent at 30 minutes, 24 hours and 4 days, respectively. The pH of the effluent using Bagasse fly ash was constant to 7.5-8 and tend to be constant although the ash amount increased, while the pH of Lignite fly ash was in the range of 8-9 and tend to increase when amount increased. Step 2: Analyzing the functional group of Bagasse fly ash using the FT-IR found that after using Bagasse fly ash for color removal in the effluent, the graph tends to decrease. Step 3: The result showed that the efficiency of color removal of the sand filter by soil mixed with Bagasse fly ash at ratio 1: 0-1:10 (Soil: Bagasse fly ash), which the efficiency of color removal tends to increase with the maximum of 93 % and the minimum of 16% at ratio 1:7 and 1:0, respectively.
... Among anthropogenic activities, the rapid development of industries is one of the flagrant abusers of water quality as it impairs water quality in several ways . Industries like textile mills (Carneiro et al., 2010), paper and pulp (Bajpai and Bajpai, 1994), sugar, thermal power plants, electroplating plants (Fresner et al., 2007;Hang et al., 2009;Liu et al., 2011), leather related industries (Dwivedi and Vankar, 2014) and fertiliser plants release their effluents directly into nearby water bodies posing serious threat to the ecosystem (Obire et al., 2008;Saranraj and Stella, 2014). The release of unprocessed wastewater effluents from fertiliser plants which include nitrogenous and phosphate compounds, micronutrients such as potassium, sodium, silica, sulphur, fluorine, as well as by-products like phosphogypsum, pyrite ashes, calcium carbonate, soluble salts are also responsible for poor water quality (Singh, 2009). ...
... Among anthropogenic activities, the rapid development of industries is one of the flagrant abusers of water quality as it impairs water quality in several ways . Industries like textile mills (Carneiro et al., 2010), paper and pulp (Bajpai and Bajpai, 1994), sugar, thermal power plants, electroplating plants (Fresner et al., 2007;Hang et al., 2009;Liu et al., 2011), leather related industries (Dwivedi and Vankar, 2014) and fertiliser plants release their effluents directly into nearby water bodies posing serious threat to the ecosystem (Obire et al., 2008;Saranraj and Stella, 2014). The release of unprocessed wastewater effluents from fertiliser plants which include nitrogenous and phosphate compounds, micronutrients such as potassium, sodium, silica, sulphur, fluorine, as well as by-products like phosphogypsum, pyrite ashes, calcium carbonate, soluble salts are also responsible for poor water quality (Singh, 2009). ...
... By employing a specific microorganism adapted to the wastewater, bioaugmentation technologies can effectively enhance the removal efficiency of refractory organics. Bioaugmentation includes utilization of enzymes, indigenous or engineered strains of bacteria, fungi, and algae (Bajpai and Bajpai 1994), microbial consortia (Pendashteh et al. 2010), and additionally, a combination of bacterialfungal treatment capabilities to partially degrade or completely mineralize the targeted compounds. ...
The quality of wastewater discharged from the process industries has high impact on all the biotic and abiotic components of the adjoining environment. Pollutants in the wastewater of different types of process industry include heavy metals, nitrates, sulfates, phosphates, fluorides, chlorides, oxalates, insecticides, herbicides, fungicides, polynuclear hydrocarbons (PAHs), phenols, polychlorinated biphenyls, halogenated aromatic hydrocarbons, formaldehyde, polybrominated biphenyls, biphenyls, detergents, oils, greases, hydrocarbons, alcohols, aldehydes, ketones, proteins, lignin. The presence of various pollutants in process industry wastewater (PIWW) directly or indirectly affects all life-forms in the vicinity. Since these are highly toxic, carcinogenic, mutagenic, and clastogenic, serious hazardous effects may run from aquatic organism to our food chain. Thus, PIWW treatment technologies are focused on three purposes, i.e., reduction in water usage, treatment of effluent, and recycling of water and other catalyst. In the last two decades, different types of physical–chemical treatment systems are established as secondary and tertiary stage wastewater treatment systems. However, these techniques are questionable due to the incurred cost, operational difficulties, and sludge generation. Augmentation of biological treatment seems to be a sustainable option in comparison with other physical and chemical processes. The biological treatment includes the aerobic and anaerobic digestion of PIWW. Ample amount of research has led to identify various aerobic and anaerobic bacterial strains having much higher treatment efficacy in comparison with the conventional activated sludge process. If these bacterial isolates are exploited in the form of consortium or augmented into the activated sludge, they may exhibit even better results. Such aerobic and anaerobic bacterial treatment has been found to reduce the level of pollutant up to 90%. Additionally, sequential treatment PIWW can be attempted, but such trials are scarcely tested and are limited to the level of a pilot plant. In this chapter, emphasis is largely given on the various augmentation strategies considering various possible sequential treatments of PIWW. It is anticipated that the recent advancements in the area of bioaugmentation will certainly help in developing ecofriendly solutions to PIWW treatment.
... The chlorolignin compounds are the main contribution to the color. 2 The large quantity of colored compounds generated is reflected by the fact that the conventional bleaching of softwood kraft pulp yields about 200 to 300 kg color/ton of pulp. 3 Some of these compounds responsible for a variety of colors are difficult to identify and quantify. Most of these high molecular weight (> 1 kDa) "colored" compounds are resistant to biological degradation, 4 hence little color removal in biosystems. ...
... Laccase, lignin peroxidase, and MnP are the most important enzymes, which are used for color reduction of bleaching effluents from pulp and paper mill. In another approach, a mixture of enzymes and microbes can be mixed together to remove recalcitrant and injurious compounds from wastewater (Bajpai and Bajpai 1994). ...
... Lignin and its derivatives are difficult to degrade because of the linkages within the molecule especially the biphenyl type carbon-to-carbon linkages [2]. Chemical recovery is not carried out in small paper mills due to economic reasons [3]. The brown color of the effluent may increase water temperature and decrease photosynthesis which may lead to decreased concentration of dissolved oxygen. ...
... BOD which indicates the pollution strength of the waste waters was recorded as 165±8.25 mg/L. High BOD is harmful to aquatic animals like fish and microorganisms [23]. The COD value of the effluent samples was recorded as 384 ± 19.2 mg/L. ...
Pulp and paper mill effluent induced phytotoxicity and genotoxicity in mung bean ( Vigna radiata L.) and root tip cells of onion ( Allium cepa L.) were investigated. Physicochemical characteristics such as electrical conductivity (EC), biological oxygen demand (BOD 5 ), chemical oxygen demand (COD), and total phenols of the pulp and paper mill effluent were beyond the permissible limit specified for the discharge of effluent in inland water bodies. Compared to control plants, seedling exposed to 100% effluent concentration showed a reduction in root and shoot length and biomass by 65%, 67%, and 84%, respectively, after 5 days of treatment. A. cepa root tip cells exposed to effluent concentrations ranging from 25 to 100% v/v showed a significant decrease in mitotic index (MI) from 32 to 11% with respect to control root tip cells (69%) indicating effluent induced cytotoxicity. Further, the effluent induced DNA damage as evidenced by the presence of various chromosomal aberrations like stickiness, chromosome loss, anaphase bridge, c-mitosis, tripolar anaphase, vagrant chromosome, and telophase bridge and micronucleated and binucleated cell in A. cepa . Findings of the present study indicate that pulp and paper mill effluents may act as genotoxic and phytotoxic agents in plant model system.
... The chlorolignin compounds are the main contribution to the color. 2 The large quantity of colored compounds generated is reflected by the fact that the conventional bleaching of softwood kraft pulp yields about 200 to 300 kg color/ton of pulp. 3 Some of these compounds responsible for a variety of colors are difficult to identify and quantify. Most of these high molecular weight (> 1 kDa) "colored" compounds are resistant to biological degradation, 4 hence little color removal in biosystems. ...
... Recent development of new technologies and/or improvement of existing technologies for the treatment of effluents of effluents of pulp and paper industries has included the use of white-rot fungi Phanerochaete chrysosporium and Tremetes versicolor for the effluents of the above mentioned industries in the recent past [11][12][13][14] . ...
In the recent past, white rot fungi have received a considerable attention for the removal of color from pulp and paper mill effluents. Investigation was carried out to compare the biobleaching potential of reported four immobilized whit-rot fungal strains (a) Phanerocheate chrysosporium, (b) Trametes versicolor, (c) Daldelia flavlda and (d) Pleurotus ostreatus. Also, the most efficient decolorizer was co-immobilized with best Chemical Oxygen Demand (COD) reducer and the suitability of the same was studied. The treated and pre-treated combined effluent samples for the study was collected from Varindra-Agros Paper Mills Ltd., Barnala, Punjab, and stored at 4±1°C, until further use. Polyurethane Foam (PUF) pieces were used for adsorption and immobilization of white-rot fungi. The study revealed T. versicolor MTCC 138 as the best decoloriser with 87.7% color reduction, while P. chrysosporium BKMF 1767 was found to reduce COD up to a maximum of 42.3%, after 72 hours incubation time at 30±1°C. The mixed immobilized cultures of P. chrysosporium BKMF 1767 and T. versicolor MTCC138 supported the maximum color reduction of 88.84% and a corresponding COD reduction of 41.60% after 120 hours of incubation at 30±1°C. The study suggests that co-Immobilized system can be more efficient for decolorization and COD reduction of pulp and paper, mill effluent and paves a good platform for further investigation of enzymatic remedial processes for the same.
... The chlorolignin compounds are the main contribution to the color. 2 The large quantity of colored compounds generated is reflected by the fact that the conventional bleaching of softwood kraft pulp yields about 200 to 300 kg color/ton of pulp. 3 Some of these compounds responsible for a variety of colors are difficult to identify and quantify. Most of these high molecular weight (> 1 kDa) "colored" compounds are resistant to biological degradation, 4 hence little color removal in biosystems. ...
... The high load of color is not only esthetically unacceptable but also inhibits the natural process of photosynthesis in the wastewater receiving streams due to absorbance of sun light. This leads to the adverse effects on the aquatic living organisms [4]. ...
This study evaluates the effectiveness of polyaluminium chloride (PAC) as a coagulant for
the treatment of pulp and paper mill wastewater. The wastewater was characterized for different
chloro-organic compounds, i.e. adsorbable organic halides (AOX), chlorophenolics,
and chlorinated resin and fatty acids (cRFA). Four categories of chlorophenolics (chlorophenols,
chlorocatechols, chloroguaiacols, and chlorosyringaldehyde) and four cRFA were
detected in the wastewater. For coagulation studies, optimization of the process variables
including initial pH, coagulant dosage, time, and initial organic load was done in terms of
chemical oxygen demand and color removal efficiency. Under optimized conditions (pH 8.0,
PAC dose 1.5 g/L, time 90 min.), the removal efficiency for AOX, chlorophenolics, and cRFA
was 66, 41, and 87%, respectively. The chlorophenolics, i.e. 2,6-dichlorophenol, 3,4-dichlorophenol,
3,4,6-trichloroguaiacol, tetrachloroguaiacol, and 2,6-dichlorosyringaldehyde were not
detected after treatment studies. Among different parameters, highest removal of color was
observed from wastewater by PAC.
A lab-scale gravity-driven bioreactor (GDB) was designed and constructed to evaluate the simultaneous treatment of black liquor and domestic wastewater. The GDB was operated with a mixture of black liquor and domestic wastewater at a ratio of 1:1 and maintained at an average organic loading rate of 1235 mg-COD/L-Day. The wastewater was fed to the primary sedimentation tank at a flow rate of approximately 12 mL/min and subsequently passed through serially connected anaerobic and aerobic chambers with the same flow rate. Each wastewater sample was allowed to undergo a hydraulic retention time of approximately 72 h, ensuring effective treatment. The GDB was actively operated for nine samples (W1–W9) at a weekly frequency. The entire process was conducted within the workstation’s ambient temperature range of 30–35 °C to sustain microbial activity and treatment efficiency in an open environment. The performance of the GDB was evaluated in terms of various pollution indicators, including COD, BOD5, lignin removal, TDS, TSS, EC, PO4 3−, SO4 2−, microbial load (CFU/mL and MPN index), total nitrogen, and color reduction. The results showed that the GDB achieved promising treatment efficiencies: 84.5% for COD, 71.80% for BOD5, 82.8% for TDS, 100% for TSS, 74.71% for E.C., 67.25% for PO4 3−, 81% for SO4 2−, and 69.36% for TN. Additionally, about 80% reduction in lignin content and 57% color reduction were observed after the treatment. The GDB substantially reduced microbial load in CFU/mL (77.98%) and MPN (90%). This study marks the first to report on wastewater treatment from two different sources (black liquor and domestic wastewater) using a simple GDB design. Furthermore, it highlights the GDB’s potential as a cost-effective, environmentally friendly, and efficient solution for wastewater treatment, with no need for supplementary chemical or physical agents and zero operational costs.
The large number of studies reviewed is indicative of the extensive
research carried out on the use of AOPs and in the field of chemical oxi�dation, mainly as a pretreatment stage for industrial wastewater reme�diation. In recent years, many authors have also developed combined
biological systems and AOPs for the remediation of various industrial
wastewaters. A wide spectrum of industrial contaminants was stud�ied and discussed from model solutions with individual substances
to real effluents containing a mixture of various persistent substances.
Furthermore, there are emerging biological reactor configurations
(fixed biomass, aerobic granular biomass systems, suspended bio�mass membrane bioreactors, etc.) to optimize the time-consuming
step in the treatment line for designing specific biological systems and
to maximize the efficiency for each industrial wastewater target.
A systematic procedure must be employed in further research stud�ies based on the biodegradability test during and after the degradation
process, using model substances before studying real wastewater and
evaluating the toxicity assessment of the chemical parameters. More
pilot-plant scale experiments with real industrial wastewater must be
performed. Integrated technology is required from the application
point of view for the complete wastewater treatment methods and in
order to be reused the same water in the industry itself.
The efficacy of different Pleurotus ostreatus (L.) isolates to treat pulp and paper industrial effluent on a shake flask were studied. In the shake flask studies, Pleurotus ostreatus (L.) decolorized the effluent 69.68 %, on 7th day of incubation. Various cultural conditions including different glucose concentrations, nitrogen sources, pH, temperature and incubation period influence on biomass and different enzymes viz; xylanase, CMCase and laccase production by Pleurotus ostreatus were optimized in shake flask cultures. The results indicated that the optimum fermentation medium in shake flask studies contained a carbon (glucose 4%), nitrogen (0.5% ammonium chloride), inoculation level (three disks, 0.5 cm in diameter), temperature (30 °C), incubation period (at 7 days) and initial pH 5.0. Under these culture conditions, the maximum level of xylanase activity (9.29 Uml-1), CMCase (7.37 Uml-1), laccase (13.57 Uml-1) and effluent decolorization (69.68 %) were observed on 7th day during shake flask studies.
The pulp and paper industry is one of the major consumers of water. Pulp and paper industrial wastewaters usually contain halogenated organic materials, because general use is made of chlorine-containing compounds as bleaching agents during pulp and paper manufacture. Kraft pulping is the most common commercial chemical delignification procedure. Chlorination is generally the first stage in kraft pulping and during this treatment phase, chlorinated organic compounds are produced. The chlorinated substances are extracted with dilute alkali from the pulp in the subsequent extraction phase. Chloro-organic compounds tend to persist in nature because of their inherent recalcitrance; they are often toxic to aquatic live; many are genotoxic and have the potential to migrate widely throughout the ecosystem, ultimately accumulating in the fatty tissues of organisms. Legislation has been introduced to limit the levels of these toxic compounds in effluents. Additionally, during bleaching treatments chromophoric, highly oxidized, polymeric lignin/chlorolignin derivatives are formed that give rise to a dark color in the effluent. The color poses an aesthetic problem and contributes to the biological oxygen demand. Several methods have been attempted for decolorization and detoxification of bleached kraft effluents. These include physicochemical and biotechnological methods. The problems underlying the physicochemical treatments are those associated with cost and reliability. Biotechnological methods have the potential to eliminate/ reduce the problems associated with physicochemical methods. This article reviews the research on the use of Biotechnological methods for treatment of pulp and paper mill effluents. The progress made and the further scope are also discussed.
Native fungal isolates F1 - F8 and control fungi Phanerochaete chrysosporium were capable of degrading pulp and paper industry effluent and also efficient producers of cellulolytic and lignolytic enzymes. F3 (Paecilomyces sp) strain showed higher enzyme activity as compared to other native fungal isolates. Weight loss, cellulose loss and organic carbon contents were found maximum in F3. Reducing sugar, protein content and colour removing potential was also higher in F3. Color reduction initiated very fast with microbial enzyme treatment (initiated only after 2h of incubation) and reached maximum reduction after 24h. Lignin peroxidase fraction I and II resulted in 53% and 34% removal of colour and 36% and 38% lignin removal. The culture extract of F3 strain grown on pulp and paper effluent consists of five protein fractions and out of them two fractions of 38 and 40 kDa molecular weight showed lignin peroxidase activity. The pH and temperature optimum for lignin peroxidase activity were 2 to 3, and 20 - 30 degrees C, respectively. Maximum activity was observed at 6 mM to 48 mM veratryl alcohol concentration and 256 mM H2O2, however, sodium azide inhibits the enzyme activity. Different metals (CoCl2, HgSO4, CaCl2, SnCl2, FeSO4, CuSO4 and ZnSO4) also affected the lignin peroxidase activity.
Effluent from textile industries were treated with enzyme from white rot fungi isolated from outskirts of Mumbai and identified as Polyporus rubidus in our laboratory. Decolorisation of 4 Reactive dyes commonly found in the effluents such as Reactive bue, Reactive orange, Ramazol black and Congo red was examined by treatment with enzyme from Polyporus rubidus. Treatment of effluent was done in a laboratory scale bioreactor constructed with laccase immobilized Na-alginate beads. Greater than 80% of dyes were degraded within 5 days under stationary incubation conditions. The enzyme had a maxmimum activity of 17.1U after 3 days and was found to be secreted extracellularly by Polyporus rubidus. In this study the Polyporus rubidus has been reported for the first time to have laccase activity offering a promising possibility to develop an easy and cost effective method for degradation of dangerous dyes.
Pulp and paper mill effluent is posing a serious threat to the water and soil components of the environment due to its brown colour and high level of toxicity. Fungal treatment is one of the efficient methods for treating pulp and paper mill effluent. In the present study, for the treatment of from pulp and paper industry, nine efficient fungal strains including Phanerochaete chrysosporium, dedicated for the selective degradation of lignin, have been isolated. Enzyme activities (Fpase, xylanases, lignin peroxidases and carboxy methyl cellulase) required for the degradation of lignocellulosic waste, protein and reducing sugar content were determined. Among all the strains, F3 (Paecilomyces sp.) strains showed highest activity of lignin peroxidase (3.3 IUml-1), Fpase (1.2 IUml-1), xylanase (0.85 IUml-1), CMcase (0.49 IUml-1), protein (2.8 mgml-1), and sugar content (2.1 mgml-1) at 120 h incubation period. Enzyme extracts of these fungal isolates were applied for the treatment of pulp and paper mill effluent. Data indicated that among all the strains, Paecilomyces sp. (F3) showed highest removal of colour (80 per cent) and other pollution parameters (73 per cent lignin, 78 per cent COD and 76 per cent AOX) in pulp and paper mill effluent, on day 3 at 3.3 international unit per ml concentration of crude enzymes.
In the present study two white rot ligninolytic fungi Daedaeleopsis confragrosa and Phellinus pectinatus were used to analyze its ability to decolorize effluent collected from four different stages namely Chlorination stage, Alkali extraction stage, Hypo chlorite stage and Chlorine dioxide stage of the paper and pulp industry. It was found that the extent of decolorization was not adversely affected by color intensity except at the lower level but certainly the BOD and COD level decreased. Addition of glucose (0.1%) to decolorization media stimulated growth of fungi faster and reduced BOD and COD level faster. Both the fungi have been shown to be effective to combat the lignin and chloride containing effluent.
The large-and still growing-pulp and paper industry is a capital- and resource-intensive industry that contributes to many environmental problems, including global warming, human toxicity, ecotoxicity, photochemical oxidation, acidification, nutrification, and solid wastes. This important reference for professionals in the pulp and paper industry details how to improve manufacturing processes that not only cut down on the emission of pollutants but also increase productivity and decrease costs. Environmentally Friendly Production of Pulp and Paper guides professionals in the pulp and paper industry to implement the internationally recognized process of Cleaner Production (CP). It provides updated information on CP measures in. Raw material storage and preparation. Pulping processes (Kraft, Sulphite, and Mechanical). Bleaching, recovery, and papermaking. Emission treatment and recycled fiber processing. In addition, the book includes a discussion on recent cleaner technologies and their implementation status and benefits in the pulp and paper industry. Covering every aspect of pulping and papermaking essential to the subject of reducing pollution, this is a must-have for paper and bioprocess engineers, environmental engineers, and corporations in the forest products industry.
The ever-increasing demand for energy, the diminishing energy source and the problem of environmental pollution have raised public awareness to the need for a non-polluting renewable energy source. Biowastes, a potential renewal energy source of different origins are associated with a negative value due to a disposal and pollution cost. Biological wastes of different origins (agricultural, industrial, municipal and domestic) undergo slow and uncontrolled degradation, which leads to environmental pollution and their disposal is a big problem due to high transportation costs and scarcity of dumping sites. Anaerobic degradation of these wastes to useful products like energy rich fuel gases can stabilize them and also serve as renewable energy source. Microbial production of methane from different biological wastes has been studied on a wide range of wastes. Thus, wastes utilization, rather than its treatment emphasizes upon shifting the process from reducing the potential for pollution to synthesis of useful products, like gases and chemicals. Biomass amenability to conversion depends largely on the characteristic of the biomass (substrate) and the process requirements for conservation technology under consideration. Among the various by-products, which can be obtained by the fermentation of waste biomass, hydrogen has gained importance. It is regarded as the strongest contender as the clean fuel of the future. Microbial production of hydrogen has been demonstrated but the yields are quite low, large scale and continuous production is still in the incipient stage. In nature, wherever organic material is degraded microbially, under anaerobic condition and in the absence of sulphate and nitrate, methane is produced. When organic matter decompose without oxygen, the anaerobic bacteria produce methane and carbon dioxide. Anaerobic digestion provides appropriate solutions to problem associated with waste disposal and also generates biofuels as by-products.
This paper discusses the environmental factors affecting the degradation efficiency of paper mill wastewater. 24 full factorial central composite designs were employed for experimental plan and analyzed using response surface methodology. The physicochemical quality of pulp in paper mill effluent has been analyzed for the degradation of pulp and paper mill effluent in 72 hours incubation period using mixed culture. The temperature and pH of the effluent sample was varied between 25 to 65 ºC and 3 to 11 respectively. The effect of individual factor in the effluent treatment process indicated that the mixed culture found to degrade COD by 90% and 99% of COD at 35 ºC temperature and pH value 7. Floc stability was sustained at 35 ºC temperature and pH 7. Study on combined effect of factors showed that the optimum values of pH, temperature and days were found to be 7, 25 °C and 3 respectively.
The pulp and paper industry is one of the major consumers of water. Pulp and paper industrial wastewaters usually contain halogenated organic materials, because general use is made of chlorine containing compounds as bleaching agents during pulp and paper manufacture. Kraft pulping is the most common commercial chemical delignification procedure. Chlorination is generally the first stage in kraft pulping and during this treatment phase chlorinated organic compounds are produced. The chlorinated substances are extracted with dilute alkali from the pulp in the subsequent extraction phase. Chloro-organic compounds tend to persist in nature because of their inherent recalcitrance; they are often toxic to aquatic live many are genotoxic and have the potential to migrate widely throughout the ecosystem, ultimately accumulating in the fatty tissues of organisms. Legislation has been introduced to limit the levels of these toxic compounds in effluents. Additionally, during bleaching treatments chromophoric, highly oxidized, polymeric lignin/chlorolignin derivatives are formed that give rise to a dark color in the effluent. The color poses an esthetic problem and contributes to the biological oxygen demand. Several methods have been attempted for decolorization and detoxification of bleached kraft effluents. These include physicochemical and biotechnological methods. The problems underlying the physicochemical treatments are those associated with cost and reliability. Biotechnological methods have the potential to eliminate/reduce the problems associated with physicochemical methods. This chapter reviews the research on the use of biotechnological methods for treatment of pulp and paper mill effluents. The progress made and the further scope are also discussed.
Paper and pulp industries can broadly be divided into three categories—(1) handmade paper industries, (2) mill-made paper industries and (3) cardboard industries. All of these industries utilise water in different stages of making paper which is later discharged to nearby water bodies due to which these are considered as a major cause of water pollution. These effluents possess very high BOD, COD and toxic substances. As paper can be recycled a limited number of times, pulp fibres accumulate in the nearby area in the form of sludge which not only pollutes the soil or land but also produces enormous odour. Mycoremediation technology is a great boon which will be helpful in improving the existing situation and to minimise environmental and health problems associated with paper industrial wastes and pollutants. Therefore, in this chapter, we have discussed about the types of wastes and pollutants generated by handmade paper, mill-made paper and cardboard industries. Besides this, we have discussed about the fungi, their enzymes and role of both in mycoremediation of these wastes. In this chapter, we have also explained the suitable types of bioreactor, availability of culture, inoculation techniques and factors affecting the process. This information provides a platform for the workers who are working in field of mycoremediation of paper and pulp industrial wastes.
The global pulp and paper industry is in physical terms one of the largest industries in the world. It is traditionally known to be a large contributor to environmental pollution owing to its large consumptions of water, energy, and chemicals. Biotechnological methods offer potential opportunities for changing the industry toward more environmentally friendly and efficient operations compared to the traditional methods. Biotechnological processes are environmentally friendly, energy efficient, more specific, and can be used in place of nonbiological processes. The use of biotechnological processes in the pulp and paper industry results in increased pulp yield, improved fiber properties, enhanced paper recycling, reduced processing and environmental problems, and energy efficiency. Many applications of biotechnology in the pulp and paper industry have been commercialized and some are on the verge of commercialization. Applications that have been commercialized are the use of xylanases for bleaching, cellulase-hemicellulase mixture for fiber modification and deinking, cellulases for improved drainage, lipases for pitch removal, esterases for stickies control, levan hydrolase, proteases, cellulases, and amylases, etc., for slime removal. Many new applications are being studied that include new enzymatic approaches to reduce mechanical pulping energy, new enzymes for kraft pulp bleaching, enzyme sensors for smart paper products, etc. Bio-based unit operations are usually combined with conventional or new chemical and mechanical unit operations to fully benefit the performance of enzymes. This chapter provides general background on pulp and paper processing and describes the use of microbes/enzymes in each of the processing areas.Keywords:pulp;paper;biotechnology;biobleaching;deinking;fiber modification;slime control;stickies control;production of dissolving-grade pulp;shive removal;retting of flax;biological treatment of effluents
Bacterial treatment to reduce lignin content, essential for upgrading the raw eucalyptus kraft pulp was evaluated. Chemical parameters of solid fraction (filtered pulp) and liquid fraction that can be correlated with the extent of pulp refining (in terms of delignification) were investigated by the action of Pseudomonas fluorescens NITDPY and Planococcus sp.TRC1 individually. In solid fraction, spectroscopic investigation showed the progressive reduction in phenol, lignin, color with successive bacterial treatment. Titrimetric process exhibited decrease of 37% and 32% in kappa number by Planococcus sp.TRC1 and P. fluorescens NITDPY, respectively. Liquid fraction showed the continuous release of lignin and its derived hydrophobic, phenolic and chromophoric components of non-cellulosic constituents. The evident improvements in the morphological features of bacterial delignified pulp were elucidated by SEM, XRD and SEM-EDXA. The analyses indicated reasonably efficient and economical route for recalcitrant lignin reduction, intended in broad range of industrial applications.
Previous studies have shown that a lignin-degrading system appears in cultures of the white rot fungus Phanerochaete chrysosporium in response to nitrogen starvation, apparently as part of secondary metabolism. We examined the influence of limiting carbohydrate, sulfur, or phosphorus and the effect of varying the concentrations of four trace metals, Ca, and Mg. Limitation of carbohydrate or sulfur but not limitation of phosphorus triggered ligninolytic activity. When only carbohydrate was limiting, supplementary carbohydrate caused a transient repression of activity. In carbohydrate-limited cultures, ligninolytic activity appeared when the supplied carbohydrate was depleted, and this activity was associated with a decrease in mycelial dry weight. The amount of lignin degraded depended on the amount of carbohydrate provided, which determined the amount of mycelium produced during primary growth. Carbohydrate-limited cultures synthesized only small amounts of the secondary metabolite veratryl alcohol compared with nitrogen-limited cultures. l-Glutamate sharply repressed ligninolytic activity in carbohydrate-starved cultures, but NH(4) did not. Ligninolytic activity was also triggered in cultures supplied with 37 muM sulfur as the only limiting nutrient. The balance of trace metals, Mg, and Ca was important for lignin degradation.
The purpose of this work was to study the nature of the chlorinated, low-molecular-weight phenols in the E//1 effluent. Numerous chlorinated organics are produced during the bleaching of pulp with chlorine, These compounds are known to be hazards in the environment, and their discharge may be regulated in the future. A wastewater treatment system using a white-rot fungus is able to degrade these chlorinated compounds. Mechanisms for degradation include methylation, oxidation, and reduction.
Bleach plant effluent from the first alkali extraction stage after chlorination is decolorized by ligninolytic cultures of the white-rot fungus Phanerochaete chrysosporium. The chromophoric material, which is polymeric, was isolated before and after 80% decolorization. Comparisons of yields and properties showed that decolorization is the result of a combination of destruction of chromophores in the polymer and decomposition of the polymer to low-molecular-weight, colorless, soluble/volatile products. The degradation shows no preference for molecular size and results in partial dechlorination of the polymer.
Color in bleached kraft mill effluents (BKME) can represent an aesthetic and biological problem. Color is readily recognizable in receiving water levels; color reduces light transmission and, in some instances, primary productivity. Degradation of lignin and its colored derivatives in nature is slow. Bacteria and fungi were thought to be the principal organisms involved in ultimate destruction of lignin. This study suggests, however, that algae can also decolorize dilute BKME. Pure and mixed algal cultures reduced color of dilute BKME (50-150 APHA color units) by up to 50% within 20 days. Decolorization by algae is of significance in alleviating any effects of BKME on light transmission and primary productivity in colored receiving waters.
Bleach plant effluents from the first alkali extraction stage were decolorized with a white-rot fungus, Phanerochaete chyrososporium. The culture conditions favoring fungal growth were quite different from those favoring fungal decolorization, with the decolorization being less sensitive to variation in culture conditions. About 60% color reduction was achieved in 2-4 days with fungal decolorization. The fungal biomass could be recycled for at least 60 days. Addition of a co-substrate such as glucose or cellulose was necessary, while addition of a nitrogen source was not necessary. Sodium chloride at low concentrations did not retard fungal decolorization.
Ligninolytic fungi can decolorize the first alkali extraction stage (E//1) effluent from kraft chlorine bleach plants. Practical aspects of partial decolorization have been studied using Phanerochaete chrysosporium. Biological oxygen demand and chemical oxygen demand were reduced by about 40% during 60% color reduction. Although the low carbohydrate content of E//1 effluent prevented it from serving as the required carbon and energy source for the fungus, primary sludge from intergrated pulp and paper mills contained enough cellulose for this purpose. An E//1 effluent from a representative commercial mill (9440 NCASI units) was decolorized at a rate equivalent to 15 ml of E//1 effluent per g of mycelium (dry wt. ) per hr; this required 28 mg of cellulose per g of mycelium (dry wt. per hr.
Dechlorination of chlorolignin in pulp bleaching wastewater was studied using the white-rot fungus P. chrysosporium immobilized on a rotating biological contactor. The total organic chlorine content of chlorolignin decreased almost by 50% during one day of treatment. The corresponding amount of inorganic chloride was liberated into the solution. Correlation studies suggested that dechlorination, decolorization, and degradation of chlorolignin (as COD decrease) are metabolically connected, although these processes have different rates. Size exclusion chromatography showed that polymerization took place in the early stage of the treatment. Low-molecular weight degradation products were not observed.
The mutagenicity of the aqueous effluents from the bleaching of kraft pulp has been assayed by the Ames Salmonella/Microsome Mutagenicity Test. Confirming the results of Swedish investigators only the chlorination stage filtrate produced a significant response, but this decreased almost linearly with increasing substitution of chlorine dioxide for equivalent chlorine. The component of pulp mainly responsible for mutagenicity produced by chlorination is shown to be lignin. Methods of decreasing or eliminating the mutagenicity as well as variations in the bleaching process which may increase the mutagenicity are discussed. In particular raising the pH to 7-8, destroys much of the mutagenicity in a relatively short time.
Biological systems have been employed successfully for many years in the treatment of pulp and paper mill waste water. Previously, not very much was known about enzymes and their possibilities in pulp and paper industry wastewater treatment. There is currently a lot of research activity in the enzymology of lignin degradation. Ligninase, cellulase, peroxidase, etc. are the most important enzymes, especially peroxidase, which is used for color removal in bleaching effluents. It is also possible to mix enzymes together with special microbes, which normally do not have high enzyme activity, and remove recalcitrant and harmless compounds from wastewater. The use of novel enzymes and rDNA technology in sludge and wastewater treatment will also be discussed.
Biological reactors of the 'air lift' type using calcium alginate beads to immobilize the fungus Coriolus versicolor have been used to study the continuous decolorization of kraft mill effluent. The effluent used contained sucrose (50 mM) but no other nutrient source was added. A kinetic model is proposed to describe the decolorization process caused by this fungus.
Chemical constituents in effluent from the caustic extraction stage of the bleach plant at a western Canada kraft pulpmill were fractionated to identify factors responsible for their toxicity to juvenile rainbow trout (Salmo gairdneri). At all stages in the fractionation procedure bioassays were carried out to monitor toxicities of the isolated materials. Five toxic compounds, separated in a pure state from the effluent, were characterized by chromatography, spectroscopy, and chemical synthesis. The compounds and their 96 h median lethal concentrations (LC50) measured in static bioassays were : 3,4,5 trichloroguaiacol (0.75 mg/l), 3,4,5,6 tetrachloroguaiacol (0.32 mg/l), monochlorodehydroabietic acid (0.6 mg/l), dichlorodehydroabietic acid (0.6 mg/l), 9,10 epoxystearic acid (1.5 mg/l). The same compounds were shown to be present in caustic extraction effluents collected from six other western kraft mills. For two samples, the concentration toxicity graphs from bioassays of solutions containing only the pure toxicants in the amounts found by analysis were similar to those of the actual effluents produced by the mills. Concentrations of the toxic constituents in samples from six different mills were equivalent to 2.3 to 24 TU (toxic units), confirming that they are important factors in the toxicity of caustic extraction effluents.
Bleached kraft effluent (BKE) is highly coloured due to the presence of high molecular weight, chlorinated, oxidised lignin. The dimethyl formamide-soluble portion of BKE was radiolabelled by methoxylation with C-methyl iodide, and the resulting product (C14-BKE) was used to Investigate the mechanism of colour removal by fungi and bacteria. The white-rot fungi Coriolus versicolor and Pleurotus sajor-caju decolorised the solutions, and depolymerised the C14-BKE. Both fungi produced about 16Z CO2 from C14-BKE In 20 days. The three bacteria tested, Bacillus cereus and two strains of Pseudomonas aeruginosa, removed colour primarily by adsorption with little depolymerisation or mineralization. The adsorbed C14-BKE could be removed from bacterial cells by washing with 0.1 M NaOH.
Decolorization of the first alkaline extraction stage (E1) effluent from a pulp mill bleach effluent using the white-rot fungus Phanerochaete chrysosporium was conducted in a rotating biological contactor (RBC) under improved conditions. The kinetic model developed for both 1 d and 2 d retention times showed a characteristic pattern. The overall decolorization process can be divided into three distinct stages, viz., a rapid color reduction in the first hour of contact between the effluent and fungus, followed by a zero order reaction, and then a first order reaction. The color removal rate on the second day of the 2 d batch treatment was less than that on the first day. The decolorization in a continuous flow reactor achieved approximately the same daily color removal rate, but had a longer working lifetime as compared to the batch reactor, thereby removing more color over the fungal lifetime.
Summary Continuous decolorization of kraft black liquor by mycelial pellets ofCoriolus versicolor in the presence of glucose as co-substrate is discussed. A linear relationship was developed between the rate of decolorization and the liquor concentration. The rate constant was equal to 0.00961 gmyc-1 h-` at 22°C. During the continuous experiments the pellets exhibited no apparent loss of activity when the liquor concentration was in the range of 400 CU l-1 to 5000 CU l-1. However, in the repeated batch experiments a loss of activity was observed which was dependent on the initial liquor concentration. The half-life of pellets was equal to 4.7, 9.4 and 20.2 days for the initial liquor concentration of 1380, 31 780 and 6990 CU l-1, respectively. The production of the extracellular enzyme, laccase, was followed but could not be used as an indicator of the ligninolytic activity. The involvement of the intracellular enzymes ofC. versicolor in the decolorization process is described.
The white-rot fungus Coriolus versicolor, used in the form of mycelial pellets, provided an effective means to decolorise lignin-containing kraft E1-stage effluent from wood treatment processes. The mycelial pellets adsorbed the chromophores of the liquor and oxidised them in the presence of glucose. For an original liquor containing 7000 colour units (CU), the mean colour removal in batch experiments was estimated to be 300 CU g−1 mycelium h−1. The adsorption process and the oxidation process (following glucose addition) generally operated best at between pH 4 and 5, and at temperatures of 25 to 30°C, with a ratio of glucose to mycelium of 0.36, for a 24 h experiment. Magnesium ions accelerated the oxidation process. Decolorisation was then tested in a continuous reactor. The rate of loss of activity of the pellets was 1% per day and no mechanical damage to the pellets was observed in the reactor. With a liquor of 5600 CU a 50% decolorisation was attained in 15 to 30 h using 4.64 g dm−3 mycelium. This represents a rate of chromophore consumption of 30 CU g−1 mycelium h−1.
The effluent from bagasse-based pulp and paper mills can be decolorized with the white-rot fungus Schizophyllum commune. The influence of pH, nutrients and aeration on the decolorizing efficiency of this fungus has been determined. It was found that it could not degrade lignin unless a more easily metabolized carbon source was made available simultaneously. The addition of carbon and nitrogen not only improved the decolorizing efficiency of the fungus, but also resulted in reduction of the biological oxygen demand (BOD) and chemical oxygen demand (COD) of effluent. A 2-day incubation period was sufficient for lignin breakdown by S. commune. The efficiency of treatment of effluent with this fungus was highest at pH 4–5 and was further improved by intermittent aeration.
Pulp and paper mill effluent was decolorized by growth ofAspergillus niger. Adding glucose (2.0 g/l) and NH4H2PO4 (1.0 g/l) improved decolorization by the fungus (leaving 19% of original colour) and reduced the BOD5 (43%) and the COD (41%) of the effluent after 48 h of incubation.L'effluent d'un atelier de pte papier a t dcolor par la croissance d'Aspergillus niger. L'ajout de glucose (2.0 g/l) et de NH4H2PO4 (1.0 g/l) a amlior la dcoloration de l'effluent par la molsissure, lalssant 19% de la couleur originale, rduisant la DBO5 de 43% et la DCO de 41%, aprs 48 h d'incubation.
This study was undertaken to better understand the reactions related to fungal treatment of pulp bleaching effluents. Color, COD (chemical oxygen demand), glucose, chloride and ammonium concentration were monitored during the course of treatment of alkali extraction stage liquor (E1) with a white-rot fungus Phanerochaete chrysosporium.The color removal rate was independent on the initial glucose concentration. The earlier used glucose concentration of 10 g l−1 was found to be unnecessary high as the residual glucose accounted for about 50% of the final COD of the effluent. The lowest practical glucose concentration was 2 g l−1. Below this the fungus lost its decolorizing activity in a few days. The lignin-related COD decreased 32% and up to 16.5 mM inorganic chloride was liberated (being 34% increase from the original concentration) from the chlorinated organic material in the effluent in 2 d. The observed rapid depletion of added ammonium nitrogen is believed to indicate a switch of a part of the mycelium to primary growth which leads to higher activity and longer active period of time due to renewal of the cells.
Young rainbow trout (Salmo gairdneri) were exposed to lignosulphonates (LS) at concentrations of 0, 40, 80, 160, 320, 640, 1 280 and 1 920 ppm for 35 or 60 days. At concentrations of 160 ppm LS and higher the growth rates were slower. The higher concentrations had the most retarding effect on growth, but a clear general relationship between LS concentration and growth retardation was not observed.The bacterial flora in the digestive tract of the fish was examined. The predominant micro-organisms were flavobacteria, bacilli, streptococci and yeasts (Cryptococcus spp.), which were also isolated from the diet. There were about 10 000 viable aerobic and 1 000 anaerobic bacteria per gramme of intestinal contents. There was no significant difference in quantitative or qualitative composition of the intestinal flora of the different groups.The following groups of digestive enzymes were studied: proteinases, amylases, lipases and deoxyribonucleases. The activities of proteinases and nucleases were significantly impaired in fish exposed to concentrations of 1 280 ppm LS and higher, and those of amylases at concentrations of 320 ppm LS and higher. A possible connection between the reduced growth rates and depressed activities of the digestive enzymes is discussed, but no firm conclusion regarding the mechanism by which LS effects fish growth can be made on the basis of the present study.
The white rot basidiomycete Coriolus (Trametes) versicolor has been shown to decolorize the stable high-molecular-weight chromophores released by kraft mill bleacheries. This report looks at the fungal requirements for optimal growth and decolorization, and the mechanism of chromophore degradation. Simple carbohydrates were shown to be essential for effective decolorization, and a medium composed of inexpensive industrial by-products provided excellent growth and decolorization. The decolorization activity was entirely O2-dependent, but unaffected by scavengers of O-2, OH, and H2O2. Free extracellular H2O2 was not necessary for E1 effluent decolorization. Decolorization was also not measurably repressed or induced by a variety of factors reportedly regulating lignin peroxidase expression and secondary metabolism in both C. versicolor and the related fungus Phanerochaete chrysosporium. These included veratryl alcohol, H2O2, nitrogen and carbon limitation, culture age, and elevated trace metals. No extracellular peroxidases or hydrogen peroxide could be detected during decolorization, although substantial levels of laccase-type phenol oxidases were present. Thus, it appears that E1 effluent decolorization by C. versicolor proceeds via a mechanism not employing secreted H2O2 and peroxidase.
The screening of 11 strains of white rot fungi for their ability to decolorize E1 effluent from a kraft bleach plant showed that Trametes versicolor B7 was the most efficient. Over 80% of the colour of the effluent was removed within 3 days in the shake culture in the presence of glucose. The fungus was used in the form of pellets, allowing its use in large amounts and eliminating the problem of recycling the biomass. The mycelial pellets oxidized the chromophores of the effluent in the presence of any of the co-substrates, sucrose, glucose, starch, ethanol, carboxymethyl cellulose, microcrystalline cellulose, pulp and malt extract. The highest decolorization was obtained in the case of glucose. The optimum pH and temperature were found to be 4·5–5·5 and 30°C respectively. In the batch reactor with an effluent of 7000 colour units, the maximum colour reduction of 93% was obtained in 48 h with a chemical oxygen demand (COD) reduction of 35%. In the continuous reactor the same level of colour/COD reduction was obtained in a 38 h residence time. No loss in decolorization ability of mycelial pellets was obtained when the reactor was operated continuously for more than 30 days.
Ten natural freshwater samples differing widely in pH and other characteristics were collected and examined for their influence as dilution waters on the acute lethality (24-h LC50 values) of a sample of bleached kraft whole mill effluent. When bioassays were conducted at the pH of each dilution water, LC50 values varied by 3.5-fold. These differences were largely accounted for by adjustment of the pH of each test solution to a common value (6.5). The remaining minor differences in LC50 values were attributed to the ionizable inorganic constituents of the dilution waters.A separate study examined the effects of test pH and the involvement of aging of solutions prior to bioassays or of pH overshoots during pH adjustment on the toxicity of a second sample of pulp mill effluent: using a single dilution water. The LC50 values obtained for bioassays conducted at pH 9.5 were significantly higher than those for tests performed at pH 6.5. Neither the adjustment of test solutions to pH 9.5 with immediate readjustment to pH 6.5, nor the prior aging of solutions at pH 9.5 or 6.5 with minimal or no aeration for 6 h, altered the differences due to test pH.The pH-toxicity relationship of the resin acid dehydroabietate and a third sample of bleached kraft whole mill effluent was similar throughout the pH range 5.0–10.5, with test solutions least toxic at pH 9.0–9.5. This pH-toxicity relationship for pulpmill effluents and the influence of dilution water pH on effluent toxicity were attributed mainly to the ionization equilibria of the effluents' resin acid constituents.
The relationship between growth, nutrient nitrogen assimilation, and the appearance of ligninolytic activity was examined in stationary batch cultures of the wood-destroying hymenomycete Phanerochaete chrysosporium Burds. grown under conditions optimized for lignin metabolism. A reproducible sequence of events followed inoculation: 0 to 24 h, germination, linear growth, and depletion of nutrient nitrogen; 24 to 48 h, cessation of linear growth and derepression of ammonium permease activity (demonstrating nitrogen starvation); 72 to 96 h, appearance of ligninolytic activity (synthetic 14C-lignin leads to 14CO2). Experiments with cycloheximide demonstrated that appearance of ligninolytic activity occurs irrespective of the presence of lignin; lignin did not induce additional activity. Addition of NH4+ to cultures immediately prior to the time of appearance of the ligninolytic system delayed its appearance, suggesting that the NH4+ led to interference with synthesis of the enzyme system. Addition of NH4+ to ligninolytic cultures resulted in an eventual, temporary decrease in ligninolytic activity. The results suggest that all or essential protein components of the ligninolytic enzyme system are synthesized as part of a series of physiological ("secondary metabolic") events that are initiated by nutrient nitrogen starvation.
Decomposition of C-labeled lignin to CO(2) by the lignin-decomposing fungi Phanerochaete chrysosporium and Coriolus versicolor required a growth substrate such as cellulose or glucose. Growth with lignin as sole carbon addition to an otherwise complete medium was negligible.
Screening fifteen strains of white-rot fungi for their ability to decolorize combined bleached kraft effluent showed that Coriolus versicolor in liquid culture removed over 60% of the color of the effluent within six days in the presence of sucrose. Treatment of the same effluent with this fungus, immobilized in beads of calcium alginate gel, resulted in 80% decolorization after three days in the presence of sucrose. Caustic extraction E(1) effluent was also decolorized by the immobilized fungus. Decolorization was achieved more rapidly at pH 5.0 than at pH 7.0. Recycled beads could remove color efficiently and repeatedly in the presence of air but not under anaerobic conditions.
Isolation and identifi-cation of constituents toxic to juvenile rainbow trout on caustic extraction effluent Decolour-ization of bleached kraft mill effluents by algae
- J M Leach
- A N Thakore
- E G Lee
- J C Mueller
- C C Walden
Leach, J.M. and Thakore, A.N. (1975) Isolation and identifi-cation of constituents toxic to juvenile rainbow trout on caustic extraction effluent. J. Fish. Res. Bd., Canada 32, 1249. Lee, E.G., Mueller, J.C. and Walden, C.C. (1978) Decolour-ization of bleached kraft mill effluents by algae. Tappi 61(7), 59-62.
Microbial decolourization and defoaming of pulping waste liquors
- Fukuzumi
Fukuzumi, T. (1980) Microbial decolourization and defoaming of pulping waste liquors. In: Kirk, T.K. Chang H.M. and Higuchi, T. (Eds.), Lignin Biodegradation, Vol. 2, CRC Press, Boca Raton, FL., pp. 161-177.
Biodegradation of lignin sulphonates
- Kawakami
Kawakami, H. (1975) Biodegradation of lignin sulphonates. Wat. Res. Abs. 9 W76-05845.
Pollution of the river Kallada by the effluents of Punalur Paper Mills
- M K Nampoothery
- K M Sashidharan
- V A Nair
Nampoothery, M.K., Sashidharan, K.M., and Nair, V.A. (1976) Pollution of the river Kallada by the effluents of Punalur Paper Mills. Bull. of Dept. of Fisheries, Kerala 1, 51.
Colour removal from pulp and paper mill waste waters
- Sastry
Sastry, C.A. (1986) Colour removal from pulp and paper mill waste waters. Ind. J. Environ. Protect. 6(2), 105-113.
Lignins, Occurrence, Formation, Structure and Reactions
- Sankaran
Sankaran, K. and Vand Ludwig, C.H. (1971) Lignins, Occur-rence, Formation, Structure and Reactions. John Wiley and Sons Inc., New York, pp. 1-18.
Pollution of the river Kallada by the effluents of Punalur
- Nampoothery