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Lejri R, Ellafi A, Valero Tebar J, Chaieb M, Mekki A, Džunková M, Ben Younes S. Phenotypic characterization for bioremediation suitability of isolates from Southern Tunisian tannery effluent. Microbiol Res 2024; 285:127771. [PMID: 38788351 DOI: 10.1016/j.micres.2024.127771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/27/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024]
Abstract
Effluents from the leather tanning industry contain diverse pollutants, including hazardous heavy metals, posing threats to public health and the surrounding environment. Indigenous bacterial isolates can represent an eco-friendly approach for tannery wastewater treatment; however, phenotypic characterization is necessary to determine whether these strains are suitable for bioremediation. In the present study, we analyzed seven new Enterococcus faecium strains and two new Bacillus subtillis strains isolated from effluents from the Southern Tunisian Tannery (ESTT). We evaluated phenotypic features beneficial for bioremediation, including biofilm formation, hydrophobicity, and exoenzyme activities. Additionally, we examined characteristics naturally occurring in environmental bacteria but less desirable in strains selected for bioremediation, such as antibiotic resistances and pathogenicity indicators. The observed phenotypes were then compared with whole-genome analysis. We observed biofilm production in two slime-producing bacteria, B. licheniformis RLT6, and E. faecium RLT8. Hydrophobicity of E. faecium strains RLT1, RLT5, RLT8, and RLT9, as well as B. licheniformis RLT6 correlated positively with increasing ESTT concentration. Exoenzyme activities were detected in E. faecium strains RLT2, RLT4, and RLT7, as well as B. licheniformis RLT6. As anticipated, all strains exhibited common resistances to antibiotics and hemolysis, which are widespread in nature and do not hinder their application for bioremediation. Importantly, none of the strains exhibited the pathogenic hypermucoviscosity phenotype. To the best of our knowledge, this is the first report consolidating all these phenotypic characteristics concurrently, providing a complete overview of strains suitability for bioremediation. IMPORTANCE: The study evaluates the bioremediation potential of seven Enterococcus faecium strains and two Bacillus subtillis strains isolated from the effluents from the Southern Tunisian tannery (ESTT), which pose threats to public health and environmental integrity. The analysis primarily examines the phenotypic traits crucial to bioremediation, including biofilm formation, hydrophobicity, and exoenzyme activities, as well as characteristics naturally occurring in environmental bacteria related to heavy metal resistance, such as antibiotic resistances. Several strains were found to have high bioremediation potential and exhibit only antibiotic resistances commonly found in nature, ensuring their application for bioremediation remains uncompromised. The results of the exhaustive phenotypic analysis are contrasted with the whole genome sequences of the nine strains, underscoring the appropriateness of these bacterial strains for eco-friendly interventions in tannery wastewater treatment.
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Affiliation(s)
- Rokaia Lejri
- Faculty of Sciences of Gafsa, Gafsa University, Campus universitaire Sidi Ahmed Zarroug, Gafsa 2112, Tunisia; Laboratory of Plant Biodiversity and Dynamics of Ecosystems in Arid Environment, Faculty of Sciences of Sfax, Sfax University, Tunisia
| | - Ali Ellafi
- Faculty of Sciences of Gafsa, Gafsa University, Campus universitaire Sidi Ahmed Zarroug, Gafsa 2112, Tunisia; Laboratory of Analysis, treatment and valorization of environment pollutants and products, Faculty of Pharmacy, Monastir University, Tunisia
| | - Juan Valero Tebar
- Institute for Integrative Systems Biology, University of Valencia and Consejo Superior de Investigaciones Científicas (CSIC), Valencia 46980, Spain
| | - Mohamed Chaieb
- Laboratory of Plant Biodiversity and Dynamics of Ecosystems in Arid Environment, Faculty of Sciences of Sfax, Sfax University, Tunisia
| | - Ali Mekki
- Faculty of Sciences of Gafsa, Gafsa University, Campus universitaire Sidi Ahmed Zarroug, Gafsa 2112, Tunisia; Laboratory of Environmental Bioprocesses, Centre of Biotechnology of Sfax, Sfax, Tunisia
| | - Mária Džunková
- Institute for Integrative Systems Biology, University of Valencia and Consejo Superior de Investigaciones Científicas (CSIC), Valencia 46980, Spain.
| | - Sonia Ben Younes
- Faculty of Sciences of Gafsa, Gafsa University, Campus universitaire Sidi Ahmed Zarroug, Gafsa 2112, Tunisia; Laboratory of Population health, environmental aggressors and alternative therapies (LR24ES10), Faculty of Medicine of Tunis.
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Li S, Zhang Y, Liu M, Du Z, Li J, Gu L, Xu L, Liu F. Ascorbic acid reduction pretreatment enhancing metal regulation to improve methane production from anaerobic digestion of waste activated sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169185. [PMID: 38092219 DOI: 10.1016/j.scitotenv.2023.169185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/18/2023]
Abstract
Conversion of waste activated sludge (WAS) to methane by anaerobic digestion (AD) is often limited by the slow rate of hydrolysis, and the presence of metal ions in sludge is regarded as a critical factor hindering sludge hydrolysis. This study developed a novel strategy to remove Fe from WAS by using ascorbic acid (VC) as a reducing agent under acidic conditions. The feasibility of reduction pretreatment in improving methane production of AD and its intrinsic mechanism were investigated. Results indicate that, under VC doses of 100 mmol/L and pH of 3.50, pretreatment removed 47.60 % of Fe, 59.88 % of Ca, and 51.86 % of Mg contained in the sludge. The removal of metal ions facilitated the disruption of sludge flocculation structure and extracellular polymeric substance (EPS) layers, leading to a 14.78 % increase in cell lysis and a decrease in fractal dimension values to 2.08. Batch AD experiments showed that VC pretreatment improved methane production, with an optimized net methane yield of 190.22 mL/g·VS, an increase of 134.75 % compared to raw WAS. The pretreatment affected the interfacial interaction energy of the sludge, leading to a transformation in the sludge surfaces from hydrophilic to hydrophobic, reducing the interaction between sludge molecules and increasing the number of binding sites available for enzymatic reactions. According to a study of microbial communities, it was found that VC pretreatment caused an increase in the presence of essential functional microbes responsible for hydrolysis, acidification, and methanation. This increase in acetoclastic and hydrogenotrophic methanogens resulted in a substantial enhancement in methane production. These results can be used to develop better pretreatment methods to enhance AD performance.
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Affiliation(s)
- Siqi Li
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing 400045, PR China
| | - Yu Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing 400045, PR China
| | - Miao Liu
- Gastrointestinal Cancer Center, Chongqing University Cancer Hospital, 174 Shapingba Road, 400045, PR China
| | - Zexuan Du
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing 400045, PR China
| | - Jinze Li
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing 400045, PR China
| | - Li Gu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing 400045, PR China.
| | - Linji Xu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing 400045, PR China
| | - Feng Liu
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, PR China
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Huang H, Ekama G, Deng YF, Chen GH, Wu D. Identifying the mechanisms of sludge reduction in the sulfidogenic oxic-settling anaerobic (SOSA) process: Side-stream sulfidogenesis-intensified sludge decay and mainstream extended aeration. WATER RESEARCH 2021; 189:116608. [PMID: 33189974 DOI: 10.1016/j.watres.2020.116608] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 06/11/2023]
Abstract
An energy-/cost-efficient and environment-friendly in-situ sludge reduction process, called the sulfidogenic oxic-settling anaerobic (SOSA) was developed recently. However, the underpinning mechanism of sludge reduction by the SOSA process remains elusive. This paper investigated the possible mechanisms of sludge reduction through biomass cultivation in three lab-scale experimental systems: one anoxic-oxic CAS process with a long sludge retention time (SRT) and extended aeration (EAO) process, and two EAO-based in-situ sludge reduction processes, i.e., the conventional oxic-settling anaerobic (COSA) process and the new SOSA process. These three comparative biosystems were operated with identical influent and reactor configurations as well as the same biomass concentrations and SRTs (approximately 5 g/L and 46 days, respectively), and the sludge interchange ratios (between the CAS and side-stream reactors) in COSA and SOSA were both 10% per day. Three systems all achieved high organic (>93%) and total nitrogen (TN) (>74%) removal efficiencies. SOSA produced 29% and 20% less sludge than EAO and COSA, respectively, simultaneously consumed 14% and 8% more oxygen than EAO and COSA, indicating that the sludge reduction in SOSA was not only caused by EAO-based aerobic digestion in the mainstream and conventional anaerobic reactions in the side-stream, but more importantly due to the bioaugmentation of sulfidogenesis. The roles of sulfidogenesis were further studied in batch tests, and the key findings were as follows: i) the SOSA biomass had a faster endogenous decay rate (0.097 d-1) than that of the COSA biomass (0.045 d-1), and ii) sulfidogenesis accelerated anaerobic solubilization, hydrolysis, acidogenesis and acetogenesis by 2.3 - 3.1 times, 6 - 22 %, 22 - 60% and 6 - 22%, respectively. Overall, the mechanisms of sludge reduction in SOSA were unraveled in this study which will help promote its full-scale application in future.
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Affiliation(s)
- Hao Huang
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Wastewater Technology Lab, Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology, Guangdong, China
| | - George Ekama
- Water Research Group, Department of Civil Engineering, University of Cape Town, Cape Town, South Africa
| | - Yang-Fan Deng
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Wastewater Technology Lab, Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology, Guangdong, China
| | - Guang-Hao Chen
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Wastewater Technology Lab, Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology, Guangdong, China
| | - Di Wu
- Department of Civil and Environmental Engineering, Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution (Hong Kong Branch) and Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Wastewater Technology Lab, Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology, Guangdong, China.
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Liu W, Yang H, Ye J, Luo J, Li YY, Liu J. Short-chain fatty acids recovery from sewage sludge via acidogenic fermentation as a carbon source for denitrification: A review. BIORESOURCE TECHNOLOGY 2020; 311:123446. [PMID: 32402992 DOI: 10.1016/j.biortech.2020.123446] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/19/2020] [Accepted: 04/21/2020] [Indexed: 06/11/2023]
Abstract
Wastewater treatment plants face the problem of a shortage of carbon source for denitrification. Acidogenic fermentation is an effective method for recovering short-chain fatty acids (SCFAs) as a carbon source from sewage sludge. Herein, the most recent advances in SCFAs production from primary sludge and waste activated sludge are systematically summarised and discussed. New technologies and problems pertaining to the improvement in SCFAs availability in fermentation liquids, including removal of ammoniacal nitrogen and phosphate and extraction of SCFAs from fermentation liquids, are analysed and evaluated. Furthermore, studies on the use of recovered SCFAs as a carbon source for denitrification are reviewed. Based on the above summarisation and discussion, some conclusions as well as perspectives on future studies and practical applications are presented. In particular, the recovery of carbon source/bioenergy from sewage sludge must be optimised considering nutrient removal/recovery simultaneously.
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Affiliation(s)
- Wen Liu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Huan Yang
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Jiongjiong Ye
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Jinghuan Luo
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Yu-You Li
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Jianyong Liu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China.
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5
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Fang W, Zhang X, Zhang P, Wan J, Guo H, Ghasimi DSM, Morera XC, Zhang T. Overview of key operation factors and strategies for improving fermentative volatile fatty acid production and product regulation from sewage sludge. J Environ Sci (China) 2020; 87:93-111. [PMID: 31791521 DOI: 10.1016/j.jes.2019.05.027] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/28/2019] [Accepted: 05/28/2019] [Indexed: 06/10/2023]
Abstract
In recent years, volatile fatty acid (VFA) production through anaerobic fermentation of sewage sludge, instead of methane production, has been regarded as a high-value and promising roadmap for sludge stabilization and resource recovery. This review first presents the effects of some essential factors that influence VFA production and composition. In the second part, we present an extensive analysis of conventional pretreatment and co-fermentation strategies ultimately addressed to improving VFA production and composition. Also, the effectiveness of these approaches is summarized in terms of sludge degradation, hydrolysis rate, and VFA production and composition. According to published studies, it is concluded that some pretreatments such as alkaline and thermal pretreatment are the most effective ways to enhance VFA production from sewage sludge. The possible reasons for the improvement of VFA production by different methods are also discussed. Finally, this review also highlights several current technical challenges and opportunities in VFA production with spectrum control, and further related research is proposed.
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Affiliation(s)
- Wei Fang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. E-mail:
| | - Xuedong Zhang
- Department of Water Management, Section Sanitary Engineering, Delft University of Technology, PO Box 5048, 2600 GA Delft, the Netherlands
| | - Panyue Zhang
- School of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Jijun Wan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Hongxiao Guo
- Department of Water Management, Section Sanitary Engineering, Delft University of Technology, PO Box 5048, 2600 GA Delft, the Netherlands
| | - Dara S M Ghasimi
- Department of Civil Engineering, University of Kurdistan Hewlêr, Erbil, Kurdistan Region, Iraq
| | - Xavier Carol Morera
- Institut Quimíc de Sarrià, Universitat Ramon Llull, Via Augusta 390, E-08017 Barcelona, Spain
| | - Tao Zhang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. E-mail: .
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Yang H, Liu J, Hu P, Zou L, Li YY. Carbon source and phosphorus recovery from iron-enhanced primary sludge via anaerobic fermentation and sulfate reduction: Performance and future application. BIORESOURCE TECHNOLOGY 2019; 294:122174. [PMID: 31563737 DOI: 10.1016/j.biortech.2019.122174] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/14/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Anaerobic fermentation and sulfate reduction (AF-SR) was firstly used for recovery of carbon sources and phosphorus from Fe-enhanced primary sludge (Fe-sludge). With FeCl3 dosage of 30 mg Fe/L, 63.0% of the chemical oxygen demand (COD) and 97.3% of the phosphorus were concentrated from sewage into Fe-sludge. Batch anaerobic fermentation tests of Fe-sludge with and without sulfate addition (AF-SR and control) were performed. The results showed that volatile fatty acid concentrations of the control and AF-SR were 211.0 and 270.2 mg COD/g volatile suspended solids, respectively. Furthermore, 33.2% (control) and 56.2% (AF-SR) of the total phosphorus in Fe-sludge was released. The recovery performances of carbon source and phosphorus were calculated based on struvite precipitation. The available carbon source of the AF-SR system was 44.5% higher than that of the control. A novel integrated wastewater and sludge treatment process based on chemically enhanced primary sedimentation and AF-SR is proposed for future application.
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Affiliation(s)
- Huan Yang
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Jianyong Liu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China.
| | - Peishan Hu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Lianpei Zou
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai 200444, China
| | - Yu-You Li
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
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7
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Potential application of Bacillus pseudofirmus SVB1 extract in effluent treatment. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Karn SK, Kumar A. Sludge: next paradigm for enzyme extraction and energy generation. Prep Biochem Biotechnol 2019; 49:105-116. [DOI: 10.1080/10826068.2019.1566146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Santosh Kumar Karn
- Department of Biochemistry and Biotechnology, Sardar Bhagwan Singh University (Formerly, Sardar Bhagwan Singh Post Graduate Institute of Biomedical Science and Research) Balawala, Dehradun, Uttarakhand, India
| | - Awanish Kumar
- Department of Biotechnology, National Institute of Technology Raipur, Raipur, Chhattisgarh, India
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Ushani U, Kavitha S, Yukesh Kannah R, Gunasekaran M, Kumar G, Nguyen DD, Chang SW, Rajesh Banu J. Sodium thiosulphate induced immobilized bacterial disintegration of sludge: An energy efficient and cost effective platform for sludge management and biomethanation. BIORESOURCE TECHNOLOGY 2018; 260:273-282. [PMID: 29631177 DOI: 10.1016/j.biortech.2018.03.118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/24/2018] [Accepted: 03/27/2018] [Indexed: 06/08/2023]
Abstract
The present study aimed to gain better insights into profitable biomethanation through sodium thiosulphate induced immobilized protease secreting bacterial disintegration (STS-IPBD) of sludge. STS disperse the flocs at 0.08 g/g SS of dosage and assists the subsequent bacterial disintegration. Immobilization of bacteria increases the hydrolytic activity of cells towards effective liquefaction of sludge. A higher liquefaction of 22% was accomplished for STS-IPBD when compared to immobilized protease secreting bacterial disintegration (IPBD alone). The kinetic parameters of Line Weaver Burk plot analysis revealed a maximal specific growth rate (µmax) of 0.320 h-1 for immobilized cells when compared to suspended free cells showing the benefit of immobilization. Floc dispersion and immobilization of bacteria imparts a major role in biomethanation as the methane generation (0.32 gCOD/g COD) was higher in STS-IPBD sample. The cost analysis showed that STS - IPBD was a feasible process with net profit of 2.6 USD/Ton of sludge.
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Affiliation(s)
- U Ushani
- Department of Biotechnology, Karpagam Academy of Higher Education (KAHE), Pollache Main Road, Eachanari Post, Coimbatore, India
| | - S Kavitha
- Department of Civil Engineering, Regional Campus, Anna University, Tirunelveli, India
| | - R Yukesh Kannah
- Department of Civil Engineering, Regional Campus, Anna University, Tirunelveli, India
| | - M Gunasekaran
- Department of Physics, Regional Campus, Anna University, Tirunelveli, India
| | - Gopalakrishnan Kumar
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Dinh Duc Nguyen
- Department of Environmental Energy Engineering, Kyonggi University, Suwon, Republic of Korea
| | - Soon Woong Chang
- Department of Environmental Energy Engineering, Kyonggi University, Suwon, Republic of Korea
| | - J Rajesh Banu
- Department of Civil Engineering, Regional Campus, Anna University, Tirunelveli, India.
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Le C, Kunacheva C, Stuckey DC. "Protein" Measurement in Biological Wastewater Treatment Systems: A Critical Evaluation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:3074-3081. [PMID: 26893149 DOI: 10.1021/acs.est.5b05261] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Five commercially available assay kits were tested on the same protein sample with the addition of 17 different types of interfering substances typically found in the biological wastewater treatment, and a comparison of the use of these assays with 22 different protein and peptide samples is also presented. It was shown that a wide variety of substances can interfere dramatically with these assays; the metachromatic response was also clearly influenced by different proteinaceous material. Measurement of the "protein" content in the effluent of an anaerobic membrane bioreactor was then carried out using these assay methods. Quantitative results of the "protein" concentration in the different effluent samples, with or without spiked additions of Bovine Serum Albumin (BSA), showed considerable disagreement. We concluded that the "protein" measured in wastewater samples using standard colorimetric assays often shows false positive results and has little correlation to their real value. A new analytical method needs to be developed in order to gain greater insight into the biological transformations occurring in anaerobic digestion, and how soluble microbial products (SMPs) are produced.
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Affiliation(s)
- Chencheng Le
- Advanced Environmental Biotechnology Center, Nanyang Environment & Water Research Institute, Nanyang Technological University , 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
- Division of Environmental and Water Resources Engineering, School of Civil and Environmental Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Chinagarn Kunacheva
- Advanced Environmental Biotechnology Center, Nanyang Environment & Water Research Institute, Nanyang Technological University , 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
| | - David C Stuckey
- Advanced Environmental Biotechnology Center, Nanyang Environment & Water Research Institute, Nanyang Technological University , 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
- Department of Chemical Engineering, Imperial College London, SW7 2AZ, U.K
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11
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Karn SK, Kumar A. Hydrolytic enzyme protease in sludge: Recovery and its application. BIOTECHNOL BIOPROC E 2015. [DOI: 10.1007/s12257-015-0161-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Oz NA, Yarimtepe CC. Ultrasound assisted biogas production from landfill leachate. WASTE MANAGEMENT (NEW YORK, N.Y.) 2014; 34:1165-70. [PMID: 24709441 DOI: 10.1016/j.wasman.2014.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 03/03/2014] [Accepted: 03/05/2014] [Indexed: 05/16/2023]
Abstract
The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions for solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman's test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p<0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann-Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p<0.05) in anaerobic batch reactors. The overall results showed that low frequency ultrasound pretreatment can be potentially used for wastewater management especially with integration of anaerobic processes.
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Affiliation(s)
- Nilgün Ayman Oz
- Çanakkale Onsekiz Mart University, Department of Environmental Engineering, Çanakkale 17100, Turkey.
| | - Canan Can Yarimtepe
- Çanakkale Onsekiz Mart University, Department of Environmental Engineering, Çanakkale 17100, Turkey
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Luo K, Yang Q, Li XM, Chen HB, Liu X, Yang GJ, Zeng GM. Novel insights into enzymatic-enhanced anaerobic digestion of waste activated sludge by three-dimensional excitation and emission matrix fluorescence spectroscopy. CHEMOSPHERE 2013; 91:579-585. [PMID: 23266409 DOI: 10.1016/j.chemosphere.2012.12.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 12/01/2012] [Accepted: 12/05/2012] [Indexed: 06/01/2023]
Abstract
In our previous study, it has been proposed that the hydrolysis of waste activated sludge (WAS) can be enhanced by hydrolytic enzymes. In this study, fluorescence spectral characteristics of extracellular polymeric substances (EPSs) and dissolved organic matter (DOM) during anaerobic digestion were investigated using three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy to explore the destruction mechanisms of WAS enhanced by additional enzymes (protease, α-amylase and the mixture). Two individual fluorescence peaks associated with protein-like fluorophores (aromatic and tryptophan protein-like substances) were identified in the EEM fluorescence spectra of the EPS after 1 and 6d, and only aromatic protein-like substances were observed after 12d of anaerobic digestion for all treatments. As for the DOM, three individual fluorescence peaks were identified, but the peaks associated with visible humic acid-like fluorophores disappeared after 12d. The EEM fluorescence intensity of EPS decreased during the entire anaerobic process, whereas that of the DOM increased at 1d and then decreased till the end. In the EPS, the residual protein-like substances were found to be the lowest during the entire anaerobic process when treated with protease. Correspondingly, the protein-like substances in the DOM increased rapidly from 1 to 6d, and decreased to the lowest level after 12d for the protease treatment.
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Affiliation(s)
- Kun Luo
- College of Environmental Science and Engineering, Hunan University, Changsha, PR China
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14
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Tang Y, Yang YL, Li XM, Yang Q, Wang DB, Zeng GM. The isolation, identification of sludge-lysing thermophilic bacteria and its utilization in solubilization for excess sludge. ENVIRONMENTAL TECHNOLOGY 2012; 33:961-966. [PMID: 22720421 DOI: 10.1080/09593330.2011.603754] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A novel strain of thermophilic bacteria with a highly efficient sludge dissolution performance was isolated from garden soil at 65 degrees C in this study. The colony morphology, physiological and biochemical characteristics of the strain were investigated. The results showed that the strain was Gram-positive, small rod-shaped, sporulating and secreted extracellular enzymes (protease and amylase). The 16S rDNA analysis demonstrated that this strain had not been previously reported. Therefore, it was labelled Bacillus thermophilic bacteria AT07-1 (registration number: FJ231108). To evaluate its capability for excess sludge solubilization, a pure culture of the strain was used in sludge solubilization tests; an enhanced solubilization process was subsequently obtained. After 36 h digestion, the protease activity in the inoculated system reached 0.37 U/ml, an increase of 0.16 U/ml compared with the non-inoculated system (0.21 U/ml). The solubilization rate for volatile suspended solids reached 46.45% in 48 h after inoculation with Bacillus thermophilic bacteria AT07-1, which was 10.24% higher than the non-inoculated system, and which could meet the standard of sludge stability suggested by the US Environmental Protection Agency.
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Affiliation(s)
- Ying Tang
- College of Environmental Science and Engineering, Hunan University, Changsha P.R. China
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15
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Lin Y, Wang D, Li Q, Xiao M. Mesophilic batch anaerobic co-digestion of pulp and paper sludge and monosodium glutamate waste liquor for methane production in a bench-scale digester. BIORESOURCE TECHNOLOGY 2011; 102:3673-3678. [PMID: 21183338 DOI: 10.1016/j.biortech.2010.10.114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 10/21/2010] [Accepted: 10/21/2010] [Indexed: 05/30/2023]
Abstract
This paper presented results from anaerobic co-digestion of pulp and paper sludge (PPS) and monosodium glutamate waste liquor (MGWL). A bench-scale anaerobic digester, 10 L in volume was developed, to operate under mesophilic (37 ± 2°C) batch condition. Under versatile and reliable anaerobic conduct, high efficiency for bioconversion of PPS and MGWL were obtained in the system. The accumulative methane yield attained to 200 mL g(-1) VS(added) and the peak value of methane daily production was 0.5m(3)/(m(3)d). No inhibitions of volatile fatty acids (VFAs) and ammonia on anaerobic co-digestion were found. pH 6.0-8.0 and alkalinity 1000-4000 mg CaCO(3)/L were got without adjustment. This work showed that there was a good potential to the use of PPS and MGWL to anaerobic co-digestion for methane production.
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Affiliation(s)
- Yunqin Lin
- College of Natural Resources and Environment, South China Agricultural University, Guangdong, Guangzhou 510642, China
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16
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Lin Yunqin, Wang Dehan, Wang Lishang. Biological pretreatment enhances biogas production in the anaerobic digestion of pulp and paper sludge. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2010; 28:800-810. [PMID: 20147578 DOI: 10.1177/0734242x09358734] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
High efficient resource recovery from pulp and paper sludge (PPS) has been the focus of attention. The objective of this research was to develop a bio-pretreatment process prior to anaerobic digestion of PPS to improve the methane productivity. Active and inactive mushroom compost extracts (MCE) were used for pretreating PPS, followed by anaerobic digestion with monosodium glutamate waste liquor (MGWL). Laboratory-scale experiments were carried out in completely mixed bioreactors, 1-L capacity with 700 ml useful capacity. Optimal amount of active MCE for organics' solubilization in the step of pretreatment was 250 A.U./gVS( sludge). Under this condition, the PPS floc structure was well disrupted, resulting in void rate and fibre size diminishment after pretreatment. In addition, SCOD and VS removal were found to be 56% and 43.6%, respectively, after anaerobic digestion, being the peak value of VFA concentration determined as 1198 mg acetic acid L(-1). The anaerobic digestion efficiency of PPS with and without pretreatment was evaluated. The highest methane yield under optimal pretreatment conditions was 0.23 m(3) CH4/kgVS(add), being 134.2% of the control. The results indicated that MCE bio-pretreatment could be a cost-effective and environmentally sound method for producing methane from PPS.
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Affiliation(s)
- Lin Yunqin
- College of Natural Resources and Environment, South China Agricultural University, Guangdong Guangzhou, China,
| | - Wang Dehan
- College of Natural Resources and Environment, South China Agricultural University, Guangdong Guangzhou, China
| | - Wang Lishang
- College of Natural Resources and Environment, South China Agricultural University, Guangdong Guangzhou, China
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17
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Recktenwald M, Wawrzynczyk J, Dey ES, Norrlöw O. Enhanced efficiency of industrial-scale anaerobic digestion by the addition of glycosidic enzymes. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2008; 43:1536-1540. [PMID: 18821240 DOI: 10.1080/10934520802293693] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The results of the action of two glycosidic enzymes added to an anaerobic digester processing mixed wastewater sludge are reported in this paper. The experiment was performed at a continuously operating full-scale wastewater treatment plant during a 6-month period. The addition of the enzyme mixture resulted in improved gas production and dewatering properties. Dewatering experiments, both on enzyme-treated and reference sludge on the local centrifuges, indicated that the carbonaceous matter was decreased by 7% in enzyme-treated sludge, and the average dry solids increased from 27% (reference) to 31% in enzyme-treated sludge. The polymer dosage was decreased from 8 to 5 kg/t dry solids. Additionally, practical experiences were gathered concerning the transformation from static laboratory-scale batch experiments to a dynamic continuous industrial scale setup. Preliminary cost calculations showed beneficial aspects and economical feasibility of enzyme addition to an anaerobic sludge digestion process.
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18
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Ayol A, Filibeli A, Sir D, Kuzyaka E. Aerobic and anaerobic bioprocessing of activated sludge: floc disintegration by enzymes. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2008; 43:1528-1535. [PMID: 18821239 DOI: 10.1080/10934520802293685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Hydrolytic enzymes such as glucosidases, lipases, and proteases have an imperative function at the hydrolysis stage of complex organic structures in the degradation of biodegradable particulate organic matter. As a key factor, extracellular polymeric substances (EPS) control the extracellular hydrolytic enzymes in this degradation mechanism. A flocculated matrix of EPS bridging with bacteria holds back the dewaterability properties of the bioprocessed sludges. Disruption of the flocculated matrix leads to improved solubilization of sludge solids by attacking the hydrolytic enzymes to polymeric substances forming enzyme-substrate complexes. To determine the floc disintegration mechanisms by enzymes during aerobic and anaerobic bioprocessing of sludges, experimental data obtained from three aerobic digesters and three anaerobic digesters were evaluated. As part of a broader project examining the overall fate and effects of hydrolytic enzymes in biological sludge stabilization, this paper compares the performances of aerobic and anaerobic reactors used in this study and reports significant improvements in enzymatic treatment of activated sludge.
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Affiliation(s)
- Azize Ayol
- Department of Environmental Engineering, Tinaztepe Campus, Dokuz Eylul University, Buca, Izmir, Turkey.
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Ras M, Girbal-Neuhauser E, Paul E, Spérandio M, Lefebvre D. Protein extraction from activated sludge: an analytical approach. WATER RESEARCH 2008; 42:1867-1878. [PMID: 18067947 DOI: 10.1016/j.watres.2007.11.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 11/12/2007] [Accepted: 11/13/2007] [Indexed: 05/25/2023]
Abstract
To investigate the efficiency of different methods on exopolymeric substance (EPS) extraction, mechanical and chemical treatments were applied on two activated sludges, regarding the yield of protein extraction as well as their compatibility with usual quantification methods. Mechanical disruption methods do not drastically affect protein measurements by both bicinchoninic acid (BCA) and modified Lowry methods. Chemical compounds such as cationic exchange resin and triton show high interference with modified Lowry method while the protein quantification by BCA method is not affected. In addition, inner sludge compounds were shown to interfere with both methods: BCA and modified Lowry measurement respectively overestimate and underestimate protein content. According to these data, BCA method was chosen in this study as the most appropriate protein quantification method in sludge extracts. Comparison of various extraction protocols, combining mechanical and/or chemical treatments, shows that efficiency can be increased by repeating the same method or by applying a prior mechanical treatment. Proteins are preferably extracted by triton treatments, indicating the importance of hydrophobic interactions linking proteins to the EPS matrix. The amount of extracted proteins reaches 182 and 148 mg eq.BSA g(-1)VSS using triton/triton and ultraturax/triton extractions, respectively. Protease activity/extracted protein ratios vary widely depending on extraction protocols. Protease seemed to be preferably extracted by ultrasound and triton treatments (150-220 U mg(-1)protein). This study underlines that the choice of a relevant coupled quantification/extraction method is of great importance for efficient EPS determination.
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Affiliation(s)
- M Ras
- LBAE, Laboratoire de Biologie Appliquée à l'Agro-Alimentaire et à l'Environnement, Institut Universitaire de Technologie, Université Toulouse III, Auch, France
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Wawrzynczyk J, Recktenwald M, Norrlöw O, Dey ES. The function of cation-binding agents in the enzymatic treatment of municipal sludge. WATER RESEARCH 2008; 42:1555-1562. [PMID: 18054984 DOI: 10.1016/j.watres.2007.11.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Revised: 10/12/2007] [Accepted: 11/06/2007] [Indexed: 05/25/2023]
Abstract
Treatment of sludge with enzymes has previously been shown to efficiently release organic matter. However, the added enzymes were partially adsorbed to, entrapped by or bound to the sludge structure. Simultaneous decrease of enzymes activities was observed. Reduced adsorption and more effective, lower, enzyme dose was achieved in sludge pre-treated with three cation-binding agents. The enzymatic solubilisation of sludge was improved by 150%, 240% and 290%, by 50mM sodium tripolyphosphate (STPP), 25mM citric acid (CA) or 50mM ethylenediaminetetraacetate (EDTA), respectively. With cation binders, the lower relative enzyme dose 0.2 (13.7mg/g total solids (TS)) released 3.5 times higher COD than enzyme dose 1 (68.5mg/g TS) alone. In the presence of 25mM CA, 75% added protease remained soluble. In the presence of 50mM CA, EDTA or STPP, 50% of alpha-amylase and cellulase remained soluble. At 200mM STPP, alpha-amylase was inactive, and the efficiency of enzymatic sludge hydrolysis decreased. CA was the most effective of the three cation-binding agents tested. It is biodegradable and can be produced endogenously by the microorganisms in sludge. CA has the greatest potential for the practical application to enhance biogas production. This paper reports on the possible mechanisms of enzymes adsorption to the sludge matrix and possible methods of decreasing the adsorption. We suggest that steric hindrances were responsible for the decreased enzymatic sludge solubilisation and that polyvalent metal ions were directly involved in adsorption of enzymes to sludge matrix. The addition of cation binders eliminated both phenomena and thereby improved the enzymatic solubilisation of sludge.
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21
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Identification of rheological parameters describing the physico-chemical properties of anaerobic sulphidogenic sludge suspensions. Enzyme Microb Technol 2007. [DOI: 10.1016/j.enzmictec.2006.05.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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22
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Watson SD, Pletschke BI. The effect of sulfide on alpha-glucosidases: implications for starch degradation in anaerobic bioreactors. CHEMOSPHERE 2006; 65:159-64. [PMID: 16624372 DOI: 10.1016/j.chemosphere.2006.03.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Revised: 03/08/2006] [Accepted: 03/08/2006] [Indexed: 05/08/2023]
Abstract
Membrane associated alpha-glucosidase activity was investigated in a methanogenic bioreactor (MR) and a biosulfidogenic bioreactor (SR). Temperature and pH optima studies showed temperature optima of 50 degrees C and pH optima of 8.0 for the alpha-glucosidases from both the MR and SR. Sulfide (at a concentration of 150 mg l(-1)) resulted in the complete loss of all alpha-glucosidase activity in both the MR and SR. beta-Glucosidase activities in our bioreactors were previously shown to be stimulated in the presence of sulfide. alpha-Glucosidases, in contrast, are inhibited by sulfide. This differential effect of sulfide on alpha-glucosidase and beta-glucosidase activities is highlighted and is of crucial consequence to the respective degradation and utilization of starch and cellulose substrates in natural anaerobic environments and anaerobic bioreactors specifically designed for the accelerated digestion of wastewater sludge under biosulfidogenic conditions.
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Affiliation(s)
- S D Watson
- Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown 6140, South Africa
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23
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Li Y, Chróst RJ. Microbial enzymatic activities in aerobic activated sludge model reactors. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2005.10.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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25
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Virkutyte J, van Hullebusch E, Sillanpää M, Lens P. Copper and trace element fractionation in electrokinetically treated methanogenic anaerobic granular sludge. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2005; 138:517-28. [PMID: 15990208 DOI: 10.1016/j.envpol.2005.04.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Accepted: 04/08/2005] [Indexed: 05/03/2023]
Abstract
The effect of electrokinetic treatment (0.15 mA cm(-2)) on the metal fractionation in anaerobic granular sludge artificially contaminated with copper (initial copper concentration 1000 mg kg(-1) wet sludge) was studied. Acidification of the sludge (final pH 4.2 in the sludge bed) with the intention to desorb the copper species bound to the organic/sulfides and residual fractions did not result in an increased mobility, despite the fact that a higher quantity of copper was measured in the more mobile (i.e. exchangeable/carbonate) fractions at final pH 4.2 compared to circum-neutral pH conditions. Also addition of the chelating agent EDTA (Cu2+:EDTA4- ratio 1.2:1) did not enhance the mobility of copper from the organic/sulfides and residual fractions, despite the fact that it induced a reduction of the total copper content of the sludge. The presence of sulfide precipitates likely influences the copper mobilisation from these less mobile fractions, and thus makes EDTA addition ineffective to solubilise copper from the granules.
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Affiliation(s)
- Jurate Virkutyte
- Subdepartment of Environmental Technology, University of Wageningen, Biotechnion-Bomenweg 2, PO Box 8129, 6700 EV Wageningen, The Netherlands
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