Biological treatment remains one of the most eco-friendly and cost-effective techniques to eliminate pollutants from wastewater in spite of the development of other technologies such as chemical treatment methods and advanced oxidation processes. This paper discusses briefly the main features and recent advances of wastewater treatment (WT). Some future trends are also viewed. Membrane Bioreactor (MBR), Moving Bed Bioreactor (MBBR), and Fixed Bed Bioreactors (FBBR) are largely employed techniques in WT particularly for industrial uses with an elevated biochemical oxygen demand charge like food and beverages, dairy, chemical, leachate and others. Integrations of minutely anaerobic and aerobic methods importantly improved the elimination of specific and non-specific in vitro toxicities. Therefore, optimizing biological WT may conduct to a considerably ameliorated detoxification. Surplus sludge treatment and disposal are regarded as an increasing defy for wastewater treatment plants (WTTPs) because of economic, environmental and regulatory elements. There is thus a fundamental need in expanding procedures for decreasing sludge generation in biological WT processes. Great attention for minimizing sludge formation occurs following procedures founded on mechanisms of lysis-cryptic growth, uncoupling metabolism, maintenance metabolism, and bacterivorous predation. On the other hand, heavy metals presence in wastewater still constitute a handicap for large acceptance of this technology based on cultivating bacteria for organic matter removal.
Published in | Applied Engineering (Volume 3, Issue 1) |
DOI | 10.11648/j.ae.20190301.16 |
Page(s) | 46-55 |
Creative Commons |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited. |
Copyright |
Copyright © The Author(s), 2019. Published by Science Publishing Group |
Wastewater Treatment (WT), Biological Process, Biofilm Bacteria, Microorganisms, Wastewater Treatment Plants (WTTPs)
[1] | D. Ghernaout, Environmental principles in the Holy Koran and the Sayings of the Prophet Muhammad, Am. J. Environ. Prot. 6 (2017) 75-79. |
[2] | Y. Liu, H. H. Ngo, W. Guo, L. Peng, D. Wang, B. Ni, The roles of free ammonia (FA) in biological wastewater treatment processes: A review, Environ. Internat. 123 (2019) 10-19. |
[3] | S. Castronovo, A. Wick, M. Scheurer, K. Nödler, M. Schulz, T. A. Ternes, Biodegradation of the artificial sweetener acesulfame in biological wastewater treatment and sandfilters, Water Research 110 (2017) 342-353. |
[4] | D. Ghernaout, Water reuse (WR): The ultimate and vital solution for water supply issues, Intern. J. Sustain. Develop. Res. 3 (2017) 36-46. |
[5] | D. Ghernaout, Increasing trends towards drinking water reclamation from treated wastewater, World J. Appl. Chem. 3 (2018) 1-9. |
[6] | M. L. Davis, Water and wastewater engineering: Design principles and practice, The McGraw-Hill Companies, Inc., 2010, New York. |
[7] | W. Wei, Q. Wang, L. Zhang, A. Laloo, H. Duan, D. J. Batstone, Z. Yuan, Z., Free nitrous acid pre-treatment of waste activated sludge enhances volatile solids destruction and improves sludge dewaterability in continuous anaerobic digestion, Water Res. 130 (2018) 13-19. |
[8] | D. Ghernaout, Y. Alshammari, A. Alghamdi, Improving energetically operational procedures in wastewater treatment plants, Int. J. Adv. Appl. Sci. 5 (2018) 64-72. |
[9] | K.-U. Schmitz, MBR, MBBR and FBBR – Comparison of wastewater treatment technologies (Part 1). https://waterfaq.blog/2019/04/10/mbr-mbbr-and-fbbr-comparison-of-wastewater-treatment-technologies-part-1/ (Accessed on 27/04/19). |
[10] | A. Suresh, E. Grygolowicz-Pawlak, S. Pathak, L. S. Poh, M. bin Abdul Majid, D. Dominiak, T. Vistisen Bugge, X. Gao, W. J. Ng, Understanding and optimization of the flocculation process in biological wastewater treatment processes: A review, Chemosphere 210 (2018) 401-416. |
[11] | B. Ghernaout, D. Ghernaout, A. Saiba, Algae and cyanotoxins removal by coagulation/flocculation: A review, Desalin. Water Treat. 20 (2010) 133-143. |
[12] | D. Ghernaout, B. Ghernaout, Sweep flocculation as a second form of charge neutralisation – A review, Desalin. Water Treat. 44 (2012) 15-28. |
[13] | D. Ghernaout, The hydrophilic/hydrophobic ratio vs. dissolved organics removal by coagulation - A review, J. King Saud Univ. – Sci. 26 (2014) 169-180. |
[14] | D. Ghernaout, S. Moulay, N. Ait Messaoudene, M. Aichouni, M. W. Naceur, A. Boucherit, Coagulation and chlorination of NOM and algae in water treatment: A review, Intern. J. Environ. Monit. Analy. 2 (2014) 23-34. |
[15] | D. Ghernaout, A. I. Al-Ghonamy, A. Boucherit, B. Ghernaout, M. W. Naceur, N. Ait Messaoudene, M. Aichouni, A. A. Mahjoubi, N. A. Elboughdiri, Brownian motion and coagulation process, Am. J. Environ. Prot. 4 (2015) 1-15. |
[16] | D. Ghernaout, A. I. Al-Ghonamy, M. W. Naceur, A. Boucherit, N. A. Messaoudene, M. Aichouni, A. A. Mahjoubi, N. A. Elboughdiri, Controlling coagulation process: From Zeta potential to streaming potential, Am. J. Environ. Prot. 4 (2015) 16-27. |
[17] | D. Ghernaout, A. Boucherit, Review of coagulation’s rapid mixing for NOM removal, J. Res. Develop. Chem., 2015, DOI: 10.5171/2015.926518. |
[18] | D. Ghernaout, A. Badis, G. Braikia, N. Matâam, M. Fekhar, B. Ghernaout, A. Boucherit, Enhanced coagulation for algae removal in a typical Algeria water treatment plant, Environ. Eng. Manag. J. 16 (2017) 2303-2315. |
[19] | Q. Chai, B. Furenes, B. Lie, Comparison of state estimation techniques, applied to a biological wastewater treatment process, 10th International IFAC Symposium on Computer Applications in Biotechnology, Proceedings Vol. 1, June 4-6, 2007, Cancún, Mexico. |
[20] | D. Ghernaout, A. El-Wakil, Requiring reverse osmosis membranes modifications – An overview, Am. J. Chem. Eng. 5 (2017) 81-88. |
[21] | D. Ghernaout, A. El-Wakil, A. Alghamdi, N. Elboughdiri, A. Mahjoubi, Membrane post-synthesis modifications and how it came about, Intern. J. Adv. Appl. Sci. 5 (2018) 60-64. |
[22] | M. Zhang, J. Gu, Y. Liu, Engineering feasibility, economic viability and environmental sustainability of energy recovery from nitrous oxide in biological wastewater treatment plant, Bioresour. Technol. 282 (2019) 514-519. |
[23] | M. L. Christensen, K. Keiding, P. H. Nielsen, M. K. Jørgensen, Dewatering in biological wastewater treatment: A review, Water Res. 82 (2015) 14-24. |
[24] | M. Sadeghassadi, C. J. B. Macnab, B. Gopaluni, D. Westwick, Application of neural networks for optimal-setpoint design and MPC control in biological wastewater treatment, Comput. Chem. Eng. 115 (2018) 150-160. |
[25] | Z.-H. Li, Z.-Y. Hang, M. Lu, T.-Y. Zhang, H.-Q. Yu, Difference of respiration-based approaches for quantifying heterotrophic biomass in activated sludge of biological wastewater treatment plants, Sci. Total Environ. 664 (2019) 45-52. |
[26] | X.-N. Song, Y.-Y. Cheng, W.-W. Li, B.-B. Li, G.-P. Sheng, C.-Y. Fang, Y.-K. Wang, X.-Y. Li, H.-Q. Yu, Quorum quenching is responsible for the underestimated quorum sensing effects in biological wastewater treatment reactors, Bioresour. Technol. 171 (2014) 472-476. |
[27] | X. Zhang, Z. Hu, J. Zhang, J. Fan, H. H. Ngo, W. Guo, C. Zeng, Y. Wu, S. Wang, A novel aerated surface flow constructed wetland using exhaust gas from biological wastewater treatment: Performance and mechanisms, Bioresour. Technol. 250 (2018) 94-101. |
[28] | Y. Xiao, C. De Araujo, C. C. Sze, D. C Stuckey, Toxicity measurement in biological wastewater treatment processes: A review, J. Hazard. Mater. 286 (2015) 15-29. |
[29] | X. Chi, A. Li, M. Li, L. Ma, Y. Tang, B. Hu, J. Yang, Influent characteristics affect biodiesel production from waste sludge in biological wastewater treatment systems, Int. Biodeterior. Biodegradation 132 (2018) 226-235. |
[30] | M. Mulas, R. Baratti, S. Skogestad, Controlled variables selection for a biological wastewater treatment process, 8th International IFAC Symposium on Dynamics and Control of Process Systems, Proceedings Vol. 2, June 4-6, 2007, Cancún, Mexico. |
[31] | K.-U. Schmitz, MBR, MBBR and FBBR (Part 2) – Comparison of wastewater treatment technologies. https://waterfaq.blog/2019/04/22/mbr-mbbr-and-fbbr-part-2-comparison-of-wastewater-treatment-technologies/ (Accessed on 27/04/19). |
[32] | K. S. Jewell, S. Castronovo, A. Wick, P. Falås, A. Joss, T. A. Ternes, New insights into the transformation of trimethoprim during biological wastewater treatment, Water Research 88 (2016) 550-557. |
[33] | K.-U. Schmitz, BOD – The water quality indicator. https://waterfaq.blog/2019/03/19/bod-the-water-quality-indicator/ (Accessed on 27/04/19). |
[34] | N. R. Maddela, B. Sheng, S. Yuan, Z. Zhou, R. Villamar-Torres, F. Meng, Roles of quorum sensing in biological wastewater treatment: A critical review, Chemosphere 221 (2019) 616-629. |
[35] | I. Santín, M. Barbu, C. Pedret, R. Vilanova, Fuzzy logic for plant-wide control of biological wastewater treatment process including greenhouse gas emissions, ISA Trans. 77 (2018) 146-166. |
[36] | X. Zhao, S. Bai, X. Zhang, Establishing a decision-support system for eco-design of biological wastewater treatment: A case study of bioaugmented constructed wetland, Bioresour. Technol. 274 (2019) 425-429. |
[37] | D. Dionisi, A. A. Rasheed, Maximisation of the organic load rate and minimisation of oxygen consumption in aerobic biological wastewater treatment processes by manipulation of the hydraulic and solids residence time, J. Water Process Eng. 22 (2018) 138-146. |
[38] | X. Zhang, C.-W. Yang, J. Li, L. Yuan, G.-P. Sheng, Spectroscopic insights into photochemical transformation of effluent organic matter from biological wastewater treatment plants, Sci. Total Environ. 649 (2019) 1260-1268. |
[39] | S. Al Arni, J. Amous, D. Ghernaout, On the perspective of applying of a new method for wastewater treatment technology: Modification of the third traditional stage with two units, one by cultivating microalgae and another by solar vaporization, Int. J. Environ. Sci. Nat. Res. 16 (2019) 555934. DOI: 10.19080/IJESNR.2019.16.555934. |
[40] | H. Chen, Y. Chen, X. Zheng, X. Li, J. Luo, How does the entering of copper nanoparticles into biological wastewater treatment system affect sludge treatment for VFA production, Water Res. 63 (2014) 125-134. |
[41] | K.-U. Schmitz, Beneficial biofilm bacteria in wastewater treatment. https://waterfaq.blog/2019/02/24/beneficial-biofilm-bacteria-in-waste-water-treatment/ (Accessed on 28/04/19). |
[42] | D. Ghernaout, Microorganisms’ electrochemical disinfection phenomena, EC Microbiol. 9 (2017) 160-169. |
[43] | Y. Shi, J. Huang, G. Zeng, Y. Gu, Y. Chen, Y. Hu, B. Tang, J. Zhou, Y. Yang, L. Shi, Exploiting extracellular polymeric substances (EPS) controlling strategies for performance enhancement of biological wastewater treatments: An overview, Chemosphere 180 (2017) 396-411. |
[44] | J. Qian, M. Zhang, J. Niu, X. Fu, X. Pei, X. Chang, L. Wei, R. Liu, G.-H. Chen, F. Jiang, Roles of sulfite and internal recirculation on organic compound removal and the microbial community structure of a sulfur cycle-driven biological wastewater treatment process, Chemosphere 226 (2019) 825-833. |
[45] | H. An, J. Liu, X. Li, Q. Yang, D. Wang, T. Xie, J. Zhao, Q. Xu, F. Chen, Y. Wang, K. Yi, J. Sun, Z. Tao, G. Zeng, The fate of cyanuric acid in biological wastewater treatment system and its impact on biological nutrient removal, J. Environ. Manag. 206 (2018) 901-909. |
[46] | C. Le, D. C. Stuckey, Colorimetric measurement of carbohydrates in biological wastewater treatment systems: A critical evaluation, Water Res. 94 (2016) 280-287. |
[47] | D. Wang, G. Tang, Z. Yang, X. Li, G. Chai, T. Liu, X. Cao, B. Pan, J. Li, G. Sheng, X. Zheng, Z. Ren, Long-term impact of heavy metals on the performance of biological wastewater treatment processes during shock-adaptation-restoration phases, J. Hazard. Mater. 373 (2019) 152-159. |
[48] | S. Bai, X. Zhao, D. Wang, X. Zhang, N. Ren, Engaging multiple weighting approaches and Conjoint Analysis to extend results acceptance of life cycle assessment in biological wastewater treatment technologies, Bioresour. Technol. 265 (2018) 349-356. |
[49] | H. An, X. Li, Q. Yang, D. Wang, T. Xie, J. Zhao, Q. Xu, F. Chen, Y. Zhong, Y. Yuan, G. Zeng, The behavior of melamine in biological wastewater treatment system. J. Hazard. Mater. 322 (2017) 445-453. |
[50] | L. Corbala-Robles, E. I. P. Volcke, A. Samijn, F. Ronsse, J. G. Pieters, Effect of foam on temperature prediction and heat recovery potential from biological wastewater treatment, Water Res. 95 (2016) 340-347. |
[51] | P. Wunderlin, J. Mohn, A. Joss, L. Emmenegger, H. Siegrist, Mechanisms of N2O production in biological wastewater treatment under nitrifying and denitrifying conditions, Water Res. 46 (2012) 1027-1037. |
[52] | K. B. Chipasa, Accumulation and fate of selected heavy metals in a biological wastewater treatment system, Waste Manag. 23 (2003) 135-143. |
[53] | M. N. Kumwimba, F. Meng, Roles of ammonia-oxidizing bacteria in improving metabolism and cometabolism of trace organic chemicals in biological wastewater treatment processes: A review, Sci. Total Enviro. 659 (2019) 419-441. |
[54] | P. Oprčkal, A. Mladenovič, J. Vidmar, A. M. Pranjić, R. Milačič, J. Ščančar, Critical evaluation of the use of different nanoscale zero-valent iron particles for the treatment of effluent water from a small biological wastewater treatment plant, Chem. Eng. J. 321 (2017) 20-30. |
[55] | H. Lu, K. Chandran, D. Stensel, Microbial ecology of denitrification in biological wastewater treatment, Water Res. 64 (2014) 237-254. |
[56] | T. Kodera, S. Akizuki, T. Toda, Formation of simultaneous denitrification and methanogenesis granules in biological wastewater treatment, Process Biochem. 58 (2017) 252-257. |
[57] | V. Ochoa-Herrera, Q. Banihani, G. León, C. Khatri, J. A. Field, R. Sierra-Alvarez, Toxicity of fluoride to microorganisms in biological wastewater treatment systems, Water Res. 43 (2009) 3177-3186. |
[58] | H. Haimi, M. Mulas, F. Corona, R. Vahala, Data-derived soft-sensors for biological wastewater treatment plants: An overview, Environ. Model. Softw. 47 (2013) 88-107. |
[59] | Y. Yang, Y. Wang, K. Hristovski, P. Westerhoff, Simultaneous removal of nanosilver and fullerene in sequencing batch reactors for biological wastewater treatment, Chemosphere 125 (2015) 115-121. |
[60] | J. Funke, C. Prasse, T. A. Ternes, Identification of transformation products of antiviral drugs formed during biological wastewater treatment and their occurrence in the urban water cycle, Water Res. 98 (2016) 75-83. |
[61] | T. Alvarino, S. Suarez, J. Lema, F. Omil, Understanding the sorption and biotransformation of organic micropollutants in innovative biological wastewater treatment technologies, Sci. Total Environ. 615 (2018) 297-306. |
[62] | S. Sathyamoorthy, C. A. Ramsburg, Assessment of quantitative structural property relationships for prediction of pharmaceutical sorption during biological wastewater treatment, Chemosphere 92 (2013) 639-646. |
[63] | N. H. Tran, H. Chen, M. Reinhard, F. Mao, K. Y.-H. Gin, Occurrence and removal of multiple classes of antibiotics and antimicrobial agents in biological wastewater treatment processes, Water Res. 104 (2016) 461-472. |
[64] | P. Falås, A. Wick, S. Castronovo, J. Habermacher, T. A. Ternes, A. Joss, Tracing the limits of organic micropollutant removal in biological wastewater treatment, Water Res. 95 (2016) 240-249. |
[65] | J. Völker, T. Vogt, S. Castronovo, A. Wick, T. A. Ternes, A. Joss, J. Oehlmann, M. Wagner, Extended anaerobic conditions in the biological wastewater treatment: Higher reduction of toxicity compared to target organic micropollutants, Water Res. 116 (2017) 220-230. |
[66] | H. Bouju, P. Nastold, B. Beck, J. Hollender, P. F.-X. Corvini, T. Wintgens, Elucidation of biotransformation of diclofenac and4’hydroxydiclofenac during biological wastewater treatment, J. Hazard. Mater. 301 (2016) 443-452. |
[67] | N.-Q. Puay, G. Qiu, Y.-P. Ting, Effect of Zinc oxide nanoparticles on biological wastewater treatment in a sequencing batch reactor, J. Clean. Product. 88 (2015) 139-145. |
[68] | G.-P. Sheng, H.-Q. Yu, X.-Y. Li, Extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment systems: A review, Biotechnol. Adv. 28 (2010) 882-894. |
[69] | M. J. Nelson, G. Nakhla, J. Zhu, Fluidized-bed bioreactor applications for biological wastewater treatment: A review of research and developments, Engineering 3 (2017) 330-342. |
[70] | I. Krasnochtanova, A. Rauh, M. Kletting, H. Aschemann, E. P. Hofer, K.-M. Schoop, Interval methods as a simulation tool for the dynamics of biological wastewater treatment processes with parameter uncertainties, Appl. Mathemat. Model. 34 (2010) 744-762. |
[71] | W. Sokoła, A. Ambaw, B. Woldeyes, Biological wastewater treatment in the inverse fluidised bed reactor, Chem. Eng. J. 150 (2009) 63-68. |
[72] | V. Piergrossi, M. De Sanctis, S. Chimienti, C. Di Iaconi, Energy recovery capacity evaluation within innovative biological wastewater treatment process, Energy Convers. Manag. 172 (2018) 529-539. |
[73] | Y. Zang, Y. Li, C. Wang, W. Zhang, W. Xiong, Towards more accurate life cycle assessment of biological wastewater treatment plants: a review, J. Clean. Product. 107 (2015) 676-692. |
[74] | D. Wolff, D. Krah, A. Dötsch, A.-K. Ghattas, A. Wick, T. A. Ternes, Insights into the variability of microbial community composition and micropollutant degradation in diverse biological wastewater treatment systems, Water Res. 143 (2018) 313-324. |
[75] | I. Ramirez, E. I. P. Volcke, J. P. Steyer, Modeling and monitoring of microbial diversity in ecosystems - Application to biological wastewater treatment processes, Proceedings of the 17th World Congress, The International Federation of Automatic Control, Seoul, Korea, July 6-11, 2008. |
[76] | Y. Wei, R. T. Van Houten, A. R. Borger, D. H. Eikelboom, Y. Fan, Minimization of excess sludge production for biological wastewater treatment, Water Res. 37 (2003) 4453-4467. |
[77] | P. M. Romero-Pareja, C. A. Aragon, J. M. Quiroga, M. D. Coello, Evaluation of a biological wastewater treatment system combining an OSA process with ultrasound for sludge reduction, Ultrason. Sonochem. 36 (2017) 336-342. |
[78] | S. Panigrahi, B. K. Dubey, A critical review on operating parameters and strategies to improve the biogas yield from anaerobic digestion of organic fraction of municipal solid waste, Renew. Energ. 143 (2019) 779-797. |
APA Style
Djamel Ghernaout. (2019). Reviviscence of Biological Wastewater Treatment – A Review. Applied Engineering, 3(1), 46-55. https://doi.org/10.11648/j.ae.20190301.16
ACS Style
Djamel Ghernaout. Reviviscence of Biological Wastewater Treatment – A Review. Appl. Eng. 2019, 3(1), 46-55. doi: 10.11648/j.ae.20190301.16
@article{10.11648/j.ae.20190301.16, author = {Djamel Ghernaout}, title = {Reviviscence of Biological Wastewater Treatment – A Review}, journal = {Applied Engineering}, volume = {3}, number = {1}, pages = {46-55}, doi = {10.11648/j.ae.20190301.16}, url = {https://doi.org/10.11648/j.ae.20190301.16}, eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ae.20190301.16}, abstract = {Biological treatment remains one of the most eco-friendly and cost-effective techniques to eliminate pollutants from wastewater in spite of the development of other technologies such as chemical treatment methods and advanced oxidation processes. This paper discusses briefly the main features and recent advances of wastewater treatment (WT). Some future trends are also viewed. Membrane Bioreactor (MBR), Moving Bed Bioreactor (MBBR), and Fixed Bed Bioreactors (FBBR) are largely employed techniques in WT particularly for industrial uses with an elevated biochemical oxygen demand charge like food and beverages, dairy, chemical, leachate and others. Integrations of minutely anaerobic and aerobic methods importantly improved the elimination of specific and non-specific in vitro toxicities. Therefore, optimizing biological WT may conduct to a considerably ameliorated detoxification. Surplus sludge treatment and disposal are regarded as an increasing defy for wastewater treatment plants (WTTPs) because of economic, environmental and regulatory elements. There is thus a fundamental need in expanding procedures for decreasing sludge generation in biological WT processes. Great attention for minimizing sludge formation occurs following procedures founded on mechanisms of lysis-cryptic growth, uncoupling metabolism, maintenance metabolism, and bacterivorous predation. On the other hand, heavy metals presence in wastewater still constitute a handicap for large acceptance of this technology based on cultivating bacteria for organic matter removal.}, year = {2019} }
TY - JOUR T1 - Reviviscence of Biological Wastewater Treatment – A Review AU - Djamel Ghernaout Y1 - 2019/06/12 PY - 2019 N1 - https://doi.org/10.11648/j.ae.20190301.16 DO - 10.11648/j.ae.20190301.16 T2 - Applied Engineering JF - Applied Engineering JO - Applied Engineering SP - 46 EP - 55 PB - Science Publishing Group SN - 2994-7456 UR - https://doi.org/10.11648/j.ae.20190301.16 AB - Biological treatment remains one of the most eco-friendly and cost-effective techniques to eliminate pollutants from wastewater in spite of the development of other technologies such as chemical treatment methods and advanced oxidation processes. This paper discusses briefly the main features and recent advances of wastewater treatment (WT). Some future trends are also viewed. Membrane Bioreactor (MBR), Moving Bed Bioreactor (MBBR), and Fixed Bed Bioreactors (FBBR) are largely employed techniques in WT particularly for industrial uses with an elevated biochemical oxygen demand charge like food and beverages, dairy, chemical, leachate and others. Integrations of minutely anaerobic and aerobic methods importantly improved the elimination of specific and non-specific in vitro toxicities. Therefore, optimizing biological WT may conduct to a considerably ameliorated detoxification. Surplus sludge treatment and disposal are regarded as an increasing defy for wastewater treatment plants (WTTPs) because of economic, environmental and regulatory elements. There is thus a fundamental need in expanding procedures for decreasing sludge generation in biological WT processes. Great attention for minimizing sludge formation occurs following procedures founded on mechanisms of lysis-cryptic growth, uncoupling metabolism, maintenance metabolism, and bacterivorous predation. On the other hand, heavy metals presence in wastewater still constitute a handicap for large acceptance of this technology based on cultivating bacteria for organic matter removal. VL - 3 IS - 1 ER -