A dissolved air flotator that treats wastewater from the manufacture of electrical equipment: Analysis and operational improvement

Authors

DOI:

https://doi.org/10.24221/jeap.10.1.2025.6402.052-059

Keywords:

dissolved air flotation, oily effluents, Turbidity

Abstract

This study investigated the efficiency of three chemical coagulants in reducing the turbidity and solids concentration of wastewater produced in an electrical equipment industry, associating the use of coagulants with improving the performance of the dissolved air flotation (DAF) unit already in place at the industry's wastewater treatment plant (WWTP). The experimental protocol was based on preliminary Jar-Test trials to define the coagulant dosages that would allow the greatest reduction in turbidity, without correcting the initial pH of the wastewater. This was followed by on-site tests in which the coagulant dosages were added before treatment in the DAF. In the preliminary stage, the coagulants tested were aluminium sulphate (Al2(SO4)3), ferric chloride (FeCl3) and aluminium polychloride (PAC). The dosages that provided the highest turbidity removal efficiencies were 4, 35 and 40 mg L-1 for the PAC, FeCl3 and Al2(SO4)3 coagulants, respectively. In the on-site tests, only the PAC and aluminium sulphate coagulants were tested. The dosage of 40 mg L-1 of Al2(SO4)3 showed greater efficiency in removing ST and TSS. Turbidity removal was more effective using PAC at a dosage of 4 mg L-1.  Due to the better performance in the on-site tests, a comparative cost analysis was carried out for the PAC and Al2(SO4)3 coagulants, with PAC being chosen as the most economical coagulant alternative for operating the existing DAF in the industrial WWTP.

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References

Alvim, C. S.; Marques, R. F. P. V.; Inácio, A. R.; Oliveira, A. S.; Santos, E. M. N.; Rodrigues, L. S.; Rezende, R. M. 2022. Comparação de coagulantes inorgânicos e floculante por meio de Jar-Test para o tratamento físico e químico de efluente de laticínio. Revista Ibero-Americana de Ciências Ambientais, 13, (3), 105-119. https://sustenere.inf.br/index.php/rica/article/view/7107/3871

APHA. 2012. Standard Methods for the Examination of Water and Wastewater. American Public Health Association, American Water Works Association, Water Environmental Federation. First Edition.

Ariano, G. C. 2009. Coagulação, floculação e flotação do efluente de reatores anaeróbios, tratando esgoto sanitário, com aplicação de diferentes dosagens de coagulante em função da variação da turbidez do esgoto afluente ao longo do dia. Dissertação de Mestrado, Universidade de São Paulo. São Carlos, São Paulo. 193p.

Asmel, N. K.; Al-Nima, R. R.; Mohammed, F. I.; Al Saadi, A. M.; Ganiyu, A. A. 2021. Forecasting Effluent Turbidity and pH In Jar Test Using Radial Basis Neural Network. Towards a Sustainable Water Future: Proceedings of OICWE2020, pp. 361-370. https://www.icevirtuallibrary.com/doi/epdf/10.1680/oicwe.65253.361

Azhar, A. A.; Haron, N. F.; Ismail, H. B. 2022. The Efficiency Assessment of Poly-Aluminium Chloride (PAC) in Water Treatment Plant Process: a case Study at Sultan Iskandar Water Treatment Plant, Johor. Journal of Sustainable Civil Engineering and Technology, 1, (2), 8-16. https://doi.org/10.24191/jscet.v1v2.8-16

Brasil. 2005. Resolução CONAMA n° 357, de 17 de março de 2005. Classificação de águas, doces, salobras e salinas do Território Nacional. Available at: https://www.icmbio.gov.br/cepsul/images/stories/legislacao/Resolucao/2005/res_conama_357_2005_classificacao_corpos_agua_rtfcda_altrd_res_393_2007_397_2008_410_2009_430_2011.pdf. Access at: September 10, 2023.

Coutinho, W. 2007. Emprego da flotação a ar dissolvido no tratamento de cursos d'água: avaliação de desempenho da estação de tratamento dos córregos Ressaca e Sarandi afluentes à Represa da Pampulha. Dissertação de Mestrado. Universidade Federal de Minas Gerais. Belo Horizonte, Minas Gerais. 118p.

Cristóvão, R. O.; Pinto, V. M. S.; Martins, R. J. E.; Loureiro, J. M.; Boaventura, R. A. R. 2016. Assessing the influence of oil and grease and salt content on fish canning wastewater biodegradation through respirometric tests. Journal of Cleaner Production, 127, 343-351. https://doi.org/10.1016/j.jclepro.2016.04.057

Di Bernardo, L.; Dantas, A. D. B. 2005. Métodos e técnicas de tratamento de água. Rima, Second Edition. 792p.

Ferrari, T. N.; Julio, M.; Julio, T. S. 2011. Emprego do sulfato de alumínio e do cloreto de polialumínio em estudos de tratabilidade da água que abastece o município de São José dos Campos-SP. Engenharia Ambiental, 8, (4), 118-137.

Han, M.; Kim, T.; Kim, J. 2007. Effects of floc and bubble size on the efficiency of the dissolved air flotation (DAF) process. Water Science & Technology, 56, (10), 109-15. https://doi.org/10.2166/wst.2007.779

Ilmos, E.; Ololade, O. O.; Ogola, H. J. O.; Selvarajan, R. 2020. Investigating industrial effluent impact on municipal wastewater treatment plant in Vaal, South Africa. International Journal of Environmental Research and Public Health, 17, (3), 1096. https://doi.org/10.3390/ijerph17031096

Lédo, P. G. S.; Lima, R. F. S.; Paulo, J. B. A. 2010. Efficiency of aluminium sulphate and Moringa oleifera seeds as coagulants for the clarification of water. Land Contamination & Reclamation, 18, (1), 57-64.

Lee, C. L.; Robinson, J.; Chong, M. F. 2014. A review on application of flocculants in wastewater treatment. Process Safety and Environmental Protection, 92, 489-508. https://doi.org/10.1016/j.psep.2014.04.010

Manda, I. K. M.; Chidya, R. C. G.; Saka, J. D. K.; Biswick, T. T. 2016. Comparative assessment of water treatment using polymeric and inorganic coagulants. Physics and Chemistry of the Earth, Parts A/B/C, 93, 119-129. https://doi.org/10.1016/j.pce.2015.09.008

Meyer, A. M.; Klein, C.; Fünfrocken, E.; Kautenburger, R.; Beck, H. P. 2019. Real-time monitoring of water quality to identify pollution pathways in small and middle scale rivers. Science of the Total Environment, 651, 2323-2333. https://doi.org/10.1016/j.scitotenv.2018.10.069

Minas Gerais. 2008. Deliberação Normativa Conjunta COPAM/CERH-MG Nº 1, de 05 de maio de 2008. Available at: https://www.compe.org.br/estadual/deliberacoes/conjunta/1-2008.pdf. Access at: September 10, 2023.

Santos, F. S.; Oliveira, S. M.; Cammarota, M. C.; Yokoyama, L. 2014. Avaliação da eficiência do processo de coagulação/floculação aplicado ao tratamento primário de efluente da indústria petroquímica. Engevista, 16, (4), 404-413. https://doi.org/10.22409/engevista.v16i4.581

Saxena, K.; Brighu, U. 2020. Comparison of floc properties of coagulation systems: Effect of particle concentration, scale and mode of flocculation. Journal of Environmental Chemical Engineering, 8, (5), 104311. https://doi.org/10.1016/j.jece.2020.104311

Souza, P. C.; Pereira, N. C.; Gonçalves, Consolin Filho, N.; Rodrigues, P. H.; Jamarim, V. M. 2016. Estudo do tratamento de efluente têxtil atraves de processos de coagulação/ floculação e eletrocoagulação. Revista E-xacta, 9, (2), 123-132. https://revistas.unibh.br/dcet/article/view/1953/1063

Shahbazi, B.; Rezai, B.; Koleini, S. M. J. 2010. Bubble–particle collision and attachment probability on fine particles flotation. Chemical Engineering and Processing: Process Intensification. 49, 622-627. https://doi.org/10.1016/j.cep.2010.04.009

Tamburus, I. E.; Rocha, V. C.; Senhuk, A. P. M. S.; Anhê, A. C. B. M. 2020. Efficiency of the activated sludge system of an electrical equipment industry. Ciência e Natura, 42, (e35), 1-19. https://doi.org/10.5902/2179460X41675

Van Berkel, R. 2007. Cleaner production and eco-efficiency initiatives in Western Australia 1996–2004. Journal of Cleaner Production, 15, (8-9), 741-755. https://doi.org/10.1016/j.jclepro.2006.06.012

Vaz, L. G.; L.; Klen, M. R.F.; Veit, M. T.; Silva, E. A.; Barbiero, T. A.; Bergamasco, R. 2010. Avaliação da eficiência de diferentes agentes coagulantes na remoção de cor e turbidez em efluente de galvanoplastia. Eclética Química, 35, (4), 45-54. https://doi.org/10.1590/S0100-46702010000400006

Voltan, P. E. N. 2007. Avaliação da ruptura e recrescimento de flocos na eficiência de sedimentação em água com turbidez elevada. Dissertação de Mestrado. Universidade de São Paulo. São Carlos, São Paulo. 205p.

Wang, Y.; Jin, X.; Yang, S.; Wang, G.; Xu, L.; Jin, P.; Shi, X.; Shi, Y. 2021. Interactions between flocs and bubbles in the separation zone of dissolved air flotation system. Science of The Total Environment, 761, 143222. https://doi.org/10.1016/j.scitotenv.2020.143222

Yukselen, M. A.; Gregory, J. 2002. Breakage and re-formation of alum flocs. Environmental Engineering Science, 19, (4), 229-236. https://doi.org/10.1089/10928750276027154

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Published

2025-03-12

How to Cite

Prado, M., Martineli, T., Lucas, B. C. L., Santos, C. E. D. dos, Silva, R. S. G. da, & Rocha, V. C. (2025). A dissolved air flotator that treats wastewater from the manufacture of electrical equipment: Analysis and operational improvement. Journal of Environmental Analysis and Progress, 10(1), 052–059. https://doi.org/10.24221/jeap.10.1.2025.6402.052-059

Issue

Vol. 10 No. 1 (2025): Journal of Environmental Analysis and Progress

Section

Articles - Artigos

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Copyright (c) 2025 Mariana Prado, Tamirys Martineli, Bárbara Cristina Lemos Lucas, Carla Eloísa Diniz dos Santos, Rodrigo Soares Garcia da Silva, Vinícius Carvalho Rocha

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