The impact of Moringa oleifera as a coagulant aid on the removal of trihalomethane (THM) precursors and iron from drinking water

Abstract

Chlorine is used as a disinfectant and an oxidant in drinking water treatment to protect the public health from pathogenic microorganisms. However, if applied to raw water with humic materials, it leads to the formation of halogenated organic compounds that are a potentially serious environmental and health problem. This renders pre-chlorination of raw waters to oxidise iron inappropriate. Coagulation, the principal treatment process for removal of THM precursors, is therefore essential for chlorination by-product control. In this study, the impact of pre-chlorination and the performance of Moringa oleifera as a coagulant aid at Masaka waterworks were assessed. An average increase of trihalomethanes of over 4,000% at aeration and pre-chlorination stage was observed at the plant. From the jar tests, alum with Moringa oleifera reduced dissolved organic concentration by 47.1%. The treated water after sedimentation tasted salty but after filtration and chlorination, the salty taste disappeared. Residual iron values of 1.38 mg/L and 3.05 mg/L were achieved with MOC-SC as coagulant aid and alum alone respectively. The jar test results indicated that use of alum with Moringa oleifera as coagulant aid is promising as a first stage in the treatment train for waters with humic materials and high content of iron.

Estudo Da Minimização De Trihalometanos Pelo Processo Combinado Coagulação/Floculação Com Coagulante Moringa Oleifera E Filtro De Carvão Ativado

“…Os ensaios de C/F foram realizados em Jar Test em diferentes condições de operação, otimizadas por Kalibbala et al (2009) Kalibbala et al (2009) Posteriormente a água passou por um processo de adsorção, utilizando uma coluna com o adsorvente carvão ativado de coco de dendê. Por fim, foi realizado o processo de desinfecção (pós-cloração) com hipoclorito de sódio na concentração de 1,5 mg.L -1 que é a utilizada pela ETA local.…”

Avaliação Do Processo Combinado De Coagulação/Floculação/Filtração Para Remoção Da Matéria Orgânica Natural De Água De Abastecimento Utilizando Coagulante Moringa Oleifera

“…Os ensaios de C/F foram realizados em Jar Test em diferentes condições de operação, otimizadas por Kalibbala et al (2009) Kalibbala et al (2009) Na etapa posterior, a água clarificada passou por um processo de filtração, utilizando uma coluna contendo carvão ativado de coco de dendê. Por fim, foi realizado o processo de desinfecção (pós-cloração) com hipoclorito de sódio na dosagem de 1,5 mg.L -1 , que é a utilizada pela SANEPAR.…”

Recent Research Every Utility Manager Needs to Know About

“…Recent work holds the promise of alternative and cheaper production as well as development of more efficient polyaluminum chloride coagulants in the foreseeable future. Work is also under way to identify and evaluate naturally occurring coagulants as greener substitutes for conventional coagulants and to improve access to coagulants in developing countries (Fabris et al, 2010; Chatterjee et al, 2009; Kalibbala et al, 2009; Nkurunziza et al, 2009; Miller et al, 2008; Rizzo et al, 2008).…”