Cyanobacteria are microorganisms capable of releasing toxic metabolites in freshwater, deleterious to humans and other living organisms even in very low concentrations. Removing both cyanobacteria cells and their metabolites in conventional water treatment systems is still a challenge that needs to be addressed. This paper evaluated the use of Moringa oleifera saline extract and polyaluminum chloride (PACl) as coagulants in order to remove cells and metabolites of M. aeruginosa from water. Samples consisted of synthetic water spiked with humic acid and M. aeruginosa cells, with a final turbidity of 25 NTU. Coagulation/flocculation/dissolved air flotation (C/D/DAF) tests were performed with 50 mg/L of M. oleifera coagulant, combined with different proportions of PACl (10–50%). For removal of metabolites, 25 μg/L of microcystin and 50 ng/L of 2-MIB and geosmin were spiked in water samples. The best results were obtained with 70:30 M. oleifera:PACl, achieving removal efficiencies of 81.37%, 74.69%, and 71.06% for turbidity, color, and cell density, respectively. For microcystin, 2-MIB, and geosmin, after filtration (30 min), global removal efficiencies (clarification + filtration) of 99.45%, 62.37%, and 100%, respectively, were obtained, using Sand+GAC filter. The results suggest that the substitution of PACl by M. oleifera extract can be a good option to remove cyanobacteria cells from water, and high removal efficiencies of metabolites can be achieved after the complete proposed treatment.

蓝细菌是能够在淡水中释放有毒代谢物的微生物，即使浓度很低，也对人类和其他生物有害。在常规的水处理系统中去除蓝细菌细胞及其代谢产物仍然是需要解决的挑战。本文评估了辣木盐提取物和聚氯化铝（PACl）作为凝结剂的用途，以便从水中去除铜绿假单胞菌的细胞和代谢产物。样品由掺有腐殖酸和铜绿假单胞菌细胞的合成水组成，最终浊度为25 NTU。混凝/絮凝/溶气浮选（C / D / DAF）测试是用50 mg / L油橄榄进行的混凝剂，以及不同比例的PACl（10–50％）。为了去除代谢物，将25μg/ L的微囊藻毒素和50 ng / L的2-MIB和土臭素加标到水样中。70:30 M. oleifera：PAC1可获得最佳结果，浊度，颜色和细胞密度的去除效率分别为81.37％，74.69％和71.06％。对于微囊藻毒素，2-MIB和土臭素，过滤（30分钟）后，使用Sand + GAC过滤器可获得的总体去除效率（澄清+过滤）分别为99.45％，62.37％和100％。结果表明，用油茶分枝杆菌提取物代替PACl可能是从水中去除蓝细菌细胞的好选择，并且在完成所提出的全部处理后，可以实现代谢物的高去除效率。