This study aimed to evaluate the use of Moringa oleifera (MO) seed aqueous extract for tertiary treatment of a domestic wastewater by coagulation, flocculation, sedimentation, and rapid granular filtration. Jar tests with sand filter coupled were performed in secondary effluent samples with MO and alum dosages to evaluate the capacity to remove apparent color, turbidity, BOD, COD, TOC, nutrients, generated sludge, pH, and alkalinity consumption. Effects on the bacterial load (total coliforms and Escherichia coli), antibacterial activity in vitro (Escherichia coli Strain ATCC 25922), and cytotoxicity (Vero cells) were also evaluated. MO at the optimal dosage of 600 mg/L showed results statistically equal to the use of alum (200 mg/L), achieving bacterial load, turbidity, and apparent color removal higher than 99 %, 92 %, and 66 %, respectively. Differently from alum, the MO dosage increase did not consume alkalinity or change pH value. MO produced a more organic sludge, with total solids 1.8 times lower, and 3 times less bulky sludge than alum. Treatment with MO did not remove nutrients and increased organic matter (BOD, COD, and TOC). However, treatment with MO resulted in an effluent with less cytotoxicity, when compared with alum. MO did not show significant antibacterial activity, which may be related to the applied dosages. These results emphasized that MO seed aqueous extract has the potential to be used as a coagulant for domestic wastewater tertiary treatment, but a purification process of extracting cationic proteins from MO seeds is recommended when the effluent organic load is a concern.

这项研究旨在评估辣木（MO）种子水提取物通过凝结，絮凝，沉淀和快速颗粒过滤在家庭废水三级处理中的应用。在具有MO和明矾剂量的次级污水样品中进行了带砂滤器的Jar测试，以评估去除表观颜色，浊度，BOD，COD，TOC，养分，产生的污泥，pH和碱度的能力。对细菌载量（大肠菌群和大肠埃希氏菌总数）的影响，体外抗菌活性（大肠埃希氏菌）还评估了菌株ATCC 25922）和细胞毒性（Vero细胞）。在600 mg / L的最佳剂量下，MO的结果在统计学上等于使用明矾（200 mg / L），达到的细菌载量，浊度和表观颜色去除率分别高于99％，92％和66％。与明矾不同，增加MO的剂量不会消耗碱度或改变pH值。MO产生了更多的有机污泥，总固体含量比明矾低1.8倍，大块污泥减少了3倍。用MO进行处理并不能去除营养物和增加有机物（BOD，COD和TOC）。但是，与明矾相比，MO处理的废水产生的细胞毒性较小。MO没有显示出明显的抗菌活性，这可能与所施用的剂量有关。