Reduction of turbidity and Escherichia coli ATCC 25922 in wastewater of dairy industry after treatment with Moringa oleifera LAM

Abstract

Several liquid wastes are generated daily in the agribusiness sector. In small dairy industry for example, the main concern is the volume of treated water used for less noble purposes within the company and the difficulty in wastewater treatment before disposal in receiving water bodies. Thus, this study aimed to evaluate the reduction of turbidity and Escherichia coli in synthetic agribusiness wastewater after treatment with Moringa seed extracts for reuse purposes and/or disposal. The extracts at a concentration of 20 mg L-1, 40 mg L-1, 60 mg L-1 and 80 mg L-1 were applied in wastewater made with reconstituted whole milk. Turbidity analysis and counts of contamination bioindicators were performed in the three repetitions. The extract of lower concentration proved to be undesirable for this treatment because it has increased the turbidity and not showed effectiveness against E. Coli to the treated samples. The results showed a turbidity reduction of 87.9% for effluents treated with 80 mg L-1 extract. The concentrations of 60 mg L-1 and 80 mg L-1, in a real situation, would be appropriate for the treatment of effluents with turbidity < 240 NTU, for later release on Class II and III water bodies. Similar to the turbidity test, after TIV-MO80mg L-1 treatment decreased the population density of E. coli to, approximately, 2.2 x 10² UFC 100 mL-1. The routine work using cleaner production, combined with the treatment of wastewater from natural coagulant, tend to minimize the negative impacts of such waste on the environment.