Physicochemical and Bacteriological Study of Sewage Before and After Treatment with Moringa Oleifera Seeds at Brazzaville (Congo)

摘要

Within the framework of the mobilization of water resources and the supply of drinking water to the populations as well as the valuation of local materials, four (4) samples of piped water from the districts of Brazzaville were analyzed for their physical quality. chemical and microbiological before and after treatment with Moringa oleifera seed powder. The physicochemical parameters were determined using standard devices. As for the microbiological parameters, they were analyzed by conventional microbiological methods which consisted of isolation on selective media, identification using cultural, morphological and biochemical criteria and then counting. The results obtained concerning the physicochemical parameters showed that the raw water exhibited pH values ranging from 6.4 to 7.02; temperatures ranging from 25 to 25.8 with high values of turbidity and dry matter. However, low levels of magnesium and calcium ions have been noted. Regarding the microbiological parameters, this water exhibited bacteria of the genus Staphylococcus as well as fecal and total coliforms, a large number of which were unidentified. The genera Salmonella and Shigella have been identified as well as the species E. coli, an indicator of contamination. After clarification of the Moringa beans with powder, the pH values varied from 5.40 to 4.02; there is a decrease in turbidity as well as the dry matter. Microbiologically, the clarified water contained unidentified coliforms with persistence of Salmonella and Staphylococci in low proportions. As for E coli and Shigella, they have been totally eliminated. After clarification and decantation, the results show that all the microorganisms are found concentrated in the sludge. Before treatment, the cloudy pipe water exhibited high concentrations of organic and mineral chemicals. These analyzed waters contained several types of germs in very high numbers. The muddy water is decanted, clarified and purified by the powder of Moringa oleifera seeds in less than 2 hours. However, there is a decrease in the number of germs in the clarified water with the formation of an activated sludge. Moringa oleifera is therefore a local plant material that can be used in the treatment of wastewater to prevent possible contamination.