Use of Moringa Oleifera in a Combined Coagulation-Filtration Process for Water Treatment

Abstract

Several coagulants/flocculants have been studied in order to remove color and turbidity of raw water, having the natural ones demonstrated advantages in relation to chemicals. Moringa oleifera Lam is a natural polymer that has been gaining prominence in water treatment, for being ecofriendly. It acts as a clarifying agent give the presence of a cationic protein that destabilizes the particles contained in a liquid medium. The combined process of ultrafiltration (UF) and coagulation/flocculation (CF) with natural coagulant can be used to treat water supply with the purpose of obtaining high-quality water. In this process we obtain an increase in permeate quality, given its excellent ability to remove particles and colloids from the UF, and reduction in membrane fouling due to a previous step of coagulation. This paper aimed at the application of the UF and the combined coagulation/ flocculation and ultrafiltration (CFU) using the natural coagulant Moringa Oleifera Lam. Samples of surface water had color and turbidity relatively high. The membranes used were 0.1 and 0.2 µm single-channel, at pressures of 1 and 2 bar, by using a unit of Netzsch UF in cross-flow filtration. The final water quality was assessed in terms of efficiency removal for: color, turbidity, compounds with absorption in UV-254 nm, physic-chemical and microbiological aspects. At the end of the process, we obtained good quality water, with reductions of over 99% of most parameters. Thus, the combined CFU, using the natural coagulant Moringa oleifera Lam is effective for the treatment of drinking water with relatively high turbidity.