Experimental Evaluation on Comparative Performance of Native Plant Species in Removing Turbidity and Microbial Load for Household Water Treatment

Abstract

Unsafe drinking water is a paramount concern because of the fact that, 75% of all diseases in developing countries are arising from polluted drinking water especially in rural parts of developing countries. This work investigates on comparative performance of native plant species in removing turbidity and microbial load as compared to alum and chlorine for household water treatment. Water treatment using Maerua subcordata (Gilg) De Wolf and Moringa stenopetala (Bakj) Cufod were able to achieve appreciable removal efficiency in both turbidity and microbial load at an optimum dose range of 0.01gm/L to 0.03 gm/L in synthetic water and natural surface water samples. Plant coagulants showed relatively lower removal efficiency (≈70%) as compared to alum (≈80%) at low turbidity (20 NTU) in synthetic water. However, in natural water samples of low turbidity, plant coagulants showed high rate of turbidity removal efficiency (≈90%) like that of alum. Plant coagulants can also achieve maximum turbidity removal (≈97%) like that of alum in medium turbidity level (200 NTU) in both natural and synthetic water samples. The experimental result revealed that plant coagulants were able to meet World Health Organization standards of drinking water quality (< 5 NTU) in terms of turbidity. The microbial reduction experiment also revealed that plant coagulants can effectively disinfect water at low turbidity but becomes less potent disinfectant as turbidity increases.

Key words:Coagulation, Disinfection, Household water treatment, Native plants, Turbidity