Application of phytodisinfectants in water purification in rural Cameroon

Abstract

Findings from a preliminary lab-scale study show strong potentials of phytodisinfectants as a low-cost, appropriate and ecological alternative technology in purifying water in rural Cameroon. A survey of plants used in water purification in Bamenda, Cameroon, indicated that there are many plants used in water treatment. A rapid screening on the coagulative and disinfection potential of four most frequently used plants was carried out on; Moringa oleifera, Jatropha curcas, calyx of Hibiscus sabdarifa, sclerotium of Pleurotus tuberregiumagainst their crude methanol extracts, aluminum sulphate and sodium hypochlorite controls on turbid surface water samples. A beaker experiment with varying weights (0.5 to 5 g) of dried pulverized plant materials and alum (control) were placed in 200 ml each of the three-turbid water samples and left for thirty minutes retention time. A 95% reduction in bacterial loads of the water samples by M. oleifera in fifteen minutes residence time was observed. J. curcas seeds, as well as H. sabdarifa calyx also reduced the bacterial loads between 75 to 90%. All the plant extracts except P. tuberregium inhibited an Escherichia coli isolate from the turbid water with highest zone of inhibition (15 mm) recorded for M. oleifera seed extract. The inhibition zones produced by three of the plant extracts were comparable to aluminum sulphate (6 mm) and sodium hypochlorite (17 mm). Crude methanol extracts from M. oleifera seeds, J. curcas seeds and H. sabdariffa calyx used directly on turbid water drastically reduced the total aerobic mesophilic bacterial counts far more than the unextracted plant powders. The turbidity of both phytodisinfectant and alum treated water samples drastically reduced while no turbidity reduction was observed with sodium hypochlorite treated water samples. The pH of alum treated water was observed to decrease from neutral to 5.0 while pH of phytocoagulant treated water was 7.0. This report suggest that M. oleifera seeds, J. curcas seeds and calyx of Hibiscus sabdariffa posses both phytodisinfectant and phytocoagulant property in water purification. Scerotium of P. tuberregium poses only phytocoagulant (mycocoagulant) activity. Plant materials can be used as phytocoagulants and phytodisinfectants in treating turbid water and can be applied in wastewater treatment. Further studies on the application of Phytodisinfectants in domestic water purification, especially the phytodisinfection potentials of M. oleifera are exigent. Key words: Phytodisinfectants, phytobiotechnology, phytocoagulants, bacteria turbid water, plants, Moringa oleifera, Cameroon.