Assessment of Disinfection Efficacy of Sodium Hypochlorite and Aloe Vera Gel for Potable Water Production from Multiple Water Sources

Abstract

The importance of potable water for human survival cannot be understated, just as human body cannot carry out its functions without water. Oftentimes, chemical such as sodium hypochlorite is used to make contaminated water fit for human consumption but overuse of this chemical has its attendant health effects including carcinogenic effect. It is therefore, important to find a substitute for sodium hypochlorite, without attendant health effects, for water disinfection purpose. The aim of this study was to evaluate and compare the antimicrobial effects of sodium hypochlorite (NaOCl) and aloe vera gel, stored under various conditions and parameters, on coliform and Escherichia coli isolates from some water samples. Four water samples including tap water, well water, oil polluted water and leachate were collected across Lagos State, Nigeria. All water samples were subjected to presumptive, confirmatory and complete tests. Disinfectant efficacies of the NaOCl and aloe vera were evaluated and compared on the eight isolated microorganisms from the water samples, using the disc diffusion method with various condition and parameters for the two disinfectants. The results showed that coliform counts were <2, 49, >1800 and >1800 cfu/100ml for the tap water, well water, oil polluted water and leachate respectively. Aloe vera looks more stable in its disinfectant capability when compared with NaOCl at the storage temperatures especially at 0, 25 and 35oC. Furthermore, the p-values for using aloe vera and NaOCl as disinfectants under various conditions of concentration, temperature and sun exposure period ranged between 0.011 and 0.749 with most of the p-values indicating non-significant differences while few ones showed significant differences. On the average, the results showed that aloe vera could be used as a substitute for sodium hypochlorite for disinfection of water from multiple sources