Abstract:
Most rural populations in developing countries use surface water which is turbid in appearance and contaminated with human feces which needs treatment. Even if there are synthetic chemicals that can reduce turbidity and pathogenic organisms from drinking water, they are neither cost effective nor eco-friendly. Instead, natural coagulants are eco-friendly solutions with minimum health risks if properly tested and promoted to be used by community dependent on such unsafe water sources. Aloe vera leaf gel was used as coagulant aid with other chemicals like Alum to clarify, and treat water. Applied medicinal discipline studies also show that Aloe vera has an antimicrobial effect. Therefore, this particular study was focused on the efficacy of Aloe vera leaf gel as a primary coagulant on turbidity and bacterial load (fecal coliform bacteria) reduction in raw water & the associated factors. Objective: To assess the efficacy of Aloe vera leaf gel on turbidity and bacterial load reduction and the associated factors from June 5-20, 2020. Methods: A laboratory-based batch experimental study design was carried out. To conduct this study both synthetically prepared turbid water from clay soil and surface water was utilized. Jar test was carried out as a batch test, accommodating a series of six beakers. One percent Aloe vera leaf gel solution was prepared by mixing 1ml of Aloe vera leaf gel to 99 ml of distilled water. Different doses of extracted aloe vera leaf gel was added and the samples agitated homogenously and allowed to settle for varied contact time. Turbidity, fecal coliform and other parameters were determined at different points. The Plate agar and Most Probable Number technique was used to count bacterial load and coliforms, respectively. To increase the quality of the result, the experiment was conducted consistently, calibrated equipment and test control was used. Correlation coefficient was used to show association between dependent and independent variable. Result: This study revealed that the efficacy of 50ml/L dosage of 20% and 30% Aloe vera leaf gel solution as a primary coagulant was of 50.4% and 50.81% from surface and synthetic water samples, respectively at 180 minutes contact time. Higher clarification was observed from high level of initial turbidity than from low turbidity. The addition of extract of Aloe vera leaf gel in water sample has slightly changed the pH and temperature of water. The optimum dose, PH and contact time resulted in higher turbidity reduction of 58.3% were 40ml/L of 20% Aloe vera leaf gel, 5.36 and 120minutes, respectively. The total and fecal coliforms reduction efficacy of Aloe vera leaf gel was 46% and 89.28% at 50ml/L of 20% solution from the surface water. Similarly, it was 89.1% and 97.75% at 50ml/L of 30% solution from synthetically prepared turbid water, respectively. Conclusion: Aloe vera leaf gel was satisfactory in turbidity & fecal coliform reduction, but further study is required.