Potential of Using Hibiscus Sabdariffa in Treating Greywater

摘要

Greywater recycling can help to curb water shortages especially in developed countries as they consumed high amount of water for their activities. Greywater can be treated using coagulation process due to its simplicity and effectiveness with usage of coagulant. Studies show that the usage of conventional coagulant has bad effect on human health, produces large volume of sludge and affect pH of treated water. Therefore, a replacement on conventional coagulant with natural coagulant is preferable as it is safer for human health, biodegradable and toxic-free. In this study, Hibiscus Sabdariffa seeds as natural coagulant is used due to high protein content compared to other parts of the plant which important for coagulation process. The objectives of this study are to investigate the performance of the seeds in treating greywater by varying pH, coagulant dosage and mixing effects and compare the performance with conventional coagulant. Jar test experiment was carried out. It was found that the seeds work the best at pH 2, 100 mg/1 of coagulant dosage, 30 rpm for slow mix and 140 rpm for rapid mix which resulted in 93.83% and 57.98% removal efficiencies of turbidity and COD respectively. Alum coagulant was used to compare the coagulation performances. Alum coagulant works the best at pH 6,200 mg/1 of coagulant dosage, 40 rpm for slow mix and 150 rpm for rapid mix which resulted in 97.48% and 65.26% removal efficiencies of turbidity and COD respectively Therefore, it shows that Hibiscus Sabdariffa seeds is comparable with alum coagulant and hence, it has potential in treating greywater.