Hibiscus sabdariffa as Coagulant to Treat Laundry Wastewater

Abstract Laundry wastewater is a major contributor to the global annual wastewater output, highlighting the importance of reusing larger volumes of the wastewater as a valuable water resource. Among the conventional wastewater, coagulation process displays promising results in treating laundry wastewater. However, studies show that the conventional chemical coagulant such as alum has been associated with health concerns. To address these drawbacks, a more environmentally friendly alternative such as natural coagulant is being explored such as Hibiscus sabdariffa due to it seed contain high protein content. This present study aims to characterize Hibiscus sabdariffa seeds and determine the optimal conditions for effectively treating laundry wastewater using Hibiscus sabdariffa as a natural coagulant. Additionally, the study compared the effectiveness of natural and chemical coagulants in this application. The studies parameter ranges include pH (2 –11) and dosages (50 – 500 mg/L). Water quality parameters such as Chemical Oxygen Demand (COD), Total Suspended Solid (TSS) and turbidity will be used to evaluate the coagulation performance. The jar test experiment was carried out and found out that natural coagulant performed best at a pH of 2 and a dosage of 100 mg/L, resulting in COD, turbidity, and TSS removal efficiencies of 32.59%, 77.98%, and 86.51% respectively, with final treated ef luent levels of 212 mg/L for COD, 11.25 NTU for turbidity, and 17 mg/L for TSS, meeting the requirements of Standard B discharge except for the COD and pH. In comparison, the alum chemical coagulant demonstrated better performance, achieving 57.96% COD removal, 95.24% turbidity removal, and over 95% TSS removal. This study successfully showed that the Hibiscus sabdariffa is capable of treating laundry wastewater, showcasing comparable performance to the chemical coagulant in removing turbidity and TSS.