Alum, Chitin and Sago as coagulants for the optimization of process parameters focussing on coagulant dose and mixing speed

Abstract

Water demand for consumption has been increasing continuously due to the expanding population worldwide. The current accessible water is continually contaminated by global climate change and anthropogenic activities. Economically viable and safe treatment technologies are required for the contemporary world to meet the water demand. The coagulation process is an economically feasible method and gaining much prominence in developing countries for water treatment. During the operation, Sludge and secondary by-products are formed due to the overdosage of the coagulant and improper mixing speeds. Optimizing process parameters is essential to reduce the costs associated with further treatment. Thus, the current study aimed to optimize the process parameters by using Alum, Chitin and Sago coagulants with three pH variations, i.e., 6, 7, and 8, with a mixing speed of 100–30 and 80–20 rpm. The results revealed that Sago performed better than other coagulants and removed the turbidity up to 99.42 %. In addition, Sludge was reduced to 90 % with a dosage of 0.4 g/L, a minor dosage compared to the literature with an optimal pH of 7. Further, the coagulants were characterized to identify the functionalized groups by FTIR, the nature of the coagulant by XRD and Surface morphology by SEM. From the current study, it can be concluded that a coagulant dose ranging from 0.1 to 0.4 g/L with a mixing speed of 100 rpm for 2 min and 30 rpm for 30 min might be the best solution for obtaining greater coagulation efficiency.