Experimental screening and selection criteria of natural coagulants towards wastewater treatment

The search for eco-friendly materials has greatly evolved ahead of basic requirements encompassing sustainable practices. The selection of such sustainable material requires procedural systematic screening tests to facilitate decision-making. Water and wastewater treatment processes involve several chemicals, and they need to transition from commercial to natural materials owing to their environmental and economic concerns. The present study aimed to select and screen natural coagulants for wastewater treatment. The criteria assessment factors for the present study were easy availability, economic value, turbidity removal efficiency, and reduced sludge generation with high dewaterability. A standard jar test apparatus was used for the coagulation experimental runs. The physicochemical parameters were analyzed using standard methods. The results presented positive insights into the efficiency of tested natural coagulants, with the least turbidity removal of 83.3% by rice husk at 1gm/500ml and the highest being 96.4% by onion peel at 1gm/500ml. The sludge obtained after treatment with natural coagulants has presented an excellent dewaterability, with the least being 29.17% by tamarind seeds at 1gm/500ml and the maximum being 90.2% by coconut fibre at 1gm/500ml. From the study, was concluded that the screening method promoted the selection of the best coagulant type and dose and reduced the efforts and time needed to eliminate the non-performers.