TAF PUBLISHING

The main objective of the present study is to investigate the effect of natural coagulants (selected seed) on the treatment of domestic grey water and to study the factors affecting the removal efficiency in terms of Turbidity and COD removal. Effect of settling time and pH variation on the removal efficiency was also studied. Grey water is all wastewater generated in households, public or commercial properties without fecal contamination. Treating and reusing grey water decreases the quantity of fresh water needed and lessens the wastewater flow flowing into the sewer system. The grey water sample was taken from a residential society in Ahmedabad and the natural coagulant used was freely and locally available Custard Apple (Annona Reticulata) seeds. The initial characteristics of the grey water were accessed based on the parameters pH, TS, TDS, Turbidity, and COD and measured as 7.79, 780 mg/L, 590 mg/L, 276 NTU, and 625 mg/L, respectively. Turbidity and COD were analyzed for different Coagulant Dosage concentrations and by varying the Settling Time and pH. The settling time was varied from 10 to 30 minutes considering the elimination of micro-flocs, and pH was varied from 4 to 9. The optimum results were obtained at a settling time of 30 minutes, pH 9 and 10 mg/L coagulant dosage giving 85% turbidity removal and 82% COD removal. It was observed that adding organic coagulant beyond the optimum level contributes to COD. Water scarcity along with climate change, population growth, and development, pose difficulties for the present water supply systems. Today, 2.1 billion people globally are living without a safe water supply near their homes. Hence, domestic wastewater treatment along with its reuse is becoming a significant topic for research.