Municipal wastewater treatment using different coagulants

ABSTRACT Secondary wastewater treatment plants often release some organic material, phosphorus and turbidity. These residual pollutants are capable of causing problems even at a low level. Therefore, tertiary treatment of secondary effluent was used as the main objective of this study. Laboratory-based experiments were conducted to achieve the objectives. The jar test was used to represent the coagulation precipitation process. Lime, dried leaves, and polymer were used as the coagulants. Alum was used for comparison. The effect of the removal of phosphorus, BOD and turbidity was investigated as part of the advanced treatment. Secondary effluents from two different wastewater treatment plants were used in this study to assess the effect of pretreatment process on the performance of wastewater treatment. The results revealed coagulation precipitation process using different coagulants were capable of removing phosphorus up to 68%, and BOD up to 100%. The results were comparable with traditional coagulant, alum with 80% for phosphorus and 100% for BOD. The increase in pretreatment appeared to increase the ability of these coagulants in removing phosphorus from 34.5% to 48% and BOD from 73.3% to 82%.