Evaluation of the Performance of Iron Coagulants in Removing TSS and BOD from Domestic Wastewater

Abstract

Coagulation The coagulation process aims to remove stable particles by forming large clumps that can be easily separated from the aqueous solution. Coagulation consists of two stages. The first stage is the coagulation process in which instability of the particles is induced. TSS and BOD removal is achieved using a chemical coagulation process using two types of iron coagulants: ferric chloride and ferric sulphate. The results proved that the best conditions used in the treatment process are a coagulant concentration of 35 mg/L and a mixing speed of 145 rpm for one minute and a sedimentation time of 55 minutes. The removal efficiency of ferric chloride for BOD and TSS was 80% and 81%, respectively, and the removal efficiency of iron sulfate for BOD and TSS was 82% and 83%, However, after increasing the concentration of coagulants for the same conditions, a decrease in removal efficiency was observed. At a concentration of 45 mg/L, the removal of BOD and TSS reached 75% and 78% for ferric chloride and 80% and 80% for ferric sulfate, respectively. The mixing speed of 145 rpm was ideal for completing the flocculation process and forming large clumps that contributed to the success of the sedimentation process. The coagulation process took place at pH 6,7 and a pH value of 6 was more effective in pollutant removal. This research concludes that factors for completing the flocculation and coagulation process, such as rapid mixing, sedimentation time, and coagulant dose, are critical in achieving the highest pollutant removal efficiency with minimal chemical consumption, thus helping to preserve the ecosystem and support sustainability.