Thickening of Sludge Using Recycled Iron Coagulants (RICS)

The suitability and effectiveness of recycled iron coagulants (RIC) extracted from groundwater treatment sludge to improve sludge settleability was investigated in this study. The groundwater treatment sludge was collected from Chicha Water Treatment Plant, Kelantan. The sludge contains iron and manganese and cannot be disposed without proper treatment because if happen, it may lead to surface water and ground water pollution. This study involved the use of RIC as a coagulant for settleability improvement in municipal sludge treatment. The result was compared to the other commercial coagulants such as alum (Al2(SO4)3), ferrous sulphate (Fe2(SO4)3), and ferric chloride (FeCl3). Apart from settleability, the study also focused on the RICs efficiency on removal of chemical oxygen demand (COD), colour, turbidity, and total suspended solid (TSS). As a result, RIC (Recycled Ferrous Sulphate) proved to be a better coagulant for sludge settleability at 5.15 cm/min and performance increased by 115%. At the same time, the respective removals achieved from RIC were found to be 31.73% for COD, 65.61% for colour, and 65.21% for turbidity.