Hybrid system using local plant as sustainable coagulation-flocculation process

Coagulation-flocculation is widely used in the treatment of water and wastewater to remove suspended and colloidal particles. Most chemical coagulants used are synthetic and after treatment, the sludge residuals will be toxic and unable to recovery as fertilizer. This study used natural coagulants which are safe because after treatment, the sludge residual no toxic. Seven types of natural coagulants were selected from Iraqi plants to investigate the 500 NTU turbidity removal prepared from Kaolin powder. The experiment parameters were coagulant concentrations ranging from 0 to 10.000 mg/L, fast mixing (200 rpm) for 5 minutes, slow mixing (30 rpm) for 15 minutes, and 25 minutes of sedimentation time. Thereafter, a hybrid system is investigated for the best three natural coagulants with aid alum concentrations of 5 mg/L and 10 mg/L. Results show that the three most effective natural coagulants had turbidity removal of 48, 47, and 47 for palm fiber, palm pith, and watermelon rinds, respectively, at 500 mg/L concentration. For a hybrid system, the best one is with 10 mg/L alum aid with 66% turbidity removal efficiencies for watermelon rinds at 500 mg/L concentration. Natural coagulant is a sustainable solution for a safe environment.