Efficiency of aluminum sulfate, ferric chloride, poly aluminum chloride, polymer and lime in marble processing effluent treatment

Because of high consumption on water in marble processing, issue of water reuse in the process, is essential. Therefore this study was conducted with purpose of survey efficiency of aluminum sulfate, ferric chloride, poly aluminum chloride, polymer and lime in removal of turbidity, total suspended solids and total solids of marble processing wastewater.
This study was performed on laboratory scale and using the jar test. The experiments was done based on various doses of coagulant (25, 50, 75, 100, 200 and 500 mg/l). Steps of rapid mixing, slow mixing and stable was done, and the factors such as turbidity, total suspended solids, total solids, pH, and electrical conductivity (EC) were investigated.
Findings: Coagulants efficiency in the turbidity removal was approximately identical. The maximum rates of removal of the turbidity related to lime (99.8%) and a minimum rate of removal was related to aluminum sulfate (86.4%). Poly aluminum chloride and lime were high efficiency in the removal of the total suspended solids. The maximum rates of removal of the total suspended solids related to lime (99.1%) and the minimum rate of removal was related to ferric chloride (57.3%). Alum and polymer efficiency in removal of the total solids was higher than other coagulants. The maximum rates of removal of total solids related to alum (82.5%) and the minimum rate of removal was related to polyaluminum chloride (70%).
Discussion and Use of coagulants can increase the treatment efficiency and accelerates return the water to cycle. Alum and lime have high performance in removal of turbidity, total suspended solids, and total solids and can be used for marble processing wastewater treatment.