Optimal Condition of Coagulation Process Using Poly Aluminium Chloride in Dairy Wastewater Treatment

With increasing the dairy products, particularly cheese, the problem of pollution arisen from the corresponding wastewaters and their treatment is being more serious than before. One of the used treatment methods for such wastewaters is coagulation process. This study was done with the aim of determining optimal condition of coagulation process for dairy wastewater treatment using poly Aluminium chloride (PAC).
At first, the coagulation process with PAC coagulant was used under laboratory conditions. By changing important parameters affecting the system pH (2-12) and coagulant dosage (5-100 mg/L), the decreasing of quality parameters of effluent such as Chemical Oxygen Demand(COD), Biological Oxygen Demand(BOD), Total Kjehldahl nitrogen (TKN), Total Phosphorous(TP) and Total Dissolved Solids (TDS) were obtained.
Experiments showed the removal efficiency ofCOD, BOD, TKN, TP, and TDS in pH 8 and coagulant dosage of 50 mg/L at 22±2 °C can be reached to 74.51, 84.81, 68.24, 65.46 and 85.69, respectively, which were the highest amounts among the pHs and coagulant dosages studied.
The results showed that PAC coagulant is able to improve quality parameters of dairy wastewaters to standard levels. Because of availability, easy operation and acceptable removal efficiency for this wastewater type, PAC coagulant can be used for treatment of dairy industries wastewater.