Determination optimum treatment conditions of paint industry wastewater by coagulation method

In the thesis, optimum treatment conditions of paint industry wastewater were determined by coagulation method. The pollution values obtained in the characterization experiments were found to be above the wastewater discharge standards. Wastewater treatment experiments were performed in jar test set up. FeCl3.6H2O, Al2(SO4)3.18H2O, FeSO4.7H2O coagulants were used in the treatment experiments. pH, coagulant dose and mixing speed were selected the most important parameters for wastewater treatment. In the preliminary experiments COD, suspended solid, turbidity and color analyzes were performed for each coagulant. Determining the coagulant (FeCl3.6H2O) which provides the best treatment efficiency, Central Composite Design was applied for optimization of treatment conditions by using Response Surface Methodology. Design Expert 7.0.0. trial program was used for design of treatment experiments and analysis of results. COD, color, turbidity and suspended solid values were processed to the program after experiments. 3D graphs and ANOVA results which shown by program were interpreted. The equations obtained using the coefficients in the model created by the program were solved and the optimum values of the independent variables were calculated. Using these values, the lowest pollution load values were determined as (mg/L) COD 68.636, color 2.42 Pt-Co, turbidity 1.79 NTU, SS 10.135. Optimization results of the program were examined, the optimum values of parameters were suggested pH 7.54, coagulant amount 1080.49 mg/L, mixing speed 146.16 rpm/min. The lowest pollution values at optimum conditions were shown as (mg/L) COD 71.07, color 1 Pt-Co, turbidity 2.74 NTU, SS 7.5.