WATER AIR AND SOIL POLLUTION, cilt.234, sa.9, 2023 (SCI-Expanded)
The laboratory graduated cylinder and jar test methods are commonly used to evaluate the effectiveness of polymers in improving suspension settling rate and flocculation performance. However, these tests have different advantages and disadvantages over each other. This study aimed to compare the two methods in terms of their ability to evaluate the flocculation performance of wastewater suspensions while examining the influence of polymer type and dose on turbidity and settling rate. Anionic (M 155 and M 5250), cationic (SPP 355), and nonionic (M 351) polymer types at doses ranging from 5 to 50 g/t were utilized in the study. Results showed that there was a substantial difference between the turbidity and settling rate values obtained from the jar test and the cylinder test. The optimum dosage for both tests was found to be 30 g/t for M 351 and 20 g/t for M 155, M 5250, and SPP 355 polymers. All polymers performed well in terms of turbidity during the jar test, while poor flocculation was observed in the graduated cylinder test due to insufficient mixing and polymer adsorption. The M 5250 in the jar test and the M 155 in the cylinder test achieved the highest settling rates. The jar test was found to be more effective in determining the optimal polymer dosage and achieving better particle removal efficiency than the graduated cylinder test. The appropriate mixing conditions for flocculation were provided in the jar test, resulting in lower turbidity values. However, the settling rate values measured from the flocs formed in the direct cylinder test were more accurate. Overall, the study highlights the importance of selecting the appropriate test method for evaluating flocculation performance. The jar test may be more suitable for determining the optimal polymer dosage and achieving better particle removal efficiency, while the graduated cylinder test may be more appropriate for obtaining more accurate settling rate values.