EFFECT OF DIFFERENT FACTORS ON MAGNETIZED ACTIVATED SLUDGE-TREATED WASTEWATER.

The performance of traditional and magnetized activated sludge treatment systems was compared in a sequencing batch reactor. Four influencing factors, namely, magnetic powder dosage, temperature, aeration time, and magnetic field size, which affected the efficiency of sludge treatment were investigated with the evolution of the principal sewage indexes: chemical oxygen demand, ammonia nitrogen, total nitrogen, and total phosphorus. Results revealed that the efficiency of sewage treatment with magnetized activated sludge was better than that of traditional activated sludge. Its elimination rates of COD, ammonia nitrogen, TN, and TP were approximately 96.4%, 98.9%, 86.4%, and 94.2%, respectively, compared with the activated sludge that was not exposed to a magnetic field (90.7%, 78.4%, 53.5%, and 87%, respectively). The magnetic powder dosage of 0.5 g/L was optimal for pollutant removal. The temperature of 25 °C-30 °C, aeration time of 4 h, and applied magnetic field of 200 Gs achieved the best effect in the comprehensive consideration of economic aspects and processing indicators. [ABSTRACT FROM AUTHOR]