Abstract:
To study effects of velocity gradient and organic loading rate on treatment of concentrated latex wastewater by ASBR system. The experiment of cycle number was performed at 1-4 cycle at 1, 3, 5 and 7 days at constant velocity gradient 60 sec[superscript -1] with organic loading rate 3 kgCOD/(m[superscript 3] .d). The system performance for COD removal were found to be 77.91, 80.59, 82.97 and 85.22 %, respectively . Then, the velocity gradients of the system were varied to 40, 60, 80 and 100 sec[superscript -1] and organic loading rates were reduced to be 3, 2, 1 and 0.5 kgCOD/(m[superscript 3].d), it was found that at organic loading rate 3 kg COD/(m[superscript 3].d) and operating velocity gradients at 40, 60, 80 and 100 sec[superscript -1] , removal percentages for COD were 77.05, 85.22, 80.97 and 79.19 %, respectively ; for sulfate were 55.35, 67.66, 63.79 and 58.85 %, respectively ; and for suspended solid were 80.36, 96.00, 92.72 and 86.72 % ; respectively. Also, at organic loading rate 2 kgCOD/(m[superscript 3] .d) and operating velocity gradients at 40, 60, 80 and 100 sec[superscript -1] , removal percentages for COD were 79.57, 87.28, 82.72 and 80.97 %, respectively ; for sulfate were 60.50, 68.44, 66.35 and 63.05 %, respectively ; and for suspended solid were 82.47, 96.62, 93.30 and 88.10 % ; respectively. It was found that at organic loading rate 1 kgCOD/(m[superscript 3] .d) and operating velocity gradients at 40, 60, 80 and 100 sec[superscript -1] , removal percentages for COD were 80.95, 89.63, 85.54 and 85.28 %, respectively ; for sulfate were 69.98, 73.98, 73.63 and 70.98 %, respectively ; and for suspended solid were 86.14, 94.21, 92.73 and 88.60 % ; respectively. Moreover, it was found that at organic loading rate 0.5 kgCOD/(m[superscript 3].d) and operating velocity gradients at 40, 60, 80 and 100 sec[superscript -1], removal percentages for COD were 85.05, 93.35, 90.65 and 88.10 %, respectively ; for sulfate were 77.30, 93.08, 88.11 and 79.74 %, respectively ; and for suspended solid were 84.19, 95.01, 90.03 and 88.64 % ; respectively. Therefore, the optimum condition for treatment of latex wastewater by ASBR system is suggested to be with cycle period of 7 days and velocity gradient of 60sec[superscript -1].