The Effect of MLSS Values on Removal of COD and Phosphorus Using Control Method of Return Activated Sludge Concentration

摘要

The process of biodegradation by activated sludge for wastewater treatment plants in operation is a common matter, especially when the appropriate conditions are available. Such conditions can include the process of sludge transportation and ease of sludge transfer; The addition of the sludgeis also easy to control. Herein we present one example where in sludge was brought to Mahram Aisha treatment plant in Iraq from another plant during the beginning of its operation. In this case, sludge was brought from another plant due to the increased velocity of the MLSS concentration. Indeed, on the 1st and 2nd days, during the addition of 20 m ~( 3 ) of the wet sludge, the sludge concentration ratios reached 550 mg. This method of adding the sludge is the best efficient method in terms of the speed of getting to the required determinants after controlling DO concentrations in the aeration basin. These concentrations were 2 mg/L during the periods of operation and the temperature remained at 25°C. After the stability of the return sludge, the concentrations of MLSS were compared with COD, phosphorus, froth and SVI by controlling the returning sludge while taking into account the influence of the returning sludge on the COD concentration, phosphorus and on the indicator of SVI and froth where the phosphorus removal efficiency is 50% without the EBPR system. At the same quantity, 95% of COD was removed. The quantity of SVI is 60 mL/g and there was a 99% reduction in the froth quantity.