Optimization of Phosphate Removal in Industrial Wastewater Treatment Plant in SBR and MBBR Units

Abstract

Nowadays, due to the increasing need for water, protection of water resources against pollution, especially prevention of dirt leakage and reuse of sewage, is one of the main priorities of societies, and extensive investment for sewage treatment has become inevitable. In this research, the simulation of the performance of the industrial wastewater treatment plant in the BioWIN software for the biological and chemical removal of phosphorus, and the change of the functional program of the sequential discontinuous reactor system in order to achieve the best efficiency, were carried out. According to the obtained results, in the SBR system, the best working conditions are found by combining the sludge return of 1.27 m3/day from the sedimentation tank to the anaerobic unit, converting the second series anaerobic units to the aerobic unit and injecting a nitrogen solution of 10 g/L with a flow rate of 1 m3/day; So that after two weeks, the amount of phosphate at the outlet of the refinery decreased to zero. In the MBBR system, any of the nitrogen source injection solutions, adequate aeration and alum injection can reduce the phosphate concentration in the effluent to zero. Nitrogen injection rate and sludge return percentage in SBR system and selection of appropriate dose of alum injection and aeration rate in MBBR system, are the key variables of wastewater treatment. In order to achieve the optimal conditions for phosphorus removal, the optimal limit of each of these main variables is selected by simulating and considering technical, executive and economic factors.

Keywords

• treatment
• industrial wastewater
• sequencing-batch-reactor
• moving-bed-biofilm-reactor
• biowin
• phosphorus