Dynamic simulation difference between inline chemical dosing injection with hybrid for phosphorous control(Case study: Standard WWTP design, A۲O method)

In wastewater treatment plants with different methods, important features are: ۱- Quality of effluent ۲- Energy consumption ۳- Chemical consumption. The aim of this study is to improve the quality of output while reducing the consumption of chemicals to remove phosphorus. In this research, the basic information of A۲O wastewater treatment plant design and laboratory results of the quality of incoming wastewater have been used. GPS-X software was used for simulation. After simulating the calibration with two modes: ۱- Daily changes of flow and ۲ -Weight of pollution and then annual temperature changes are applied. Three different scenarios for the injection of a specific chemical (lime & alum) are considered, which include the injection of the chemical in: ۱- sludge line only ۲- water line only ۳- both water & sludge line. The simulation results performed at the mean temperature and mean flow show that in the case of no chemical injection, the amount of phosphorus has a relatively high output in the period of ۴۶۲-۲۲۹ days (summer season). The amount of chemical used in the water line is more than the sludge line, but its performance is much better, and in the case that both are injected together, the amount of phosphorus is proportional to the dose of the chemical used. It is concluded that the amount of injection dose to the sludge line for stabilization (to reduce the phosphorus return line of the sludge after processing) depends on the final pH and about ۲.۸۴ kg / day, while to control the increase in sludge production due to the use of Line, holding tank can be used before drying bed. The amount of fine alum is about ۱.۵ kg per day for injection in the water line to reduce phosphorus, especially in summer.

Keywords:

A۲O , wastewater , dynamic simulation , GPS-X software , Phosphorous control