تحسين أداء محطة معالجة مياه الصرف الصحي في كربلاء من خلال التغير في العوامل التشغيلية المؤثرة للمحطة باستخدام نموذج GPS-X

Improving the Performance of the Karbala Wastewater Treatment Plant by Manipulating the Influencing Operational Parameters of the Plant Using GPS-X Model

Abstract

Conventional wastewater treatment plants, especially those containing tertiary phase and nutrient removal, have very complex chemical and biological kinetics. Because of the characteristics and nature of wastewater, it always needs continuous improvements, which must be carefully studied before they are made. An optimized operating system increases plant efficiency, reduces energy consumption, and achieves environmental limits for plant output. In the present study, a new strategy to reduce nutrient concentrations, reduce energy, and improve plant output in a large-scale plant is studied by the GPS-X model. The data were collected accurately from the management of the station.
Calibration and model validation were performed, some sensitive parameters were modified, and the results were validated by using statistical parameters of R and RMSE. Sensitivity analysis showed that the most important factor for reducing nitrogen and phosphorous concentrations is the biodegradable fraction Readily Biodegradable COD (rbCOD). Internal Recycl (IR), Return Activated Sludge (RAS), Dissolved Oxygen (DO), and waste Activated Sludge (WAS) fluxes were reduced from 3% to 1%, from 100 to 20%, from 3.5 to 2 mg/L, and from 3,500 to 1,000 m3/day, respectively. Optimization results provided power of 688.4 kWh and sludge reduction by 32%. The results showed that it is not feasible to obtain an IR of 3% due to the deficiency of rbCOD at concentrations sufficient to contribute to the nitrate reduction. The decrease in rbCOD concentrations in the wastewater of Karbala city requires chemical upgrade, that was done by adding an external source of carbon represented by acetic acid, propionic acid, methanol, and glycerol, and the results were good, and this led to an improvement by reducing TN and TP by (60% and 77%), (68% and 79%), (71% and 77%), and (29% and 38%), respectively. The best external carbon source was methanol, while glycerol was less effective than the rest. The pre-denitrification process was compared with the post-denitrification process by adding methanol as an external carbon source. The results were good for reducing TN in the post-denitrification process, which reached 80%, while the effect was negative on the remaining pollutants.
The study concluded that process of organizing treatment plant and conducting a proper mass balance contributes to reducing energy and improving the biological processes of the plant. The GPS-X program has contributed to giving a complete effective and very close to reality, also its recommend use in the departments of sewage directorates and engineers working in this field.