Improvement of the Treatment Performance of the Conventional Wastewater Treatment Plant: A Case Study of the Central Wastewater Treatment Plant in Ulaanbaatar, Mongolia

This study is carried out within the framework of the requirements of ensuring reliable operation of the Central Wastewater Treatment Plant of Ulaanbaatar to increase the treatment performance and mitigate the adverse impacts of the current poor performance on nature and ecology. The dynamic of the current influent was studied in order to find the best-suited solution as a means of improvement for the WWTP. As an immediate and fast-to-build solution, an equalization tank and pre-aeration facilities were proposed. The positive effect of the facilities on the biological treatment stage and the overall treatment performance was estimated both theoretically and empirically. The results showed that the overall performance of the treatment for BOD5 and TSS will be increased by up to 30% and 10%, respectively. Furthermore, the high fluctuation problems the central WWTP in terms of hydraulic and pollution load will be positively affected by the intervention, eliminating the main cause of the current poor treatment performance.