Water purification plant promotes the increase of river network water quality

¹ School of Environmental Science and Engineering, Tianjin University, Jinnan district, Tianjin 300350, China
² Tianjin Water Conservancy Engineering Group Co., Ltd, Tianjin 300202, China
³ Tianjin Water Planning Survey and Design Co., Ltd, Tianjin 300204, China

^* Corresponding author: xyyou@tju.edu.cn

Abstract

This study investigates the potential of integrating Water Purification Plant (WPP) with Ecological Water Supplement (EWS) to improve urban river network water quality. The Tianjin Haihe River network is used to assess the effects of various water quality improvement scenarios, focusing on three key indicators: TP, NH₃-N and COD. Study results demonstrate that WPP significantly reduces water pollution. For the Water standards (Class V), compliance rates for COD, NH₃-N, and TP increasing from 44.63%, 65.16%, and 60.51% under no management to 64.38%, 93.10%, and 74.24%, respectively, when the WPP operates independently. The integration of EWS further improves water quality compliance, with compliance rates reaching 79.66%, 96.92%, and 98.12% in the scenario with 5.6 million tons of EWS treatment, and 93.88%, 99.22%, and 100.00% in the scenario with 28 million tons of EWS. The result shows that Scenario 3 is the optimal scheme, which combines 20 million tons of WPP and 5.6 million tons of EWS, with a total operating cost of 32.2 million yuan per year.