An obstacle to China's WWTPs: the COD and BOD standards for discharge into municipal sewers.
In 2001, a construction campaign regarding wastewater treatment plants (WWTPs) occurred in China. Unfortunately, the treatment has not yet achieved anticipated effectiveness. A critical reason for this is that the influent chemical oxygen demand (COD) and biochemical oxygen demand (BOD) concentrations in WWTPs are unacceptably low. This paper indicates that a fundamental, but commonly overlooked contributing factor to this problem is that a large portion of easily degradable COD and BOD is degraded prematurely before entering municipal sewers, and this is directly correlated to China's standards for pollutant discharging into municipal sewers. This perspective is further unfolded through retrospection of the history of Chinese wastewater treatment and the investigation of standards among developed zones and districts. This paper suggests that in China, the standards for pollutant discharging into municipal sewers should be relaxed. Meanwhile, unnecessary pretreatment of COD and BOD should cease for the purpose of ensuring that easily degradable COD and BOD can be transferred to WWTPs to improve treatment efficiency. Moreover, additional alternatives are presented to resolve this problem.
Key Laboratory of Yangtze River Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China. zl_liao@tongji.edu.cn.|United Nations Environment Program-Tongji Institute of Environment for Sustainable Development, Tongji University, 1239 Siping Road, Shanghai, 200092, China. zl_liao@tongji.edu.cn.
Zhenliang
http://orcid.org/0000-0002-1267-7460
Z
Liao
Key Laboratory of Yangtze River Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
Tiantian
T
Hu
United Nations Environment Program-Tongji Institute of Environment for Sustainable Development, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
Scott Albert C
SA
Roker
D057919:Biological Oxygen Demand Analysis / Q000592:standards*; D002681:China; D002947:Cities; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000592:standards*; D014874:Water Pollutants, Chemical / Q000737:chemistry
D012722:Sewage; D014874:Water Pollutants, Chemical
Discharge; Influent concentrations; Municipal sewers; Standards; Wastewater treatment plants