Liao Zhenliang, Hu Tiantian, Roker Scott Albert C
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.
United Nations Environment Program-Tongji Institute of Environment for Sustainable Development, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
Environ Sci Pollut Res Int. 2015 Nov;22(21):16434-40. doi: 10.1007/s11356-015-5307-8. Epub 2015 Sep 5.
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.
2001年,中国开展了一场关于污水处理厂的建设运动。遗憾的是,处理效果尚未达到预期。造成这种情况的一个关键原因是污水处理厂进水的化学需氧量(COD)和生化需氧量(BOD)浓度低得令人无法接受。本文指出,造成这一问题的一个基本但常被忽视的因素是,很大一部分易降解的COD和BOD在进入城市下水道之前就被过早降解了,这与中国向城市下水道排放污染物的标准直接相关。通过回顾中国污水处理的历史以及对发达地区标准的调查,进一步阐述了这一观点。本文建议,在中国,应放宽向城市下水道排放污染物的标准。同时,应停止对COD和BOD进行不必要的预处理,以确保易降解的COD和BOD能够转移到污水处理厂,提高处理效率。此外,还提出了其他解决这一问题的办法。