《深入打好城市黑臭水体治理攻坚战实施方案》的发布，让不少目光聚焦到了更为细致的地方，如：建立健全垃圾收集(打捞)转运体系，不应盲目提高污水处理厂出水标准、新扩建污水处理厂，到 2025 年，进水BOD 浓度高于 100 毫克/升的城市生活污水处理厂规模占比达90%以上，严格做好‘农家乐’、种植采摘园等范围内的生活及农产品产生污水及垃圾治理，黑臭水体整治不力问题纳入中央生态环境保护督察和长江经济带、黄河流域生态环境警示片现场调查拍摄范畴，落实污水处理收费政策，推广以污水处理厂进水污染物浓度、污染物削减量和pollutant treatment quantity等支付运营服务费。
本文就“进water BOD”这个问题来探讨一下。
What is BOD?
BOD, Biochemical Oxygen Demand, refers to the amount of dissolved oxygen consumed by microorganisms in the process of decomposing organic matter in water under certain conditions. It is a comprehensive indicator reflecting the content of organic pollutants in water and an important parameter for assessing water quality.
Why can't we just reduce BOD levels?
From the above definition, high BOD values indicate higher levels of organic pollutants. However, it's not that low BOD values are always better. The main contradiction lies in whether or not there is a clear separation between sewage and rainwater.
From BOD to rain-water separation and pipe network improvement
Experts generally believe that most direct causes of low incoming wastewater BOD concentrations can be attributed to non-domestic wastewater discharges into rivers and slow pipe flow rates (where much of the BDO settles within pipes). This is why "incoming wastewater BOD" has become such a focus point: it highlights issues with cities' mixed sewer systems where both sanitary sewage and stormwater are combined into one system before reaching treatment plants; inadequate or outdated pipe networks; as well as lack of maintenance.
Rainwater separation renovation projects have been repeatedly emphasized but remain challenging due to their widespread nature across cities. Moreover, there are concerns about price mechanisms involved in supporting infrastructure improvements for pipework construction which makes this task even more daunting.
The industry estimates new pipeline construction investment per kilometer at around 170 million yuan ($24 million), indicating substantial market potential for improving urban drainage systems during China's "14th Five-Year Plan" period (2021-2025).
Notably, applications have opened for the second batch of nationwide demonstration projects promoting sponge city construction work until its end date when all participating cities must achieve an average incoming wastewater biochemical oxygen demand (BODB) concentration exceeding 100 mg/L according to official guidelines—a goal that will likely spur further efforts towards upgrading urban drainage networks among related businesses concerned about these opportunities arising from such initiatives.
This article explores how policymakers' attention on incoming wastewater biochemical oxygen demand (BODB) reflects deeper concerns over polluted river bodies through addressing shortcomings like inadequate waste collection systems and insufficiently separated sewage outlets along with plans aimed at improving urban drainage networks during China's "14th Five-Year Plan".
标签： 地理人物
