摘要
Abstract
[Objective]In recent years,the surrounding areas of cities in northern China have been undergoing rapid development.However,in early stage of development,many wastewater treatment plants(WWTPs)supporting the construction of various regions are faced with problems such as low water temperature and small load,while domestic research on this issue is still inadequate.[Methods]To explore the operational optimization of WWTPs under low temperature and low load conditions,taking a newly built small-scale urban domestic WWTP in the north as an example,comparing its design scale as well as the actual water quality and quantity of the inflow after its completion and operation.This study analyzed the existing problems and proposed technical reconstruction plans through process design research and full-process tracking experiments.[Results]During the initial operational period,the influent load of WWTP was less than 10%of the design capacity,and the extreme influent water temperature was only 2℃.This resulted in difficulties in equipment control,reduced microbial activity,and complete inhibition of biological nitrogen and phosphorus removal,severely affecting the normal operation of the WWTP.Through optimization and renovation of the biochemical and aeration systems,as well as the construction of a new heating system,the living environment for microorganisms was improved,and the operational efficiency of the WWTP was significantly enhanced.After the design and reconstruction were completed,the water temperature of the biological pool was stable at(15.1±1.3)℃,and the average temperature rise was 10.37℃.Compared with before the reconstruction,the comprehensive chemical consumption was saved by 46%,and the power consumption was reduced by 455 000 kW·h/a.At the same time,the effluent could meet the A emission limit requirements stipulated in the Integrated Discharge Standard of Water Pollutants(DB11/307-2013).[Conclusion]For small-scale urban domestic WWTPs under low temperature and low load conditions,operational optimization could be carried out by reducing the operational tank capacity,increasing the sludge load,and adding a heating system to achieve the goals of stable operation,energy saving,and consumption reduction.关键词
地表水Ⅲ类/低温/低负荷/系统改造/节能降耗Key words
class Ⅲ surface water/low temperature/low load/system reconstruction/energy saving and comsumption reduction分类
建筑与水利
