Improving the efficiency of small-scale wastewater treatment by pneumatic agitation

Sun，Shaohua1; Tong，Yanming1; Hou，Aiying1; Yin，Lijun1; Zheng，Tong1; Zheng，Jie2; Liu，Jicheng3; Cao，Bing1; Hu，Qing4,5; Coulon，Frederic6; Yang，Xiao Jin1

2022-05-01

10.1016/j.eti.2021.102220

Environmental Technology and Innovation   影响因子和分区

2352-1864

Small-scale anaerobic and aerobic systems for wastewater treatment suffer relatively low efficiencies due primarily to a lack of mechanical agitation/mixing. Here, a pneumatic agitation system was designed by installing a U-tube between the anaerobic and anoxic units, pumping air to the closed headspace of the anaerobic unit and releasing the pressurized air through the U-tube to create turbulence of the fluid. Computational Fluid Dynamics (CFD) simulation and fluid tracer trial were used to describe the fluid status in a lab-scale system (13 L). The results demonstrated that a continuous 5-cycle pneumatic agitation achieved a complete mixing of the static fluid. The retention time factor (β) and short-circuiting flow coefficient (t/HRT) were increased from 0.93 to 1.14 and 0.02 to 0.27, respectively, indicating that pneumatic agitation significantly reduced dead zone and short-circuiting flow. A prototype at a treatment capacity of 300 L/d was installed in the North-East suburb of Beijing (40.15° N, 116.95° E) to treat rural household wastewater consisting of 630–1200 mg/L chemical oxygen demand and 20–45 mg/L total nitrogen. The field test was monitored in a period of 75 days from September to November 2018. The average removal rate for COD and TN was 96% and 92%, respectively by 10 times/h pneumatic agitation as compared to 49% and 45% without pneumatic agitation. The pneumatic agitation provides a low cost, easy operation and maintenance and efficient means for small-scale domestic wastewater treatment.

Chemical oxygen demand Domestic wastewater treatment Pneumatic agitation Small-scale Total nitrogen

EI

英语

其他

20220211452326

Air ; Computational fluid dynamics ; Efficiency ; Nitrogen ; Oxygen ; Pneumatics ; Reclamation ; Wastewater treatment

Industrial Wastes Treatment and Disposal:452.4 ; Pneumatics:632.3 ; Computer Applications:723.5 ; Chemical Products Generally:804 ; Production Engineering:913.1 ; Mechanics:931.1

2-s2.0-85122511542

Scopus

1.State Key Laboratory of Chemical Resource Engineering and Department of Environmental Science and Engineering,Beijing University of Chemical Technology,Beijing,100029,China
2.Shunyi District Commission of Housing and Urban-Rural Development,Beijing,101300,China
3.Beijing OriginWater Technology Co.,Ltd,Beijing,102206,China
4.Engineering Innovation Center,Southern University of Science and Technology,Guangdong,Shenzhen,518055,China
5.Beijing Huanding Environmental Big Data Institute,Beijing,1 Wangzhuang Road,100083,China
6.School of Water,Energy and Environment,Cranfield University,Cranfield,MK43 0AL,United Kingdom

Sun，Shaohua,Tong，Yanming,Hou，Aiying,et al. Improving the efficiency of small-scale wastewater treatment by pneumatic agitation[J]. Environmental Technology and Innovation,2022,26.

Sun，Shaohua.,Tong，Yanming.,Hou，Aiying.,Yin，Lijun.,Zheng，Tong.,...&Yang，Xiao Jin.(2022).Improving the efficiency of small-scale wastewater treatment by pneumatic agitation.Environmental Technology and Innovation,26.

Sun，Shaohua,et al."Improving the efficiency of small-scale wastewater treatment by pneumatic agitation".Environmental Technology and Innovation 26(2022).