折流板水车驱动生物转盘水力流态及启动挂膜试验

Experiment of Hydraulic Flow Pattern and Biofilm Formation Start-Up for the Waterwheel Driving Baffled Rotating Biological Contactor

针对水车驱动生物转盘(wdRBC)存在的短流问题,提出了在接触槽内增设折流板的措施加以改进,运用示踪剂NaCl脉冲响应试验,研究改进前后反应器水力特性,并采用快速排泥法启动折流板水车驱动生物转盘(wdbRBC)。结果表明:在同一水力停留时间(hydraulic retention time,HRT)下,改进后的反应器死区率降低,由35.29%、28.83%下降到3.10%、8.19%,水力流态明显改善,N值由2.03、2.78提高到7.77、5.78,Pe值由2.64、4.27增大到14.47、10.45;在不同HRT下,wdbRBC的停留时间分布(RTD)曲线相似,随着HRT的增大,N值和Pe值略有减小,死区率略有上升;此外,wdbRBC历时10 d即实现了反应器的稳定运行,最终出水CODCr<15 mg/L,氨氮<5 mg/L,COD和氨氮平均去除率均在90%左右,达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。

In order to solve the short-flow problem of waterwheel driving rotating biological contactors(wdRBC),it was proposed to add baffles in contact tank.In clear water,the hydraulic flow pattern of wdRBC and waterwheel driving baffled rotating biological contactors(wdbRBC)was studied by pulse response method using NaCl as the tracer.In addition,wdbRBC was started by rapid mud discharge method.Result indicated that under the same hydraulic retention time(HRT),the dead zone rate of improved reactor was reduced,from 35.29%and 28.83%to 3.10%and 8.19%,the hydraulic flow pattern was obviously improved,N value was increased from 2.03 and 2.78 to 7.77 and 5.78,and Pe value was increased from 2.64 and 4.27 to 14.47 and 10.45.Under different HRTs,the RTD curve of wdbRBC was similar,with the increase of HRT,N value and Pe value decreased slightly,and dead zone rate increased slightly.Stable operation of wdbRBC was realized in 10 d.Final effluent concentration of CODCr was stably below 15 mg/L,final effluent concentration of ammonia nitrogen was below 5 mg/L,and the average removal rate of COD and ammonia nitrogen was about 90%,reaching the first class A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918—2002).