浸没式MBR在高盐高钙选矿废水深度处理中应用工艺优化  

Operational conditions optimization for tertiary treatment of salt and calcium enriched mineral processing wastewater using submerged MBR

作　　者：李爽 杨永哲[1] 樊嘉文 LI Shuang;YANG Yongzhe;FAN Jiawen(School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055

出　　处：《环境工程学报》2021年第1期203-214,共12页Chinese Journal of Environmental Engineering

基　　金：陕西省重点科技创新团队计划(2017KCT-19-01);陕西省重点产业链(群)项目(2017ZDCXL-GY-07-02)。

摘　　要：为实现高盐高钙选矿废水高效脱氮并探明浸没式膜生物反应器(submerged membrane bioreactor,SMBR)在选矿废水深度脱氮中应用的工艺条件,研究了水力停留时间(hydraulic retention time,HRT)和水温对硝化-反硝化特征的影响,运行与间歇时间之比和运行周期对膜污染特征和机理的影响,根据出水水质及其稳定性、膜污染周期和SMBR运行稳定性确定最佳工艺条件。结果表明:在水温高于15℃及HRT分别为1.25、2.34、2.50NH^(+)_(4)-N浓度为(593.15±134.23)mg·L^(-1)(平均值±标准差),平均去除率分别为95.90%、81.30%、98.38%和99.91%;进水TN浓度为(688.39±163.97)mg·L^(-1),平均去除率分别为85.84%、56.97%、54.46%和87.93%。SMBR脱氮良好,且随着HRT的延长,脱氮效率提高,运行稳定性增加,最佳HRT为4.50 d。根据不同水温条件下的硝化-反硝化特征,确定硝化速率和反硝化速率的温度修正系数分别为1.05和1.03;20℃和9℃(最不利水温)的硝化速率分别为0.0229 kg·(kg·d)^(-1)和0.0129 kg·(kg·d)^(-1),反硝化速率分别为0.0907 kg·(kg·d)^(-1)和0.0642 kg·(kg·d)^(-1)。为确保最不利水温条件下的硝化-反硝化效果,HRT应不小于5.40 d。当最不利水温持续时间较短时,HRT宜采用4.50 d,并通过延长污泥龄的方法保证脱氮效果。在运行周期固定为12 min、运行与间歇时间之比分别为5∶1和2∶1的条件下,膜运行时长分别为6.70 d和11.14 d,缩短运行与间歇时间的比例有利于延长膜运行时长;在运行与间歇时间之比固定为2∶1,运行周期分别为12 min和6 min的条件下,膜运行时长分别为11.14 d和65.42 d,缩短运行周期有助于控制膜污染;根据膜污染特征与运行时长,确定最佳运行/间歇时间为4 min/2 min。以上结果表明了SMBR处理高盐高钙选矿废水的最佳工艺条件,可为SMBR在实践工程应用中提供理论依据。To achieve the aim of efficient nitrogen removal from salt and calcium enriched mineral processing wastewater and explore the operational conditions for tertiary nitrogen removal by submerged membrane bioreactor(SMBR),the effects of hydraulic retention time(HRT)and water temperature on the characteristics of nitrification-denitrification were studied,and the effects of the ratio of operation to intermittent time and the operation period on the characteristics and mechanism of membrane fouling were also investigated.The optimum operational conditions were determined by the effluent quality and stability,membrane fouling cycle and operation stability.Results showed that when the water temperature was above 15℃and HRT was 1.25,NH^(+)_(4)-N concentration was(593.15±134.23)mg·L^(-1),the corresponding average removal efficiencies were 95.90%,81.30%,98.38%and 99.91%,respectively.The influent TN concentration was(688.39±163.97)mg·L^(-1),the corresponding average removal efficiencies were85.84%,56.97%,54.46%and 87.93%,respectively.SMBR had an excellent nitrogen removal performance.The nitrogen removal efficiency and operation stability increased with the increase of HRT,and the optimal HRT was 4.50 d.According to the nitrification-denitrification characteristics at different water temperature,the temperature correction coefficient for nitrification-denitrification rates were 1.05 and 1.03,respectively.At20℃and 9℃(the lowest water temperature),the nitrification rates were 0.0229 kg·(kg·d)^(-1) and 0.0129 kg·(kg·d)^(-1),the denitrification rates were 0.0907 kg·(kg·d)^(-1) and 0.0642 kg·(kg·d)^(-1),respectively.To ensure the nitrification-denitrification ability under the most unfavorable water temperature(the lowest water temperature,9℃),HRT should not be less than 5.40 d.When the duration of the most unfavorable water temperature was short,HRT should be 4.50 d,and the nitrogen removal effect could be ensured by prolonging sludge retention time.At the operation period of 12 min and the operation time to

关 键 词：浸没式膜生物反应器 高盐高钙选矿废水 硝化-反硝化特征 运行/间歇时间 

分 类 号：X703.1[环境科学与工程—环境工程]