氢基质生物膜反应器去除水中硒酸盐研究

利用连续搅拌氢基质生物膜反应器研究氢气(H2)分压,NO3--N,SO42-,SeO42-进水浓度对水中硒酸盐去除效果的影响.结果表明,H2分压是水中氧化态污染物NO3-,SO42-,SeO42-去除效果的重要影响因素,随着H2分压从0.02MPa上升到0.08MPa,SO42-的去除率从3.5%上升到46.3%,总Se的去除率从60.7%上升到82.1%,NO3-全过程都完全被还原为N2;随着NO3--N进水浓度从5mg/L增加到50mg/L,SO42-,SeO42-的去除率逐渐下降至0,并出现NO2-的积累;SO42-进水浓度的增加对NO3-,SeO42-去除效果影响不大,去除率分别保持在99.5%和65%以上,三种氧化态污染物得电子的优先级为NO3->SeO42->SO42-.在NO3--N浓度为10mg/L,SO42-浓度为25mg/L的水质条件下,反应器设置H2分压为0.04MPa,进水Se(VI)浓度在0.25~2mg/L的范围内总Se可以取得80%以上的去除效果.

Removal of selenate from aqueous solution by hydrogen-based membrane biofilm reactor.

A continuous stirred hydrogen-based membrane biofilm reactor (CS-MBfR) was used to investigate the effects of the H2 pressure and the influent concentrations of NO3-, SO42- and SeO42- on the removal of SeO42- from aqueous solution. As the experiment results showed, H2 pressure was a key factor influencing the removal of NO3-, SO42- and SeO42-. With the increase of H2pressure from 0.02MPa to 0.08MPa, the removal rates of SO42- and total Se increased from 3.5% and 60.7% to 46.3% and 2.1%, respectively, while NO3- was completely reduced to N2 throughout the process. When influent NO3- concentration increased from 5 to 50mg/L, the removal rates of SO42- and SeO42- gradually decreased to 0, and the NO2- accumulation was observed. The removal of NO3- and SeO42- was not affected by increasing influent SO42- concentration, and their removal rates were above 99.5% and 65%, respectively. The priority sequence of electron accepting ability is NO3->SeO42->SO42-. Under the conditions of H2 pressure 0.04MPa, NO3- 10mg/L, SO42- 25mg/L, and Se (VI) 0.25~2mg/L, the removal rate of total Se was above 80%.