Biological removal of selenate in saline wastewater by activated sludge under alternating anoxic/oxic conditions  

作　　者：Yuanyuan Zhang Masashi Kuroda Shunsuke Arai Fumitaka Kato Daisuke Inoue Michihiko Ike 

机构地区：[1]Division of Sustainable Energy and Environmental Engineering,Graduate School of Engineering,Osaka University,2-1 Yamadaoka,Suita,Osaka 565-0871,Japan [2]Nippon Steel&Sumitomo Metal Corporation,20-1 Shintomi,Futtsu,Chiba 293-8511,Japan

出　　处：《Frontiers of Environmental Science & Engineering》2019年第5期39-49,共11页环境科学与工程前沿（英文）

摘　　要：Selenium (Se)-containing industrial wastewater is often coupled with notable salinity. However, limited studies have examined biological treatment of Se-containing wastewater under high salinity conditions. In this study, a sequencing batch reactor (SBR) inoculated with activated sludge was applied to treat selenate in synthetic saline wastewater (3% w/v NaCl) supplemented with lactate as the carbon source. Start-up of the SBR was performed with addition of 1–5 mM of selenate under oxygen-limiting conditions, which succeeded in removing more than 99% of the soluble Se. Then, the treatment of 1 mM Se with cycle duration of 3 days was carried out under alternating anoxic/oxic conditions by adding aeration period after oxygen-limiting period. Although the SBR maintained soluble Se removal of above 97%, considerable amount of solid Se remained in the effluent as suspended solids and total Se removal fluctuated between about 40 and 80%. Surprisingly, the mass balance calculation found a considerable decrease of Se accumulated in the SBR when the aeration period was prolonged to 7 h, indicating very efficient Se biovolatilization. Furthermore, microbial community analysis suggested that various Se-reducing bacteria coordinately contributed to the removal of Se in the SBR and main contributors varied depending on the operational conditions. This study will offer implications for practical biological treatment of selenium in saline wastewater.

关 键 词：Activated sludge SELENATE reduction SALINE wastewater Sequencing batch reactor ALTERNATING anoxic/oxic CONDITIONS Selenium biovolatilization 

分 类 号：X70[环境科学与工程—环境工程]