利用氢基质生物膜反应器同步去除多种污染物

Simultaneous Removal of Selected Oxidized Contaminants from Groundwater with a Hydrogen based Membrane Biofilm Reactor

摘要:

利用氢基质生物膜反应器(hydrogenbased membrane biofilm reactor, MBfR)对含有多种氧化性污染物包括硝酸盐(NO-3N)、硫酸盐(SO2-4)、溴酸盐(BrO-3)、六价铬(Cr(Ⅵ))和对氯硝基苯(pCNB)的模拟地下水进行同步去除试验研究.结果表明，MBfR中生长于中空纤维膜表面的氢自养还原菌利用氢气作为电子供体进行自养还原反应，将水中NO-3N还原成N2，SO2-4还原成硫化物(S2-/H2S)，BrO-3还原成Br-，Cr(Ⅵ)还原成Cr(Ⅲ)，pCNB逐步还原成对氯苯铵(pCAN)和苯胺(AN).通过生物还原达到对氧化性污染物的去除或毒性的降低.在氢分压为0.06 MPa和水力停留时间为4.67 h条件下，经过生物膜驯化及32 d的连续运行，反应器对各种氧化性污染物的去除性能达到稳定：NO-3N和 BrO-3近于完全去除，SO2-4去除率达19.8%，Cr(Ⅵ)去除率达85.8%，pCNB去除率达86.1%.研究表明，利用氢基质生物膜反应器处理含多种氧化性污染物的地下水可行，且具有一定应用潜力.

Abstract:

A hydrogen based membrane biofilm reactor (MBfR) was applied for simultaneous biodegradation of selected oxidized contaminants in groundwater including nitrate (NO-3N), sulfate (SO2-4), bromate (BrO-3), chromate (Cr(Ⅵ)) and para chloronitrobenzene (pCNB). The autohydrogentrophic bacteria lived on the membrane surface bioreduced nitrate to N2, sulfate to sulfide (S2-/HM2S), bromate to bromide ion (Br-), Cr(Ⅵ) to Cr(Ⅲ) and pCNB to pCAN and AN with hydrogen as electron donor. Removal and/or toxicity decrease of these oxidized contaminates was achieved through biological reduction. After biofilm enrichment and 32 d continuous running, the reactor reached a steady state for removing oxidized contaminates with a nearly complete removal for nitrate and bromate, 19.8% for sulfate, 85.6% for chromate, and 86.1% for pCNB, under the hydrogen pressure at 0.06 MPa and hydraulic retention time at 4.67 h. The results show that the MBfR technology can be effective for removal of oxidized contaminates and of a potential application in the treatment of groundwater.