【摘要】：在自然環(huán)境中,砷通常吸附于鐵氧化物、鋁氧化物等金屬氧化物礦物上,或與這些氧化物礦物形成共沉淀。厭氧條件下,微生物可能通過直接還原砷或者還原鐵氧化物等載砷礦物從而影響砷的遷移轉(zhuǎn)化。本研究篩選得到芽孢桿菌屬的一株細(xì)菌DX-04,并研究了該菌株對不同形態(tài)砷酸鹽的還原作用和還原途徑。厭氧條件下,在12~24 h內(nèi)菌株DX-04對溶解態(tài)砷的還原能力最強(qiáng),溶解態(tài)砷對提高細(xì)菌生物量具有明顯的促進(jìn)作用。接種菌株DX-04的鐵砷共沉淀培養(yǎng)基中液相As(III)濃度呈先升高后降低的趨勢,砷發(fā)生還原與釋放,進(jìn)而發(fā)生二次沉淀再次被固持。當(dāng)以載砷氧化鋁礦物為載砷的模型礦物時,在DX-04菌株的還原作用下,吸附的As(V)首先從氫氧化鋁礦物上釋放到液相,進(jìn)一步被還原為As(III)。微生物的這一作用能夠引起含砷礦物中的砷向水體、沉積物環(huán)境中釋放,成為人類健康的潛在威脅。
[Abstract]:In the natural environment, arsenic is usually adsorbed on or coprecipitated with iron oxide, aluminum oxide and other metal oxide minerals. Under anaerobic conditions, microbes may influence the migration and transformation of arsenic through direct reduction of arsenic or reduction of arsenic bearing minerals such as iron oxides. In this study, a Bacillus strain DX-04was selected, and the reduction of arsenate in different forms was studied. Under anaerobic condition, the strain DX-04 had the strongest ability to reduce dissolved arsenic within 24 h, and dissolved arsenic could obviously promote the biomass of bacteria. The concentration of As (III) in the ferric arsenic coprecipitation medium of the inoculated strain DX-04 increased first and then decreased, the arsenic was reduced and released, and then the secondary precipitation was fixed again. When the arsenic bearing alumina mineral was used as the model mineral, the adsorbed As (V) was first released from the aluminum hydroxide mineral to the liquid phase under the reduction of DX-04 strain, and further reduced to As (III). This action of microorganism can cause arsenic from arsenic bearing minerals to release into water and sediment environment and become a potential threat to human health.
【作者單位】： 中國科學(xué)院沈陽應(yīng)用生態(tài)研究所污染生態(tài)與環(huán)境工程重點實驗室;中國科學(xué)院大學(xué);
【基金】：國家自然科學(xué)基金項目(41273133)資助
【分類號】：X172;Q939.9
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本文編號：2186521