碱性介质中还原高浓度Cr(VI)细菌的分离及其特性

Isolation and Characteristics of Bacteria Reducing High Concentration of Cr (VI) in Alkaline Solution

目前国内外处理含铬废水的微生物仅局限于酸性或中性环境,且处理Cr(VI)的浓度仅为200mgL-1左右,难以工业化应用,尤其是不可能处理诸如铬渣渗滤液之类的碱性含铬废水及铬渣.本研究从铬渣堆埋场附近取得菌样,经富集、分离、驯化,得到能在碱性介质中高效还原Cr(VI)的无色杆菌属(Achromobactersp.)菌株,该菌为G-,具有周身鞭毛及可运动性.对其生理及还原Cr(VI)的特性进行了研究,结果表明:该菌嗜碱,好氧,耐盐及高Cr(VI),在有氧、pH为10.30、30℃等条件下,含Cr(VI)1570mgL-1的废水经该菌处理16h后浓度降至0.6mgL-1.处理后的沉淀物中铬以Cr(OH)3的非晶形态存在,其中总铬含量为21.44%,Cr(VI)检测不出,具有很大的回收价值.

The microorganisms for treating Cr （Ⅵ）-containing wastewater were limited in acidic and neutral systems at home and abroad. Moreover the concentration of Cr （Ⅵ） treated was only about 200 mg L-1 , which was difficult to be applied industrially and was impossible to deal with alkaline wastewater containing Cr （Ⅵ）. From the sludge next to the chromium slag, a strain with high reduction efficiency under alkaline condition was obtained and it belonged to genus Achromobacter sp. Its cell was of rod shape, gram-negative, flagellum and movability. The characteristics of its physiology and reduction of hexavalent chromium were also studied. The results showed that the strain could tolerate high salinity, concentration of Cr （Ⅵ） and alkalinity under aerobic condition. After 16 hours＇ treatment, the concentration of Cr （Ⅵ） in wastewater was reduced from 1 570 mg·L^-1 to 0.6 mg ·L^-1 under optimized conditions, i. e. , aerobic, pH = 10.30 and 300℃ The treated sediment contained 21.44% chromium in form of non-crystal, in which Cr （Ⅵ） was hardly detected, and it had great value of recycle. Fig 4, Tab 3, Ref 16