一株典型伯克氏菌对Cr（Ⅵ）/Cu（Ⅱ）复合污染的吸附转化

Biosorption and biotransformation of Cr(Ⅵ)/Cu(Ⅱ) combined pollutant by Burkholderia sp.

工业废水和环境污染中往往含有两种或以上的金属离子,因此筛选分离能吸附多种重金属的菌株是利用微生物技术治理环境重金属污染的关键。从剩余污泥中筛选获得一株能耐受重金属Cr和Cu的细菌,经鉴定为伯克氏菌(Burkholderia sp.),命名为Y-12,用于开展水体Cr(Ⅵ)/Cu(Ⅱ)复合污染微生物吸附转化研究。结果表明,Y-12对Cr(Ⅵ)和Cu(Ⅱ)的吸附规律不同。随时间延长,Cr(Ⅵ)的去除率逐渐增大,但是共存Cu(Ⅱ)的去除率在2.00h达到最大值之后却又逐渐被解吸出来;Y-12去除Cr(Ⅵ)/Cu(Ⅱ)复合污染的最佳pH为6,强酸条件下,Y-12对Cr(Ⅵ)的吸附受到抑制,而当溶液pH为9时,Y-12主要通过还原作用对Cr(Ⅵ)进行解毒;Cr(Ⅵ)浓度越大越不利于Cr(Ⅵ)的去除,溶液中Cu(Ⅱ)浓度变化对Cr(Ⅵ)去除没有显著影响。由此可见,在适宜环境条件下,Y-12能有效去除水体中Cr(Ⅵ)/Cu(Ⅱ)复合污染,具有广泛的应用前景。

Screening and isolation of strains capable of adsorbing various heavy metals is the key to control the pollution of heavy metals by microbial technology.The biosorption and biotransformation properties of Cr(Ⅵ)/Cu(Ⅱ)by an isolated strain named Y-12 were used to reveal the removal of combined heavy metals by microbe.The results indicated that the specific strain Y-12 with high adsorption performance was isolated from urban sludge,and had been identified as Burkholderia sp.The adsorption properties of Cr(Ⅵ)and Cu(Ⅱ)by Y-12 were totally different.The removal rate of Cr(Ⅵ)gradually increased with time.The adsorption rate of Cu(Ⅱ)by Y-12 increased rapidly in initial stages,and reached the maximum at the 2.00 h,but then,the adsorbed Cu(Ⅱ)was gradually desorbed.The optimum solution pH for Cr(Ⅵ)and Cu(Ⅱ)adsorption was 6,but the capability of Y-12 to remove Cr(Ⅵ)was inhibited in strong acidic condition.When the solution pH was 9,the detoxification of Cr(Ⅵ)by Y-12 was mainly through reduction.The higher the original concentration of Cr(Ⅵ),the lower the removal rate,but the changes of Cu(Ⅱ)concentration in solution had no obvious effect on Cr(Ⅵ)removal.Y-12 could effectively remove Cr(Ⅵ)/Cu(Ⅱ)under suitable environmental conditions,and it had abroad prospect in application.