Citrobacter sp. strain YS1抑制煤矸石产酸及重金属释放的研究

Inhibition of acid production and heavy metal release from coal gangue by Citrobacter sp.strain YS1

从长期受煤矸石酸性废水污染的底泥中分离筛选出一株非传统硫酸盐还原菌Citrobacter sp.strain YS1(以下简称YS1),考察了菌株YS1对煤矸石产酸及重金属释放的抑制效应。结果表明,菌株YS1能有效抑制煤矸石产酸及重金属释放,加菌(SM)组煤矸石浸出液中Mn、Zn、Cu、Ni、Cd、Fe的浓度比空白对照(CK)组分别降低30.91%、42.12%、51.50%、56.25%、45.45%、34.02%。加菌+碳源(SMR)组的抑制效果更优,煤矸石浸出液中Zn、Cu、Cd均低于仪器检出限,Mn、Ni、Fe浓度相比CK组分别降低99.78%、98.75%、99.95%。SMR组的抑酸效果也更明显,可将煤矸石浸出液pH从5.45提升至7.88。菌株YS1可将SO_(4)^(2-)还原为S^(2-)并与重金属离子生成固体硫化物覆盖在煤矸石表面,减缓煤矸石中黄铁矿氧化。YS1表面的多糖、蛋白以及脂质中的羟基、氨基等基团均可能参与了对重金属离子的络合作用。

A non-traditional sulfate reducing bacteria Citrobacter sp.strain YS1(hereinafter referred to YS1 for short)was isolated from the subsoil polluted by long-term coal gangue leaching.The inhibitory effect of strain YS1 on acid production and heavy metals release of coal gangue was studied.The results showed that strain YS1 could effectively inhibit acid production of coal gangue and the release of heavy metals.The concentration of Mn,Zn,Cu,Ni,Cd,Fe in coal gangue leachate of group with only bacteria addition(SM group)were reduced by 30.91%,42.12%,51.50%,56.25%,45.45%,34.02%,respectively,compared with the control groups(CK group),while the inhibition effect was optimum after adding bacteria and carbon sources(SMR group).The concentrations of Zn,Cu and Cd in coal gangue leachate of SMR group were below the limit of instrumental detection,and the concentrations of Mn,Ni and Fe were reduced by 99.78%,98.75%and 99.95%,respectively,compared with CK groups.The acid inhibition of SMR group was also more apparent,with the pH of coal gangue leachate raising from 5.45 to 7.88 after experiment.Strain YS1 could reduce SO_(4)^(2-) to S^(2-)and form solid sulfides with heavy metals.The product could cover the surface of coal gangue and slow down the oxidation of pyrite in coal gangue.The polysaccharides,proteins and hydroxyl,amino groups of lipids on the surface of YS1 might be involved in the complexation of heavy metal ions.