生物炭及其水溶组分促进水铁矿微生物还原  

Effects of biochar and its dissolved fractions on microbial reduction of ferrihydrite

作　　者：夏金霞 孙金涛 于蕊 王一初 安伟奇 金洁 曹丹丹 XIA Jin-xia;SUN Jin-tao;YU Rui;WANG Yi-chu;AN Wei-qi;JIN Jie;CAO Dan-dan(College of Environmental Science and Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学环境科学与工程学院,北京102206

出　　处：《中国环境科学》2023年第10期5522-5532,共11页China Environmental Science

基　　金：国家自然科学基金资助项目(42177204);持久性有毒污染物环境与健康危害湖北省重点实验室开放基金资助项目(PTS-2020-04);中央高校基本科研业务费专项资金(2020MS038)。

摘　　要：采用水稻秸秆在300,400和500℃热解温度下制备生物炭(BC),并从中提取生物炭水溶组分(DBC),结合微生物还原实验和傅里叶转换红外光谱仪(FTIR)、X射线衍射晶体衍射(XRD)、电子顺磁(EPR)等表征手段考察BC和DBC对Geobacter sulphurreducens PCA还原水铁矿的影响和作用机制.结果表明,400℃热解BC可使微生物异化铁还原的速率增加12倍,还原率最高,这是由于其含有最多的醌基、羧基基团,可以作为电子穿梭体促进电子转移.BC不能作为电子供体直接向微生物或水铁矿提供电子.DBC使水铁矿的长期微生物异化铁还原程度和初始还原速率分别增加了10倍和2倍以上.500℃热解DBC可以充当电子供体或者电子穿梭体,促进水铁矿的微生物还原,但是不能直接化学还原水铁矿.In this study,biochar(BC)was prepared from rice straw at different pyrolysis temperatures(300,400,and 500°C),and was used for dissolved fractions(DBC)extraction.In this study,the effects of BC and DBC on the reduction of ferrihydrite by Geobacter sulphurreducens PCA were investigated by combining microbial reduction experiments and various characterization methods including Fourier transition infrared spectroscopy(FTIR),X-ray diffraction crystal diffraction(XRD),and Electron paramagnetic resonance(EPR).The results showed that the highest reduction rate of ferrihydrite was achieved after the addition of BC prepared at 400°C(BC-400),which increased the rate of microbial dissimilatory iron reduction by 12 times.Containing the most quinone and carboxyl groups,BC-400 could function as an electron shuttle to promote electron transfer.BC could not serve as an electron donor to provide electrons directly to PCA or ferrihydrite.DBC increased the degree of long-term microbial reduction extent and initial reduction rate by more than 10 times and 2 times,respectively.DBC extracted from BC prepared at 500°C served as an both electron shuttle and electron donor to promote the microbial reduction of ferrihydrite,but it cannot directly chemically reduce ferrihydrite.

关 键 词：生物炭 生物炭水溶组分 水铁矿 异化铁还原菌 

分 类 号：X172[环境科学与工程—环境科学]