摘要
以玉米秸秆、猪粪为原料,在不同温度下制备生物炭,并对其物化性质进行了表征.研究了厌氧条件下,Fe(Ⅱ)/生物炭体系对硝基苯的还原降解,并对降解条件进行了优化,对降解机理进行了讨论.结果表明,在Fe(Ⅱ)/生物炭体系中,Fe(Ⅱ)的还原性显著增强;原料、制备温度、Fe(Ⅱ)初始浓度、p H值都会对Fe(Ⅱ)的还原活性造成影响.其中在p H=7、固水比=1∶500、25℃,Fe(Ⅱ)和硝基苯的初始量分别为12 mmol·L^(-1)和0.08 mmol·L^(-1)的条件下,Fe(Ⅱ)/PBC700可将93%的硝基苯降解,为最佳降解体系.为了揭示Fe(Ⅱ)/生物炭体系还原硝基苯的关键结构与机理,分别研究了生物炭除灰处理和除有机质处理对Fe(Ⅱ)/生物炭体系还原能力的影响.发现两种处理都可使反应加速,由此推断,一方面生物炭灰分中的金属氧化物与Fe(Ⅱ)组成表面结合铁还原系统使Fe(Ⅱ)的还原性增强;另一方面生物炭的类石墨烯片层有机质结构起到了电子传递的作用,也可促进Fe(Ⅱ)对硝基苯的还原.本文为Fe(Ⅱ)还原去除有机污染物发现了一个新的载体.
Biochars were prepared from corn straw and pig manure at different temperatures,and the properties of biochars were characterized. Reduction of nitrobenzene by Fe（ Ⅱ） with biochar was studied under anaerobic conditions,the degradation conditions were optimized,and degradation mechanisms were discussed. The results showed that the combination of biochar and Fe（ Ⅱ）enhanced the reduction of nitrobenzene. Pyrolyzing temperature, raw material, Fe（ Ⅱ）concentration and pH all had influences on nitrobenzene reduction. The conditions were optimized as follow： pH 7,the ratio of solid and water 1∶ 500,temperature 25 ℃,the initial concentrations of Fe（ Ⅱ） and nitrobenzene were 12 mmol·L^-1 and 0. 08 mmol·L^-1,respectively. Under these conditions,93% of nitrobenzene were degraded by Fe（ Ⅱ）/PBC700. The reduction of nitrobenzene by Fe（ Ⅱ） was also studied using treated biochars,which were deprived of ash and organic moiety,respectively,so as to identify the key structure and mechanisms of the enhanced reduction. Both treatments showed a promotion effect on the reaction. Hence,the enhancement was inferred to be due to interfacial electron transfer from adsorbed Fe（ Ⅱ） to metal oxides and shuttled electron effects of graphene like structure in biochar organic moiety between Fe（ Ⅱ） and nitrobenzene. The present paper has provided a novel carrier for Fe（ II） reduction of organic pollutants.
作者
张慧鸣
张鹏
殷哲云
孙红文
ZHANG Huiming;ZHANG Peng;YIN Zheyun;SUN Hongwen(College of Environmental Science and Engineering, Nankai university, Tianjin, 300350, Chin)
出处
《环境化学》
CAS
CSCD
北大核心
2017年第11期2297-2303,共7页
Environmental Chemistry
基金
973计划课题(2014CB441104)资助~~
关键词
生物炭
Fe(Ⅱ)
硝基苯
还原降解
biochar, Fe（ II ） , nitrobenzene, reduction degradation.
