中高热解温度下秸秆基生物炭对铅、镉的吸附特性研究  

The adsorption characteristics of Pb2+ and Cd2+ by straw based biochars generated at medium-high pyrolysis temperatures

作　　者：杨育振 高宝龙 黄屹 肖德长 陈飞 罗恒 李丽芬 吴刚 YANG Yuzhen;GAO Baolong;HUANG Yi;XIAO Dechang;CHEN Fei;LUO Heng;LI Lifen;WU Gang(Central South Geological Survey Institute,China Metallurgical Geology Bureau,Wuhan 430080,Hubei,China;Institute of Mineral Resources Research,China Metallurgical Geology Bureau,Beijing 101300,China)

机构地区：[1]中国冶金地质总局中南地质调查院,湖北武汉430080 [2]中国冶金地质总局矿产资源研究院,北京101300

出　　处：《中国地质》2023年第1期52-60,共9页Geology in China

基　　金：湖北省自然资源科技项目(ZRZY2020KJ05)资助。

摘　　要：【研究目的】热解温度和原材料对秸秆基生物炭吸附重金属性能的影响。【研究方法】本文以玉米秸秆和水稻秸秆作为原料,在限氧条件下,通过热解法于中温(450℃)和高温(600℃)下制备秸秆基生物炭S450、S600、Y450和Y600,研究不同类型生物炭的材料表面特性差异及对溶液中Pb^(2+)、Cd^(2+)吸附特性的影响。【研究结果】结果表明,热解温度对生物炭理化性质影响明显,随着热解温度的升高,产率下降,碳元素含量增大,氮、氢和氧元素含量有所降低,而且比表面积、总孔体积和平均孔径均有所减小。4种秸秆基生物炭对Pb^(2+)和Cd^(2+)的吸附以化学沉淀反应为主,随着热解温度的升高,生物炭对Pb^(2+)、Cd^(2+)的吸附量和吸附速率也随之增大,而且玉米秸秆生物炭对Pb^(2+)、Cd^(2+)的吸附量明显高于水稻秸秆生物炭的吸附量。【结论】4种生物炭对溶液中Pb^(2+)和Cd^(2+)的吸附分别为多层吸附和单分子层吸附,而且热解温度较高的秸秆基生物炭均表现出对重金属Pb^(2+)和Cd^(2+)更强的吸附能力。研究结果可为秸秆资源化利用、重金属污染及环境修复提供参考。This paper is the result of environmental geological survey engineering.[Objective] Effect of pyrolysis temperature and raw materials on adsorption of heavy metals by straw-based biochar. [Methods]Corn straw and rice straw were used as raw materials to prepare straw based biochars(i.e. S450, S600, Y450, Y600) under anoxic conditions at 450℃ and 600℃. And the differences in their surface characteristics and their adsorption capacity for Pb^(2+)and Cd^(2+)in solutions were studied. [Results] The results showed that the pyrolysis temperature had a significant effect on the physicochemical properties of different biochars. With the increase of pyrolysis temperature, the C contents of biochars increased, but N, H, O contents decreased. Besides, their specific surface area, total pore volume and average pore diameter all showed a decreased tendency. As the result of the increase of pyrolysis temperature, the adsorption capacity and rate of Pb^(2+)and Cd^(2+)increased.Meanwhile, the adsorption capacity of Pb^(2+)and Cd^(2+)of corn straw biochar was significantly higher than that of rice straw biochar.The adsorption of Pb^(2+)and Cd^(2+)by the four biochars was dominated by chemical precipitation. [Conclusions] The adsorption of Pb^(2+)and Cd^(2+)was mainly multilayer and monolayer adsorption, respectively. Straw based biochars with higher pyrolysis temperature had higher adsorption capacity for Pb^(2+)and Cd^(2+). This study is useful for straw resource utilization and heavy metal pollution remediation.

关 键 词：热解温度 秸秆生物炭 PB2+ Cd2+ 吸附 废水 土壤 环境地质调查工程 

分 类 号：X505[环境科学与工程—环境工程] X71