裂解温度和离子强度对不同来源生物炭胶体释放行为的影响  

Influence of pyrolysis temperature and ionic strength on the release behavior of biochar colloid from different feedstocks

作　　者：程磊磊 孟庆康 金亮 杨溢琪 方婧[1] 林道辉[2] CHENG Leilei;MENG Qingkang;JIN Liang;YANG Yiqi;FANG Jing;LIN Daohui(School of Environmental Science and Engineering,Zhejiang Gongshang University,Hangzhou 310018;Department of Environmental Science,Zhejiang University,Hangzhou 310058)

机构地区：[1]浙江工商大学环境科学与工程学院,杭州310018 [2]浙江大学环境与资源学院,杭州310058

出　　处：《环境科学学报》2020年第5期1768-1778,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.21976158,21677129)。

摘　　要：近年来环境中生物炭胶体形成受到广泛关注,它是生物炭在环境中物理分解作用的重要过程,对污染物迁移有着重要影响.然而,目前对生物炭胶体释放过程和影响因素的研究甚少,人们对生物炭胶体释放机理的认识还很有限.本研究以小麦秸秆和花生壳为生物质来源,系统地探讨了生物炭的裂解温度(300~700℃)和溶液离子强度(0.1~10 mmol·L^-1)对生物炭胶体产率的影响.结果表明,随着裂解温度的升高,生物炭的耐磨性增强,且在较高的裂解温度下(≥500℃)花生壳生物炭的耐磨性显著强于小麦秸秆生物炭.生物炭的胶体产率受到生物质来源和裂解温度的显著影响,花生壳生物炭的胶体产率低于小麦秸秆生物炭,高温裂解(≥600℃)生物炭的胶体产率显著低于中低温裂解生物炭.在相同溶液离子强度下,生物炭胶体产率与其亚微米级碎片率呈显著正相关(p<0.05),即生物炭中亚微米级碎片率越高,生物炭胶体产率越高.当溶液离子强度从1 mmol·L^-1增加到10 mmol·L^-1时,两种来源生物炭的胶体产率均显著降低,其降低的程度因生物炭裂解温度而异,其中低温裂解(300℃)生物炭的胶体产率降低了11.1%~11.2%,中高温裂解(≥500℃)生物炭的胶体产率降低了60.0%~97.2%.In recent years,the formation of biochar colloids in the environment has attracted more and more attention,which is an important process of biochar physical decomposition and has an important impact on pollutant migration.However,fundamental studies on the release processes and the influencing factors of biochar colloids are scarce,and the current understanding of the mechanisms of biochar colloids release is rather limited.In this study,we systematically explored the effects of pyrolysis temperature(300~700℃)and solution ionic strength(0.1~10 mmol·L^-1)on the yield of biochar colloids from bulk biochar prepared from wheat straw and peanut shell.Results showed that the abrasive resistance of biochar increased with the increase of pyrolysis temperature.At higher pyrolysis temperature(≥500℃),the abrasive resistance of peanut shell biochar was significantly better than that of wheat straw biochar.The yield of biochars colloid was significantly affected by both feedstock and pyrolysis temperature.The colloids from peanut shell biochar was lower than from wheat straw biochar.The yield of biochar colloids at high pyrolysis temperature(≥600℃)was significantly lower than the lower pyrolysis temperature,which was significantly positively correlated with the content of submicron fragments in biochar(p<0.05).When solution ionic strength increased from 1 mmol·L^-1 to 10 mmol·L^-1,the yield of biochar colloids decreased,the inhibition of which varied with pyrolysis temperature.The yield of biochar colloids from higher pyrolysis temperatures(≥500℃)was greatly inhibited by ionic strength,which decreased by 60.0%~97.2%,but it slightly changed from biochar with a lower temperature(300℃),which decreased by 11.1%~11.2%.

关 键 词：生物炭胶体 裂解温度 生物质来源 耐磨性 离子强度 

分 类 号：X131.3[环境科学与工程—环境科学]