不同生物炭吸附乙草胺的特征及机理  

Sorption of acetochlor by biochars derived from wood dust and swine manure at different pyrolytic temperatures

作　　者：王子莹[1] 邱梦怡 杨妍[1] 孙可[1] 

机构地区：[1]北京师范大学环境学院水环境模拟国家重点实验室,北京100875

出　　处：《农业环境科学学报》2016年第1期93-100,共8页Journal of Agro-Environment Science

基　　金：国家自然科学基金面上项目(41273106);国家自然基金创新团体项目(51421065)

摘　　要：研究了两种原材料(松树木屑和猪粪便)分别在7个温度条件下制备的14种生物炭对乙草胺的吸附,结果表明生物炭的理化性质随原料来源以及热解温度的不同会发生明显的变化。生物炭的总极性随着热解温度的升高而降低,同时芳香度和比表面积(CO2-SA)显著增加,生物炭样品的表面有机碳(OC)含量高于总体OC含量;猪粪便来源的生物炭(SWBs)的灰分含量显著高于松树木屑来源的生物炭(WDBs),这可能是导致SWBs对乙草胺的吸附能力大于WDBs的原因。生物炭的表面极性[(O+N)/C]和吸附能力lg K_(oc)之间呈正相关关系,表明表面极性官能团的氢键作用可能是控制低温WDBs(热解温度<450℃)吸附乙草胺的主要因素;而高温生物炭(热解温度≥450℃)的芳香度和lg K_(oc)之间呈显著的正相关关系,说明高温生物炭对吸附乙草胺主要受芳香碳组分的影响。此外,吸附参数(非线性因子n和lg K_(oc))和OC标准化的比表面积(CO_2-SA/OC)之间的相关关系表明,孔填充效应可能是影响生物炭吸附乙草胺的主要作用之一。Raw material and pyrolytic temperature of biochar greatly influence its properties and thus pollutant adsorption. Fourteen biochars obtained from two raw material sources（wood dust and swine manure） at seven pyrolytic temperatures were used to investigate their adsorp- tion of acetochlor. As pyrolytic temperature increased, the polarity of biochars decreased, while their aromaticity and CO2-surface area（CO2- SA） enhanced. The organic carbon（ OC ） concentrations on the biochar surface were generally higher than the corresponding bulk OC con- tents. Acetochlor had higher sorption capacity on swine manure biochars （SWBs） than on wood dust biochars（WDBs）, mainly due to higher ash content of SWBs. At low pyrolytic temperatures（ 〈 450 ~C ）, a positive correlation between biochar surface polarity[（O＋N ）/C] and the sorption affinity lgK~ indicated that the surface polarity might dominate the sorption of acetochlor by WDBs through H-bonding interaction. At high pyrolytic temperatures（ ~〉 450 ~C ）, however, a positive correlation between the biochar aromaticity and lgK~ suggested that aro- matic C might control the sorption of acetochlor on biochars. Moreover, there were significant correlations between sorption coefficients（non- linearity index n and lgK~） and OC normalized CO2-SA（CO2-SA/OC ） of biochars, indicating that pore filling could be a factor affecting acetochlor adsorption on biochars.

关 键 词：生物炭 乙草胺 吸附 比表面积 表面极性 芳香碳 

分 类 号：X71[环境科学与工程—环境工程]