摘要
为了研究老化作用对生物炭性质及其对重金属Cd吸附的影响,将浮萍生物炭(LM)分别进行了高温老化(high temperature aging)、冻融循环老化(freeze-thaw cyclesaging)和自然老化(spontaneous aging),通过SEM-EDS、FTIR和吸附实验探究可能存在的变化机理。结果显示:冻融循环老化和高温老化会使生物炭表面O/C分别增加56.98%和90.14%,自然老化比较缓慢,对生物炭O/C影响不大。高温老化使生物炭表面羟基转化为羧基,为羧基化过程;冻融循环老化会使生物炭表面羟基增加,其他官能团基本不变;自然老化条件下,生物炭表面官能团无明显变化。老化作用增强了生物炭对Cd(Ⅱ)的吸附,冻融循环、高温、自然老化作用使LM最大平衡吸附量分别增加了32.67%,83.17%,15.97%。研究表明生物炭的老化会使生物炭本身性质发生变化,但这一变化有利于生物炭对Cd(Ⅱ)的吸附,生物炭在环境中具有较好的稳定性。
In order to study the effects of biochar ageing on Cd（ Ⅱ） adsorption,the paper analyzed the surface properties before and after biochar ageing with scanning electron microscopy（ SEM） coupled to an energy dispersive spectrometer（ EDS）and fourier transform infrared spectroscopy（ FTIR）,and then explored the influence of the ageing process on Cd（ Ⅱ）adsorption by batch experiments. Biochar were conducted by high temperature ageing, freeze-thaw cycles ageing and spontaneous ageing. After high temperature ageing and freeze-thaw cycles ageing progress,the O/C ratio increased,but the O/C ratio had no significant changes by spontaneous ageing. After high temperature ageing,carboxyl groups increased,hydroxyl groups decreased. After freeze-thaw cycles ageing,hydroxyl groups increased. There were no significant changes by spontaneous ageing. After the ageing process,adsorption capacity of Cd（ Ⅱ） on the aged biochar were larger than those unaged. The maximum adsorption capacity were increased by 32. 67%,83. 17%,15. 97% after high temperature ageing,freeze-thaw cycles ageing and spontaneous ageing. Results indicated that the properties of biochar were changed and the adsorption capacity of Cd（ Ⅱ） were enhanced after ageing process. The stability of biochar in environment was pretty good.
出处
《环境工程》
CAS
CSCD
北大核心
2016年第10期60-64,共5页
Environmental Engineering
基金
国家自然科学基金(31570515
21507097)
江苏省自然科学基金(BK20150288)
江苏省高校自然科学研究项目(14KJD610003)
苏州市科技发展支撑计划(SS201421
SS201521)
