摘要
采用室内实验方法,研究了两种低分子有机酸(草酸和柠檬酸)对生物炭(热解温度200、300、400、500℃)吸附Cu(Ⅱ)的影响。结果表明:柠檬酸浓度在10 mg·L^(-1)以下时,其在生物炭表面的吸附为Cu(Ⅱ)提供了更多的吸附位点,从而促进了Cu(Ⅱ)吸附;柠檬酸浓度增大以后,堵塞生物炭的内部孔隙,从而抑制了Cu(Ⅱ)在生物炭上的吸附。草酸浓度在0.5~50 mg·L^(-1)范围内,对生物炭吸附Cu(Ⅱ)始终为抑制作用,这与液相中的草酸与Cu(Ⅱ)的强络合、固相吸附的草酸竞争Cu(Ⅱ)吸附位点(比如占据含氧官能团、生物炭内部孔隙)有关。
Effect of low molecular weight organic acids on adsorption of Cu（Ⅱ）by biochars was investigated using indoor experiment. The results showed that the sorption of Cu（Ⅱ）in biochar was prompted by citric acid at low concentrations（below 10 mg·L-1）, but inhibited at high concentrations. The adsorption of citric acid on biochars provided more adsorption sites for Cu（Ⅱ） at low citric acid concentration,while the increased citric acid loading on biochars may block the internal pores in biochars. The oxalic acid inhibited the adsorption of Cu（Ⅱ）on biochars at the tested concentrations（0.5～50 mg·L-1）. This result may be explained by the strong complexation between oxalic acid with Cu（Ⅱ）in the aqueous phase, and the competition between oxalic acid and Cu（Ⅱ）for adsorption sites（such as the oxygen-containing functional groups, and the internal pores of biochar）on solid particles.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2016年第10期1923-1930,共8页
Journal of Agro-Environment Science
基金
国家自然科学青年基金项目(41303092)
