添加H_(2)O_(2)改性和HNO_(3)/H_(2)SO_(4)改性生物质炭对一种酸性水稻土吸附Cd(Ⅱ)的影响  

Effects of H_(2)O_(2)and HNO_(3)/H_(2)SO_(4)Modified Biochars on Adsorption of Cd(Ⅱ)by an Acidic Paddy Soil

作　　者：何娴 徐仁扣[1,2] HE Xian;XU Renkou(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049

出　　处：《土壤》2022年第5期1016-1023,共8页Soils

基　　金：国家自然科学基金项目(41877036)资助。

摘　　要：选择稻草、玉米秸秆和油菜秸秆作为制备生物质炭的原料,分别用H_(2)O_(2)和HNO_(3)/H_(2)SO_(4)对生物质炭进行改性处理,以未改性的生物质炭和HCl处理的生物质炭作为对照。按土重3%的比例向采自安徽郎溪的酸性水稻土中添加上述生物质炭,在经历一个干湿交替周期后,进行Cd(Ⅱ)吸附/解吸试验,研究添加生物质炭对水稻土吸附Cd(Ⅱ)的影响及其机制。结果表明,两种改性方法均有效增加了生物质炭表面的质子结合位点数,且HNO_(3)/H_(2)SO_(4)改性对生物质炭表面羧基官能团的扩增效果更显著。官能团的增加使得添加了HNO_(3)/H_(2)SO_(4)改性生物质炭的水稻土对Cd(Ⅱ)的专性吸附能力显著增强。因此,添加HNO_(3)/H_(2)SO_(4)改性生物质炭可作为酸性水稻土吸附固定重金属Cd的一种新型方法。The straws of rice,maize and rape were selected as raw materials for preparing biochars.The biochars were modified with H_(2)O_(2)and HNO_(3)/H_(2)SO_(4),respectively,and the unmodified biochar and HCl treated biochar were used as control.The above biochars were added to an acidic paddy soil from Langxi,Anhui Province at the rate of 3%.The mixed soil samples were submerged for one month at 25℃,and then dried naturally.After a wet/dry cycle,Cd(Ⅱ)adsorption/desorption experiments were carried out.Results indicate that the modifications of H_(2)O_(2)and HNO_(3)/H_(2)SO_(4)increase the number of proton binding sites on biochars and HNO_(3)/H_(2)SO_(4)modification leads to greater increase in the number of proton binding sites due to the greater increase of carboxyl functional groups than H_(2)O_(2)modification.The addition of modified biochars improve the adsorption capacity of the acidic paddy soil for Cd(Ⅱ),especially the addition of HNO_(3)/H_(2)SO_(4)modified biochar.Therefore,adding HNO_(3)/H_(2)SO_(4)modified biochar could be used as a new method for adsorption and immobilization of Cd in acidic paddy soils.

关 键 词：H_(2)O_(2)改性 HNO_(3)/H_(2)SO_(4)改性 生物质炭 酸性水稻土 Cd吸附 

分 类 号：S156.2[农业科学—土壤学]