摘要
通过一次平衡法研究了双氧水去除有机质、添加1%腐殖酸和DCB法(连二亚硫酸钠-柠檬酸钠-碳酸氢钠)去除游离氧化铁、铝对红黏土发育的红壤吸附草酸、柠檬酸、酒石酸和苹果酸的影响。结果表明,去除有机质后,由于受溶液pH、表面吸附点位变化、土壤结构变化、表面基团活性变化、草酸根生成等多种因素的影响,红壤对低分子量有机酸的吸附量虽略有增加,但增加并不明显。添加腐殖酸培养一个月后,由于受土壤表面电荷变化、吸附点位覆盖、氧化铁活性改变、基团质子化等因素的影响,红壤对低分子量有机酸的吸附量虽有轻微的减少,但减少也不明显。去除占土壤总量3.79%的游离氧化铁、铝后,土壤表面正电荷将会显著减少,而导致红壤对低分子量有机酸的吸附量显著减少,其减少程度因有机酸种类而异,与原土对有机酸的最大吸附量(Sm)大小顺序相反。
Effects of removing organic matter with hydrogen peroxide,adding 1% humic acid,and removing free Fe-Al oxides with DCB（dithionite-citrate-bicarbonate） on adsorption of oxalic,citric,tartaric and malic acids by red soil developed from red clay were studied with the batch equilibrium method.Results show that due to the possible change of solution pH,surface sites,soil structure,activity of surface group,and the formation of oxalate,removal of organic matter slightly increased adsorption amount of low molecular weight organic acids,but the increase was not obvious;due to the possible change of surface charge,the cover of surface sites,the activity of Fe oxides,and the protonation of groups,addition of humic acid slightly decreased the adsorption amount after one month incubation,but the reduction was also not obvious;and the adsorption amount was reduced significantly in the soil with 3.79% of the free Fe-Al oxides removed because of the significant decrease of positive charge,and the reduction of adsorption amount varied with the kind of organic acids,showing an order in reverse to that of the original soil in terms of maximum adsorption of organic acids.
出处
《土壤学报》
CAS
CSCD
北大核心
2010年第6期1144-1150,共7页
Acta Pedologica Sinica
基金
中国科学院知识创新工程项目(KZCX2-YW-438和KSCX1-YW-09)资助
关键词
低分子量有机酸
吸附
有机质
腐殖酸
游离氧化铁、铝
Low molecular weight organic acids
Adsorption
Organic matter
Humic acid
Free Fe-Al oxides
