摘要
采用批量平衡法,研究了除草剂咪唑乙烟酸在东北地区4种代表性土壤中的吸附特征.试验结果表明,Freund lich等温式最适合描述咪唑乙烟酸在土壤中的吸附行为,4种土壤对咪唑乙烟酸的吸附能力大小顺序为:黑土>水稻土>盐碱土>白浆土.咪唑乙烟酸的吸附常数Kf与土壤有机质含量呈显著正相关.经过过氧化氢去除土壤有机质后,4种土壤对咪唑乙烟酸的吸附量均大大降低,仅为原土的32.74%—46.07%,其吸附常数与土壤pH呈负相关.表明影响土壤对咪唑乙烟酸吸附能力的主要因素是土壤有机质和pH.在土壤-水环境系统pH<6.5时,4种土壤对咪唑乙烟酸吸附量均随pH的增加而快速下降,pH≥6.5时,除盐碱土对咪唑乙烟酸的吸附量几乎不变化外,其余均随pH升高而缓慢下降.咪唑乙烟酸在土壤中具有较高的移动性,以物理吸附为主.
Adsorption of imazethapyr on four representative soils of northeast China was studied with the batch equilibrium method.The results showed that imazethapyr adsorption on soil could be most suitably described using Freundlich isotherm.The order of imazethapyr adsorption capacity on four types of soils was described as follows： Black soil〉Paddy soil〉Saline soil〉Planosol soil.Adsorption constant K f of imazethapyr was significantly and positively correlated with soil organic matter content.When organic matter was removed with hydrogen peroxide,the adsorption of imazethapyr on the soil greatly decreased to only 32.74%—46.07% of raw soil,and the adsorption constant of imazethapyr was negatively correlated with pH value,It obviously suggests that organic matter and pH were the dominant factor affecting the adsorption of imazethapyr on soils.When pH value of soil-water system was less than 6.5,the adsorption capacity of imazethapyr fell rapidly with increasing pH value.When pH value was greater than 6.5,the adsorption capacity fell slowly as pH increased on Black soil,Paddy soil and Planosol soil.However,the adsorption capacity on Saline soil almost did not change with pH value.The mobility of imazethapyr in soils was high.The main adsorptive mechanism of imazethapyr on soils was physical adsorption.
出处
《环境化学》
CAS
CSCD
北大核心
2011年第3期668-672,共5页
Environmental Chemistry
基金
东北农业大学创新团队基金(CXT003-1-3)
黑龙江省博士后基金项目(LBH-206162)
关键词
咪唑乙烟酸
土壤
吸附
有机质
PH
imazethapyr
adsorption
soil
organic matter
pH value
