几种粉煤灰对磷素吸附与解吸特性的研究  

Phosphate adsorption and desorption characteristics of several fly ashes.

作　　者：冯跃华[1] 胡瑞芝[1] 张杨珠[1] 邹应斌[2] 黄运湘[1] 王翠红[1] 李法云[3] 

机构地区：[1]湖南农业大学资源环境学院,长沙410128 [2]湖南农业大学农学院,长沙410128 [3]辽宁大学环境与生命科学院,沈阳110036

出　　处：《应用生态学报》2005年第9期1756-1760,共5页Chinese Journal of Applied Ecology

基　　金：国家农业科技成果转化基金项目(02EFN214300453);湖南省科技厅资助项目(01SSY2003-2).

摘　　要：通过吸附解吸和培养试验,研究了几种粉煤灰对磷素吸附与解吸特性.结果表明,粉煤灰的全磷含量和有效磷含量分别为0.545～4.540 g·kg-1和19.55～163.0 mg·kg-1,显著高于土壤,粉煤灰对磷吸附量随着加入溶液磷浓度的增加而增加,但其吸附率随着加入溶液磷浓度的增加而减少;粉煤灰的吸磷率比土壤高,但其解吸率低.这主要是由于粉煤灰比土壤存在更多的磷吸附位点且结合能大,不易解吸.Langmuir方程、Freundlich方程和Temkin方程都能很好地拟合粉煤灰对磷吸附,其中Langmuir方程的MBC、Freundlich方程的a和Temkin方程的k2都可以表征粉煤灰对磷吸附能力,MBC、a和k2值越大,则吸磷能力越强.不同来源的粉煤灰的MBC、a和k2值不同,其大小顺序为:湘潭电厂(5 167.7,4 056.2,831.5)＞岳阳纸厂(1 650.7,2 803.4,711.9)＞华能电厂(303.0,1 677.6,368.7)＞株洲电厂(76.2,464.2,211.0)＞洞庭氮肥厂(34.7,413.48,213.8).粉煤灰对磷吸附固定作用随粉煤灰含水量的增加有增大的趋势.粉煤灰对磷吸附主要是专性吸附和化学沉淀反应,所以在施用粉煤灰改良土壤或利用粉煤灰制造复混肥时,须考虑粉煤灰对磷的固定作用及粉煤灰含水量的影响.Through adsorption-desorption experiment and incubation test, this paper studied the phosphate adsorption and desorption characteristics of several fly ashes. The test fly ashes contained 0. 545 - 4. 540 g· kg^- 1 of total P and 19.55 -- 163.0 mg· kg^- 1 of available P, which were significantly higher than those in soils. The P adsorption capacity of fly ashes increased with increasing added P, while their P adsorption rate was in adverse. Fly ashes had a higher P adsorption rate but a lower P desorption rate than soils, mainly because fly ashes had more P adsorption sites and stronger bound energy. In this study, Langmuir, Freundlich, and Temkin equations were fit to the measured data, and the MBC value in Langmuir equation, a value in Freundlich equation, and k2 value in Temkin equation could be used as a comprehensive index to characterize the potential phosphate adsorptivity of fly ashes. The larger these values were, the stronger the P adsorptivity was. The MBC, a and k2 value of 5 fly ashes collected from different locations was in order of Xiangtan power factory （5 167.7, 4 056.2 and 831.5） 〉Yueyang paper factory （ 1 650.7, 2 803.4 and 711.9） 〉 Huaneng power factory （ 303.0, 1 677.6 and 368.7 ） 〉 Zhuzhou power factory （34.7,413.48 and 213.8） 〉Dongting nitrogen fertilizer factory （34.7,413.48 and 213.8）. The P fixation by fly ashes generally increased with their increasing water content, and their phosphate adsorption was mainly specific adsorption and chemical precipitation, suggesting that the P fixation and the water content of fly ashes should be considered when fly ash was used as soil amendment or as compound fertilizer filling substance.

关 键 词：粉煤灰 吸附量 吸磷率 解吸率 

分 类 号：X773[环境科学与工程—环境工程]