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.
出处
《应用生态学报》
CAS
CSCD
北大核心
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).
关键词
粉煤灰
吸附量
吸磷率
解吸率
Fly ash, Adsorption capacity, P adsorption rate, P desorption rate.
作者简介
通讯联系人，E-mail：fengyhua@263．net，hruiz56@hotmail．com。冯跃华，男，1969年生，讲师，在读博士，主要从事农业资源利用方面的研究，发表论文10余篇，Tel：13107494389；E—mail：fengyhua@263．net
