生态与农村环境学报Issue(3)：372-379,8.DOI:10.11934/j.issn.1673-4831.2015.03.016
镧生物质炭对磷酸根离子的吸附特性
Phosphate Adsorption Characteristics of La-containing Biochar
摘要
Abstract
As a kind of high⁃effect, low⁃cost, environment⁃friendly and recyclable PO4 3- adsorbent intended for use in farmlands, La⁃containing cornstalk based biochar was prepared for the first time for analysis of phosphate adsorption char⁃acteristics with thermodynamic, isothermic and kinetic methods. During the adsorption process,its Gibbs free energy de⁃clined below zero, while enthalpy and entropy both rose above zero. Its adsorption isotherm fitted the Langmuir model and its adsorption peaked up to 78�36 mg·g-1 at 25℃. Its kinetics fitted the pseudo⁃second⁃order kinetic model with its ad⁃sorption rate constant being 23�19×10-2 mg·g-1·min-1 when the initial phosphate concentration was 50 mg·L-1. The straightline fitted with the intra⁃particle diffusion model failed to pass the origin of the coordinates, but was displayed in a two⁃section line. When soil pH lingered in the range of 3-7, its phosphate adsorption capacity was quite high and not af⁃fected by any of the coexisting ions, except 200 mg·L-1 of CO3 2- and 2 000 mg·L-1 of CO3 2-and F-. Its phosphate ad⁃sorption was a kind of spontaneous endothermic reaction, and physical adsorption dominated monolayer adsorption. Its ad⁃sorption process was governed mainly by surface diffusion and intra⁃particle diffusion and its adsorption rate by thickness of the boundary layer. The La⁃containing cornstalk⁃based biochar is extensively applicable to farmlands with pH in a wide range, quite strong in disturbance resisting ability and quite high in phosphate adsorption and adsorption rate. The La⁃con⁃taining cornstalk⁃based biochar enjoys a broad application prospect in the future in remedying eutrophied bodies and purif⁃ying phosphorus⁃polluted wastewater.关键词
玉米秸秆炭/吸附热力学/吸附等温线/吸附动力学/pH/共存离子Key words
cornstalk-based biochar/adsorption thermodynamics/adsorption isotherm/adsorption kinetics/pH/co-existing ions分类
资源环境引用本文复制引用
戴敏,王建国,巢军委,汤芳,朱励军..镧生物质炭对磷酸根离子的吸附特性[J].生态与农村环境学报,2015,(3):372-379,8.基金项目
国家自然科学基金面上项目 （）
