摘要本文以牛粪为原料,在350℃、700℃下制备生物炭,分别记录为CM、CMC350、CMC700。采用经典的批量法研究牛粪及其生物炭在不同平衡时间、浓度下对土壤中Pb、Cd的吸附特征,并将相关参数进行比较,最后考察了生物炭施用对土壤的Pb、Cd的吸附特征影响,主要结果如下:72776
1、Langmuir模型、Frenudlich模型、Herry模型这三个等温吸附模型中Langmuir等温吸附模型对于Pb、Cd的拟合效果最好。牛粪及其生物炭对Pb的等温吸附量要明显高于Cd。
2、热解温度升高不利于对Pb、Cd的吸附,通过时间动力学、等温吸附实验发现牛粪生物炭对Pb的吸附动力学数据在浓度90mg/L时符合Elovich方程和双常数动力学时间方程,在180mg/L时更符合拟二级动力学模型;Cd在90mg/L时则更加符合拟一级动力学模型和拟二级动力学模型,在180mg/L时则符合Elovich方程和双常数动力学时间方程。
3、Pb的吸附率从大到小依次排列的顺序为CMC700>CMC350>CM,且CMC700比CMC350不容易解吸出来;Cd 在CMC350的吸附率较好,CMC700的解吸率较好。综合来说,CMC350对Pb的吸附固持效果好于Cd,原样的吸附能力最差。
Abstract In this paper, dairy manure as raw materials in 350 ℃, 700 ℃ under preparation biochar were recorded as CM, CMC350, CMC700。 Classical batch Study dairy manure and its biochar under different equilibration time, the concentration of the soil adsorption characteristics of Cadmium and Lead, and will compare the relevant parameters。 Additionally, the influence of land application of biochar on the Cadmium and Lead adsorption characteristics of soil were also evaluated 。The main results are as follows:
1。When the Sample Langmuir equation、Freundlich equation、Herry equation could be well described by Langmuir isotherm equation model of Pb and Cd。
2。Pyrolysis temperature is not conducive to the adsorption of Pb and Cd, and by the Time dynamics,adsorption isotherm was found that cattle manure biochar adsorption dynamics data for Pb concentration in the 90mg / L when conform Elovich equation and Two-constant equation。 At a concentration of 180mg / L when more in line with the Pseudo-second order kinetics。In the 90mg / L Cd adsorption data is more in line with the Pseudo-first order kinetics and the Pseudo-second order kinetics, at a concentration of 180mg / L when the accord Elovich equation and the Pseudo-second order kinetics。
3。Order adsorption rate of Pb descending order of priority for CMC700> CMC350> CM, and CMC700 than CMC350 not easy to parse out。 In CMC350 adsorption rate of Cd better analytical rate CMC700 better。 In summary, CMC350 adsorption of Pb is holding better than Cd, adsorption capacity as the worst。
毕业论文关键词:生物炭; 牛粪; 吸附;解吸
Key Word:biochar; dairy manure; Adsorption; desorption
目 录 4
引言 5
1。材料和方法 7
1。1材料来源及制备 7
1。2 研究方法 7
1。2。1 生物炭对Pb的吸附-解吸曲线 7
1。2。2 生物炭对Cd的吸附-解吸曲线 8
1。2。3 吸附动力学试验 8
1。2。4 计算方法 8
2 结果与讨论 9
2。1 牛粪及其生物炭对PB、CD的等温吸附特性 9
2。1。1 对Pb的等温吸附特性 9
2。1。2 对Cd的等温吸附特性