xx 学 院
本科毕业论文(设计)
( 20xx届)
题 目: 板栗壳生物炭对Cr(VI)吸附性能的研究 姓 名： xxx 学 号： xxxx 学 院： 化学与环境学院 专 业： 环境科学 指导教师： xxx 申请学位： 理学士学位
xxxx 教 务 处
xxxx毕业论文(设计)
板栗壳生物炭对水中Cr(VI)的吸附性能研究
摘要：本论文采用板栗壳制备成生物炭对废水中Cr(VI)进行吸附，研究了溶液的pH值、初始浓度、吸附剂用量、吸附时间和吸附温度对吸附Cr(VI)性能的影响，用Langmuir和Freundlich等温吸附方程对板栗壳的吸附等温线进行了拟合，并用动力学方程对吸附过程进行描述。实验结果表明：
(1)pH值是影响板栗壳吸附Cr(VI)性能的最主要的影响因素，在强酸条件下对Cr(VI)的吸附效果好。
(2)板栗壳吸附Cr(VI)的动力学实验表明，吸附Cr(VI)的吸附规律遵循准二级动力学模型，吸附主要由化学吸附控制。
(3)采用Langmuir等温吸附方程和Freundlich等温吸附方程对吸附等温线进行拟合可知，板栗壳的吸附过程更符合Langmuir等温吸附过程，说明板栗壳生物炭吸附过程类似于表面均匀的单分子层吸附。经Freundlich拟合后，可知n=5.8>2，说明板栗壳生物炭属于易吸附过程。
(4)在吸附时间120 min，吸附剂投加量为8.0 g/L，pH值为2.0，Cr(VI)溶液初始浓度为60 mg/L，温度为30 ℃的条件下，板栗壳对Cr(VI)离子的吸附率达到99.7%。 关键词：板栗壳；生物炭；Cr(VI)；吸附
I
xxx毕业论文(设计)
Study on the Adsorption of Water Chestnut Shell Biochar
Hexavalent Chromium
Abstract：In this paper, a chestnut shell prepared using biochar wastewater Cr(VI) adsorption was studied pH value of the solution,initial concentration, amount of adsorbent, adsorption time and adsorption temperature on adsorption Cr(VI) performance, using Langmuir and Freundlich isotherm equation chestnut shell adsorption isotherms were fitted with kinetic equation to describe the adsorption process.The results showed that:
⑴pH value is the most important factor affecting the adsorption of chestnut shell Cr(VI) performance.Under the strong acid conditions, the adsorption effect of Cr(VI) is good . ⑵Adsorption chestnut shell Cr(VI) kinetic experiments show adsorbent Cr(VI) adsorption followed pseudo-second rule Cr kinetic model, the adsorption is mainly controlled by the chemical adsorption .
⑶Using the Langmuir isotherm equation and Freundlich isotherm equation for adsorption isotherms were fitted shows that the adsorption process chestnut shell more consistent temperature adsorption process Langmuir,etc., indicating monolayer adsorption chestnut shell biological carbon adsorption process is similar to a uniform surface.After Freundlich fitting,shows n = 5.8> 2, instructions are easy chestnut shell biochar adsorption process.
⑷The adsorption time 120 min,adsorbent dosage of 8.0 g/L, pH value of 2.0, Cr(VI) initial concentration of 60 mg/L, the temperature is under 30 ℃, the chestnut shell of Cr(VI) ion adsorption rate reached 99.7%.
Key words:Chestnut shell, biological carbon, Cr (VI), adsorption
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xxxx毕业论文(设计)
目 录
摘要 ........................................................................................................................................ I 关键词 .................................................................................................................................... I Abstract .................................................................................................................................. 1 Key words .............................................................................................................................. 1 1前言 .................................................................................................................................... 1 1.1 含铬废水来源及影响 .................................................................................................... 1 1.2 Cr(VI)污染的危害 .......................................................................................................... 1 1.3含 Cr(VI) 废水处理方法简述 ...................................................................................... 2
1.3.1还原法 .................................................................................................................. 2 1.3.2电解法 .................................................................................................................. 2 1.3.3离子交换树脂法 .................................................................................................. 3 1.3.4生物法 .................................................................................................................. 3 1.3.5吸附法 .................................................................................................................. 3 1.4生物炭吸附的优势 ......................................................................................................... 3 1.5生物炭吸附法研究进展 ................................................................................................. 4
1.5.1吸附机理 .............................................................................................................. 4 1.5.2研究现状 .............................................................................................................. 5 1.6 生物炭吸附剂的前景展望 ............................................................................................ 6 2实验部分 ............................................................................................................................ 7 2.1实验仪器与药品 ............................................................................................................. 7
2.1.1 实验仪器 ............................................................................................................. 7 2.1.2 实验药品 ........................................................................................................... 7 2.2样品与试剂的制备 ......................................................................................................... 7
2.2.1试剂的配制 .......................................................................................................... 7 2.2.2板栗壳生物碳的制备 .......................................................................................... 8 2.3实验方法与原理 ............................................................................................................. 8 2.4标准曲线的绘制 ............................................................................................................. 8 2.5实验步骤 ......................................................................................................................... 9
xxx毕业论文(设计)
2.6吸附效果影响因素的研究 ............................................................................................. 9
2.6.1 Cr(VI)废水的pH对吸附效果的影响 ............................................................ 9 2.6.2 Cr(VI)废水的初始浓度对吸附效果的影响 ................................................. 10 2.6.3 生物碳吸附剂的用量对吸附效果的影响 ................................................... 11 2.6.4 实验的吸附时间对吸附效果的影响 ........................................................... 12 2.6.5实验的吸附温度对吸附效果的影响 ............................................................ 13 3结果与讨论 ...................................................................................................................... 13 3.1 吸附动力学 ................................................................................................................ 14
3.1.1 吸附动力学理论 ......................................................................................... 14 3.1.2 吸附动力学模型 ......................................................................................... 14 3.2 吸附等温线 ................................................................................................................ 16
3.2.1 吸附等温模型 ............................................................................................. 16 3.2.2 实验方法及结果分析 ................................................................................. 16 4结论 .................................................................................................................................. 17 参考文献 ............................................................................................................................. 19 致谢 ..................................................................................................................................... 20