摘要本实验选用经柠檬酸改性过的花生壳为吸附剂原料，将从城郊结合处取得的花 生壳反复清洗、漂煮至清澈，烘干后破碎，过 40 目筛，保存备用。本实验分别对改 性条件和吸附的最佳条件进行考察。改性条件包括：改性时的柠檬酸浓度，花生壳 与柠檬酸的固液比，花生壳的改性时间，改性温度。吸附条件包括：吸附反应时长， Cr(Ⅵ)的初始浓度，改性花生壳与含铬废水的固液比和吸附温度。经反复实验验证 得出，最佳改性条件为：柠檬酸浓度为 1mol/L，花生壳与柠檬酸的固液比为 1g： 100mL，花生壳的改性时间为 45min，改性温度为 30℃。而在废水处理过程中 Cr(Ⅵ) 初始浓度为 10mg/L，改性花生壳与含铬废水的固液比为 1。5g：50mL，吸附 90min， 吸附温度为 50℃时，Cr(Ⅵ)的去除率为佳。在最佳吸附条件下，吸附效率可达 99。6%。 因此可得，经柠檬酸改性的花生壳是一种较为高效的 Cr(Ⅵ)吸附剂。83167

毕业论文关键词：柠檬酸；花生壳；改性；Cr(Ⅵ)；吸附

Abstract In this experiment,peanut shells are used as a new kind of adsorbent material,citric acid is used as modification to raise the effect。Obtained from the suburbs in the neighborhood, peanut shells go through boiling and washing repeatedly until the liquid is clear。After that,those shells should be dried,broken,sieved through 40 mesh and then  reserved waiting to be use。In this experiment,different conditions in both modification and absorption are studied。During the course of modification,such conditions are in concern: the concerntration of citric acid,the ratio of peanut shells and the acid,the lengthy of reaction time and the temperature,while during absorpting reaction,following condition are considered:the  time  of  absorption,the  ratio of  modified  peanut  shells  and the wast

water containing Cr(Ⅵ),the initial concentration of Cr(Ⅵ) and the temperature。

In conclude,it is evident that the best modified effect hapens when the concentration of citric acid is 1mol/L,the ratio ofpeanut shells and the acid is 1g:100mL,45min and in 30℃,and the best absorption effect happens when the reaction goes through 90 min,in

50℃,the initial concentration of Cr(Ⅵ) is  10mg/L and the  ratio of modified    absorption

and waste water containing Cr(Ⅵ) is 1。5g:50mL。

Keywords:Citric acid;peanut shell;modification;Cr(Ⅵ);adsorption

目 录

第一章 绪论 1

1。1 我国水资源现状 1

1。2 重金属废水概述 2

1。3 含铬废水概述 2

1。3。1 Cr(Ⅵ)的危害 3

1。3。2 含铬废水的处理方法 4

1。4 实验研究的背景、内容及意义 7

1。4。1 研究背景及意义 7

1。4。2 研究思路与内容 9

第二章 实验部分 10

2。1 废水来源 10

2。2 实验仪器与药品 10

2。2。1 实验仪器 10

2。2。2 材料及实验药品 10

2。3 Cr(Ⅵ)标准溶液的配制及改性花生壳的制备 11

2。3。1 Cr(Ⅵ)标准溶液 11

2。3。2  改性花生壳的制备