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牛粪源蚓粪及其生物炭对Cu、Zn的吸附特性研究

时间:2020-12-08 15:29来源:毕业论文
以牛粪源蚓粪为生物炭原料,在0℃、350℃和700℃热解出生物炭,分别标记为CV、CVC350和CVC700,比较这三种吸附材料的吸附解吸特性及动力学行为,研究了溶液初始浓度

摘要随着工农业的不断发展,重金属污染日益加剧,严重威胁生态环境、食品安全、人类的健康与生命和农业可持续发展。为减轻当前重金属污染对生态和环境的压力,如何安全有效地去除水体和土壤中的重金属污染已成为当前十分迫切的任务。本课题以牛粪源蚓粪为生物炭原料,在0℃、350℃和700℃热解出生物炭,分别标记为CV、CVC350和CVC700,比较这三种吸附材料的吸附解吸特性及动力学行为,研究了溶液初始浓度、pH和吸附时间对牛粪源蚓粪吸附Cu2+、Zn2+的影响。结果表明,随着溶液初始浓度的增加,吸附材料对溶液中Cu2+、Zn2+的吸附量呈上升趋势;溶液初始pH=7时,吸附材料对Cu2+、Zn2+的吸附效果达到最高点;随着溶液中Cu2+、Zn2+的浓度增大,当Cu2+、Zn2+含量超过吸附剂的最大吸附值,其吸附效果反而会降低。对实验数据进行吸附等温线和时间动力学分析,吸附材料对Cu2+、Zn2+的吸附等温曲线与Langmuir方程(Cu:R2=0.9979,Zn:R2=0.9933)拟合性最好;在振荡条件下,随着时间的不断增加,吸附量不断上升,到达一定的时间点,吸附量基本处于平衡状态,与两个常量方程、准一级动力学方程和准二级动力学方程相比,Elovich动力学模型能更好地描述Cu2+、Zn2+在牛粪源蚓粪中吸附动力过程。60563

毕业论文关键词:牛粪源蚓粪; 生物炭; Cu; Zn; 吸附; 解吸; 动力学

Abstract:With the development of industry and agriculture, heavy metal pollution has become more and more serious, which has a bad effect on ecological environment, food security, human health and the sustainable development of agriculture. Therefore, how to degraded the heavy metals in the environment and water has become an urgent problem which needs to be solved. This paper discussed the removal effect of Cu and Zn by three different kind of biological carbon as adsorption materials, which were pyrolysis at 0℃、350℃ and 700℃.Comparison of this three different temperatures of biological carbon adsorption desorption characteristics,dynamic behaviors of adsorption material,and the influence of initial concentration,pH and adsorption time.The results showed that at the beginning of the reaction, the adsorption amounts of Cu and Zn by three adsorption materials were on the increase, and the adsorption effect reached the highest point when pH=7. As the solution Cu and Zn concentration increases,when the Cu and Zn content exceeding the maximum adsorption of the adsorbent, the adsorption effect will be reduce. The adsorption isotherm of Cu、Zn by the absorbent could significantly conform to Freundlich equations(Cu:R2=0.9979,Zn:R2=0.9933);two constant equations, quasi first order kinetic equation and pseudo two order kinetic equation and Elovich kinetic model were used for the fitting of the removal data of Cu and Zn. Results showed that the removal data of three different kind of biological carbon were generally best described by the Elovich kinetic model.

Keywords:cow dung source vermis dung; biochar; Cu; Zn;adsorption; desorption; dynamics

摘    要 1

1. 引言 4

2. 材料与方法 5

2.1生物炭的制备 5

2.2 溶液的制备 6

2.3 实验方法 6

2.3.1 标准曲线 6

2.3.2 吸附实验 6

2.3.3 解吸实验 6

2.3.4 吸附动力学实验 7

2.3.5 溶液初始pH值对吸附的影响 7

2.4 计算方法 牛粪源蚓粪及其生物炭对Cu、Zn的吸附特性研究:http://www.751com.cn/huaxue/lunwen_66053.html

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