含镍电镀污泥的资源化技术及动力学研究

发布时间：2018-04-08 21:56

  本文选题：电镀污泥　切入点：浸出　出处：《武汉工程大学》2015年硕士论文

【摘要】：电镀污泥是电镀过程中产生的电镀底泥及废水处理后的固体物。电镀污泥的危害性比废水的危害要大,如何处理电镀污泥,避免其任意堆放或处置不当造成更严重的二次污染,使其实现资源化成为亟待解决的问题。本文以某电镀处理工业园含镍电镀污泥为研究对象,通过对其成分检测可知,镍在污泥中的含量占14.63%,具有良好的资源化利用价值。通过正交试验与单因素优化试验,考察了酸浸条件对重金属镍的浸出率的影响与离子交换树脂对酸浸液中镍的吸附及解吸效果的主要影响因素,同时,也研究了酸浸动力学与离子交换吸附动力学机理。选取硫酸为浸出剂,对含镍电镀污泥进行了浸出试验。通过正交试验得出了最佳浸出方案,通过单因素优化试验,得到浸出的最佳条件：硫酸质量分数为15%、固液比为1：7、污泥粒径小于0.15 mm、时间为60 min、温度20℃,此条件下镍的浸出率可达96.02%。分别对电镀污泥进行放大10倍和40倍试验,镍的浸出率仍在95%左右。浸出过程动力学分析发现,该电镀污泥的硫酸浸出过程符合固体产物层扩散控制模型,反应级数是1,反应扩散系数K=0.0117×e(?),Ea=3.127 kJ/mol。浸出热力学研究表明：ΔH=-95.93 kJ·mol-1ΔS0=-146.96 J·mol·K-,ΔG=-52.14 kJ·mol-1。ΔH0,表明浸出过程为放热过程。ΔG0,表明浸出过程自发进行。进行铁离子去除试验,研究发现,SI-2树脂对Fe3+最佳吸附条件为：pH是1.5,吸附时间为80 min,温度是20℃。SIAP树脂对Fe3+的最佳吸附条件为：pH是2,吸附时间是40 min,温度是20℃。两种树脂的饱和吸附量均为35.00 mg/g左右。选用SI-2树脂对镍离子进行了提取研究,其静态吸附的研究结果为：最佳pH是5,吸附时间是100 min,温度是20℃,饱和吸附量为3000 mg/g。最佳静态洗脱条件为：洗脱剂是盐酸,浓度是4 mo1·L-1。脱80 min后洗脱率保持在93%左右。吸附过程动力学研究表明,SI-2树脂对镍离子的吸附过程与拟二级动力学模型t/Qt=1/(K2Qe)+t/Qe相符,并且线性相关系数大于0.99,液膜扩散控制是主要速率控制步骤,吸附表观活化能Ea=1.532 kJ/mol。吸附过程热力学研究表明,SI-2树脂对镍离子的吸附过程同时符合Langmuir和Freundlich两种等温吸附模型,并且Freundlich常数在2-3之间,说明吸附过程简单易行。根据热力学公式计算得出：在298K时,吸附过程的△H=3.39 kJ/mol,△S=73.05 J/(mol·K),△G=-18.38 kJ/mmol。△H0,表明整个过程为吸热过程,△G0,说明吸附过程可以自发进行。
[Abstract]:Electroplating sludge is a kind of solid matter produced in electroplating process.The harm of electroplating sludge is greater than that of wastewater. How to treat electroplating sludge to avoid more serious secondary pollution caused by random stacking or improper disposal has become an urgent problem to be solved.In this paper, the nickel electroplating sludge in an industrial park is taken as the research object. The content of nickel in the sludge is 14.63, which has good value of resource utilization.The effects of acid leaching conditions on the leaching rate of heavy metal nickel and the main factors affecting the adsorption and desorption of nickel in acid leaching solution by ion exchange resin were investigated by orthogonal test and single factor optimization test.The kinetic mechanism of acid leaching and ion exchange adsorption was also studied.The leaching test of nickel-containing electroplating sludge was carried out with sulfuric acid as leaching agent.The optimum leaching scheme was obtained by orthogonal test. The optimum leaching conditions were obtained by single factor optimization test: the mass fraction of sulfuric acid was 15, the ratio of solid to liquid was 1: 7, the diameter of sludge was less than 0.15 mm, the time was 60 min, and the temperature was 20 鈩，

本文编号：1723491