改性磷渣的制备及对水中砷（Ⅲ）的吸附研究

发布时间：2018-06-04 09:24

  本文选题：磷渣 + 含砷废水　； 参考：《昆明理工大学》2017年硕士论文

【摘要】：砷及砷的化合物对人体的健康有着极大的毒害作用,砷污染成为人们越来越关注的问题,尤其是日益严重的水体砷污染现象,随着磷化工企业的迅速发展,大量的磷渣因得不到充分的利用,而对环境造成危害。本研究采用磷渣作为砷吸附材料,并将其进行改性从而提高对砷的吸附性能,不仅制备出了一种对废水中的砷有良好去除效果的环境材料,还为磷渣的综合利用提供了一条新的途径,同时解决了两大环境问题,达到了以废治废的效果。研究选用多种方法对磷渣进行改性,从中筛选出铁盐恒温浸润和铁盐超声辅助两种改性方法,并对改性的实验条件进行了优化。结果表明:铁盐恒温浸润改性磷渣的最佳制备条件为:在80℃条件下,利用浓度为0.8mol· L-1的FeCl3溶液,熟化6h,所制备的改性磷渣对废水中As(Ⅲ)的去除率可达到99.1%;铁盐超声辅助改性磷渣的最佳制备条件为:FeCl3溶液的浓度0.8mol·L-1、超声时间15min,所制备的改性黄磷水淬渣对废水中As(Ⅲ)的去除率可达到98.9%。通过两种方法,在最佳改性条件下制备的改性磷渣对As(Ⅲ)的去除率比未改性磷渣分别提高了 38.2%和38%。共存离子对两种改性磷渣吸附As(Ⅲ)均有一定的影响,当溶液中As(Ⅲ)的浓度固定时,影响的大小顺序为:SiO32、PO43_SO42-CO32-、Cl-;溶液中As(Ⅲ)的浓度改变时,影响的大小顺序为:SiO32-、PO43-SO42-、CO32-、Cl-,SiO32-和PO43-对改性磷渣吸附砷的影响较大。用NaOH溶液对吸附后的两种改性磷渣进行解吸,3次解吸后,改性磷渣对As(Ⅲ)的吸附效果依然稳定,说明两种改性磷渣均有良好的再生性能。采用比表面积和孔径测定(BET)、傅里叶红外光谱(FT-IR)、扫描电镜与X射线能谱(SEM/DES)和X射线光电子能谱(XPS)对改性前、后及吸附后的磷渣进行表征。改性后的磷渣比表面积和孔容增大、孔径减小,铁和羟基的含量增多,并且吸附后磷渣中三价砷和五价砷均存在,表明两种改性方式都能使铁很好的负载在磷渣上,增加其对As(Ⅲ)的去除效果。研究还对改性磷渣吸附As(Ⅲ)的过程进行了吸附等温式及动力学方程的模拟。两种改性磷渣对As(Ⅲ)的吸附过程与Langmuir·吸附等温方程和Freundlich吸附等温方程均能很好的拟合,但Langmuir吸附等温方程更能很好的描述其对As(Ⅲ)的吸附过程,拟合的相关系数R2分别为0.99和0.98,其吸附的方式均以单分子层吸附为主。Lagergren准二级动力学方程更能准确地描述两种改性磷渣对As(Ⅲ)的吸附动力学过程,拟合所得的平衡吸附容量的理论值与实验值更为接近,其拟合方程的相关系数R2分别为0.97和0.96,吸附速率被化学吸附所控制。
[Abstract]:Arsenic and arsenic compounds have a great toxic effect on human health. People pay more and more attention to arsenic pollution, especially the increasingly serious arsenic pollution phenomenon in water, with the rapid development of phosphorus chemical industry. A large amount of phosphorus residue is harmful to the environment because it is not fully utilized. In this study, phosphorus residue was used as arsenic adsorption material and modified to improve the adsorption performance of arsenic. Not only a kind of environmental material with good removal efficiency of arsenic in wastewater was prepared. It also provides a new way for the comprehensive utilization of phosphorus residue, and solves two major environmental problems at the same time, and achieves the effect of treating waste with waste. In this paper, a variety of methods were selected to modify phosphorus slag. Two methods of iron salt constant temperature wetting and iron salt ultrasonic assisted modification were selected, and the experimental conditions of the modification were optimized. The results showed that the optimum preparation conditions of iron salt modified phosphorous slag at constant temperature were as follows: at 80 鈩，

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