柠檬酸浸提污泥中重金属Zn的影响因素研究

采用化学浸出法对城市污泥中重金属Zn的浸提影响因素展开了研究,对比处理前后Zn的含量,研究柠檬酸浸提Zn的能力.通过单因素和正交试验,对可能影响Zn浸提率的柠檬酸浓度、反应体系pH、浸提时间和浸提温度等因素进行了数据分析.单因素试验结果显示,在柠檬酸浓度0.2mol/L、浸提时间15h、浸提温度20℃、pH3的条件下,Zn的最高浸提率为75.5%;对正交试验结果进行方差分析,温度对Zn的浸提率影响最显著;构建近似模型并选择合适的优化算法,优化组合条件下柠檬酸对Zn的最高浸提率为81.6%,比单因素试验浸提率提高了6.1%.研究表明,化学浸提是一种简便易行的城市污泥无害化处理方法,柠檬酸可以有效浸提污泥中的重金属Zn.

Research on Digestion Factors of Metal Zn in Sludge by Citric Acid

The paper researches on the digestion of the heavy metal Zn in the city sludge by the chemical digestion method. By comparing the Zn content before and after disposal, the paper measures the Zn digestion capability of citric acid. Through single-factor and orthogonal array experiments, the paper analyses citric acid concentration, reaction system pH, digestion time duration and temperature, the factors could affect the Zn digestion rate. The results of single-factor experiments show that, under the condition of the citric acid concentration 0.2mol/L, digestion time duration 15h,temperature 20℃ and reaction system pH,the highest Zn digestion rate is 75.5%; By applying the variance analysis for the orthogonal array experiments,as compared to other factors,the effect of the temperature on the Zn digestion rate is the most significant. Via building an approximation model and selecting the suitable optimization algorithm, the paper analyses the highest Zn digestion by using citric acid is 81.6%, increasing by 6.1 % when compared with that concluded by the single-factor experiments. This research validates that the chemical digestion is one handy method for the city sludge innocuous disposing, and citric acid can extract the heavy metal Zn in the sludge effectively.