柠檬酸改性颗粒活性炭吸附水中Cr6+的试验

摘要

目的 研究柠檬酸改性处理颗粒活性炭,比较改性前后活性炭对废水中Cr6+处理的试验方法,明确影响因素对去除Cr6+的效果影响,探讨各因素影响原因.方法 采用柠檬酸对活性炭进行改性处理,通过改变柠檬酸质量浓度、吸附时间、活性炭投加量、pH值、温度,考察主要因素对水中Cr6+去除的影响并进行机理分析.结果 结果表明Cr6+初始质量浓度为50 mg/L、活性炭投加量为3.5g、pH=5.5、室温25℃、吸附4h时经过质量分数为60％和70％柠檬酸改性的活性炭对Cr6+的吸附去除率都达到了99.05％,是GAC对Cr6+吸附去除率的6.57倍；活性炭吸附Cr6+,240 min基本达到吸附平衡；活性炭对Cr6+的吸附去除率随着pH值的升高而减少,pH =2时去除率最大,GAC -6对Cr6+的去除率几乎达到100％；温度对吸附Cr6+的影响较小.结论 在不同投加量,pH值,温度等条件下,柠檬酸改性后的活性炭对Cr6+去除率明显高于GAC对Cr6+的去除率.结果证明柠檬酸改性活性炭对Cr6+具有较好的吸附性.%The paper studied on citric acid modified activated carbon,comparison of modified activated carbon treated with wastewater in Cr6 + test method before and after, and clarification of influence factors of removal of Cr6+ , and analysis of the reasons. Using citric acid modified activated carbon, by changing the citric acid concentration,adsorption time,carbon dosage,pH,temperature,examining,the main factors for removal of Cr6+ in water are analyzed and discussed. The results show that when the initial concentration of Cr6+ is 50 mg/L,the dosage of GAC 3.5 g,pH value 5. 5,room temperature 25 ℃ .adsorption time 240 min,Cr6+ removal rate by the GAC-6 or GAC-7 reaches 99. 05%. It is 6. 57 times higher than that by the GAC adsorption; when the adsorption lasts 240 min.GAC adsorption of Cr6+ almost reached equilibrium;removal efficiency increased with the decrease of pH. When pH =2,GAC-6 removal efficiency for Cr6+ almost reaches 100% ;Temperature has small effect on the results. According to the study with different GAC, pH, temperature and other conditions,citric acid modified GAC removal of Cr6+ was significantly higher than GAC to remove Cr6+. Results show that citric acid modified activated carbon for Cr6+ has better adsorption.