摘要
对废轮胎回转窑中试热解炭的重金属离子Pb2+、Cr3+和Cr6+吸附特性进行了研究,分析了溶液pH值、接触时间、吸附剂用量以及溶液初始浓度对重金属去除率的影响。结果表明,溶液pH值对热解炭的重金属去除率有显著影响,阳离子Pb2+、Cr3+的去除率随pH的增加而增大,在弱酸和中性环境中去除率接近100%;Cr6+在强酸性溶液中被还原成为Cr3+,经二次吸附,总Cr去除率可达99%以上;Pb2+和Cr3+的去除率随热解炭用量和吸附时间的增大而增加,热解炭用量和吸附时间有一个最佳值。Pb2+和Cr3+的吸附为单分子层吸附,可用Langnu ir和两段Freund lich等温吸附式描述,Freund lich拟合指数表明,热解炭具有较好的吸附性能。经酸洗后的热解炭对Pb2+的去除率变低。
The Characteristic of heavy metal ions （pb^2 ＋ , Cr^3＋~ and Cr^6＋ ） adsorption by carbon blacks from pyrolysis of used tires in pilot-scale rotary kiln was studied. The effect of initial solution pH, adsorption time and dosage of PCB （ pyrolytic carbon black） on the heavy metal removal was examined. It is found that the initial solution pH has a great effect on the heavy metal removal efficiency. The removal of cations such as Pb^2＋ , Cr^3 ＋ increases with the increase of solution pH and reaches about 100% in weak acidic and neutral solutions. Cr^6＋ can be reduced to Cr^3＋ in strong acidic solutions. After the second adsorption, the removal of total Cr reaches above 99%. The removal of Pb^2＋ and Cr^3＋ increases with the increase of adsorption time and PCB dosage which have an optimum value. The adsorption of Pb^2 ＋ and Cr^3＋ is monolayer adsorption which can be described by Langnuir and two-stage Freundlich equations, and the fitting exponential of Freundlich indicates that PCB has a favorable adsorption effect for Pb^2＋ and Cr^3 ＋. After acid wash, the adsorption effect of PCB for Pb^2 ＋ will be reduced.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2006年第3期353-358,共6页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(50076037)
关键词
废轮胎
回转窑
热解炭
重金属
吸附
used tire
rotary kiln
pyrolytic carbon black
heavy metal
adsorption
