摘要
采用市政污泥在300℃缺氧条件下制得污泥生物碳,研究了污泥生物碳添加量、溶液pH及吸附反应时间对溶液中Pb2+、Cu2+、Zn2+吸附效果的影响,并分析了各因素影响机制及污泥生物碳对重金属的吸附机理.结果表明,污泥生物碳对溶液中重金属的去除率与重金属水合离子半径呈负相关,随着污泥生物碳添加量的增加,溶液中重金属的去除率不断增加,但单位吸附量总体上呈下降趋势.重金属吸附量随溶液pH的增加而增大,当溶液初始pH为6.00时,污泥生物碳对溶液中Pb2+、Cu2+和Zn2+的吸附量最大,分别达42.941、25.769和12.484 mgg.伪二级动力学方程可有效描述溶液中重金属离子在生物碳上的吸附过程,重金属在污泥生物碳表面的吸附主要受化学反应控制,Pb2+、Cu2+和Zn2+的平衡吸附量分别为39.747、6.849和10.004 mgg,达到吸附平衡的时间为Pb2+>Zn2+>Cu2+.
Sludge-derived biochars were prepared at 300 ℃ and hypoxia. The effects of addition amount, pH and contact time on adsorption of Pb2＋ , Cu2＋, Zn2＋ in solution by sludge-derived biochars were firstly investigated, and the influence and adsorption mechanisms were further discussed. The results showed that the removal rate of heavy metals in solution adsorbed by sludge derived biochar was inversely proportional to the hydrated ionic radius of heavy metals. The removal rate of heavy metals increased with the increase of sludge-derived biochars. However, the adsorption amount per unit mass decreased. The adsorption amount of heavy metals increased with the increase of pH in solution, and the maximum value appeared when pH was equal to 6. 00. Tile adsorption capacities of Pb2＋, Cu2＋ and Zn2＋ were 42. 941,25. 769 and 12. 484 mg/g respectively. Pseudo second-order model can effectively describe the adsorption process of heavy metal ions on sludge-derived biochar, which was mainly controlled by the chemical reaction. The equilibrium adsorption capacities of Pb2＋ , Cu2＋ and Zn2＋ were 39. 747, 6. 849 and 10. 004 mg/g respectively, and the equilibrium time followed the order： Pb2＋ 〉Zn2＋ 〉Cu2＋.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2013年第11期1246-1251,共6页
Research of Environmental Sciences
基金
国家水体污染控制与治理科技重大专项(2012ZX07104-002)
武汉市高新技术成果转化及产业化项目(2013060803010403)
国家重点基础研究发展计划(973)项目(2012CB719802)
关键词
污泥
生物碳
重金属
吸附
sludge
biochar
heavy metal
absorption
