摘要
研究了实验室自制的纳米铁对人工配制的含硫废水中S2-吸附的影响因素、吸附等温线、吸附动力学,并对纳米铁去除S2-的机制进行了初探.结果表明,增加纳米铁的投加量能增大S2-的去除率;增加初始S2-浓度,去除率下降,<100 mg.L-1的初始S2-浓度能被10 g.L-1纳米铁完全去除;纳米铁对S2-的吸附能力随pH值的升高而下降,且变化较大,pH为2、7、13时的去除率分别为87.34%、65.80%和44.61%;25℃时纳米铁对S2-的吸附能力最强,平衡吸附量为19.17 mg.g-1;温度升高或降低,吸附能力均下降,但变化不大;纳米铁对S2-的吸附等温线符合Langmuir和Freundlich方程;纳米铁吸附S2-的过程符合拟二级动力学方程,初始时刻的吸附速率h在25℃最大,为1.575 3 mg.(g.mg)-1,而吸附速率常数随温度的升高而增大;吸附反应的活化能Ea为8.22 kJ.mol-1;纳米铁对S2-的去除主要是通过形成表面络合物、硫氢基氧化铁和硫化铁(FeS、FeS2、FeSn)沉淀吸附在纳米铁表面来去除.
Influencing factors, adsorption isotherm, adsorption kinetics and preliminary discussion on the mechanism of sulfide adsorption by nanoscale iron prepared in laboratory were studied using manual simulation sulfide wastewater. Experimental results indicate that the removal efficiency of S^2- increases with increasing iron dosage and decreases with increasing initial S^2- concentration and pH values. The removal efficiency of S^2- is 100% when initial concentration is less than 100 mg·L^-1 and are 87.34%, 65.80% and 44.61% at pH 2, 7 and 13. The temperature at 25℃ favors the maximum adsorption of S^2- with 19.17 mg·g^-1 of equilibrium adsorption quantity and the adsorption capacity decreas at higher or lower temperature. The adsorption data fit well to the Langmuir equation and the Freundlich equation. The sulfide adsorption follows the pseudo second order equation with the maximum initial sorption rate（ h ） is 1. 575 3 mg·（g·mg）^-1 at 25 ℃ and the adsorption rate constant increases with the increasing of temperature. The activation energy（ Ea ） is 8.22 kJ·mol^-1. The mechanism of sulfide removal is being sorbed onto the iorn nanoparticles via formation of surface compleses, FeOSH and iron sulfides（ FeS, FeS2, FeSn ）.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2008年第9期2529-2535,共7页
Environmental Science
基金
国家自然科学基金项目(40102027
50578151)
北京市自然科学基金项目(8052017)
北京市教委校企合作项目(51900265005)
关键词
纳米铁
硫
恶臭
吸附等温线
动力学
机制
nanoscale iron
sulfide
odour
adsorption isotherm
kinetics
mechanism
