摘要
湿法提钒工艺中会产生大量含钒废水,直接排放会造成环境污染和资源浪费。硅藻土具有比表面积大、孔隙多、密度小、吸附性能及渗透性较强等优点,广泛应用在环境治理领域。以硅藻土为吸附剂,采用静态吸附试验研究吸附时间、污染液初始浓度、pH值和硅藻土投入量对钒的吸附效果;对试验数据进行吸附热力学和动力学拟合,探究了吸附机理及特征。研究表明:硅藻土的主要成分是SiO_(2),含有少量蒙脱石和绿泥石,硅藻壳体为圆盘状,壳体表面有数量众多的微孔结构。热力学拟合中,硅藻土的吸附过程更符合Freundlich模型,R^(2)为0.901 0,属于多分子层吸附和表面吸附;动力学拟合中,准二级动力学模型的相关系数比准一级动力学模型高,R^(2)为0.995 4,说明吸附过程以化学吸附为主导。当吸附时间24 h,钒污染液初始浓度1 mg/L,污染液用量50 mL,pH值5,硅藻土投加量2 g时,去除率最优,达到98.21%。硅藻土对污染液中钒的吸附效果较好,可作为吸附剂治理钒污染。
A large amount of vanadium containing wastewater is produced in the wet process of vanadium extraction, and its direct discharge causes serious environmental pollution and resource waste. Due to the advantages of large specific surface area, many pores, low density, strong adsorption performance and permeability of the diatomite, it has been widely used in environmental management fields.Using diatomite as an adsorbent, the effect of adsorption time, initial concentration of polluted liquid,pH value and diatomite dosage on the vanadium adsorption was conducted by static adsorption experiments. The adsorption thermodynamics fitting and kinetics fitting were researched according to the experimental data, and the adsorption mechanism and characteristics was analyzed. The results show that the main component of diatomite is SiO_(2), with a small amount of montmorillonite and chlorite. The shape of diatom shell is discoid, the surface of the shell has numerous microporous structures. In the thermodynamic fitting, the adsorption process of diatomite is more in line with the Freundlich model,and the R^(2) is 0.901 0, which belongs to the multi-molecular layer adsorption and surface adsorption. In the kinetic fitting, the correlation coefficient of the quasi-second-order kinetic model is higher than that of the quasi-first-order kinetic model, the R^(2) is 0.995 4, indicating that the adsorption process is dominated by chemisorption. When the adsorption time is 24 h, the initial concentration of contaminated vanadium solution is 1 mg/L, the amount of contaminated solution is 50 mL, the pH is 5, and the dosage of diatomite is 2 g, the removal rate of vanadium can reach 98.21%. Therefore, diatomite has a good adsorption effect on vanadium in vanadium-containing waste liquid, and can be used as an adsorbent to treat vanadium pollution.
作者
孙宁
李俊翰
Sun Ning;Li Junhan(School of Vanadium and Titanium,Panzhihua University,Panzhihua 617000,Sichuan,China)
出处
《钢铁钒钛》
CAS
北大核心
2022年第5期111-116,共6页
Iron Steel Vanadium Titanium
基金
国家环境保护水土污染协同控制与联合修复重点实验室开放基金(GHBK-2020-009)
四川大学-攀枝花市科技合作专项资金项目(2019CDPZH-6)
攀枝花大学科技园种子资金项目(2019-23)。
关键词
含钒废液
硅藻土
吸附
钒
去除率
vanadium-containing waste liquid
diatomite
adsorption
vanadium
removal rate
