天然黄铁矿对水溶液中硒酸根的吸附性能研究

Adsorption behavior of natural pyrite for removal of selenium ions from aqueous solution

进行了不同黄铁矿粒径、初始硒浓度、温度和pH条件下黄铁矿吸附Se(Ⅳ)(SeO23-)的实验研究。在12h的实验时间内,微米级的黄铁矿对初始硒质量浓度为7.896、19.740、39.480mg/L的Se(Ⅳ)的去除率分别为18%、11%和6%,而纳米级的黄铁矿对同浓度Se(Ⅳ)的去除率均达到91%以上。室温下,纳米级黄铁矿对Se(Ⅳ)饱和吸附量为3.89mg/g。在pH为2.2~11.5时,黄铁矿对Se(Ⅳ)的吸附率均超过92%,纳米级黄铁矿吸附Se(Ⅳ)的过程符合准二级动力学方程,反应活化能为26.003kJ/mol,实验数据与Langmuir吸附等温模型拟合较好。

Batch experiments of selenium （Se（ Ⅳ ）） adsorption from aqueous solution were conducted by using natural pyrite as adsorbent. The effect of pyrite particle sizes, initial Se（IV） concentration, temperature and solution pH on Se（Ⅳ） adsorption efficiency was investigated. Results showed that when the initial concentration of selenium was 7. 896,19. 740,39. 480 mg/L,the SeO^- removal rate was 18% ,1t~ ,60/00 respectively after 12 h of adsorption by micro-sized pyrite, while the nano-sized pyrite could achieve the Se（ Ⅳ ） removal efficiency of more than 91 %when ini- tial selenium concentration was no more than 39. 480 mg/L. The saturated Se（IV） adsorption capacity of nano-sized pyrite was 3.89 mg/g at room temperature;the Se（Ⅳ） removal rate was more than 92% when solution pH ranged 2.2-11.5. The dynamic adsorption data of Se（ Ⅳ ） on nano-sized pyrite were well described by pseudo second-order ki- netic equation with the activation energy was 26. 003 kJ/mol. The Langmuir adsorption isotherm model fitted the ex- perimental data better than Freundlich isotherm model.