膨润土-白云石复合吸附剂对Fe^(2+)和Mn^(2+)的吸附性能

The Adsorption Regularity of Modified Bentonite-dolomite to Fe^(2+)、Mn^(2+) Heavy Metal Ions

针对煤矿排出的大量含重金属离子的酸性矿山废水污染问题,采用自制膨润土-白云石复合颗粒吸附剂对含Fe2+和Mn2+的酸性矿山废水进行吸附试验研究。结果表明:膨润土-白云石复合颗粒吸附剂释放总碱度达118.39mg/g(以CaCO3计),可中和酸性矿山废水;随着废水中Fe2+和Mn2+浓度增加,膨润土复合颗粒吸附剂的吸附量在不断增加,且大于原膨润土颗粒吸附剂;建立了膨润土复合颗粒吸附剂对Fe2+和Mn2+的吸附等温式和吸附动力学方程式:膨润土复合颗粒吸附剂对Fe2+的吸附符合BET吸附,对Mn2+的吸附符合Freundlich吸附,对Fe2+、Mn2+的吸附动力学均符合准二级动力学。膨润土-白云石复合颗粒吸附剂既能释放碱度、又对Fe2+和Mn2+具有优良的吸附性能,可作为处理含重金属离子酸性矿山废水的绿色环保矿物材料应用于实际。

According to the environmental pollution of acid mine drainage which is caused by the emission of large quantities of heavy metal ions, anexperimental research of adsorption of acid mine drainage by using the selbmade bentonite - dolomite com posite particle adsorbent is adopted. The results showed that bentonite-dolomite composite particles adsorbent released total al- kalinity of 118.39 mg/g （as CaCO3） which could neutralize the acid mine wastewater. With the concentration of F32＋ and Mn2＋ increasing, adsorption quantity of bentonite-dolomite composite particles adsorbent was growing, and heavier than the o- riginal bentonite particles adsorbent. Then through carrying out the adsorption isotherms and adsorption kinetics of fitting, it drawed bentonite-dolomite particles adsorbent for Fe2＋ fitted the BET equation and Mn2＋ fitted the Freundlich equation. And the bentonite composite particles adsorbent of Fe2＋ and Mn2＋ of adsorption were both in line with the pseudo-second-order ki- netic model. Bentonite-dolomite composite particles adsorbent could release the alkalinity, have good adsorption performance to Fe2＋ and Mn2＋ , and could be used as the green environmental mineral materials processing heavy metal ions from acid mine drainage.