活性炭-膨胀石墨吸附处理制药废水及其微波再生

AC-EG adsorption treatment of pharmaceutical wastewater and adsorbents' microwave regeneration

针对制药企业生化出水中污染物难生化降解,且微波再生过程中活性炭加热不均匀、损耗率大等问题,采用活性炭掺杂膨胀石墨的方法制得AC-EG吸附材料,并使用该材料(AC-EG)吸附处理某制药厂生化处理后的尾水.在对该制药企业的废水进行组分分析的基础上,研究该材料对污染物的吸附热力学和动力学机制,并对AC-EG吸附材料的微波再生效果进行考察.结果表明,该尾水中含有多种吡啶类、酰胺类、唑类、吡嗪等难生化降解有机污染物;在膨胀石墨掺杂量为15%(质量分数)时,通过吸附处理后,尾水中COD去除率达58.25%,并且该掺杂量的AC-EG吸附材料对制药废水中污染物的吸附过程是放热(ΔH=-16.918 k J/mol)、熵减(ΔS=-54 J/(mol·K))的物理吸附(符合Freundlich模型);该吸附过程更符合拟二级动力学模型;掺杂膨胀石墨的活性炭吸波受热更加均匀,且随着掺杂量的升高,吸附剂再生率升高,损耗率下降.

Aiming to treat pharmaceutical wastewater containing pollutants that are difficult to be biodegraded,and deal with the inhomogeneous temperature and big attrition rate during the microwave regeneration of activated carbon,this study adopted a method,using a mixture of activated carbon and expanded graphite as AC-EG adsorption materials,to adsorb and treat the wastewater of a pharmaceutical factory after biochemical treatment.Based on the component analysis of wastewater from a pharmaceutical company,the adsorption thermodynamics and dynamics mechanism of pollutants in pharmaceutical wastewater adsorbed by adsorption material was studied,and the effect of microwave regeneration was investigated. The results showed that the wastewater contained a variety of unbiodegradable pollutants like pyridine,amide,azole,pyrazine and so on. The removal rate of COD in wastewater reached 58. 25% when adsorbent was a mixture of activated carbon and 15% expanded graphite. The adsorption process,which AC-EG with 15 wt% expanded graphite adsorbed pollutants in pharmaceutical wastewater,is an exothermic physical adsorption which follows Freundlich model（ ΔH =-16. 918 k J/mol）,and its entropy reduced（ ΔS =-54 J/（ mol·K））. Its kinetics model was relatively consistent with the second-order equation. A mixture of activated carbon and expanded graphite was heated and adsorbed microwave radiation more uniformly. With the increase of expanded graphite＇s doping amount,the adsorbent regeneration rate increased and the attrition rate declined.