生物质吸附剂对硝酸盐氮的吸附及再生

Adsorption and Regeneration of Nitrate-nitrogen by Biomass Adsorbent

近年来,硝酸盐氮污染逐渐成为中外学者所关注的重要的水污染问题。为了去除水中的硝酸盐氮,采用化学方法对锯末进行改性,得到一种经济高效的生物质吸附剂。对该吸附剂进行了扫描电子显微镜(scanning electron microscope,SEM)、傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FT-IR)和Zeta电位(Zeta)表征,探讨了吸附剂添加量、时间、pH和硝酸盐氮初始浓度对硝酸盐氮去除效果的影响,并对吸附剂的再生效果进行了研究。结果表明:当吸附剂添加量为10 g/L、吸附时间为20 min、pH为7、硝酸盐氮初始浓度为20~60 mg/L时,改性锯末对硝酸盐氮的去除率稳定在96%±0.2%,再生后的改性锯末对硝酸盐氮的去除率仍能达到95%。吸附过程符合Freundlich等温吸附模型。可见改性锯末对废水中的硝酸盐氮有很好的去除能力。

In recent years,nitrate nitrogen pollution has gradually become an important water pollution problem that domestic and foreign scholars pay attention to.In order to remove the nitrate nitrogen in the water,the sawdust was modified by chemical methods to obtain an economical and efficient biomass adsorbent.The adsorbent was characterized by scanning electron microscopy(SEM),Fourier infrared spectroscopy(FT-IR),and Zeta potential(Zeta).The influences of adsorbent dosage,adsorption time,pH,and initial concentration of nitrate-nitrogen on the removal of nitrate-nitrogen were mainly analyzed.The regeneration of the material was carried out research.The results show that the removal rate of modified sawdust for nitrate nitrogen stabilizes at 96%±0.2%when the adsorbent addition is 10 g/L,the adsorption time is 20 min,the pH is 7,and the initial concentration of nitrate-nitrogen is 20~60 mg/L,and the removal rate of nitrate nitrogen by modified sawdust after regeneration can reach 95%.The adsorption process conforms to the Freundlich isotherm model.It is concluded that the modified sawdust has a good ability to remove nitrate-nitrogen in wastewater.