餐厨垃圾生物质炭制备及其吸附水中亚甲基蓝性能

Research on the adsorption performance of kitchen waste biochar for methylene blue

以餐厨垃圾为原材料,通过高温热解法和共沉淀法制备了餐厨垃圾生物质炭(Natural kitchen waste biochar,NKB)和磁性餐厨垃圾生物质炭(Magnetic kitchen waste biochar,MKB),研究了热解温度、热解时间、吸附剂量、吸附时间和溶液pH值等条件对生物质炭吸附水中亚甲基蓝(MB)性能的影响。结果发现,在热解温度450℃、热解时间1 h条件下制备的NKB对MB吸附性能最好;在生物质炭投加量1.0 g·L^(-1)、吸附时间20 min、pH值为9的条件下,MKB对MB的去除率和吸附量分别为97.94%和9.2 mg·g^(-1),分别比NKB提高18.54个百分点和1.6 mg·g^(-1);经过多次再生后,MKB对MB的吸附去除率仍在90%以上;吸附过程符合Langmuir等温吸附模型。研究表明,餐厨垃圾生物质炭经过赋磁可提高对亚甲基蓝的吸附性能,碱性条件下吸附性能较好,且能多次循环再生。

Natural kitchen waste biochar(NKB)and magnetic kitchen waste biochar(MKB)were prepared by pyrolysis and coprecipitation method using food waste as raw material.The effects of pyrolysis temperature,pyrolysis time,adsorbent dosage,adsorption time and the pH of solution on the adsorption capacity of methylene blue(MB)were investigated.The results showed that the optimum adsorption capacity of NKB was obtained at the pyrolysis temperature of 450 ℃ and the pyrolysis time of 1 h.When the MKB was 1.0 g·L^-1,the adsorption time was 20 min,and pH was 9,the adsorption capacity and removal rate of MB arrived 97.94% and 9.2 mg·g^-1,which was 18.54% and 1.6 mg·g^-1 higher than that of NKB,respectively.For MKB,after 4 cycles regeneration,the removal rate of MB was still above 90%.The adsorption process of kitchen waste biochar for MB could be described by Langmuir isothermal adsorption model.