生物炭负载铁锰氧化物吸附去除Cr(Ⅵ)的试验研究

Experimental study on removal of Cr(Ⅵ)by adsorption of iron and manganese oxides supported by biochar

采用热解法制备负载铁锰氧化物的改性生物炭,并用于去除水中的Cr(Ⅵ)。通过SEM,XRD,FTIR等表征手段对材料进行分析,同时探究材料投加量、Cr(Ⅵ)初始浓度、初始pH值对Cr(Ⅵ)去除的影响。在铁锰物质的量比为1:3,香蒲质量为5 g的条件下,经600℃热解2 h制得改性生物炭F1M3BC5。改性后的香蒲草生物炭孔隙丰富,比表面积显著增大,更有利于材料对Cr(Ⅵ)的吸附。批量吸附试验结果表明,对于100 mL初始质量浓度为20 mg/L的含Cr(Ⅵ)废水,F1M3BC5的最佳吸附条件为pH值为3、投加量为0.15 g、温度为25℃、吸附时间为5 h。吸附过程与准二级动力学模型拟合,最大吸附量可达18.24 mg/g。

Modified biochar-loaded iron and manganese oxide were prepared by pyrolysis and used to remove Cr(Ⅵ)from water.The materials were analyzed by SEM,XRD,FTIR,and other characterization methods,the effect of materials dosage,initial concentration of Cr(Ⅵ),and initial pH value on the removal of Cr(Ⅵ)were investigated at the same time.Under the condition that the molar ratio of iron to manganese was 1:3,the dosage of cattail was 5 g,modified biochar F1M3BC5 was prepared by pyrolysis at 600℃ for 2 h.The modified cattail biochar had abundant pores and larger specific surface area,which was more conducive to the adsorption of Cr(Ⅵ).The results of batch adsorption test showed that the optimal adsorption conditions of F1M3BC5 for 100 mL of Cr(Ⅵ)-containing wastewater with initial mass concentration of 20 mg/L were as follows:the pH value was 3,the adsorbent dosage was 0.15 g,the temperature was 25℃ and the adsorption time was 5 h.The adsorption process fits quasi-second-order kinetic model,and the maximum adsorption capacity can reach 18.24 mg/g.