【摘要】 以当地农业废弃物荞麦壳为原料,用硝酸改性后负载磁性Fe3O4,得到一种易于分离的吸附剂荞麦壳磁性炭。在空气为载气的氛围中,用SHMADZU DTG-60差热-热重分析仪得到荞麦壳的最佳热解温度为589℃,XRD分析结果表明磁性荞麦壳炭晶体构成主要由半晶体涡轮层碳和一些矿物质组成,并检测到了Fe3O4的特征峰,通过傅里叶红外光谱分析(FTIR)表明磁性荞麦壳炭表面在3 426 cm-1较宽的吸收峰为磁性物质与荞麦壳炭缔合形成的—OH。探究了在不同影响因素下荞麦壳磁性炭对水中Cr(Ⅵ)的吸附效果,结果表明,当pH值为5、Cr(Ⅵ)浓度150 mg/L、吸附时间为150 min、荞麦壳磁性炭对Cr(Ⅵ)的去除率达到98.3%。用Langmuir和Freundlich吸附模型对该吸附过程进行拟合,发现磁性荞麦壳炭对Cr(Ⅵ)的吸附更符合Langmuir吸附模型。更多还原

【Abstract】 The objective of the experimental research is to develop a novel biochar as an adsorbent for removing Cr（Ⅵ） from aqueous solution,with buckwheat hull,a sort of agricultural waste,as raw materials,which was modified by nitric acid and loaded with magnetic iron oxide（Fe₃O₄）.In preparation of the magnetic biochar in the atmosphere of nitrogen that was used as a carrier gas,differential thermal-thermogravimetric analyzer（SHMADZU DTG-60） was used to measure the optimum pyrolysis temperature of buckwheat-hull,which was 589 ℃.XRD analysis showed that the composition of magnetic buckwheat-hull carbon crystals were mainly composed of semi-crystal turbine layer carbon and some minerals,and detecting the characteristic peak of Fe₃O₄ by FTIR showed that the surface of magnetic buckwheat-hull biochar at 3 426 cm^-1 broad absorption peak was —OH formed by magnetic materials and buckwheat hull charcoal.The testing of Cr（Ⅵ） adsorption onto magnetic buckwheat-hull biochar showed that Cr（Ⅵ） removal rate attained 98.3%,as pH value of the solution was 5,Cr（Ⅵ） concentration was 150 mg/L and adsorption duration was 150 min.It was found that the adsorption of Cr（Ⅵ） on magnetic buckwheat-hull biochar better fit the Langmuir kinetic model than Freundlich model.更多还原