铁氧化物改性玉米芯生物炭对水体中砷的吸附特性研究

Adsorption Characteristics of Arsenic in Water Body by Iron Oxide-modified Corncob Biochar

为探究铁氧化物改性玉米芯生物炭对水体中砷的吸附特性,修复砷污染水体,利用比表面积测试仪(BET)、扫描电子显微镜(SEM)和傅里叶红外光谱(FTIR)对铁氧化物改性玉米芯生物炭(FX)和玉米芯生物炭(X)的比表面积、表面形貌和官能团进行表征,并分析了不同溶液初始pH值、初始砷浓度和吸附时间对水体中砷去除率的影响。结果表明:经铁氧化物改性后的玉米芯生物炭的比表面积和孔体积增加,铁氧化物负载在玉米芯生物炭上,有丰富的官能团;在溶液初始pH值为3时,FX对砷的去除率为97.8%,FX对砷的去除率随pH值的升高而下降;FX对水体中砷的吸附过程符合准二级动力学模型和Langmuir模型,对砷的最大吸附容量为18.02 mg/g;FX对水体中砷的吸附机制主要是静电吸附和化学吸附,且FX具有良好的循环利用潜力。

In order to repair arsenic-polluted water,iron oxide-modified corncob biochar(FX)is prepared to explore the adsorption characteristics of arsenic.Specific surface area,surface topography and functional groups of iron oxide-modified corncob biochar(FX)and corncob biochar(X)are characterized by surface ar-ea analyzer(BET),scanning electron microscope(SEM)and fourier transform infrared(FTIR),and the effects of initial pH value,initial arsenic content and adsorption time on removal rate of arsenic in water body were investigated.The results show an increase of the specific surface area and pore size of FX,and the iron oxide is loaded on the corncob biochar with abundant functional groups.When the initial pH value of the solution is 3,the removal rate of arsenic by FX is 97.8%.The removal rate decreases due to the in-crease of pH value.The maximum adsorption capacity of FX is 18.02 mg/g,in accordance with Langmuir adsorption model and quasi-second-order kinetic equation,The adsorption mechanism of FX arsenic is main-ly electrostatic adsorption and chemisorption,and FX shows a good recycling ability.