改性玉米秸秆生物吸附剂的制备及吸附Cr(Ⅵ)的应用性能

Preparation and application of modified corn straw as biosorbent for Cr(Ⅵ)adsorption

通过预处理和酯化方法制备改性玉米秸秆,通过正交试验和单因素对比试验探究改性秸秆对Cr(Ⅵ)的吸附机制与最佳吸附条件。结果表明:秸秆投加量和p H值对Cr(Ⅵ)的吸附影响较大,在温度40℃,投加量0.04g,吸附时间45min,pH=3,Cr(Ⅵ)初始浓度10mg/L最佳条件下,吸附率达到最大值96.8%,吸附容量为121mg/g,是未改性秸秆的10.3倍。FT-IR显示改性后玉米秸秆有酯基生成和羧基的引入,电镋扫描结果表明纤维素结构更加有序,改性玉米秸秆作为新型生物吸附剂用于吸附皮革废水中的Cr(Ⅵ)具有潜在应用前景。

Modified com straw(MCS)was prepared by pretreatment and esterification modification technology.The optimization and mechanism of Cr(Ⅵ)adsorption performance were critically investigated via orthogonal experimental design and single-factor comparison experiments.Experimental results indicate that the MCS dosage and pH value has a far greater effect on Cr(Ⅵ)adsorption process.Moreover,the Cr(Ⅵ)adsorption rate(CrAR)and maximum adsorption capacity(CrAC)are 96.8%and 121mg/g respectively under the optimal conditions of MCS dosage 0.04 g,adsorption time 45 min,pH value 3,adsorption temperature 40℃,Cr(Ⅵ)initial concentration 10 mg/L,which increases by 10.3 times compared to unmodified corn straw.FT-IR analysis testifies that carboxyl and ester groups are introduced in MCS.Meanwhile,it turns out that cellulose structure of MCS is more orderly by SEM analysis.The MCS might he great potential for application in adsorption of Cr(Ⅵ)in tannery wastewater as a new type of biosorbent.