改性棉籽壳对铬(Ⅵ)的吸附效果研究

Adsorption Effect of Cr(Ⅵ) by Modified Cottonseed Hulls

重金属铬是一种毒性较大的金属,铬污染也引起了越来越广泛的重视。本文研究开发一种高效低廉的铬吸附材料——农林废弃物棉籽壳,并对其进行改性,以提高对铬的吸附效果。研究结果显示,未改性棉籽壳的最佳吸附条件为:温度为35℃,p H值为6,棉籽壳投加量为2 g,吸附时间为48 h时,Cr(Ⅵ)的去除率最高,达到72.42%,吸附容量为0.21 mg/g。采用Na Cl和交联改性方法改性后的棉籽壳对Cr(Ⅵ)的去除率有大幅提高,Na Cl改性棉籽壳吸附Cr在48 h的去除率为96.34%,交联改性棉籽壳在48 h吸附Cr(Ⅵ)的去除率为99.80%,分别比未改性之前提高了23.92%和27.38%。后续将进行进一步的研究,以期在将来制备出高吸附性能的吸附剂并实现工程应用。

Heavy metal chromium is a kind of metal with high toxicity,and its pollution has also attracted more and more extensive attention. This article studies and develops an efficient and inexpensive Cr（ Ⅵ） adsorbing material--agricultural and forest residues cottonseed hulls-and modifies them to improve the adsorption of chromium. The results show that： the best adsorption conditions for unmodified cottonseed hull are： temperature 35℃,p H value 6,cottonseed hull dosage 2 g,adsorption time 48 h,under which the Cr（ Ⅵ） removal rate is the highest,reaching 72.42%and the adsorption capacity is 0.21 mg/g. The Cr（ Ⅵ） removal rate is greatly increased when using cottonseed hulls modified by Na Cl and cross-linking modification methods. The 48 h Cr（ Ⅵ） removal rate is 96.34% with Na Cl modified cottonseed hulls and 99. 80% with cross-linking modified cottonseed hulls,increased by 23. 92% and 27. 38%than with unmodified cottonseed hulls respectively. Further studies will be carried out in order to prepare an adsorbent with high adsorption performance and achieve engineering applications in the future.