用有机膨润土吸附处理含铬(Ⅵ)废水的研究

Study of Adsorption of Cr(Ⅵ)-Containing Wastewater by Organobentonite

采用溴化十六烷基三甲铵（CTMAB）对天然膨润土进行了有机改性处理，并在静态条件下，进行了有机膨润土对含Cr（Ⅵ）工业废水的吸附试验。研究了CTMAB浓度、有机膨润土用量、废水pH值、搅拌时间等因素对Cr（Ⅵ）去除率的影响，确定了用有机膨润土处理含cr（Ⅵ）废水的适宜条件。结果表明，有机膨润土能有效地除去废水中的Cr（Ⅵ），其最佳工艺条件为废水pH值3．0～5．0、搅拌时间约30min、有机膨润土用量10g／L，按该工艺条件对含Cr（Ⅵ）35mg／L左右的废水进行处理。铬的去除率达到98．0％以上，处理后的水样中Cr（Ⅵ）含量小于O．50mg／L，达到国家排放标准。

Crude bentonite was organically modified using hexadecyltri-methylammonium bromide (CTMAB).The resulting modified organobentonite was used to adsorb Cr(Ⅵ)-containing wastewater under static conditions.The effects of the concentration of CTMAB,organobentonite dosage,pH value of wastewater,and stirring time on the removal rate of Cr(Ⅵ) ions were studied,while the optimized processing conditions for the treatment of Cr(Ⅵ)-containing wastewater by organobentonite were determined.Results showed that the modified organobentonite was capable of effectively adsorbing and removing Cr(Ⅵ) in the wastewater.The optimum technological conditions were suggested as pH value of wastewater 3.0 to 5.0,stirring time about 30 min,and organobentonite dosage 10 g/L.Moreover,it was feasible to remove the Cr(Ⅵ) ions in the wastewater containing about 35 mg/L Cr(Ⅵ) at a removal rate over 98.0%,using the optimized processing conditions.And the content of Cr(Ⅵ) ions in the resulting treated wastewater was less than 0.50 mg/L,qualified in terms of the relevant national discharge standard.