表面活性剂改性活性炭对高氯酸盐的吸附和再生

选用阳离子表面活性剂十六烷基三甲基氯化铵(CTAC)改性活性炭以提高活性炭对高氯酸盐的吸附能力.CTAC改性前后活性炭吸附能力通过吸附穿透曲线来比较.结果表明,未改性活性炭对高氯酸盐几乎没有吸附.CTAC改性则能显著提高活性炭对高氯酸盐的吸附能力.进水pH值对高氯酸盐的吸附影响较小,但水中干扰离子如NO3-、SO42-、SiO42-和PO43-会与高氯酸盐离子发生竞争吸附,从而降低活性炭对高氯酸盐的吸附能力.1mol/L HCl溶液的化学再生的效率在95%左右,再生后的活性炭能重复使用.水蒸汽热再生则能有效恢复活性炭的孔径结构.高氯酸盐在高温下降解得到完全去除,但再生后的炭必须重新改性后才能再次使用.

Adsorption of perchlorate by surfactant-modified activated carbon and its regeneration

Cationic surfactant cetyltrimethylammonium chloride was employed to modify an activated carbon(AC) in an attempt to enhance AC’s adsorption for perchlorate.Breakthrough curves were compared before and after modification.Non-modified AC had very little capacity for perchlorate.CTAC modification greatly improved AC’s adsorption.In addition,adsorption capacity was resilient again changes in influent pH.However,interfering anions,such as NO3-,SO42-,SiO42-and PO43-,showed competition for adsorption,which resulted in decrease in perchlorate removal.Activated carbon was regenerated when it reached breakthrough.A regeneration efficiency of 95% was observed when AC was chemically regenerated by 1 mol/L of HCl solution.And activated carbon was able to be reused directly after regeneration.Thermal regeneration by steam was effective in restoring AC’s pore structure.Perchlorate decomposed at high temperature and was removed thoroughly.However,thermal regeneration caused CTAC to degrade thus regenerated AC had to be re-modified before further application.