摘要
采用壳聚糖和氢氧化钠对天然沸石粉进行改性,制备了一种新型的改性沸石粉吸附材料,对其进行傅里叶红外光谱和扫描电镜分析,并将其用于微污染源水中对镉(Ⅱ)的吸附去除,考察了吸附时间、pH、镉(Ⅱ)初始浓度和沸石粉投加量等因素对镉(Ⅱ)去除效果的影响。结果表明,改性沸石粉由原来的团状结构变为孔隙状结构,且壳聚糖负载于其上,形成了内比表面积更大的多孔物质;在试验条件下,吸附时间越长、pH越高、沸石粉投加量越大,两种沸石粉对镉(Ⅱ)的吸附去除效果越好,且改性沸石粉对镉(Ⅱ)的吸附去除效果明显优于天然沸石粉;当镉(Ⅱ)浓度<60μg/L时,投加0.8 g/L的改性沸石粉可使处理后的镉(Ⅱ)浓度达到《生活饮用水卫生标准》(GB 5749—2006)的要求;改性沸石粉与镉(Ⅱ)之间的吸附以单分子层吸附为主,基本符合Freud-lich模型。
Modified zeolite powder, a new adsorbent, was prepared by natural zeolite powder, chitosan and sodium hydroxide, and was analyzed by Fourier transform infrared spectrometer （FTIR） and scanning electron microscope （SEM）. It was used to remove cadmium （ Ⅱ ） from micro-polluted source water, and the effects of adsorption time, pH, initial concentration of cadmium （ Ⅱ ） and zeolite powder dosages on the removal of cadmium （ Ⅱ ） were investigated. The results show that cluster structure becomes pore structure of the modified zeolite powder, and chitosan is supported on it, forming porous material with bigger inner specific surface area. Under the experimental conditions, longer adsorption time, higher pH and larger zeolite powder dosages can make better removal efficiency of cadmium （ Ⅱ ） by natural and modified zeolite powder. The removal efficiency of cadmium （ Ⅱ ） by modified zeolite powder is better than that by natural zeolite powder. When cadmium （ Ⅱ ） concentration is less than 60 μg/L, 0.8 g/L modified zeolite powder can make cadmium （ Ⅱ ） concentration after treatment meet the requirement of Sanitary Standard for Drinking Water （ GB 5749 - 2006 ）. The adsorption between cadmium （ Ⅱ ） and modified zeolite powder bases mainly on monolayer and accords with Freudlich adsorption isothermal model.
出处
《中国给水排水》
CAS
CSCD
北大核心
2008年第17期79-83,共5页
China Water & Wastewater
基金
广东省科技计划重大专项(2006A36802001)
广东省“十一五”重大科技专项(2007A032400001)
关键词
微污染源水
镉(Ⅱ)
改性沸石粉
壳聚糖
micro-polluted source water
cadmium （ Ⅱ ）
modified zeolite powder
chitosan
