HTMAC/KH550/膨润土吸附剂的制备、表征及其在甲基橙废水的吸附行为

Preparation,characterization of HTMAC/KH550/bentonite adsorbent and its adsorption behavior on methyl orange wastewater

利用十六烷基三甲基氯化铵(HTMAC)、硅烷偶联剂(KH550)作为有机插层剂改性钙基膨润土,制得新型吸附剂HTMAC/KH550/膨润土。对改性膨润土的膨胀容、胶质价、吸蓝量进行测试,并对其进行FTIR、XRD、SEM和BET表征。结果表明:改性膨润土的胶质价、吸蓝量增大,使得分散性和对有机物的吸附能力增大。在HTMAC和KH550共同改性作用下,部分分子进入膨润土层间,d_(001)由1.53nm增大至2.89nm。有机改性土N_2吸附-脱附模型属于有明显H3滞后Ⅳ等温线,说明改性土是一种有微孔和介孔混合材料。以HTMAC/KH550/膨润土为吸附剂,考察了加量、吸附时间、吸附温度及pH对甲基橙废水脱色率的影响。结果表明,20℃时,pH为7~8、最佳加量为2g/L、吸附时间30min条件下,甲基橙废水脱色率达89.8%。吸附平衡模型研究表明:20℃时,改性膨润土吸附甲基橙符合Langmuir等温吸附模型,最大吸附量为71.53mg/g。指出HTMAC/KH550/膨润土是一种新型吸附容量大的吸附剂,为染料去除提供新的方法。

Organobentonites were prepared by modifying calcium bentonite using hexadecyltrimethylammonium chloride （HTMAC） and silane coupling agent （KH550） as intercalation agents. The characteristics of swelling volume, colloid valence, and ethylene blue adsorbed were measured. Organobentonites were characterized with fourier transform infrared （FTIR）, X-ray powder diffraction （XRD）, scanning electron microscope （SEM） and brtmauer -emmett-teller （BET）. Results showed that the ability of dispersion and adsorption of organics increase with the increase of colloid valence and ethylene blue adsorbed. Under the co-modification of HTMAC and KH550, the modified reagents has been intercalated to the layer of bentonite, and the d001 values increase from 1.53nm to 2.89nm. The N2 adsorption-desorption isotherm exhibited that organobentonite has type 1V isotherm with a clear H3 hysteresis loop, which indicated that HTMAC/KH550/bentonite was a mixed microporous/mesoporous material. Organobentonites were used to treat methyl orange wastewater. The effects of dosage, flocculation time, adsorption temperature and pH were investigated. Result showed that the highest removal rate of methyl orange wastewater was 89.8%. The optimum operationcondition were dosage of organobentonite 2g/L, flocculation time 30min, pH7-8 and adsorption temperature 20℃. Adsorption equilibrium studies showed that methyl orange adsorption follows the Langmuir model. In addition, the maximum adsorption capacity of the organobentonite was determined to be 71.53mg/g. HTMAC/KH550/bentonite is a kind of high adsorption capability adsorbent. It can provide a new method for dye removal.