摘要
为研究柠檬渣对污水中Cu^(2+)的吸附性能,利用H_2SO_4与NaOH对柠檬渣进行改性制备吸附剂,并采用响应曲面法对制备工艺进行了优化.测试了吸附剂的比表面积、孔容与孔径等性能,并利用红外光谱(IR)、紫外光谱(UV)、差热分析(TG-DTA)、X射线衍射(XRD)、电镜(SEM)和能谱(EDS)对吸附剂进行了表征.通过响应面法优化后的最佳改性条件:H_2SO_4改性后的炭化温度为80℃,NaOH改性后的炭化温度为90℃,w(NaOH)∶w(H_2SO_4)为0.3.改性后的柠檬渣较原柠檬渣比表面积由88.3 m^2/g增至392.2 m^2/g,灰分率降低了90.7%,碘吸附值提高了近5倍,孔径分布主要是中孔;柠檬渣属于无定型结构,改性后的柠檬渣有CC生成,形成了芳香烃,表面形成了密集的孔;改性后柠檬渣主要由碳元素组成,从而能有效吸附Cu^(2+),对Cu^(2+)的吸附率能达到85.3%.由红外分析可知,改性后的柠檬渣吸附Cu^(2+)后3 804 cm^(-1)处的吸收峰消失,说明Cu^(2+)取代了这个吸收峰所代表的官能团及部分O—H中的H^+.
To study properties of Cu^2＋ in wastewater adsorbed by lemon residues, sulfuric acid and sodium hydroxide were used to modify lemon residues to produce adsorbent, and the preparation process was optimized by response surface technique. The specific surface area, pore volume, pore size and other properties of the adsorbent were tested. The samples were characterized by IR, UV, XRD, TG-DTA and SEM/EDS. The results showed that when sulfuric acid carbonization temperature was 80 ℃ and sodium hydroxide carbonization temperature was 90 ℃, the mass fraction ratio of sodium hydroxide concentration and sulfuric acid concentration was 0.3.After the original lemon residues were modified, the specific surface area increased from 88.3 m^2/g to 392.2 m^2/g, ash rate was reduced by nearly 90.7%, iodine adsorption increased nearly 5-fold, and the pore size distribution mainly was medium. The structure of the lemon residues was amorphous, modified lemon residues generated CC and aromatic hydrocarbons, and many pore formed on the surface. The modified lemon residues were mainly composed of carbon. Copper ions could be adsorbed effectively, and the Cu^2＋ adsorption rate reached 85.3%. After the copper was adsorbed by the modified lemon residues, the absorption peak at 3804 cm^-1 disappeared, as analyzed by IR. This indicated that the functional groups represented by this absorption peak were replaced by Cu^2＋, and H^＋in O—H was also replaced by Cu^2＋.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2016年第1期146-154,共9页
Research of Environmental Sciences
基金
2013年四川省教育厅重点项目(13ZA0002)
关键词
化学改性
吸附率
响应曲面法
物理性质
chemical modification
adsorption rate
response surface methodology
physical properties
