摘要
以Fe(Ш)和Al(Ш)对砷有较强的亲和性为理论基础,用沉淀法制备了9种同时含有Fe(Ш)和Al(Ш)的砷吸附剂———复合铁铝氢氧化物.X射线衍射和扫描电镜测定结果表明,有5种复合铁铝氢氧化物具有微晶无定形态的结构特征.比表面测定结果表明,复合铁铝氢氧化物的孔体积和孔径明显低于相同实验条件下制得的氢氧化铁,说明铝的掺杂能明显改变氢氧化铁中规则的晶体结构和表面性质.用复合铁铝氢氧化物进行了水中砷的吸附研究,结果表明,该复合材料具有优良的除砷效能,吸附容量大;当pH为5.0～9.0、溶液中初始砷浓度为2mg·L-1时,不同组成的铁铝复合氢氧化物都能使溶液中的砷含量降到世界卫生组织标准0.01mg·L-1以下,其中以Fe(Ш)/Al(Ш)摩尔比为7∶3的复合物吸附除砷能力最强.pH为5.0～9.0时各复合物对砷的吸附模式均符合Freundlich和Langmuir等温吸附方程.
Based on the strong affinities of Fe（Ⅲ） and Al（Ⅲ） to arsenate, nine iron-aluminum hydroxide complexes were synthesized as adsorbents for the arsenic removal. The scanning electron microscopy （SEM） images and X-ray diffraction （XRD） spectra demonstrated that five iron - aluminum hydroxide complexes had the minicrystal - amorphous morphology. The nitrogen sorption experiments indicated that the pore volume and the pore diameter of these complexes were lower than those of the pure iron hydroxide synthesized under the same conditions, The addition of aluminum hydroxide into iron hydroxide could change the superficial characteristic and crystal frame, Moreover, the adsorption experiments showed that all iron-aluminum complexes could adsorb aqueous arsenate effectively and with a high capacity. When an arsenic solution of 2 mg· L^-1 was added with anyone of these complexes at pH 5.0-9.0, the arsenic concentration could be decreased to less than 0.01 mg·L^-1, the standard for drinking water set by the World Health Organization, Among these absorbents, the complex with the Fe（Ⅲ）/Al（Ⅲ） molar ratio of 7/3 owned the highest adsorption capacity, Furthermore, the adsorption isotherms of arsenic on these complexes agreed well with the Freundlich or Langmuir equations at pH 5.0-9.0.
出处
《环境科学学报》
CAS
CSCD
北大核心
2006年第3期438-446,共9页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.40263001)
教育部留学回国人员科研启动基金(教外司留200314)
广西高校百名中青年学科带头人资助计划(桂教人200397)~~
关键词
复合铁铝氢氧化物
吸附剂
砷
iron-aluminum hydroxide complex
adsorbent
arsenate
aqueous solution
