摘要
为了研制高效廉价的脱汞吸附剂,选用生物质废弃物稻壳制备稻壳焦,并对其进行NH4Cl和NH4Br化学浸渍改性.利用比表面积及孔隙度分析仪、扫描电子显微镜和X射线能谱分析仪等,对稻壳焦进行表征.在固定床汞吸附实验台上进行改性前后稻壳焦吸附脱除汞的实验,研究了稻壳粒径、改性剂种类和改性剂添加浓度对汞吸附的影响.实验结果表明,稻壳焦孔隙结构比较发达.随稻壳粒径减小,比表面积和微孔容积减小.改性后的稻壳焦微观形貌有较大改善,稻壳焦表面载氯/溴量显著增加.改性后稻壳焦的汞吸附量提高了约10倍.使用质量分数为1%的改性溶液即可显著提高稻壳焦的汞吸附脱除能力,且NH4Br改性后稻壳焦汞吸附性能略优于NH4Cl改性后稻壳焦.
In order to develop high-efficient but low-cost sorbents for mercury control, rice husk was chosen to prepare the rice husk chars which were then treated by NHnC1 and NH4Br solutions for modification. These rice husk chars were characterized by means of surface area and porosity analyzer, scanning electron microscopy and X-ray energy dispersive spectroscope. Experimental studies on removal of Hg were performed in a fixed bed reactor system. The effects of the factors, including particle size, modifying agents and modifying solution concentrations, on the efficiency of mercury sorbents were investigated. The experimental results show that the rice husk char has a well-developed pore structure. With the diameter decreasing, the specific surface area and the micropore volume of the chars decrease. There is a considerable improvement on the micro-morphology features of the bio- mass chars after modification. The bromine/chlorine content on the rice husk char surface increases after treated by NH4Cl and NH4Br. the Hg removal quantities of the modified rice husk chars is 10 times higher compared with the raw samples. It suggests that 1% additive of NH4Cl or NH4Br into the rice husk char can obviously improve the Hg adsorption and removal efficiency. Modification by NH4Br seems more efficient than NH4Cl.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第1期99-104,共6页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51076030)
江苏省环保科研课题基金资助项目(201113)
华中科技大学煤燃烧国家重点实验室开放基金资助项目(FSKLCC1002)
关键词
卤化铵盐
改性
稻壳焦
固定床
汞吸附
ammonium halide
modification
rice husk char
fixed bed
mercury adsorption
