Arsenic removal from water using a novel amorphous adsorbent developed from coal fly ash.
A novel effective adsorbent of alumina/silica oxide hydrate (ASOH) for arsenic removal was developed through simple chemical reactions using coal fly ash. The iron-modified ASOH with enhancing adsorption activity was further developed from raw fly ash based on the in situ technique. The adsorbents were characterized by X-ray diffraction, Fourier transform infrared spectrometry, scanning electron micrograph, laser particle size and Brunauer-Emmet-Teller surface area. The results show that the adsorbents are in amorphous and porous structure, the surface areas of which are 8-12 times that of the raw ash. The acidic hydrothermal treatment acts an important role in the formation of the amorphous structure of ASOH rather than zeolite crystal. A series of adsorption experiments for arsenic on them were studied. ASOH can achieve a high removal efficiency for arsenic of 96.4% from water, which is more than 2.5 times that of the raw ash. Iron-modified ASOH can enhance the removal efficiency to reach 99.8% due to the in situ loading of iron (Fe). The condition of synthesis pH = 2-4 is better for iron-modified ASOH to adsorb arsenic from water.
Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation, North China Electric Power University, Beijing 102206, China E-mail: myzkh2@126.com; Department of Energy Power & Mechanical Engineering, North China Electric Power University, Beijing 102206, China.
Kaihua
K
Zhang
Department of Energy Power & Mechanical Engineering, North China Electric Power University, Beijing 102206, China.
Dongxue
D
Zhang
Beijing Key Laboratory of Emission Surveillance and Control for Thermal Power Generation, North China Electric Power University, Beijing 102206, China E-mail: myzkh2@126.com; Department of Energy Power & Mechanical Engineering, North China Electric Power University, Beijing 102206, China.
Kai
K
Zhang
D000327:Adsorption; D000537:Aluminum Oxide; D001151:Arsenic / Q000737:chemistry*; D003031:Coal / Q000032:analysis; D060729:Coal Ash / Q000737:chemistry*; D005290:Ferric Compounds; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis; D012822:Silicon Dioxide; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D017641:Zeolites / Q000737:chemistry
D003031:Coal; D060729:Coal Ash; D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; D014867:Water; D017641:Zeolites; C000499:ferric oxide; D012822:Silicon Dioxide; D007501:Iron; D000537:Aluminum Oxide; D001151:Arsenic