title: Enhanced removal of arsenic from a highly laden industrial effluent using a combined coprecipitation/nano-adsorption process.
abstract: Effective arsenic removal from highly laden industrial wastewater is an important but challenging task. Here, a combined coprecipitation/nano-adsorption process, with ferric chloride and calcium chloride as coprecipitation agents and polymer-based nanocomposite as selective adsorbent, has been validated for arsenic removal from tungsten-smelting wastewater. On the basis of operating optimization, a binary FeCl3 (520 mg/L)-CaCl2 (300 mg/L) coprecipitation agent could remove more than 93% arsenic from the wastewater. The resulting precipitate has proved environmental safety based on leaching toxicity test. Fixed-bed column packed with zirconium or ferric-oxide-loaded nanocomposite was employed for further elimination of arsenic in coprecipitated effluent, resulting in a significant decrease of arsenic (from 0.96 to less than 0.5 mg/L). The working capacity of zirconium-loaded nanocomposite was 220 bed volumes per run, much higher than that of ferric-loaded nanocomposite (40 bed volumes per run). The exhausted zirconium-loaded nanocomposite could be efficiently in situ regenerated with a binary NaOH-NaCl solution for reuse without any significant capacity loss. The results validated the combinational coprecipitation/nano-adsorption process to be a potential alternative for effective arsenic removal from highly laden industrial effluent.
authors: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
authors: Yingnan
authors: Y
authors: Jiang
authors: Ming
authors: M
authors: Hua
authors: Bian
authors: B
authors: Wu
authors: Hongrui
authors: H
authors: Ma
authors: Bingcai
authors: B
authors: Pan
authors: Quanxing
authors: Q
authors: Zhang
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000032:analysis*; D002712:Chlorides / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D007220:Industrial Waste / Q000032:analysis*; D011108:Polymers; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D015040:Zirconium / Q000737:chemistry
chemical_list: D001151:Arsenic; D002712:Chlorides; D005290:Ferric Compounds; D007220:Industrial Waste; D011108:Polymers; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015040:Zirconium; C000499:ferric oxide; C024555:ferric chloride