title: Boron removal from aqueous solution by direct contact membrane distillation.
abstract: The removal of boron from aqueous solution by direct contact membrane distillation (DCMD) was studied with self-prepared polyvinylidene fluoride (PVDF) hollow fiber membranes in the present work. The effect of pH, boron concentration, temperature and salt concentration of the feed solution on the boron rejection was investigated. The experimental results indicated that boron rejection was less dependent on the feed pH and salt concentration. DCMD process had high boron removal efficiency (>99.8%) and the permeate boron was below the maximum permissible level even at feed concentration as high as 750 mg/L. Although the permeate flux was enhanced exponentially with the feed temperature increasing, the influence of feed temperature on the boron rejection could be neglected. Finally, the natural groundwater sample containing 12.7 mg/L of boron was treated by DCMD process. The permeate boron kept below 20 microg/L whether the feed was acidified or not, but pre-acidification was helpful to maintain the permeate flux stability. All the experimental results indicated that DCMD could be efficiently used for boron removal from aqueous solution.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, China.
authors.forename: Deyin
authors.initials: D
authors.lastname: Hou
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Xiangcheng
authors.initials: X
authors.lastname: Sun
authors.forename: Zhaokun
authors.initials: Z
authors.lastname: Luan
authors.forename: Changwei
authors.initials: C
authors.lastname: Zhao
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Ren
mesh_terms: D001895:Boron / Q000302:isolation & purification*; D057168:Distillation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D011145:Polyvinyls; D012996:Solutions; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D005465:Fluorocarbon Polymers
chemical_list: D001895:Boron; D008567:Membranes, Artificial; D011145:Polyvinyls; D012996:Solutions; D014874:Water Pollutants, Chemical; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers