Lead removal from water using organic acrylic amine fiber(AAF)and inorganic-organic P-AAF,fixed bed filtration and surface-induced precipitation

Granular porous sorbents were normally used for heavy metals removal from water.To search for the new commercial sorbent and treatment strategy,an organic acrylic amine fiber(AAF)and phosphorus loading inorganic-organic AAF(P-AAF)were prepared and used for lead(Pb)removal from water.A new strategy of inorganic-organic coupling technology was proposed for Pb removal,based on the hypothesis of surface-induced precipitation mechanism.The AAF showed a Pb adsorption capacity of 417 mg/g from the Langmuir fitting,while the column filtration technology was further applied to measure the adsorption edge and applications.Effects of different initial Pb concentrations,hydraulic retention time,and co-existing P were considered in the filtration experiments.The presence of 0.8 mg/L P in water significantly improved the Pb breakthrough point from 15,000 to 41,000 bed volumes of water spiked with 85μg/L Pb,while the P-AAF fixed bed showed better removal of Pb than AAF SEM/EDX and XRD spectra were employed for determining the surface functional groups and the formation of surface-induced precipitation of pyromorphite(Pb_5(PO_4)_3 OH)on AAF.This study verified the application of AAF sorbent for Pb removal and the enhanced effect of coating P on AAF,thus improved our fundamental understanding and application of the surface chemistry process of Pb with P.

Adsorption and recovery of phosphate from water by amine fiber,effects of co-existing ions and column filtration

A weak-base adsorption fiber,acrylic amine fiber(AAF),was prepared for removal and recovery of phosphate from water.The adsorption properties of the AAF for phosphate and effects of co-existing ions were investigated using batch and column filtration experiments,scanning electron microscope,and Fourier transform infrared techniques.Experimental results showed that AAF had a high phosphate adsorption capacity of 119 mg/g at pH 7.0.The effects of calcium,sulfate,carbonate,nitrate,and fluoride showed that sulfate and calcium inhibited phosphate adsorption.However,AAF showed higher binding affinity toward phosphate than sulfate.Column filtration results showed that AAF could filter 1420 bed volumes of tap water containing 1.0 mg-P/L of phosphate.The saturated AAF could be regenerated using 0.5 mol/L hydrochloric acid solution and reused.After desorption,phosphate was recovered through precipitation of hydroxyapatite(Ca5(PO4)3OH).The easy of regeneration,good adsorption performance,and the fiber morphology of AAF make it an attractive alternative for phosphate recovery from multiple water sources.