Highly Efficient Removal Of Phosphate In Water By Amyloid Fibrils Supported Ferric Hydroxide

Release of phosphorous into groundwater and surface water has caused serious eutrophication problems on a global scale,which affects the survival of many aquatic species and the safety of drinking water supplies.Thus,enhanced removal of phosphate from waste effluents is of considerable significance before their discharge into the receiving waterways.Adsorption has been regarded as an attractive alternative because of its simple operation,low cost,and potential for phosphate recovery from wastewater.Among the available adsorbents,ferric hydroxide has been extensively studied and widely used in phosphate removal in wastewater because of its satisfactory and relatively low operation cost.Therefore,this paper uses a simple method to prepare amyloid fibrils-Fe（OH）₃ nanocomposite for phosphate removal.Moreover,based on amyloid fibrils-Fe（OH）₃ reagent,D201-Fiber-Fe（OH）₃ membrane was prepared by vacuum filtration using D201 powder as the substrate and used to remove phosphate from wastewater,studying its adsorption performance and adsorption mechanism.Firstly,ferric hydroxide coatedβ-lactoglobulin nanofibrils were synthesized via chemical precipitation method.The detailed characterizations of the materials have been systematically investigated by TEM,FTIR and XRD.The result showed thatβ-lactoglobulin nanofibrils were a fibrous amorphous nano-structure（～10 nm width and2-4μm length）.The length of nanofibrils loaded with Fe（OH）₃ unchanged and Fe（OH）₃nanoparticles smaller than 10 nm.Batch experiments were performed to investigate various adsorption conditions on the adsorption performance.It was discovered that the hybrid Fiber-Fe（OH）₃ exhibited an efficient scavenging activity toward phosphate with effective removal efficiency as high as 95%,under the background of high levels of ionic strengths were used.Hybrid Fiber-Fe（OH）₃ achieved a favorable adsorption performance over a wide range of pH conditions,which could result in operation cost saving.Additionally,the kinetic equilibrium of the scavening phosphate could be achived in 5 min and the hybrid material showed a remarkable performance for low concentration of phosphate contamination（removal efficiency>90%）.The results suggested that hybrid Fiber-Fe（OH）₃ has a great potential in efficient removal of phosphate in wastewater.On this basis,D201 hybrid membrane was prepared by vacuum filtration using D201powder as the substrate.The D201-Fiber-Fe（OH）₃ membrane was characterized using TEM、XRD and FTIR.These hybrid membranes exhibit superior selectivity for phosphate against various competitive ions,with removal efficiency>90%.Significantly,the hybrid membranes showed a remarkable performance,as low（1 mg/L）concentrations of phosphate contamination can be reduced to below 0.13 mg/L.Additionally,the hybrid membrane not only exhibits good selectivity for phosphate adsorption but also a wide range of pH applications.The hybrid membrane effectively treated～6400 kg contaminated water/kg sorbent and could be regenerated.The effluent phosphate concentration could be reduced to below 0.5 mg/L.The efficient performance of these hybrid membrane makes them highly promising for alleviating phosphate contamination problems.