A Novel Polymer-Supported Tin Phosphate Nanocomposite For Heavymetal Absorption

Lead and cadmium are two kinds of heavy metal pollutants with the most typical water pollution.The unique size structure of sub-10nm nanomaterials makes it possible to efficiently remove lead and cadmium ions in wastewater,which has become one of the current research hotspots.It has strong complexing ability for heavy metal ions.Therefore,this paper uses a simple method to prepare sub-10 nm tin phosphate nanomaterials below the critical size.In order to overcome the application bottleneck of nanomaterials agglomeration,the sub-10 nm material is stably loaded onto the surface of D001 resin matrix to develop a new resin-based nanometer.Composite materials,using the above two materials as adsorbents to purify lead and cadmium heavy metal wastewater,study its adsorption performance,and further explore the adsorption mechanism of nano-phosphorus composite resin on lead ions in sewage.Firstly,a new type of nano-adsorbed material,sub-10 nm tin phosphate,was prepared by chemical precipitation method.The material was characterized by TEM and XRD.It was confirmed that the sub-10 nm tin phosphate material was successfully prepared.It was verified by static adsorption experiments that the kinetic equilibrium of the adsorbed lead ions could be achieved within 2 min and the adsorption capacity reached 1300 mg/g.In the presence of Ca(?),Mg(?)and Na(I)competing ions,the removal rate of lead ions in the water by the adsorbent is higher than 99%,which has excellent adsorption selectivity,which proves the application feasibility of the material.On this basis,dopamine can be self-polymerized on the surface of D001 resin to form polydopamine film,which has strong adhesion characteristics.The sub-10 nm tin phosphate is grown in situ on the surface of dopamine coated resin to prepare synthetic resin.The morphological appearance,size and crystal structure of the materials were observed and analyzed by SEM,TEM,XRD,BET and other characterization methods.Through a series of static batch experiments of adsorbed lead ions,it is proved that the material has a wide pH range(pH:2.0-7.0);the maximum adsorption capacity is 450 mg/g by Langmuir fitting;the composite has lead ion Significantly high selectivity,K_d is 450times than the matrix material.The capacity of the composite material for the effective treatment of lead-containing ion wastewater was 8400 L/Kg,the Pb(?)ion concentration in the effluent was<10?g/L,and the lead ion was removed during the 5 cycles of adsorption-desorption regeneration.The rate is higher than 90%and has excellent adsorption regeneration performance.The ultra-high-speed filtration experiment of 10cycles was quickly completed within 2 minutes,and the removal efficiency was as high as~98.8-99.8%,which further proved the practical application of the material.At the same time,this paper preliminarily discussed the removal effect of resin-based sub-10 nm tin phosphate composite on cadmium ions,and verified that the material has good applicability to various heavy metals.