| Water is an important resource for ensuring the sustainable development of human’s economy society.However,in recent years,with the acceleration of urbanization and industrialization process,the natural water bodies suffer from severer pollution.Among them,the phosphorus pollution is of great concern because of its high existing concentration and great harm.Excessive phosphate concentration in the water body not only easily causes the problem of water eutrophication,but also is often accompanied by the possibility of explosive growth of microorganisms,which is a great threat to the environment and human health.How to remove phosphorus efficiently and accurately and prevent the rapid growth of microorganisms has become a hot spot in current research.The adsorption method is easy to operate,low cost,and could effectively recycle available resources.However,most of the currently used phosphorus removal adsorbents exhibit low adsorption capacity,poor selectivity and single function.Therefore,it is very important to find an adsorbent with high adsorption capacity,good selectivity,and antibacterial effect.Lanthanum is an eco-friendly and low-cost rare earth element which is popular as a typical phosphate-removing material in recent years.It has strong affinity for phosphate.However,bare La-compound may be improper to use in adsorption directly since it is difficult to be separated from water phase for its small particle size.Besides,agglomeration leads to low utilization efficiency,which is troublesome during the synthesis process.Fortunately,previous studies have shown that loading nanomaterials on certain matrix materials may solve such problems.Polymeric organic quaternary ammonium salt（POQAs）is an antibacterial material that can effectively kill microorganisms.Besides,POQAs is positively charged which makes it have the functions of promoting the dispersion of nano-materials,increasing the zero potential point and binding anionic pollutants.Therefore,POQAs can be considered as a reasonable matrix material.Based on the above,a novel and bi-functional composite PEE@La（La（OH）3 loaded poly（epichlorohydrin）-ethylenediamine）was fabricated from La-compound and PEE through a one-step copolymerization and subsequent in situ precipitation in this study.And the adsorption studies and antibacterial experiments were carried out systematically.Conclusions are as follows:（1）According to the morphological characterization results,the La-compound in the composite material is mainly attached to the outer surface of the PEE in the form of rod-like nano-crystallite structures.The amount of adhesion is positively correlated with the dosage of La source,the optimal ratio is 1:1.In addition,through XRD,XPS and other characterizations,the supported La-compound should be La（OH）3.（2）In terms of adsorption,PEE@La-100%exhibits a maximum capacity with PO43-of186.6 mg g-1,and the behavior of PEE@La-100%fits well with Langmuir model and Pseudo second-order kinetic,implying that this process should be a monolayer and chemical adsorption.In addition,PEE@La-100%maintained a high removal rate in a wide p H range,and the competitive anions had little effect on adsorption of phosphate except for sulfate.Compared to some adsorbents reported in pervious papers,PEE@La-100%exhibited a larger adsorption capacity and a wider application.The analysis results of XPS,XRD and FT-IR showed that both electrostatic attraction and chemical bonding played an important role in adsorption.（3）In terms of sterilization,PEE@La-100%also exhibited excellent inhibition on the growth of E.coli,which has rarely been reported previously.After further investigation,it was found that the bactericidal effect may come from phosphate starvation sterilization and quaternary ammonium salt sterilization.Overall,this work provides a novel insight in developing bi-functional composite with large adsorption capacity and its applications for phosphate adsorption and bacterial inhibition. |
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