Synthesis Of Functionalized Nano-materials Based On Irradiation Technology And Their Applications In Pollution Control

The release of industrial wastewater and the abuse of pesticide and fertilizer have become the main sources of environmental pollution,which is seriously harmful to human health.Functionalized nanomaterials are widely applied in industrial,electronic,biological,and medical fields because of their excellent electronic,mechanical,magnetic,optimal,and chemical properties.However,the traditional fabrication approaches of nanomaterials are complicated,high-cost,and time-consuming.Therefore,the application of high energy electron beam irradiation in fabrication of nanomaterials has gained more and more attentions due to its efficient and facile properties.This dissertation mainly studies on the modification and fabrication of nanomaterials using high energy electron beam irradiation,which were then applied in the preparation of catalyst support,new kind of foliar fertilizer and the removal of pollutants in waste water.In summary,the results are included in six chapters as follows:1.Contact method has been widely applied to produce sulfuric acid,and the supporter of vanadium catalyst used in this process is diatomite.However,the natural diatomite usually possesses a small pore size distribution and high impurity contents,which decreases the transfer speed of reactants in the pores,and thus reduces the production efficiency of sulfuric acid.Therefore,in chapter two of this dissertation,we proposed a facile approach to modify natural diatomite using high energy electron beam irradiation,which could effectively improve the pore size distribution of diatomite and thus enhance the performance of the corresponding vanadium catalyst.The study shows that high energy electron beam irradiation possesses the properties of etching,thermal,oxidation and reduction effects could effectively increase the pore size of diatomite.Besides,the analysis of specific surface area and the catalytic performance also demonstrated that the clogged pores could be dredged and enlarged,which enhanced the transfer speed of SO2 and O2 during the fabrication process of sulfuric acid and thus a high catalytic efficiency could be finally obtained.2.The unused traditional foliar fertilizer sprayed on crop leaves tends to be discharge into the water,air and soil through the effect of washoff and volatilization,which could cause a waste of manpower and energy and severe environmental contamination.Therefore,it is needed to develop a new kind of foliar fertilizer which possesses the properties of high adhesion ability and utilization efficiency.Therefore,in chapter three of this dissertation,we proposed a new approach to modify natural attapulgite using high energy electron beam irradiation,which could effectively improve its dispersibility and specific surface area.Then the straw ash consists of biochar and biosilica was added to the modified attapulgite with a proper amount to fabricate a new loss-control agent of foliar fertilizer.The results indicated that the loss-control agent possessed a micro-nano network structure with high porosity and large specific surface area,which could adsorb a large amount of fertilizer molecules and then held them in the networks.Therefore,the new loss-control foliar fertilizer displayed a high adhesion ability on leaf surface compared with traditional foliar fertilizer.Meanwhile,this foliar fertilizer network system could be retained by the flakes on the crop leaf surface after sprayed,which was beneficial to control the loss of fertilizer,enhance the utilization efficiency and ultimately decrease the environmental pollution of fertilizer.3.Iron is one of the vital microelements for the growth of crops.Iron deficiency can lead to the leaf chlorosis and thus seriously affect the yield and quality of crops.Compared with the traditional rhizosphere fertilization,the foliar ferrous fertilizer could effectively and rapidly supply the ferrous microelement,which is beneficial for the normal growth of crops.However,the ferrous foliar fertilizer tends to discharge into environment by washoff,and besides,the ferrous ion is easily oxidized to ferric ion,which are the key problems of the reduction of fertilizer utilization.Therefore,a new ferrous foliar fertilizer which possesses the excellent properties of high ferrous ion content,good oxidation resistance and high adhesion ability needs to be developed.Therefore,in chapter four of this dissertation,we provide a new method to fabricate a pH controlled-release ferrous foliar fertilizer(PCRFFF)based on microcrystalline cellulose,attapulgite and ferrous sulfate.The microcrystalline was first oxidized to carboxyl cellulose,which could effectively bind ferrous ion and then produced the composite of carboxyl cellulose-Fe(?).Subsequently,the attalpulgite was added to the above system to obtain the PCRFFF.The results indicated that the PCRFFF could not only display a high adhesion ability on leaf surface,but also slow down the oxidation of Fe(?)to Fe(?).Besides,Fe(?)could be released from PCRFFF in acid conditions,and thus the amount of Fe(?)could be modulated by pH,which could meet the different demands of crops in different growth periods.4.Ultraviolet accounts for only two percent to five percent of the sunlight,which causes a decrease in the catalytic efficiency of photocatalysts and thus limits the application of photocatalysts in removing pollutants.Therefore,degrading pollutants using photocatalysts under visible light attracts more and more attentions.In chapter five of this dissertation,we provided an approach to fabricate a new photocatalyst(MnO2/C composite)which could degrade organophosphate pesticide under sunlight using high energy electron beam.The active particles such as eaq-,e-,and ·H generated during HEEB irradiation could reduce MnO4-to MnO2 nanoparticles.Meanwhile,the thermal and etching effect of high energy electron beam irradiation contributed to the generation of rough surface of graphite oxide,which was beneficial for binding MnO2 nanoparticles on the surface of graphite oxide through the hydrogen bonds between hydroxyl of MnO2 and the oxygen-containing groups of graphite oxide.The results indicated that the obtained MnO2/C composite displayed the properties with good dispersibility,large specific surface area and excellent photocatalytic activity,which could decomposite organophosphate pesticide into non-toxic inorganic molecules under sunlight.5.A large amount of medical intravenous infusion bottles(MIIBs)with antibiotic residues(ARs)were generated and discharged to environment,which causes the drug resistance of bacteria and thus leads to seriously harmful effects on human health and ecological balance.Therefore,in chapter six of this dissertation,we provide a new approach of in situ degradation of antibiotic residues in medical intravenous infusion bottles using high energy electron beam irradiation.Besides,the effects of irradiation doses,the initial concentrations of antibiotics,initial pH values of reaction systems,the scavengers of active radicals and the co-existence substances on the degradation efficiency of antibiotics were investigated respectively.The results showed that 97.02%,97.61%and 96.87%of amoxicillin,ofloxacin,and cefradine in medical intravenous infusion bottles were degraded in situ using high energy electron beam irradiation respectively.Besides,the analysis of high performance liquid chromatography-mass spectrometry and Fourier transform infrared spectroscopy demonstrated that three antibiotics possessed the similar degradation products,which were mainly composed of inorganic ions and alkanes.Meanwhile,the degradation mechanism of antibiotics was also researched,and it was found that the dominant active particle inducing the degradation of antibiotics was hydroxyl radical.