Radioactive Organic Liquid Waste Absorbent: Synthesis,Properties And Absorption Mechanism

In recent years,with the rapid development of nuclear power industry,a great deal of radioactive organic liquid waste has been produced.In addition to the traditional treatment methods,Nochar Company in the United States in using adsorbents to absorb radioactive organic liquid waste have attracted other countries'great interest.A new type of absorbent for treating radioactive organic liquid waste is synthesized by using styrene?St?and lauryl methacrylate?LMA?as reaction monomers in this study.In order to improve the property of the absorbent,several composite absorbent resins were prepared.Its composition,thermal stability and microstructure were characterized by FTIR,thermal analyzer and SEM.The oil absorption rate,recyclability and oil retention of resin to TBP,kerosene and 30%TBP-kerosene(V_TBP:V_kerosene=3:7)were investigated.The absorption of resin to other organic liquid was studied and the results were analyzed by cluster analysis.The main research work is summarized as follows:?1?A new type of oil absorption resin was prepared by suspension polymerization using styrene?St?and lauryl methacrylate?LMA?as monomers.By investigating the effects of different polymerization technological parameters,we obtained an optimized oil-absorbent.The optimum preparation conditions were obtained as follows:m_st/m_lma=3:4,m_water/m_oil=3:1,m_PVA/m_monomer=1.5 wt%,m_BPO/m_monomer=0.8 wt%,m_DVB/m_monomer=0.8 wt%?where m is the mass?.The saturated absorption capacities of P?St-LMA?resin for TBP,kerosene and 30%TBP-kerosene was 0.58 g/g,6.23 g/g and 7.07g/g,respectively.The saturated oil absorption time was about 240 minutes,and the oil absorption process conformed to the pseudo second-order kinetics model.P?St-LMA?resin has good thermal stability and compact microstructure,which provides a good adhesion condition for organic liquid.The oil retention of P?St-LMA?resin for the three organic liquids is all above 90%.After five cycles of use,the resin still maintains good oil absorption capacity.?2?Two kinds of porous P?St-LMA?resin were synthesized by using ethyl acetate and cyclohexane as pore-foaming agent.The optimum pore-foaming agent is ethyl acetate with 20 wt%.The saturated oil absorption capacities and oil absorption time of the porous resin are slightly increased compared with the resin without pore-foaming agent.The oil retention of resin for the three organic liquids is all above 88%.After five reuses,the saturated absorption capacities of the porous P?St-LMA?resin to the three organic liquids remained above 85%of the initial value.?3?The attapulgite modified by KH-550 was introduced to prepare P?St-LMA?/attapulgite composite resin.The optimum polymerization parameters were obtained by orthogonal experiment as follows:m_PVA/m_monomer=1.5 wt%,m_DVB/m_monomer=0.8 wt%,m_BPO/m_monomer=1.2 wt%,m_m-ATP/m_monomer=5 wt%?where m is the mass,m-ATP=modified attapulgite?.The saturated oil absorption capacity and oil absorption rate of the composite resin toward the three organic liquids are higher than before,and the oil absorption process still conforms to the pseudo second-order kinetics model.In addition,the thermal stability of the P?St-LMA?/attapulgite composite resin has been greatly improved compared with the P?St-LMA?resin,and its recycling performance is also better.?4?In this study,Fe₃O₄ particles were prepared by co-precipitation method,and the surface was hydrophobic modified by KH-550 to prepare magnetic Fe₃O₄/P?St-LMA?composite resin.The optimum Fe3O4 content was 4 wt%.The saturated oil absorption capacity of magnetic composite resins toward the three organic liquids were higher than before.The magnetic composite resin was used to treat oil slick on water surface,it was found that the oil absorption rate was accelerated,and the resin still had good magnetism,which was convenient to recycle the resin.?5?The results of cluster analysis showed that P?St-LMA?resin,attapulgite composite resin and magnetic composite resin have similar chemical properties.That is to say,the attapulgite and Fe3O4 particles can dredge the cross-linking pore structure and improve its absorption property.These resins can be used not only for the treatment of oil pollution in water,but also for the treatment of organic liquids such as carbon tetrachloride and benzene in water.It can improve the flash point and ignition point of kerosene,and can be used for emergency treatment of oil leakage.