刘海弟 1岳仁亮 1陈运法 1沙顺萍 2陈彦 2赵璇 3高永林4
作者信息
- 1. 中国科学院 过程工程研究所 介科学与工程全国重点实验室,北京 100190
- 2. 中国原子能科学研究院,北京 102413
- 3. 清华大学 核能与新能源研究院,北京 100084
- 4. 凯瑞环保科技股份有限公司,河北 沧州 061014
- 折叠
摘要
Abstract
As one of the most notorious long-lived radionuclides with strong radioactivity,Cs+is particularly difficult to sequester due to its alkali-metal-ion chemical properties.Therefore,selective Cs+adsorbents are urgently needed in radioactive wastewater treatment.Stabilized potassium hexacyanoferrates(Ⅱ)have proven effective for selective Cs+removal;however,their practical application is severely constrained because they are typically obtained as nano-or microparticles that are extremely difficult to granulate.When granulated or supported particles are subjected to water flow,fine solids tend to be washed away,significantly increasing the radioactivity of the effluent due to the entrained Cs+-laden particulates.To address this issue,composite materials with high selective Cs+uptake were prepared by incorporating stabilized potassium hexacyanoferrates(Ⅱ)into porous spherical activated carbon.The spherical activated carbon support was derived from strong-acid ion-exchange resin beads through calcination and activation.Using a rationally designed procedure,co-precipitation reactions that yield stabilized potassium hexacyanoferrates(Ⅱ)were conducted within the internal pores of the spherical carbon.The resulting composites were characterized by XRD,N2 adsorption-desorption(BET method),SEM-EDX,and ICP-OES/MS.The results show that the specific surface areas of the samples exceed 700 m2/g,with micropores,mesopores,and macropores all being present.It can be safely concluded that the stabilized potassium hexacyanoferrates(Ⅱ)were successfully embedded in the inner crevices of the porous spherical activated carbon,and the composites exhibited excellent selective Cs+capture ability,with distribution coefficients(Kd)of 344 170,57 919,and 42 540 mL/g in the presence of 0.1 mol/L Na+,K+,or H+,respectively.Under strong acid interference(1.0 mol/L HNO3),the sample using copper-stabilized potassium hexacyanoferrate(Ⅱ)as the active ingredient achieved the highest Kd of 14 692 mL/g.In the presence of concentrated K+(1.0 mol/L),the cobalt-stabilized analogue gave a Kd of 92 872 mL/g.The outer shell of the porous spherical carbon is permeable to water and ions but impermeable to the stabilized hexacyanoferrate(Ⅱ)nanoparticles.Hence,the active sites remain fully accessible to Cs+in solution without being washed away,and the treated liquids remained completely colorless.Moreover,the smooth shell endows the composites with good abrasion resistance and crack-proof properties,preventing pulverization or scaling-off during solid-liquid contact.These characteristics make the prepared materials a promising candidate for treating real radioactive wastewater.关键词
球形活性炭/固定化六氰合铁(Ⅱ)酸钾/Cs+/吸附分配系数/放射性废水Key words
spherical active carbon/stabilized potassium hexacynoferrate/Cs+/absorption distribution coefficient/radioactive waste water分类
资源环境
