Low radioactive rare earth waste (containing 232 Th,specific activity 5 000 8 000 Bq·kg -1 ) were diluted 20 times by cement,sand and carbide ash and were made into special cement.The radioactivity of...Low radioactive rare earth waste (containing 232 Th,specific activity 5 000 8 000 Bq·kg -1 ) were diluted 20 times by cement,sand and carbide ash and were made into special cement.The radioactivity of this special cement complied with the healthy protect standard for radioactive materials (GB6566 86).Test results showed that this special cement could lower COD,the degradation rate increased as the time went on.In acidic medium,this special cement could remove E Coli effectively.Applying aeration and adding lumps of cement,the degradation of COD versus time complied with Logistic model through fitting by computer.The two “S” curves indicated that aeration and adding lumps of cement had synergistic action on sewage treatment.展开更多
Zircon was employed to immobilize simulated tetravalentactinide nuclide（Ce^4＋）. Zr_（1–x）Ce_xSiO_4（0≤x≤0.10） ceramics were synthesized and their chemical durabilities were investigated systematically. The eff...Zircon was employed to immobilize simulated tetravalentactinide nuclide（Ce^4＋）. Zr_（1–x）Ce_xSiO_4（0≤x≤0.10） ceramics were synthesized and their chemical durabilities were investigated systematically. The effects of p H and temperature on the chemical durability of the as-prepared compounds were investigated using the MCC-1 static leaching test, and their coupling effects were also explored. It was found that the normalized release rates of Ce in deionized water and alkaline solutions（pH=10） were smaller than those in acid solutions（p H=4）. At a certain p H value, the normalized release rate of Ce（LR Ce） increased with the temperature in the initial period. However, the leaching progress almost reached a balance after 14 days, and both of the p H and the temperature had slight impact on the leaching of Ce element. Moreover, the LR_（Ce） were below 10^（–5）g/m^2/d after 42 days, which was lower than those of other nuclear waste forms in all discussed leachates.展开更多
文摘Low radioactive rare earth waste (containing 232 Th,specific activity 5 000 8 000 Bq·kg -1 ) were diluted 20 times by cement,sand and carbide ash and were made into special cement.The radioactivity of this special cement complied with the healthy protect standard for radioactive materials (GB6566 86).Test results showed that this special cement could lower COD,the degradation rate increased as the time went on.In acidic medium,this special cement could remove E Coli effectively.Applying aeration and adding lumps of cement,the degradation of COD versus time complied with Logistic model through fitting by computer.The two “S” curves indicated that aeration and adding lumps of cement had synergistic action on sewage treatment.
基金Project supported by the National Natural Science Foundation of China(21507105,41302029)Thousand Youth Talents Plan(Y42H831301)+3 种基金Key Project of Sichuan Education Department(15ZB0116)Foundation of Laboratory of National Defense Key Discipline for Nuclear Waste and Environmental Safety,Southwest University of Science and Technology(15yyhk10)the Doctor Foundation in Southwest University of Science and Technology(10zx7126)Sichuan’s Training Program of Innovation and Entrepreneurship for Undergraduate(201610619039)
文摘Zircon was employed to immobilize simulated tetravalentactinide nuclide（Ce^4＋）. Zr_（1–x）Ce_xSiO_4（0≤x≤0.10） ceramics were synthesized and their chemical durabilities were investigated systematically. The effects of p H and temperature on the chemical durability of the as-prepared compounds were investigated using the MCC-1 static leaching test, and their coupling effects were also explored. It was found that the normalized release rates of Ce in deionized water and alkaline solutions（pH=10） were smaller than those in acid solutions（p H=4）. At a certain p H value, the normalized release rate of Ce（LR Ce） increased with the temperature in the initial period. However, the leaching progress almost reached a balance after 14 days, and both of the p H and the temperature had slight impact on the leaching of Ce element. Moreover, the LR_（Ce） were below 10^（–5）g/m^2/d after 42 days, which was lower than those of other nuclear waste forms in all discussed leachates.
