Patent Number: 045444994
Section: claims

1. A process for separating and immobilizing radioactive anions from a liquid containing same comprising contacting said liquid with a porous silica glass or gel comprising at least 82 mol percent silica having interconnected pores and non-radioactive cationic polyvalent metals bonded to silicon of the glass or gel through divalent oxygen linkages on the internal surfaces of said pores and non-radioactive anions ionically bonded to said cationic polyvalent metals and displaceable by said radioactive anions, to provide a distribution of radioactive anions internally bonded within the pores to silicon of the glass or gel through a cationic polyvalent metal and a divalent oxygen linkage as represented by the formula: ##STR15## Wherein M.sup.+ are said cationic polyvalent metals. 2. Process as claimed in claim 1 wherein a porous silica glass is used and said non-radioactive cationic polyvalent metal is selected from the group consisting of --Zr.sup.3+, --Pb.sup.+, --Th.sup.3+ and --Ti.sup.3+. 3. Process as claimed in claim 1 wherein the porous silica glass is represented by the formula: ##STR16## in which M is a polyvalent metal and the two unfilled valences of M are bonded ionically to additional OH.sup.- anions, are bonded through divalent oxygen linkage to another silicon of the glass and/or are bonded through divalent oxygen linkage to other M atoms. 4. Process as claimed in claim 1 wherein porous silica glass containing integral boron is used and some of said polyvalent metals are bonded through oxy linkages to boron of said porous glass. 5. The process as claimed in claim 1 wherein said porous silica glass or gel contains at least 1 ppb radioactive material encapsulated and immobilized in said porous silica glass or gel. 6. The process as claimed in claim 1 wherein said porous silica glass or gel contains at least 10 ppb radioactive material encapsulated and immobilized in said porous silica glass or gel. 7. The process as claimed in claim 1 wherein said radioactive anions are chromium, technetium and/or molybdenum anions. 8. The process as claimed in claim 1 wherein said porous silica glass or gel is characterized by a radiation activity of at least one microcurie per cubic centimeter. 9. The process as claimed in claim 1 wherein said radioactive anions are derived from radioactive nuclear waste. 10. The process as claimed in claim 1 wherein said radioactive anions are iodine.