RECOVERY OF LIQUID HAZARDOUS WASTES FROM CARBON ADSORPTION STEAM REGENERATION STREAMS

CARBON ADSORPTION IS A WIDELY USED TECHNIQUE TO REMOVE AND CONCENTRATE VOCS FROM DILUTED AIR AND WATER STREAMS. PERIODICALLY CARBON BEDS ARE REGENERATED WITH STEAM. THE RESULTS OF THIS REGENERATION AFTER COOLING, IS A CONCENTRATED MIXTURE OF HAZARDOUS COMPOUNDS AND WATER. COMMON AND PARTICULARLY TROUBLESOME STREAM CONDENSATES ARE THOSE CONTAINING MIXTURES OF CHLORINATED SOLVENTS AND WATER-MISCIBLE (HYDROPHILIC) SOLVENTS. THE PRESENCE OF THE CHLORINATED SOLVENTS MAKES SOLVENT RECLAMATION VERY DIFFICULT AND THE ENTIRE STREAM MUST BE TREATED AS A HAZARDOUS WASTE AND SENT TO INCINERATORS FITTED WITH APPROPRIATE SCRUBBERS FOR DISPOSAL. MEMBRANE TECHNOLOGY ANDRESEARCH, INC., PROPOSES TO DEVELOP A PERVAPORATION PROCESS TO SELECTIVELY REMOVE THE CHLORINATED SOLVENT FROM THE STREAM. RECLAMATION OF SOLVENTS FROM THESE TWO SEPARATE STREAMS IS THEN STRAIGHTFORWARD. THE PROCESS WILL BE DEMONSTRATED WITH ACETONE-METHYLENE CHLORIDE-WATER MIXTURES IN PHASE I. A SMALL BENCH-SCALE INTEGRATED SYSTEM WILL BE BUILT AND OPERATED IN PHASE II ON SOLVENT MIXTURES OF INCREASING COMPLEXITY. CARBON ADSORPTION IS A WIDELY USED TECHNIQUE TO REMOVE AND CONCENTRATE VOCS FROM DILUTED AIR AND WATER STREAMS. PERIODICALLY CARBON BEDS ARE REGENERATED WITH STEAM. THE RESULTS OF THIS REGENERATION AFTER COOLING, IS A CONCENTRATED MIXTURE OF HAZARDOUS COMPOUNDS AND WATER. COMMON AND PARTICULARLY TROUBLESOME STREAM CONDENSATES ARE THOSE CONTAINING MIXTURES OF CHLORINATED SOLVENTS AND WATER-MISCIBLE (HYDROPHILIC) SOLVENTS. THE PRESENCE OF THE CHLORINATED SOLVENTS MAKES SOLVENT RECLAMATION VERY DIFFICULT AND THE ENTIRE STREAM MUST BE TREATED AS A HAZARDOUS WASTE AND SENT TO INCINERATORS FITTED WITH APPROPRIATE SCRUBBERS FOR DISPOSAL. MEMBRANE TECHNOLOGY ANDRESEARCH, INC., PROPOSES TO DEVELOP A PERVAPORATION PROCESS TO SELECTIVELY REMOVE THE CHLORINATED SOLVENT FROM THE STREAM. RECLAMATION OF SOLVENTS FROM THESE TWO SEPARATE STREAMS IS THEN STRAIGHTFORWARD. THE PROCESS WILL BE DEMONSTRATED WITH ACETONE-METHYLENE CHLORIDE-WATER MIXTURES IN PHASE I. A SMALL BENCH-SCALE INTEGRATED SYSTEM WILL BE BUILT AND OPERATED IN PHASE II ON SOLVENT MIXTURES OF INCREASING COMPLEXITY.