A BIOPOLYMER BASED SELECTIVE BARRIER FOOR THE CONTAINMENT OF GROUNDWATER CONTAMINANTS

THE CONTAMINATION OF GROUNDWATER BY HEAVY METALS, RADIONUCLIDES, AND ORGANICS IS A SERIOUS ENVIRONMENTAL PROBLEM. IN SOME CASES IT MAY NOT BE POSSIBLE TO REMOVE ALL OF THE MATERIAL FROM THE SOIL BY CONVENTIONAL PUMP-AND-TREAT TECHNIQUES. IN SUCH CASES, THE RESIDUAL MATERIAL MUST BE CONTAINED TO PREVENT FURTHER MIGRATION. AN IDEAL SOLUTION WOULD BE A PERMEABLE BARRIER THAT IS READILY INSTALLED AND RETAINS THE CONTAMINANTS YET ALLOWS WATER AND INNOCUOUS IONS TO PASS THROUGH. THE OBJECTIVE OF THIS PROJECT IS THE DEVELOPMENT OF A BIOPOLYMER BASED PERMEABLE BARRIER. THIS SYSTEM IS ENVIRONMENTALLY SOUND AND INEXPENSIVE. IT CAN BE FORMULATED AS A LIQUID FOR EASE OF EMPLACEMENT, BUT ONCE IN PLACE, IT GRADUALLY HARDENS INTO A PERMEABLE SOLID. THE RESULTING BARRIER HAS A HIGH ADSORPTION CAPACITY FOR METAL CATIONS, IS SELECTIVE FOR SOME OF THE MOST HAZARDOUS HEAVY METALS AND RADIONUCLIDES, AND CAN ALSO SORB ANIONS AND ORGANICS. PHASE I WILL EVALUATE THE SORPTIVE CAPACITY OF THE BARRIER MATERIAL, DETERMINE FORMULATIONS SUITABLE FOR EMPLACEMENT BY CONVENTIONAL METHODS, AND DEMONSTRATE THE FORMATION OF A CONTINUOUS BARRIER. DURING PHASE I A SITE WILL BE SELECTED FOR A PHSE II TEST AND EFFORTS WILL BE FOCUSED ON DEVELOPING A FORMULATION THAT WILL SUCCESSFULLY ADDRESS PROBLEMS ASSOCIATED WITH THAT SITE. THE PROJECTED COST AND POTENTIAL EFFECTIVENESS OF THE SYSTEM WILL BE DETERMINED. PHASE II, IF WARRANTED, WILL SYSTEMATICALLY INVESTIGATE THE EFFECTS OF CHANGES IN COMPOSITION ON THE PROPERTIES OF THE BARRIER, INCLUDING THE METHODS FOR EMPLACEMENT.