FEASIBILITY OF BIODEGRADATION OF WASTE LIQUID COAL TAR

COAL TAR IS A BY-PRODUCT OF THE COAL GASIFICATION PROCESS USED WIDELY BETWEEN 1820 AND 1950 TO PRODUCE A NATURAL GAS SUBSTITUTE. DURING THAT TIME, BILLIONS OF GALLONS OF TAR WERE PRODUCED AT MORE THAN 1500 GAS MANUFACTURING FACILITIESLOCATED THROUGHOUT THE U.S. A LARGE PORTION OF THIS WASTE TAR REMAINS IN STORAGE OR WAS DISPOSED OF BY INJECTION INTO SUBSURFACE SITES. COAL TAR IS A MIXTURE OF HYDROCARBONS INCLUDING SIXTEEN POLYNUCLEAR AROMATIC HYDROCARBONS (PAH) THAT HAVE BEEN PLACED ON THE EPA PRIORITY POLLUTANT LIST BECAUSE OF THEIR TOXICITY AND MUTAGENICITY. EFFECTIVE REMEDIATION METHODS FOR WASTE LIQUID COAL TAR ARE NOT CURRENTLY AVAILABLE. CONTAINMENT OF SUBSURFACE TAR IS NOT FEASIBLE BECAUSE OF ITS TENDENCY TO MIGRATE INDEPENDENTLY OF GROUNDWATER. STORED TAR CANNOT BE INCINERATED BECAUSE OF CONCERN FOR TOXIC AIR EMISSIONS. MANY OF THE CHEMICAL CONSTITUENTS OF COAL TAR ARE KNOWN TO BE BIODEGRADABLE. BIOREMEDIATION SYSTEMS HAS SHOWN THAT SOIL CONTAMINATED WITH UP TO 1% COAL TAR CAN BE SUCCESSFULLYTREATED BY AERATION AND THE ADDITION OF TAR-DEGRADING BACTERIA. THE PURPOSE OF THIS PROJECT IS TO DEVELOP METHODS FOR THE TREATMENT OF LIQUID COAL TAR AND TO DOCUMENTTHE BIODEGRADATION PROCESS IN A LABORATORY-SCALE BIOREACTOR.