Dora petroleum refinery waste water is the one of the important source of pollution by priority pollutant aromatic compound discharged to Tigris river in Iraq. the station has waste water treatment unit contains many treatment subunits The most important sub units is :skimmer units ,physiochemical unit ,daf unit, biological unit. the aim of research project is to study the ability of unit to remove the priority pollutant aromatic compound and follow up these compounds in river to study ability of river to self removal.A solid phase extraction (SPE) followed by high performance liquid chromatography-ultra violet (HPLC-UV) technique is depicted for the quantitative estimation of benzidines and phenols. Experimental studies were performed to detect the optimum oxidation conditions for benzidine and phenol. The enzymatic method and the use of soybean peroxidase enzyme for the continuous removal of the molecules enable to provide simple and alternateive method to the traditional methods used for removal of hazardous aromatic compounds including the phenol and benzidine studied here.