A study on the analytical control in the tertiary water treatment process of the petrochemical effluents

The purpose of this work is to present original results concerning the year ly mean values of the removal efficiencies related to the quality specific indicators for the tertiary treatment stage of petrochemical effluent obtai ned during eight years of operation of the plant. On the other hand we pres ent the dynamics of sulfides, phenols and COD along the tertiary treatment plant. Studies were performed on the most modern wastewater treatment plant in Romania, located on the Black Sea coast, which processes about 1800 m(3 ).h(-1) effluent from an important petrochemical complex. We present the av erage removal efficiencies for oil products, total suspended solids, sulfid es, chemical oxygen demand (CODCr), biochemical oxygen demand (BOD5) and ph enols, for the tertiary treatment processes. We observed that in this stage all pollutants suffer important removal efficiencies due to mechanical, ph ysical - chemical and biochemical processes. The mean values of yearly aver age removal efficiencies obtained on the studied tertiary treatment plans a re: oil products 50%, TSS 51'%, sulfides 57%, phenols 63%, CODCr 34% and BO D 39%.