Investigation of the Ozonation Process Efficiency in Total Petroleum Hydrocarbons Removal from Produced Waters

: Large amounts of oilfield water production in oil reserves of countries, such as Iran, is one of the most important environmental predicaments, and since this water contains large quantities of pollutants (aliphatic and aromatic hydrocarbons), its treatment is necessity. The produced waters contain great amounts of refractory substances. Nowadays, using chemical methods for pretreatments and primary conversion of resistant compounds to degradable compounds is more acceptable due to significant lower operational costs. The aim of this study was to survey the efficiency of ozone oxidant removal of oil hydrocarbons of water.
This experimental study was done in an impinger reactor in a laboratory scale. The impact of effective variables including reaction time (10 to 40 minutes), pH (6 to 12), ozone concentration (1 to 10 mg/minute) and initial total petroleum hydrocarbons concentration (0.5 to 1.5g/l) on TPH removal efficiency was studied. Thirty samples were taken with regards to the Central Composite Design (CCD) and results were analyzed by Response Surface Methodology (RSM) and Design Expert 7 software and statistical tests including an analysis of variance and regression.
Results showed that under optimized conditions, total petroleum hydrocarbons removal efficiency was 73.3% according to statistical tests (ANOVA and regression) and showed that the model had a high accordance with lab results.
This study showed that ozonation process is an efficient way for removing total petroleum hydrocarbons from produced waters.