R CHEMINI
"Assessment of atmospheric emissions from deoiling process and treatment of reject water"
The deoiling process is an essential treatment in the petroleum industry. The rejected wastewater resulting from the crude oil and gas production goes through a pretreatment in the sedimentation basin, before complete evacuation towards the sewers. The elimination of pollutants mainly oil and metals, from oily water are always accompanied by atmospheric emissions. However, the characterization before treatment shows that reject water is charged with oxidable matters with high chemical oxygen demand COD.
The total suspended solids TSS are also too high, so the effluent is classified as very turbid. An acidic pH and high concentrations of Ca2+ and Mg2+ give a very significant hardness. Sulfates, nitrates, and nitrites are existing in high concentrations. Most contaminants present in the reject water are not easily biodegradable.
This work aims to evaluate the air emissions in the deoiling station and treat a rejected water. The simulation results obtained for air emissions are too low, which meets national and international standards. A series of treatments for the reject water is carried out to reduce the suspended matters and eliminate the traces from dissolved hydrocarbons, such as coagulation-flocculation, adsorption on the activated carbon, catalytic reduction on activated carbon, and filtration on the sand.
The characterization of wastewater after treatment using the catalytic reduction on activated carbon gives the best results. The effectiveness is 98.88% for traces of hydrocarbons, 97% for COD, 100% for turbidity, and 94.67% for TSS. The efficiency treatment of the effluent by a series of processes (coagulation-flocculation-adsorption-ultrafiltration) is evaluated by the reduction rates of pollution, which reach more than 99% for turbidity and suspended matters.