The wastewater is sourced from petroleum refinery or petrochemical production (drainage, cleaning, boiler blowdown, process contaminated water or condensate, accidentally contaminated storm water, sewer, etc.).
It is highly contaminated by oil & grease, organics, salinity, total suspended solids, heavy metals, sulphide, metals, ammonia (in some cases).
It cannot be discharged directly neither to surface water nor in wells, due to its high environmental impact.
PSC S.r.l. Engineering & Contracting (PSC) has an extensive cumulative experience in these kinds of processes:
- API separators to remove mainly free oil, total suspended solids. Sometimes also a screening system is provided upstream to protect the API separator by mechanical damages from coarse solids;
- Coagulation, flocculation and dissolved air flotation to remove the residual free and emulsified oil and total suspended solids as secondary treatment, to protect the next obliged process step;
- Aerobic biological treatment to biodegrade the dissolved organics, producing activated sludge to be disposed;
- Tertiary filtration and disinfection to remove fine particle and to reduce again the relevant COD, BOD5 contribution from the still presence of the suspended solid matter (colloidal and other fine particles) and bacteria;
- The sludge production from the above biological treatment is treated to reduce its volume to be finally disposed to the dedicated dump or landfill (usually mechanical thickening and dewatering processes are provide for this task).
The treated water can be used for industrial services as irrigation, or for the final discharge that complies with the local legislations.