Antipinsky Refinery is one of the major water consumers in Tyumen. Therefore, the Refinery is committed to continuous improvement of its manufacturing technology, implementing wastewater treatment methods, monitoring water consumption and water disposal volumes, and the quality of wastewater discharged. Among the projects aimed at minimizing environmental risks are the Refinery’s existing treatment facilities. They enable the company to improve the treatment quality of its industrial wastewater.
1 Water Intake and Water Treatment Facilities
To satisfy the need of the oil refinery in process and treated water, the water intake and water treatment facilities have been constructed.
The refinery’s water intake facilities are located on the right bank of the Tura River.
The facilities ensure the supply of industrial and softened water to the Refinery. Industrial water passes through three stages of treatment (the filtering run-of-river water receiver, the settler combined with a coagulator and clarifying filters). The water intake flow rate is 300 m3/h, softened water capacity is 120 m3/h.
The facilities comprise:
- filtering run-of-river water receiver;
- first stage pumping station;
- settler combined with a coagulator;
- filter unit building;
- clear water tanks;
- pumping station unit;
- chemically treated water tanks;
- chemically treated water pumping station.
Water intake facilities are unique in that they supply consistent quality water (virtually free of suspended substances, iron and manganese ions) whatever the water quality in the Tura River may be. The following cutting edge solutions were used in water-intake facilities design and construction: the underflow intake facility without aboveground structures equipped with sinking axial and angular pumps, the use of diving operations without dewatering of trenches and pits during the construction.
2 Water Treatment Facilities
At the beggining of 2014, JSC Antipinsky Refinery commissioned five-step water treatment and water conditioning facilities taking up 10.7 ha which are unique for Tyumen enterprises.
The treatment facilities capacity provides for intake and purification of all operation and storm wastewater produced by the enterprise units, as well as domestic wastewater intake.
At the treatment facilities, wastewaters undergo the complete cycle of treatment before they are discharged into the Tuva River: preliminary treatment (grit-removal plants with coagulators), physical-and-chemical treatment (separators, flotation installations), biological treatment with the membrane bioreactors, advanced treatment (sorbtion filters and UV disinfection). The forming bottom deposits, mud, excess biological solids and trapped petroleum products are treated in the dehydration facility using the three-phase centrifuge firm, Andritz Separation AG.
1) Preliminary Treatment Facility
Wastewater undergoes preliminary treatment by sand collectors with settlers. The preliminary treatment unit is intended for protecting the main facilities from waste, volley and emergency pollutant discharges, for regulating irregular primary wastewater intake. The unit peak capacity does not exceed 2670 m?/h.
2) Physical and Chemical Treatment Facility
The unit consists of the separation sub-unit and floatation sub-unit.
The separation facility consists of two separators. The separators operating principal makes it possible to simultaneously separate suspensions and petroleum products from wastewater. Due to tangential water supply, oil products accumulate in the center at the top of the separator and suspended substances peripherally at the bottom of the separator. Separated petroleum products and suspended substances are pumped for further dehydration to the residue and petroleum product dehydration facility.
The impeller floatation facility consists of two Separation Specialists units. The separation principle used is a follows: air bubbles stick to poorly watered particles (petroleum products and suspended substances) and take them up to the surface. The slime collector rotated by an electric motor moves the floatation slime into the so-called slime pocket, wherefrom the slime is goes to the slime pump transporting slime to further disposal. The unit capacity is 400 m?/h.
3) Biological Treatment Facility
The biological treatment facility is intended for wastewater treatment using unique technologies of GE Water & Process Technologies. The technology uses membrane bioreactors making it possible to intensify the processes the manyfold, exclude secondary sludge basins from the process chart, remove suspended substances by 100%, biological oxygen demand by 99% and reduce the space occupied by 4 times compared to traditional sludge basins.
Up to 60% of wastewaters go back to the production facilities to replenish water circulation systems yielding a significant environmental and economic effect with respect to reducing the consumption of natural resources, namely, water from the Tura River to meet the needs of Antipinsky Refinery by at least 1.7 million m?/year. The remaining water is put through advanced treatment and discharged into the Tura River.
Excessive sludge goes to the residue and excessive sludge collection and dehydration unit. The unit capacity is 400 m?/h.
4) Advanced Treatment and Decontamination Facility
The purified water which is not used for the replenishment of water circulation systems goes to the advanced wastewater treatment and decontamination facility.
Treated wastewater passed through the carbon sorption and UV decontamination units meets all the requirements imposed on wastewater discharged into fishery waters. After the advanced treatment, purified wastewater is discharged into the Tura River.The facility capacity is up to 400 m?/h.
5) Trapped Petroleum Products, Residue and Surplus Activated Sludge Dehydration Facility
The unit receives trapped watered petroleum products from the preliminary treatment facility and the separation unit, foam from the floatation unit, surplus activated sludge from the biological treatment facility.
Watered residues, watered oil products and surplus activated sludge are forwarded for further treatment to tanks for the accumulation and homogenization of watered petroleum products. The tanks are essentially vertical steel reservoirs equipped with a mixing device. The tanks are intended for accumulating necessary amounts of raw material for centrifugation and averaging the raw material fed quantity- and quality-wise.
A “pipe in pipe” heat exchanger is intended for heating raw materials (heated raw materials separate better) before centrifugation.
Two three-phase centrifuges manufactured by Andritz Separation AG are intended for separating watered petroleum products into three phases:
- petroleum product phase;
- water phase (centrate);
- solid phase (cake).
The petroleum product phase goes through the dewatered petroleum product tank to be pumped out for further treatment.
The water phase goes to the preliminary treatment facility.
The solid phase goes to the sludge disposal unit.
Dewatered sludge is disposed of by slime bio-destruction at bio-destruction sites. After bio-destruction, cake is classified as waste of hazard class IV and can be used to backfill trenches and pits.
Unique Features of Water Treatment Facilities
The treatment facilities ensure that the quality of water discharged into the Tura River fully meets fishery water requirements, i.e. the quality of water discharged is better than the quality of source water from the Tura River.
All types of waste undergo necessary treatment (dewatering, purification, bio-destruction), which makes them reusable: trapped petroleum products are used as raw hydrocarbons, and sludge and residues as soil for backfilling in construction.
The treatment facilities take up a record-small area (of about 6 hectares). Such a limited area could not have accommodated treatment facilities of that scale were it not for the cutting-edge equipment and water purification and wastewater slime treatment technologies used. For instance, the biological treatment facility built using the GE membrane bioreactor (MBR) technology saved the Refinery the trouble of building bulky secondary sludge basins for trapping activated sludge after aeration tanks, thus reducing the area used 3-4 times. Using Separation Specialists separators and impeller floaters helped to reduce 2-3 times the area of physical and chemical treatment facility structures by making it possible to separate petroleum products and suspended substances as the wastewater moves spiral-wise in a vertical, rather than horizontal direction normally used in oil traps at Russian treatment facilities.
Using the centrifuges manufactured by Andritz Separation AG helped the Refinery to do without a bulky system of the following facilities: sludge concentration, stabilization, fermentation, sludge dewatering, excess sludge and wastewater slime, and at the same time, the technologies used improve the quality of dewatered slime and sludge for further treatment and disposal.
The water treatment, water intake and water conditioning facilities:
- neither have negative impact on the bed of the Tura River nor restrain the water transport traffic (operation of the water intake facilities);
- provide the oil refinery with water the quality complies with the requirements to the primary and support process facilities;
- minimize the operating expenses (low energy consumption, use of the most recent chemicals, etc.)
- reduce the harmful impact on the environment and personnel (noise, vibration, effluents and waste waters).
3 Auxiliary Facilities
The auxiliary facilities include:
- treatment facilities control room;
- 10/0.4 kV transformer substation equipped with 0.4 êV switchgear.
The operations of water intake, water conditioning and treatment facilities are managed by a shared process control system located in the treatment facilities control room.
It should be emphasized that the Refinery’s new facility uses only hi-tech equipment manufactured by most advanced Russian companies, such as ZAVKOM Industries, LIT, ECO-Umvelt, TEKO-FILTER, and foreign companies, such as Zickert (Sweden), Separation Specialist (USA), GE Water & Process Technologies (Hungary), Andritz Separation AG (Germany) and other companies known throughout the world.
The implementation of the aforesaid project has won Antipisky Refinery 2014 “Russian Water” First National Water Industry Award in the category “Best project aimed at reducing water pollution”.
Wastewater quality is controlled at all treatment stages using the modern equipment installed at the Eco-Analytical Laboratory of JSC Antipinsky Refinery.