February 10, 2014
Antipinsky Oil Refinery: Progressive Water Treatment In Operation
Being a sustainable and dynamically developing enterprise Antipinsky Oil Refinery cannot stay aside from current challenges of today’s reality. That is why the enterprise is carrying out efficient activity in the area of industrial and environmental safety.
The refinery is trying to comply with international quality standards and fulfills all requirements of the Russian Federation’s legislation, as well as of its own regulatory documents forming the basis for prevention of breakdowns, accidents, and incidents at a hazardous industrial facility.
Technologies of minimization
In the course of construction and technical development of Antipinsky Oil Refinery special attention was paid to selection of up-to-date technological equipment compliant with the strictest international environmental regulations and standards. To reduce the impact on the environment, a number of technological solutions were taken into account at the design stage of the refinery making it possible to minimize impact on the environment including to reduce water consumption what means to considerably reduce sewage discharge, pollutant emissions into the atmosphere, and prevent oil and oil-product spillage in the soil, and underground waters.
Such technological solutions include:
- the use of burner units in process furnaces which comply with the most stringent environmental requirements;
- the application of a sealed system within the entire process flow;
- the control, computerization, and telemetry of technological processes to prevent accidents, as well as to minimize pollutant emissions to the atmosphere by strict adherence to established technological parameters;
- the provision of a leak-proof filling of light oil products with gas removal to tanks via gas equalizing lines;
- the use of water removal systems which prevent untreated-wastewater discharge to surface waters;
- the construction of concrete platforms for processing equipment and oil loading racks with guard rails and ladders
Five steps to clear water
At the beginning of 2014 water treatment and water conditioning systems are to be commissioned at Antipinsky Oil Refinery. The treatment facilities provide for the intake and purification of all industrial and rainfall effluents formed at the units of the enterprise, as well as the intake of domestic wastewaters. The construction of the river-water intake and conditioning facilities is required for the purpose of supplying the refinery’s own technical and softened water to the functioning and projected units thereof.
Sewage waters flowing to treatment facilities pass the full cycle of purification before discharge to the Tura River: preliminary treatment (sand collectors with settlers), physical-chemical wastewater treatment (separators, impeller floaters), biological treatment with membrane bioreactors, post-treatment (sorption filters and UV disinfection). Residues, slimes, active sludge and trapped oil products resultant in the course of wastewater treatment are conversed in the dehydration block using Andritz centrifuges.
At first stage effluents are treated at sand collectors and settlers. The preliminary treatment block is intended for protecting the basic facilities from waste, volley and emergency pollutant discharges, for regulating irregular primary sewage intake. The operating efficiency of the block is 2,500 cu.m./h.
The second block of physical-chemical treatment consists of separation and floatation units. Two separators function in the separation unit in such a way that they make it possible to simultaneously separate suspensions and oil products from effluents. 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 oil products and suspended substances are pumped for further dehydration to the residue and oil-product dehydration block.
Impeller floatation block consists of two SeparationSpecialists units. The principle of separation here is as follows: air bubbles stick to poorly watered particles (oil products and suspended substances) subsequently raising them to the surface. The slime collector rotated by an electric motor moves the floatation slime into a so called slime pocket from which slime is directed to the slime pump transporting slime to further utilization. The operating efficiency of the block is 400 cu.m. per hour.
The biological treatment block the operating efficiency of which is also 400 cu.m. per hour is intended for wastewater treatment using unique technologies of GE company. Such technology applies membrane bioreactors which enable on to intensify processes many times, exclude secondary sludge basins, liquidate suspended substances by 100%, and reduce biological oxygen demand by 99%.
Up to 60% of wastewaters flow back to production facilities for replenishment of water-circulation systems, the remaining portion goes to post-treatment subsequently being discharged to the Tura River. Excessive sludge is directed to the collection and dehydration unit of residue and excessive-sludge.
Purified water which is not used for replenishment of water-circulation systems is directed to the advanced post-treatment block with the operating efficiency of 200 cu.m. per hour. After passing through sorption carbon apparatuses and UV disinfection units treated wastewater meets all requirements imposed on wastewaters discharged to fishery water bodies. After post-treatment purified wastewaters are discharged to the Tura River.
Trapped moist oil products are transferred to the block of dehydration of trapped oil products, residues, and excess sludge from the preliminary treatment block and the separation unit, foam enters it from the floatation unit, active sludge is provided there from the biological treatment block. Moist residues, moist oil products, excessive sludge are directed for further treatment to tanks for the purpose of accumulation and homogenization of the moist oil product.
Tanks are like steel vertical reservoirs equipped with a mixing device. Tanks are intended for accumulating the necessary volume of raw material before centrifugation and for making this raw material homogenous as required. A double pipe heat exchanger is intended for warming the raw material (warm raw material is separated better) before centrifugation.The Industry of Russia
Two Andritz centrifuges are intended for separating moist oil products into three portions: oil-product, water (centrate), and solid (cake) portions. The oil-product portion is directed through the dehydrated oil-product tank to be pumped for further treatment. The water portion is directed to the preliminary treatment block. The solid portion is directed to the sludge utilization block. Dried sludge is utilized by the slime bio-destruction at bio-destruction sites. After bio-destruction sludge cake can be used for back filing.
Treatment facilities provide for such quality of water discharged to the Tura River which meets the requirements imposed on fishery water bodies in full (the quality of discharges is better than the water in Tura River itself!). As is mentioned above some purified effluents (up to 60%) flow back to production facilities. It will make a significant environmental and economic effect on reducing consumption of natural resources, namely, fresh water from the Tura River needed by Antipinsky Oil Refinery, in the volume of no less than 1.7 million cu.m. p.a.
Treatment facilities occupy record-small areas (about 6 hectares). Installation of the treatment facilities like these on such a small territory is possible due to the application of up-to-date equipment and water-treatment technologies, as well as to sewage-slime treatment. For instance, the GE technology of the biological treatment block with a membrane bioreactor has made it possible to do without any bulky secondary sludge basins for trapping active sludge after aeration tanks what enabled the refinery to reduce areas threefold or fourfold.
The application of SeparationSpecialists separators and impeller floaters made it possible to reduce the area of the facilities of the physical-chemical treatment block due to a possibility to separate oil products and suspended substances when effluents flow in a vertical spiral, but not in a horizontal direction as is usually the case when using oil traps at treatment facilities of Russia.
The application of Andritz centrifuges has enabled the refinery to do without a bulky system of the following facilities: sludge concentration, stabilization, fermentation, sludge dewatering, excess sludge and slime of effluents, meanwhile the technologies applied will improve the quality of dried slime and sludge for further treatment and utilization.
The system of water intake includes such facilities as the filtering run-of-river water receiver, the first stage pumping station, the settler combined with a coagulator, the filter production facility, clear water tanks, the pumping station block, the tanks of chemically treated water, the chemically treated water pumping station. The facilities in question are to supply 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). Softened water is produced from some portion of industrial water (two stages of ion-exchange filters).
The water intake operating efficiency is 300 cu.m. p.h., softened water productivity makes up 120 cu.m. p.h.
Water intake facilities are unique because they provide water of permanent quality (practically without suspended substances, iron and manganese ions) irrespective of the quality of water in Tura. The following up-to-date solutions were used in the course of water-intake design and construction: the underflow-intake facility without aboveground structures is equipped with sinking axial and angular pumps, the construction was carried out using diving operations without dewatering of trenches and pits.
Operation of water intake, water conditioning, and sewage treatment facilities is supervised from the unified computerized process control system located in the operator’s control-center of treatment facilities.
Equipment of wastewater treatment, water intake and water conditioning facilities makes it possible to:
- prevent changes of the Tura River bottom and any limitations of water traffic when using water intake structures;
- provide the refinery with water of required quality complying with regulations imposed on equipment installed in the basic and auxiliary technological units;
- reduce the area of construction four times as compared with traditional treatment technology at primary and secondary sludge basins (biological wastewater treatment technology);
- minimize operational costs (low power consumption equipment, use of advanced chemical agents, etc.);
- reduce the impact of harmful factors (noise, vibration, emissions, and discharges, etc.) on the environment and employees).
It should be specially noted that only high-technology equipment of such most advanced Russian enterprises as “Komsomolets” Tambov Plant OJSC, LIT Research and Production Association, EKO-Umvelt CJSC, TEKO-FILTR Production Enterprise LLC, as well as of such foreign companies as Zickert (Sweden), Separation Specialist (USA), GE Water & Process Technologies (Hungary), and other firms well known all over the world, is used at the new facility of the refinery.
The accredited ecological and analytical laboratory of Antipinsky Oil Refinery CJSC exercises quality control over wastewaters at all stages using up-to-date equipment.
In total Antipinsky Oil Refinery has spent more than 3.8 billion rubles for the construction of treatment facilities as well as for industrial and environmental safety. Such considerable investments have certainly become a serious contribution of the enterprise to public healthcare and nature protection in the native region.