Study of Change Surface Aerator to Submerged Nonporous Aerator in Biological Pond in an Industrial Wastewater Treatment in Daura Refinery

Abstract

Daura refinery, with a capacity of 140,000 barrel per stream day as a refining capacity, wastewater discharged from refining and treatment processing units, polluted water as foul water, drainages, oil spills, blowdown of boilers and cooling towers, and many other polluted water sources, aims to remove pollutants and reject clean water to the river; wastewater treatment system takes place in this treatment process. Wastewater treatment system suffers from many problems and specifically biological stage; at this stage, activated sludge with bacteria, should be supplied with oxygen, aeration system done by surface aerators with four surface fans; these fans suffer from high vibration, loss support, and in consequence, lack in oxygen supply to aerobic bacteria less than 4 ppm. The nonporous aerator is suggested as an oxygen source for the biological pool. The pilot plant builds the aim to study the ability to apply the new aeration system at the biological pool, pilot plant build with 1 cubic meter capacity tank and continuous overflow of wastewater of 10 liters.min−1, air injected with the pressure of (0.5–0.75) bar(g), and airflow of (7.6–9.7) liter.min−1 respectively. Oxygen concentration was recorded as (3.4–6.0) ppm; in terms of consumption power, changing the aeration system reduces it to less than 20%.

The Iraqi Petroleum Refining Industry: A Review of Environmental Impact Assessment

“…Therefore, after the agglomeration of the pollutants, they are removed by making them float on the surface with the help of a stream of pressurized oxygen through special devices to release air bubbles, lifting the agglomerated particles to the surface and then removing them through scrapers. Third, biological treatment, the organic and inorganic substances dissolved in the lagging water are removed by aerobic bacteria [54], where phosphoric acid and urea are added as nutrients to these bacteria with the presence of aerators to generate the oxygen necessary for bacterial respiration and oxidation [55,56]. After these stages, the treated water is discharged into the river after being examined and samples are withdrawn on a daily basis to monitor the variables affecting the environment [57].…”