Activated sludge: In this biological step, the industrial wastewater is digested by
microorganisms like bacteria, protozoa in presence of oxygen.
Trickling Filter
Trickling filter is a fixed bed filter of polymeric materials, polyurathanes foam,
ceramic, rocks, coke and gravel designed for development of bio-layer using microorganisms. This bio-layer is used for removal of pollutants mainly organic compounds (oil, grease, heavy hydrocarbons) from wastewater by absorption or
adsorption in presence of oxygen, releasing carbon dioxide (Environmental Protection Agency, Washington 2000; Environmental Protection Agency, Washington
2011).
Oxidation Ponds
Oxidation ponds or stabilization ponds are designed for reducing the pollutants
mostly organic matter from industrial wastewater. This treatment requires several
days. In these large and shallow ponds, the wastewater is interacted with sunlight,
bacteria and algae. The wastewater is discharged into oxidation ponds where organic
pollutants are consumed by living microorganisms for their growth, reproduction,
energy generation and converted into carbon dioxide on the surface of pond in
presence of sunlight and oxygen which is generated during photosynthesis of algae.
In some cases, mechanical agitators are incorporated to increase the dissolved
oxygen level (Tharavathy et al. 2014; Environmental Protection Agency,
Washington 2011).
Lagoons
Lagoons are artificial aeration ponds or pond like water bodies or basins for
treatment of polluted water for a predetermined period of time. These types of
ponds are stabilized with clay, artificial liner to avoid any leaks to the groundwater
below. Here, the wastes are treated by bacteria, algae in presence of dissolved or
supplied oxygen in warm, sunny climate (Tharavathy et al. 2014; Cavaseno 1980).
Aerobic Digestion
In aerobic digestion, organic pollutants are digested by aerobic bacteria
(saprotrophic bacteria) in presence of oxygen in a digester tank; it is a batch process.
Aerobic bacteria consume organic matter, oil, grease as food and produce carbon
dioxide and hydrogen sulphide. This process results in degradation of solids up to a
level of 10–20%.
8 Treatment of Petroleum Hydrocarbon Pollutants in Water
249
microorganisms like bacteria, protozoa in presence of oxygen.
Trickling Filter
Trickling filter is a fixed bed filter of polymeric materials, polyurathanes foam,
ceramic, rocks, coke and gravel designed for development of bio-layer using microorganisms. This bio-layer is used for removal of pollutants mainly organic compounds (oil, grease, heavy hydrocarbons) from wastewater by absorption or
adsorption in presence of oxygen, releasing carbon dioxide (Environmental Protection Agency, Washington 2000; Environmental Protection Agency, Washington
2011).
Oxidation Ponds
Oxidation ponds or stabilization ponds are designed for reducing the pollutants
mostly organic matter from industrial wastewater. This treatment requires several
days. In these large and shallow ponds, the wastewater is interacted with sunlight,
bacteria and algae. The wastewater is discharged into oxidation ponds where organic
pollutants are consumed by living microorganisms for their growth, reproduction,
energy generation and converted into carbon dioxide on the surface of pond in
presence of sunlight and oxygen which is generated during photosynthesis of algae.
In some cases, mechanical agitators are incorporated to increase the dissolved
oxygen level (Tharavathy et al. 2014; Environmental Protection Agency,
Washington 2011).
Lagoons
Lagoons are artificial aeration ponds or pond like water bodies or basins for
treatment of polluted water for a predetermined period of time. These types of
ponds are stabilized with clay, artificial liner to avoid any leaks to the groundwater
below. Here, the wastes are treated by bacteria, algae in presence of dissolved or
supplied oxygen in warm, sunny climate (Tharavathy et al. 2014; Cavaseno 1980).
Aerobic Digestion
In aerobic digestion, organic pollutants are digested by aerobic bacteria
(saprotrophic bacteria) in presence of oxygen in a digester tank; it is a batch process.
Aerobic bacteria consume organic matter, oil, grease as food and produce carbon
dioxide and hydrogen sulphide. This process results in degradation of solids up to a
level of 10–20%.
8 Treatment of Petroleum Hydrocarbon Pollutants in Water
249