When you see a sewage treatment plant or a wastewater treatment plant at work, it uses the same bacteria that are billions of years old that are used in nature to decompose or oxidize organic material except the process is done at a faster rate but with Oxidation Ponds the natural process is put back in control slowing it all down again. What is an Oxidation Pond in wastewater treatment?
Oxidation Ponds are large basins where wastewater is treated by natural processes using bacteria & algae at a slow rate.
Aerobic Pond-bacteria use oxygen
Anaerobic Ponds-bacteria use no oxygen
Facultative Ponds-use both bacteria
Maturation or Tertiary Ponds- aerobic bacteria used for polishing effluents
Oxidation Ponds are considered Advanced oxidation processes (AOPs) a set of treatment procedures designed to remove organic and sometimes inorganic materials in water and wastewater by oxidation set over a big area and a slow period of time.
Oxidation Ponds in Wastewater Treatment
Oxidation ponds, also called lagoons or stabilization ponds treatment, are large, shallow ponds designed to treat wastewater through the interaction of sunlight, bacteria, and algae. Algae grow using energy from the sun and carbon dioxide and inorganic compounds released by bacteria in water.
The quality of wastewater is a factor that decides the type of treatment method that has to be employed. Initially, the stabilization pond treats the strong industrial organic wastes. Domestic wastewater can be subjected to tertiary treatment.
The microorganisms in the stabilization pond perform a fundamental role in converting organic wastes into simple forms. Bacteria, algae, fungi, protozoans, insects, larvae, crustaceans, viruses, rotifers, nematodes, etc., are the common microorganisms in the stabilization pond treatment.
Among these microorganisms, bacteria and algae dominate and convert organic matter by reduction-oxidation reactions. Some organisms compete in a stabilization pond, and some live symbiotically to convert the wastewater influent into reclaimed effluent.
For the oxidation of biodegradable organic waste, there must be considerable demand for oxygen. The bacteria need oxygen to convert the organics into simple inorganic compounds. The heterotrophic bacteria fulfill their oxygen requirement through the oxygen released by the algae and the atmospheric oxygen
Oxidation pond refers to the stabilization pond stabilizing the domestic, trade, industrial wastes, etc., by the microbial interaction (primarily bacteria and algae). It seems like a large shallow pond with a 2-6 feet height of water body. Oxidation pond requires the presence of sunlight and oxygen for the secondary treatment of domestic and trade wastes.
How an Oxidation Pond Waste Water Treatment Works
The secondary treatment of the organic and inorganic waste coming from raw sewage and industrial effluents is necessary. The direct disposal of the wastewater to the aquatic system can affect the life of water bodies and the quality of water as well.
The mechanism or working of the oxidation pond can be made simple by understanding the following steps:
- First, the bacteria present in the oxidation pond will oxidize the organic waste of the domestic as well as industrial sewage. By doing this, bacteria release carbon dioxide, water, and ammonia.
- The algal growth occurs in the presence of sunlight. It utilizes the inorganic wastes formed by the organic matter decomposition and releases oxygen.
From the above two mechanisms, it is clear that the algae and bacteria work mutually to fulfill each other’s requirements. The bacteria use oxygen released by the algae to oxidize the biodegradable organics. The oxidation of organic waste by the bacteria releases carbon dioxide. Later, algae harness carbon dioxide to reduce inorganic wastes like nitrogen, phosphorus compounds, etc.
Treating Wastewater: Oxidation Pond-Stabilization Pond-Sewage Treatment
Oxidation ponds, also called lagoons or stabilization ponds, are large, shallow ponds designed to treat wastewater through the interaction of sunlight, bacteria, and algae. Algae grow using energy from the sun and carbon dioxide and inorganic compounds released by bacteria in water. During the process of photosynthesis, the algae release oxygen needed by aerobic bacteria.
Types of Oxidation Ponds are:
- Aerobic Ponds-Large ponds that treat wastewater with bacteria and algae requiring oxygen
- Anaerobic Ponds-Require no Dissolved oxygen-Anaerobic digestion happens at the bottom of the pond
- Facultative Ponds- Use anaerobic bacteria at night and aerobic bacteria produced by algae during the day to degrade waste.
- Maturation or Tertiary Ponds-finishing pond -These are aerobic ponds used for effluent polishing-reduction of fecal coliform- nutrients removed (nitrogen and phosphorous)
Storm Water System:
- Collects outside runoff rain & snowmelt
- Transports it to waterways preventing flooding-Under NPDES Permit
Sanitary Sewer System:
- Collects and transports for treatment of domestic, commercial & industrial wastewater from inside buildings
- Normally Separate from the Storm System–Under NPDES Permit ..……………………………………………………………………………………………………… Read more
Do Oxidation Ponds Remove Heavy Metals-Wastewater Treatment
During the process of photosynthesis, the algae release oxygen needed by aerobic bacteria. Mechanical aerators are sometimes installed to supply yet more oxygen, thereby reducing the required size of the pond. Sludge deposits in the sewage ponds must eventually be removed by dredging. Algae remaining in the pond effluent can be removed by filtration or by a combination of chemical treatment and settling.
The amount of putrescible organic material in sewage is indicated by the biochemical oxygen demand or BOD; the more organic material there is in the sewage, the higher the BOD, which is the amount of oxygen required by microorganisms to decompose breakdown, and treat the organic substances in sewage. Unfortunately, this type of treatment cannot remove heavy metals in wastewater.
More pollutants in the wastewater may affect the efficiency of the entire stabilization pond community. Contaminants in the wastewater can sometimes be toxic and may cause shock load and release effluent of poor quality.
During the process of photosynthesis, the algae release oxygen needed by aerobic bacteria. Mechanical aerators are sometimes installed to supply yet more oxygen, thereby reducing the required size of the pond. Sludge deposits in the pond must eventually be removed by dredging. Algae remaining in the pond effluent can be removed by filtration or by a combination of chemical treatment and settling.
The amount of putrescible organic material in sewage is indicated by the biochemical oxygen demand or BOD; the more organic material there is in the sewage, the higher the BOD, which is the amount of oxygen required by microorganisms to decompose breakdown, and treat the organic substances in sewage.
- Primary Stage-separates settable organic solids & inorganic material that won’t degrade
- Secondary Stage-removes suspended & soluble solids converting them to settable solids using Biological Oxidation
- The tertiary stage uses chemical & physical treatment to create H2O closer to potable quality .……………………………………………………………………………………… Read more
It is among the most important parameters for the design and operation of sewage treatment plants. Industrial sewage may have BOD levels many times that of domestic sewage. The BOD of storm sewage is of particular concern when it is mixed with domestic sewage in combined sewerage systems
Dissolved oxygen is an important water quality factor for lakes and rivers. The higher the concentration of dissolved oxygen, the better the water quality. When sewage enters a lake or stream, decomposition of the organic materials begins. Oxygen is consumed as microorganisms use it in their metabolism.
This can quickly deplete the available oxygen in the water. When the dissolved oxygen levels drop too low, trout and other aquatic species soon perish. In fact, if the oxygen level drops to zero, the water will become septic. The decomposition of organic compounds without oxygen causes undesirable odors usually associated with septic or putrid conditions.
Aerobic and conventional anaerobic digestion convert about half of the organic sludge solids to liquids and gases. Thermal hydrolysis followed by anaerobic digestion can convert some 60 to 70 percent of the solid matter to liquids and gases.
Trickling filters are used to remove organic matter from wastewater an aerobic treatment system that uses microbes attached to a filter medium rock, gravel, or plastic that removes organic matter from wastewater sprayed on it, followed by a recirculation tank It can handle peak shock loads to loads……………………………………………………………………. Read more