Water treatment methods can be difficult to choose. Alternatives to traditional methods such as ozone, which is readily available, might provide a more lasting solution as compared to chlorine based solutions. Continue reading to learn more about ozone treatment for COD & BOD removal.
A COD is an indirect measurement of oxidizable compounds in wastewater and water and can be used to determine wastewater and water quality. If released into the environment, COD evaluates all chemically oxidizable substances and can provide a direct correlation with the actual oxygen demand of the effluent. A potential discharge of wastewater into the environment can thus be used to give an idea of the environmental impact.
As a result of ozonation, the effluent contains more dissolved oxygen (DO). By increasing DO, reaeration can be eliminated and the receiving stream can also be aerated.
Municipal wastewater treatment plants discharge effluent into water bodies like rivers and lakes that provide drinking water to many municipalities.
In the early 1970s, various studies confirmed that chlorine formed disinfection by-products (DBPs) such as trihalomethane and haloacetic acid when it reacted with organics. The carcinogenic properties of DBPs present a risk to public health and aquatic life.
Moreover, killing of fish have also been reported in the waters of municipalities that disinfect wastewater with chlorine. United States Environmental Protection Agency (USEPA) leaders promoted research on alternative disinfection methods such as ozonation due to the adverse effects of chlorinated effluent.
What is Ozone?
You may recognize the word even if you don’t know exactly what ozone is. Increasing global warming and ice cap melting have been linked to the destruction of the ozone layer, an important environmental concern for decades.
It is a simple molecule called “ozone” that makes up the ozone layer. The molecule is composed of three oxygen atoms, called O3.
Naturally, this is unusual since the natural state of oxygen at room temperature and surface pressure is O2, or two atoms bound together in a molecule.
As a result, a completely new substance is created, with its own properties and characteristics. Several of these properties make ozone an appealing candidate for wastewater treatment and filtration.
During wastewater treatment, ozone is added to remove bacteria and organic compounds. Ozone filtration, as its name suggests, is a way to filter wastewater by using a chemical called O3 instead of water.
The Benefits of Using an Ozone Generator
- By using atmospheric oxygen, one can produce ozone on-site, so there is no need to transport chemicals.
- Since the raw material for ozone is oxygen, it is a renewable resource. In addition to eliminating ozone storage needs, this also reduces storage requirements for other hazardous chemicals, such as chlorine.
- As ozone dissolves into oxygen, hazardous residues in wastewater effluent are not a concern as it leaves no residues behind.
- The oxidation potential of ozone is higher than that of chlorine.
- Ozone is a better disinfectant for killing both bacteria and viruses from wastewater.
- The removal of coloration from wastewater is more effective using ozone than chlorine.
- The ozone forms fewer carcinogens.
- Water’s pH can be lowered with ozone.
- Biochemical Oxygen Demand, or BOD, is a method of measuring the amount of oxygen in water based on the amount of oxygen consumed as microorganisms are responsible for oxidation (instead of chemical oxidants as in COD).
- Since not all organic matter is biodegradable, COD concentrations are usually higher than BOD concentrations in wastewater. Domestic wastewaters are usually 100 – 450 mg/L and chemical process wastewaters are typically 200 – 40000 mg/L. This illustration shows how ozone can be used to treat a variety of kinds of compounds.
- In addition to the chemicals and compounds found in wastewater, other ecological concerns may result from their concentrations.
- In general, contaminants of emerging concern (CECs) are referred to as pollutants of concern that have been recently discovered.
- There are other industries that produce high COD levels in their effluents, such as breweries, dairy, iron & steel, pulp & paper and mining. Wastewater may contain non-biodegradable or biodegradable organic COD.
Non – Biodegrable COD
Non-biodegradable COD consists of soluble substrates found in wastewater treatment plants and escaping as micro pollutants in small concentrations. There are several examples, such as pharmaceuticals (diclofenac, paracetamol, propofol, etc.), persistent organic pollutants (pesticides, industrial chemicals, hormones, etc.), and other organic molecules, including fluorinated and bromated organic compounds.
Ozone in Wastewater Disinfection
Water with concentrations of industrial byproducts can be treated effectively with ozone. Through ozone oxidation, BOD pesticides, COD and organics are thoroughly and effectively treated.
In order to determine the required ozone dosage, pilot tests are usually conducted to determine the variability of the contaminant makeup and loading.
Some of the benefits include the reduction or elimination of penalties for disposal of contaminated water, as well as the reduction of processing costs. Another advantage is the use of a cleaner, more environmentally friendly technology that is just as efficient and economical as older technologies.
Other benefits associated with the ozonation of wastewater effluents include increased dissolved oxygen levels, reduced chemical oxygen demand, and improved aesthetics due to a reduction in turbidity and color. These benefits are not provided by chlorination or UV radiation. Further, thanks to the significant advances in ozone manufacturing technology made by Ozongenerator in the last two decades, as well as the experiences we’ve gained from supplying wastewater and water treatment systems, ozonation is now an innovative technology that is being used all over the world to treat municipal wastewater in some of the biggest cities. other benefits of ozone disinfection include:
- Viruses and bacteria are more easily destroyed by ozone than by chlorine.
- The ozonation process utilizes a short contact time (approximately 10 to 30 minutes).
- Due to the rapid decay of ozone, there are no harmful residuals following ozonation.
- After ozonation, microorganisms no longer grow, except for those that are protected by the particulates in the waste water.
- Due to the onsite generation of ozone, there are fewer safety issues associated with shipping and handling.
All things considered, ozone treatment for COD & BOD removal from water is the ideal solution as compared to traditional chemical solutions like chlorine. If you need help choosing right equipment to treat effluent water from your facility, you can reach us out at contact us page. We will help you out.