How is refractory COD treated in Waste Water Treatment Plants?
Human activities are reflected in the chemistry of wastewater. The wastewater produced by industrial, agricultural, and municipal activities represents each of these activities. Wastewater is processed, discharged to a receiving stream, and withdrawn for reuse by the downstream population due to its value and scarcity. As a result, the chemical and bacteriological composition must be closely controlled in order to assure public safety.
What is Chemical Oxygen Demand (COD)?
The chemical oxygen demand (COD) test is an alternative to the BOD test for measuring the oxygen consumption potential of a wastewater sample. The COD test oxidizes the carbonaceous oxygen demand chemically, as the name implies. COD is measured in milligrams of oxygen per liter, just as BOD.
This test has the advantage of being quick and repeatable. The downside is that not all of the COD detected can be naturally destroyed. As a result, it's still necessary to figure out how much of the oxygen demand is biodegradable.
Advantages of COD Test
1. The COD test has the advantage of being a measure of the system's energetics.
2. To keep track of a biological process, one must first understand the energetics of the reaction (i.e., what electron donors and acceptors are present in the system).
3. In biological treatment systems, microorganisms destroy contaminants for our benefit as well as their own growth and reproduction.
4. We can follow the flow of carbon and energy in a system, as well as the nature and scope of biological events that are taking place.
What is Refractory COD?
Molecules that show up in COD tests as chemically oxidizable but are not readily biodegradable are known as refractory COD. Some detergents, as well as detergent additives such as complexing and sequestering agents, are examples of refractory organics.
Treatment of Refractory COD
Wet oxidation and thermal oxidation are the treatment procedures utilized to eliminate these pollutants because refractory COD limits biological treatment in effluents (incineration).
The following are the primary types of moist oxidation technologies:
1. Oxidation of supercritical water (SCWO)
It's employed when a lot of mineralization is required. This is accomplished via catalysts that increase the rate of degradation of organic and inorganic compounds, as well as oxidizing chemicals like cyanides and ammonia using O2 as the oxidizing agent. Catalysts are metals that reduce the required operating conditions, such as pressure, temperature, and reaction time, considerably.
2. Wet air oxidation without catalysis (WAO)
It is a well-known method in which oxidation takes place using dissolved oxygen from the air or O2-enriched gaseous streams. When the hydroxyl radical is formed and functions as the oxidizing agent, it is referred to as indirect oxidation; otherwise, it is referred to as direct oxidation. Some final products of this type of oxidation of organic materials, such as carboxylic, acetic, formic, and oxalic acids, are not mineralizable but biodegradable.
3. Wet air oxidation with a catalytic catalyst (CWAO)
It's employed when a lot of mineralization is required. This is accomplished via catalysts that increase the rate of degradation of organic and inorganic compounds, as well as oxidizing chemicals like cyanides and ammonia using O2 as the oxidizing agent. Catalysts are metals that reduce the required operating conditions, such as pressure, temperature, and reaction time, considerably.
We at Netsol Water Solutions not only design but manufacture waste water treatment plants for the overall treatment of water and waste water. Treating is basically done to ensure safe disposal of waste water into our surroundings and minimizing the effects of harmful substances to water and life.
Netsol Water is Greater Noida-based leading water & wastewater treatment plant manufacturer. We are industry's most demanding company based on client review and work quality. We are known as best commercial RO plant manufacturers, industrial RO plant manufacturer, sewage treatment plant manufacturer, Water Softener Plant Manufacturers and effluent treatment plant manufacturers. Apart from this 24x7 customer support is our USP. Call on +91-9650608473, or write us at enquiry@netsolwater.com for any support, inquiry or product-purchase related query.