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Activated carbon for cod removal from wastewater

Date :2021-07-06
Classify: Activated Carbon

How to reduce COD from wastewater?

Wastewater must be treated before discharge. How to test the water quality of wastewater? Generally, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) are two important aspects to show water impurity.

What is chemical oxygen demand?

It is the amount of oxidizer consumed when a certain strong oxidizer is used to treat water samples under certain conditions. It reflects the degree of pollution in the water. The greater the chemical oxygen demand, the more serious the pollution of organic matter in the water.
COD is expressed in mg/L. The COD value detected by the water quality monitoring instrument can be divided into five major categories. Among them, the first and second categories have COD≤15mg/L, which can basically meet the drinking water standard. The value is greater than the second category of water, and it cannot be used as drinking water, of which three types of COD≤20mg/L, four types of COD≤30mg/L, and five types of COD≤40mg/L belong to polluted water quality. The higher the COD value, the more serious the pollution.

The significance of chemical oxygen demand

It refers to the mass concentration of dissolved oxygen required in the biochemical process of the decomposition of organic matter by microorganisms in water under aerobic conditions. The larger the BOD value, the more organic matter contained in the water, and therefore the pollution will be more serious.
BOD is an environmental monitoring indicator used to monitor the pollution of organic matter in water. Organic matter can be decomposed by microorganisms. Oxygen is consumed in this process. If the dissolved oxygen in water is not enough to supply the needs of microorganisms, the water will be in the pollution state.

What are the difference between COD & BOD?

Many people tend to confuse these two metrics since they are used for the same purpose – to find out the degree of water contamination. However, unlike BOD, COD measures all oxidizable matter in a sample of water, and not just organic compounds. Thus, BOD is typically lower than COD for the same sample.
Moreover, a standard COD test can be done in a few hours, unlike a BOD test which requires a standard 5-day incubation period.

What is cod in wastewater?

COD in wastewater refers to the amount of oxygen required to degrade all oxidizable compounds in a measured sample of effluent. You can find the COD value in wastewater by carrying out a COD test.

COD test

A COD test indirectly measures the concentration of organic compounds in a sample of water by measuring the amount of oxygen required for oxidation of all the organic compounds present. The common technique uses COD vials for measurement and results are typically achieved within 2 – 3 hours.

How to reduce COD in wastewater?

There are various proven ways for COD reduction in wastewater. The following is the most common and cost effective way.
Wastewater separation (coagulation and flocculation), like PAC and PAM
2. COD removal by coal activated carbon powder.

Wastewater separation

Wastewater separation techniques remove colloidal solids suspended in wastewater by coagulation and flocculation in wastewater treatment.
In coagulation, polyaluminum chloride (PAC) is added to the water to bring all the suspended particles together to form a lump. Once they are bound into big enough masses that they can be easily filtered out and deposited into a sedimentation tank for removal.
The flocs then undergo the sedimentation process in wastewater treatment by being deposited into a sedimentation tank for further treatment prior to disposal. This treatment is to lower the COD in the effluent of any industry rejecting process water to a wastewater pre-treatment: printing, tannery, electroplating, glass, etc…

COD removal throught coal activated carbon powder

The latter method is widely used in the finishing process or post treatment after primary treatment process. Usually used as an activated carbon filter. Most clients will choose coal activated carbon powder. It will absorb organic substances, ozone or chlorine substances remaining on the processing results. So safe effluent to be discharged into the environment.
Filtration using activated carbon is also commonly used in water treatment processes to remove odors, and reduce the chemicals in the water.
PAC can work on the waste water to remove COD and other metal materails. Aggregation, flocculation, coagulation, precipitation to achieve purification treatment effect,  Another efficient technique for COD removal is to introduce bacteria or microorganisms that break down organic compounds present in the wastewater. Microbes in sewage treatment can be aerobic or anaerobic. 
Aerobic COD removal introduces microorganisms or bacteria that break down organic compounds present in wastewater into carbon dioxide and water in the presence of air. Aerobic COD removal is ideal for wastewater with COD < 3000 mg/L.
Anaerobic COD removal uses microbes to convert organic compounds in the wastewater to biomass in the absence of oxygen. It is a highly beneficial method because the biofuel generated from the process can be utilized as an alternative energy source for power, heating, and drying applications. Anaerobic COD removal is suitable for wastewater with COD > 2000 mg/L.

FAQ about activated carbon for COD removal

1. which type of activated carbon are suitable to remove COD from  groundwater treatment of petrochemical pollution?
IV 900-1000mg/g coal base briquette crushed carbon is better for COD, petrol smell removal.

Zhulin for the waste water COD removal

Our lab workers can do the test about the COD content, and do the specific experiement to reduce COD value. They can get the best solutions about the waste water management.
Serving the industry since 2001, Zhulin Treatment Solutions provides a wide range of water treatment solutions including wastewater, drinking water, tap water, dechlorination, phosphorus removal and odor control. 
With 20 years experience, Zhulin has provided hundreds water treatment solutions for a diverse range of clients including private businesses, corporations, and government agencies.
COD can be found in the wastewater of landfills, the food and beverage industry, the diary industry and more. If you are interested in industry specific solutions, call +86-19949132731 or contact us online today. 

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