How do you reduce COD and BOD?

You can reduce COD and BOD by adding hydrogen peroxide to the wastewater solution. The hydrogen peroxide will chemically attack the organics in the wastewater, degrading them and reducing the measured COD and BOD.

How do you lower COD?

One way to reduce COD in water is to use coagulants and flocculants to bind sludge together. Once they are bound into big enough masses that they can be easily filtered out and deposited into a sedimentation tank for removal. This method does however rely on the use of chemicals, and requires high reoccurring cost.

How do you reduce COD in effluent?

  1. Heavy metals removing.
  2. Coagulant wastewater treatment.
  3. Flocculant wastewater treatment.
  4. COD wastewater treatment.
  5. The vacuum evaporation : zero discharge.
  6. Antifoam wastewater treatment.
  7. Request infos.

What is meant by BOD How is it reduced?

Biochemical oxygen demand (BOD) is the amount of dissolved oxygen (DO) needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.

Does chlorine reduce BOD?

BOD reduction: Chlorine accomplishes BOD reduction by oxidation of organic compounds present in wastewaters. 4. Oxidation of metal ions: Metal ions which are in reduced state are oxidized by chlorine (e.g., ferrous to ferric ion and manganous to manganic ions).

Does aeration reduce BOD?

Aeration is used to operate activated sludge process units and is perhaps the most frequently used process to remove biochemical oxygen demand (BOD) from wastewater.

What happens if BOD is high?

The greater the BOD, the more rapidly oxygen is depleted in the stream. This means less oxygen is available to higher forms of aquatic life. The consequences of high BOD are the same as those for low dissolved oxygen: aquatic organisms become stressed, suffocate, and die.

How do you reduce BOD in wastewater?

  1. Focus on removing TSS from wastewater first.
  2. Get a properly sized EQ tank.
  3. Control the pH of the waste stream.
  4. Install a modern plate pack DAF made of stainless steel or plastic.
  5. Use a regenerative turbine air dissolution pump.

What happens if COD is high?

Higher COD levels mean a greater amount of oxidizable organic material in the sample, which will reduce dissolved oxygen (DO) levels. A reduction in DO can lead to anaerobic conditions, which is deleterious to higher aquatic life forms.

What causes high BOD levels?

Sources: BOD represents the amount of organic matter in a water supply; therefore, it increases when decaying plants, human or animal waste, and other organic compounds are added to water.

Does aeration reduce COD?

Aeration should help reduce the COD in 2 ways. First it may evaporate some volatiles like hexane. Second it will add oxygen to the water speeding up any biological oxidation of the less volatile organics by the bacteria (microbial growth).

What causes COD to increase?

COD increases as the concentration of organic material increases. It also increases if inorganic compounds susceptible to oxidation by the oxidant (typically dichromate) are present. Water with high COD typically contains high levels of decaying plant matter, human waste, or industrial effluent.

Does activated carbon remove BOD?

It was found that for dosages of activated carbon in the range of 50–150 mg/l, the removal efficiencies for BOD increased from 27–70% to 76–94% while those for COD increased from 16–64% to 72–92.5% for inlet values of 45–95 mg/l and 110–200 mg/l for BOD and COD respectively.

Which increases BOD of water?

Organic loading is occurrence of excess organic matter inside water due to sewage disposal and eutrophication. This leads to an increase in biological oxygen demand (BOD) for putrefaction. Explosive multiplication of alga leads to algal bloom.

What affects BOD?

The factors affecting BOD include the type and amount of organic material present, the temperature, the pH, the dissolved oxygen concentration, and the presence of bacteria.

What is BOD in waste water?

BOD is a measure of the amount of oxygen required to remove waste organic matter from water in the process of decomposition by aerobic bacteria (those bacteria that live only in an environment containing oxygen).

Why is BOD important in wastewater treatment?

The BOD is an important parameter for assessing water quality. It deals with the amount of oxygen consumption (mg O2 L− 1) by aerobic biological organisms to oxidize organic compounds. Sewage with high BOD can cause a decrease in oxygen of receiving waters, which in turn can cause the death of some organism.

What are the 7 steps of wastewater treatment?

  1. Step 1: Screening and Pumping.
  2. Step 2: Grit Removal.
  3. Step 3: Primary Settling.
  4. Step 4: Aeration / Activated Sludge.
  5. Step 5: Secondary Settling.
  6. Step 6: Filtration.
  7. Step 7: Disinfection.
  8. Step 8: Oxygen Uptake.

Does activated sludge remove BOD?

There are many variants of activated sludge processes, including variations in the aeration method and the way the sludge is returned to the process. Activated sludge process offers efficient removal of BOD, COD and nutrients when designed professionally and operated properly.

Why does aeration tank increase pH?

When water is aerated, it creates turbulence. The turbulence then causes the aqueous CO2 (carbon dioxide) to outgas. Outgassing of CO2 from water results in an increase in pH. Aeration is the only means of increasing pH that will not increase the Total Alkalinity.

Why do you aerate water?

Proper aeration will distribute cooler oxygenated water to warmer areas with lower amounts of dissolved oxygen. This allows inhabitants to occupy all areas of the pond. Water quality and clarity is also improved through aeration. Pond debris and muck release noxious gases.

Does BOD increase with temperature?

The BOD removal rate in the bioreactor increased when the temperature increased from 20 degrees C to 30 degrees C, 40 degrees C, and 50 degrees C, but it decreased when the temperature increased from 50 degrees C to 60 degrees C. Higher temperature enhanced the endogenous respiration of microbes in the bioreactor.

What is a good BOD number?

A BOD level of 1-2 ppm is considered very good. There will not be much organic waste present in the water supply. A water supply with a BOD level of 3-5 ppm is considered moderately clean.

Which wastewater treatment is reducing BOD levels the most?

The activated sludge (AS) biological treatment process is the most common process for reducing five-day biochemical oxygen demand (BOD5) in wastewater, for both industrial and municipal applications.

Does hydrogen peroxide reduce COD?

Hydrogen peroxide will reduce BOD/COD/TOC in a wide range of wastewaters. This reduction can be achieved by two mechanisms: Direct Oxidation – Hydrogen peroxide can reduce BOD/COD/TOC by direct oxidation (either complete or partial) of wastewater components.

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