What is BOD limit in wastewater?

What is BOD limit in wastewater?

For drinking water BOD has to be less than 5 mg/L and for treated wastewater to be disposed of in the water bodies it is 30 mg/L, 100 mg/L if treated waste water is discharged into the sewerage system in India.

What are the limitations of BOD?

Limitations Of Test The method takes five days to perform and uses a discrete sample. The test has poor reproducibility and toxic chemicals can inhibit measurement. Short-term BOD determinations magnify errors and still require relatively long sample periods. The test is not suited for on-line, continuous measurement.

What is biochemical oxygen demand BOD levels?

Biochemical oxygen demand (BOD) represents the amount of oxygen consumed by bacteria and other microorganisms while they decompose organic matter under aerobic (oxygen is present) conditions at a specified temperature.

What is the maximum and minimum DO consumption permitted in BOD test 5 days?

The sample dilutions should deplete at least 2.0 mg/L DO after five days incubation at 20°C. 2. The sample dilutions should have a final DO of at least 1.0 mg/L after five days incubation at 20°C. The BOD, using the seed correction, should be calculated for the sample dilutions which meet both criteria.

What are the methods for reducing BOD and allowed limits?

These are the best practices for reducing BOD and TSS that facility managers should know:

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 is a major disadvantage of using the BOD test for operational control?

From an operations perspective, time lag is the biggest drawback to BOD (also referred to as Biological Oxygen Demand) analysis. It is too slow to provide timely information to the operator for control purposes. In addition, there is no measure of accuracy with BOD analysis.

What is the difference between biological oxygen demand and biochemical oxygen demand?

Ask the expert: What are the differences between Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD)? COD is the amount of oxygen required to chemically breakdown the pollutants whereas BOD is the amount of oxygen required to do this biologically through micro-organisms.

What happen 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.

What is biochemical oxygen demand class 12?

Biochemical oxygen demand (BOD) is defined as the amount of oxygen used by bacteria and other microorganisms during the process of decomposition of organic matter under aerobic (oxygen is present) conditions at a particular temperature and in specific time periods.

Why is BOD a 5 day test?

The standard oxidation (or incubation) test period for BOD is 5 days at 20 degrees Celsius (°C) (BOD5). The BOD5 value has been used and reported for many applications, most commonly to indicate the effects of sewage and other organic wastes on dissolved oxygen in surface waters (see TECHNICAL NOTE).

How is biochemical oxygen demand tested?

The COD test uses a chemical (potassium dichromate in a 50\% sulfuric acid solution) that “oxidizes” both organic (predominate) and inorganic substances in a wastewater sample, which results in a higher COD concentration than BOD concentration for the same wastewater sample since only organic compounds are consumed …

What is the minimum quantity of dissolved oxygen that should be present in the treated sewage?

4ppm
What is the minimum quantity of dissolved oxygen that should be present in the treated sewage? Explanation: At least, 4ppm of dissolved oxygen should be present in treating sewage otherwise, fishes will die due to lack of dissolved oxygen.

What is biological oxygen demand (BOD)?

Biological oxygen demand is often used in wastewater treatment plants as an index of the degree of organic pollution in water. Industries that discharge wastewater into municipal sanitary sewers or waterways are facing strict regulations on levels of BOD.

What are the applications of biological oxygen demand in wastewater treatment?

Applications of Biological Oxygen Demand in Wastewater Treatment. Wastewater treatment plants use BOD value as an index to ascertain the overall degree of organic pollution in a water source. A BOD test is typically carried out over a standard 5-day incubation period at 20°C (68°F) for the most accurate results.

What is the use of the BOD in wastewater treatment?

BOD is used to gauge the short-term impact wastewater effluents will have on the oxygen levels of receiving water. BOD is used as a representative of the organic oxygen demanding portion of wastewater at various locations throughout the process from influent to effluent.

What is the BOD limit for drinking water?

According to WHO for drinking water BOD limit is less than < 5.0 mg/l at this limit BOD will not cause any harmful impacts on human body, wastewater sewage must has BOD around 80 ppm and COD 200 ppm for discharge in see. Cite. 15th May, 2019.