COD and BOD tests are important because they help in the determination of the amount of waste in wastewater. This is important because the organic content in wastewater needs to be reduced before the wastewater is discharged.
Why is it important to determine COD in wastewater treatment?
In wastewater treatment, the Chemical Oxygen Demand (COD) is an important measurement for the amount of oxygen that is required to break down pollutants (organic substances) in water. The chemical oxygen demand can be measured using different methods, direct or indirect.
What is BOD and COD write its importance in environmental studies?
BOD means Biochemical oxygen demand. The microorganisms use organic matter as a food source through oxidation which oxygen is consumed. COD, Chemical Oxygen Demand, is a measure of the total quantity of oxygen required to oxidize all organic material into carbon dioxide and water.
What is the importance of determining BOD?
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.
Why is COD important in water quality?
COD is a water quality measure used not only to determine the amount of biologically active substances such as bacteria but also biologically inactive organic matter in water [8]. It is an important and rapidly measured variable for characterizing water bodies, sewage, industrial wastes, and treatment plant effluents.
Are BOD and COD important parameters for assessing water quality?
Yes, both are important. BOD is indirect measures of biodegradable organics in water. COD is indirect measures of total organic pollution in water.
What are the significance of BOD and COD in water pollution is talked about?
BOD of wastewater effluents is used to indicate the short-term impact on the oxygen levels of the receiving water. BOD analysis is similar in function to chemical oxygen demand (COD) analysis, in that both measure the amount of organic compounds in water.
How do you determine COD and BOD?
Testing for BOD involves incubating a sealed water sample at 20C for five days, followed by measuring the difference in oxygen content before and after incubation. COD measures how much DO is consumed by the oxidation of organic matter and inorganic compounds such as ammonia or nitrite under controlled conditions.
Why is the BOD the most important measurement in wastewater?
IMPORTANCE FOR WASTEWATER
The higher the BOD value, the greater the amount of organic matter or “food” available for oxygen consuming bacteria. If the rate of DO consumption by bacteria exceeds the supply of DO from aquatic plants, algae photosynthesis or diffusing from air, unfavourable conditions occur.
What is the difference between BOD and COD?
Biochemical oxygen demand (BOD) is the amount of oxygen required by the microorganisms to break down the organic materials, whereas chemical oxygen demand (COD) is the amount of oxygen required to break down the organic material via oxidation.
What does BOD tell us about water quality?
Higher BOD indicates more oxygen is required, signifying lower water quality. Low BOD means less oxygen is being removed from water, so the water is usually more pure. Since cold water retains oxygen better than warmer water, DO is usually lower in summer months.
What is COD and its significance?
2)COD(chemical oxygen demand)- It is defined as the amount of oxygen required by organic matter in sample water for its oxidation by strong oxidizing agents (K2Cr2O7) in the hot conditions. It is a measure of both the biologically oxidisable & biologically inert organic matter.
What are the applications for COD analysis?
COD is often used as a measurement of pollutants in water, wastewater, and aqueous hazardous wastes. One application of the COD test is to measure soluble COD in wastewater, since characterization of total COD in wastewater is critical for accurate modeling of biotransformation in wastewater treatment processes.
How does BOD and COD reduce in water?
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.
What is BOD and COD in wastewater?
The biochemical oxygen demand (BOD) represents the amount of dissolved oxygen (DO) consumed by biological organisms when they decompose organic matter in water. The chemical oxygen demand (COD) is the amount of oxygen consumed when the water sample is chemically oxidised.
Why do the COD analysis and BOD analysis give different results for the same waste?
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
Why is BOD as an index of sewage concentration preferred to COD?
D. BOD represent both carbonaceous and nitrogenous organic matter while amd nitrogenous organic matter while COD may indicate carbonaceous matter only.
Which is better BOD or COD?
BOD measures the amount of oxygen required by the aerobic organisms to decompose organic matter and COD measures the oxygen required to decompose organic and inorganic constituents present in the wastewater by chemical reaction. Hence, the value of COD is greater than BOD.
What is the ratio of BOD and COD?
BOD : COD (Chemical oxygen demand) ratio using the formulated seed comes in the range of 0.7-0.8 whereas that using BODSEED comes in the ratio of 0.5-0.6. The ultimate BOD (UBOD) was also performed by exceeding the 3-day dilution BOD test.
What causes high COD in wastewater?
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.
What happens if COD is high?
When the COD levels are higher, there is a greater demand for oxygen. This means that there is likely more oxidizable organic material in water with high COD levels. This also means that there are reduced Dissolved Oxygen (DO) concentrations in wastewater with high COD levels.
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