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Is a high BOD good or bad?

The greater the value, 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 control COD in wastewater?

The most important way to get rid of the sludge is to use coagulants and flocculants. The principle is to bind the sludge to one another so that a larger clumps of sludge and then be deposited in a sedimentation tank. Some chemicals commonly used as a coagulant, among others; PAC, FeCl3 (Ferric Chloride) and Alum.

What is BOD and COD in water treatment?

Indian Institute of Science. COD or Chemical Oxygen Demand is the total measurement of all chemicals (organics & in-organics) in the water / waste water; BOD is a measure of, the amount of oxygen that require for the bacteria to degrade the organic components present in water / waste water.

What is BOD COD and do?

BOD is the amount of oxygen that will be consumed by bacteria or other aerobic microorganisms while decomposing organic matter under aerobic conditions. COD measures the amount of oxygen that will be consumed by the chemical breakdown, or oxidation (degeneration) of organic pollutants in water.

What is BOD COD ratio?

BOD (Biochemical oxygen demand) is the pollution index of any water sample. 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 is difference between BOD and COD?

The main difference between BOD and COD is that BOD is the amount of oxygen which is consumed by bacteria while decomposing organic matter under aerobic conditions whereas COD is the amount of oxygen required for the chemical oxidation of total organic matter in water.

What is BOD of drinking water?

BOD is the biochemical oxygen demand of the water and it is related to the concentration of the bacterial facilitated decomposable organic material in the water. For freshwater the concentration should be less than 0.0004 mg/L.

Does aeration reduce cod?

More specifically, utilizing certain types of bacteria can reduce COD. To do this you must first aerate the wastewater in order to provide an environment in which the bacteria can live. Aeration provides oxygen to the bacteria. The bacteria can treat and stabilize the wastewater without the use of chemicals.

What is COD in wastewater?

The chemical oxygen demand (COD) is a measure of water and wastewater quality. The COD test is often used to monitor water treatment plant efficiency. The COD is the amount of oxygen consumed to chemically oxidize organic water contaminants to inorganic end products.

What is a good COD level?

BMS have recorded average ratios of 2-3 mg/l COD to 1 mg/l BOD over its 30 years of business. Influent COD in normal domestic sewage is therefore generally 600 – 900 mg/l and it is then treated to at least 75 -100 mg/l before discharge to minimise pollution potential.

How do you calculate wastewater COD?

There is a formula for calculating COD. Consider the formula for COD calculation: (a – b) X C X 8,000 / the volume of the sample in mL. Let “a” represent the titrant used for your sample expressed in mL. Let “b” represent the titrant used for your blank sample in mL.

How is COD load calculated?

BOD (or COD) load: Units: kg/day This is simply done by multiplying the BOD in mg/l by the daily effluent volume in cubic metres (m3) and dividing the product by 1000.

What is volumetric loading rate?

The volumetric organic load is used to design wastewater treatment units. It can be calculated by multiplying the BOD (mg/L) of the raw water by the influent flow Q (m3/day) and then dividing this volumetric load by the pond volume. Abbreviation. gBOD/m3/day.

How is solid loading rate calculated?

Solids loading rate is the overflow rate multiplied by the incoming solids concentration NA = νXa (kg·m-2·s-1), typically expressed in kg/m2 h, in the US kg/m2 d. It is actually the applied solids flux. The bulk flux is the applied solids flux multiplied by (R+1).