What is BOD formula?

What is BOD formula?

Biochemical Oxygen Demand ???, ??/? = ?1 − ?2 ? When the dilution water is seeded ?????/?, = ?1 − ?2 − ?1 − ?2 ? ? Where: D1: Dissolved oxygen of diluted sample immediately after preparation, mg/L D2: Dissolved oxygen of diluted sample immediately after 5day incubation at 20⁰C, mg/L B1: Dissolved oxygen of seed control …

What is BOD ratio?

BOD is oxygen demand for oxidation of organic matter by micro organism. COD is oxygen demand for oxidation of organic and non biodegradable organic matter. In domestic waste the ratio between BOD/COD is 1:2. The COD/BOD ratio is useful for assessing the amount of sewage available for biological treatment.

How is COD BOD ratio calculated?

To establish the COD:BOD ratio for your wastewater, simply have both COD and BOD run on several wastewater samples. Divide the COD concentration by the BOD concentration for each sample and average the results.

What causes high COD in wastewater?

However, soluble organic compounds are most likely to contribute to escalated COD concentrations. Residual food waste from bottles and cans, antifreeze, emulsified oils are all high in COD and are common sources of COD for industrial stormwater. A typical COD concentration for soda and beer is about 100,000 mg/L.

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 is the BOD value of pure water?

about 1 ppm

What is BOD and COD in ETP?

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.

How do you calculate COD removal?

I have the influent and effluent COD concentrations (mg l-1), HRT, and OLR for my batch bioreactor system. The COD removal efficiency can be computed using ((Cin-Ceff)/Cin)*100) and expressed in %.

What is BOD removal?

BOD is fairly easy to remove from sewage by providing a supply of oxygen during the treatment process; the oxygen supports bacterial growth which breaks down the organic BOD. Reduction of BOD is a relatively easy and efficient process, and results in sewage of low BOD flowing to the leaching field.

What is BOD wastewater?

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). BOD is used, often in wastewater-treatment plants, as an index of the degree of organic pollution in water.

How do you calculate removal efficiency?

So, coming into the plant is 245 mg per liter of BOD and leaving there’s 22 mg per liter. We have a formula that says efficiency or removal efficiency equals what’s coming in minus what’s coming out then you divide that by what’s coming in and then we multiply by a 100 to convert the decimal to a percent.

What is removal percentage?

Simply put, it’s the amount of waste removed in percent format. For example, it can be used to calculate how much BOD was removed in the primary clarifier. Therefore, the percent removal efficiency formula is frequently used to calculate the performance of the plant to assess how much contaminants were removed.

How do you calculate the efficiency of a sedimentation tank?

Area (A) = Volume of water/ over flow velocity The breadth of sedimentation tank should be provided is 10 to 12 meters while the length of sedimentation tank should be at least 4 times the breadth of sedimentation tank.

How is MLSS calculated?

2. Determination of MLSS

1. Set the temperature of the muffle at 105°C;
2. Weight the blank filter and take note (Mo) [mg];
3. Filter 25 ml of sample and take note of the volume (V) used [ml];
4. Take the filter (after filtration) and put it in the muffle at 105°C for 2h;
5. Let the dried filter for 15 min at room temperature;

What is the formula for sludge age?

The sludge age of an activated sludge process can be calculated by dividing the pounds of suspended solids or MLSS in the aeration tanks by the pounds of suspended solids that enter the aeration tanks (Equation I. 10).

What is BOD loading rate?

Introduction: Organic loading rate is defined as the application of soluble and particulate organic matter. It is typically expressed on an area basis as pounds of BOD5 per unit area per unit time, such as pounds of BOD5 per square foot per day (lb/ft2/day).

How do I build my MLSS in aeration tank?

Fill the aeration tank with 50% primary treated wastewater + 50 % water and add some bacterial seed material (say 500 litre mixed liquor from an operating ASP plant or 100 kg cattle dung) aerate for 12 hours (as a batch reactor) to acclimatize and develop more biomass.

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).

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 do you calculate loading rate?

Loading rate – the speed at which forces impact the body, calculated by dividing the maximal vertical force by the time to the maximal vertical force (Bauer et al., 2001; Crossley et al., 1999).

How is BOD loading rate calculated?

BOD (or COD) load: Units: kg/day The concentration of BOD (in mg/l) in the influent can be used to calculate the total BOD load per day being treated. 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 hydraulic loading rate?

Hydraulic loading rate means the rate at which wastes or wastewaters are discharged to a land disposal or land treatment system, expressed in volume per unit area per unit time or depth of water per unit area per unit.

Why is COD higher than BOD?

COD is normally higher than BOD because more organic compounds can be chemically oxidised than biologically oxidised. This includes chemicals toxic to biological life, which can make COD tests very useful when testing industrial sewage as they will not be captured by BOD testing.

Is high COD good or bad?

COD is an indicative measurement of the amount of oxygen that can be consumed by reactions in a measured solution. COD detection can be used to easily quantify the amount of organics in water. The higher the COD value, the more serious the pollution of organic matter by water.

How do you reduce 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 a good BOD level?

1-2 ppm

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 relation between BOD and COD?

Biochemical Oxygen Demand (BOD) can be estimated from Chemical Oxygen Demand (COD) measurements, if a correlation is established. One would then multiply their COD results by this factor to estimate BOD. COD values are almost always higher than BOD values for the same sample.

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.

What is BOD value?

What is BOD example?

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.

What increases BOD 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. These conditions result in decrease in dissolved oxygen in water.

How can we reduce BOD and COD in industrial wastewater?

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 should be the COD of drinking water?

water at 0°C is 14.6 mg/L. The amount of oxygen dissolved in water is usually measured with the Winkler test. Amount of oxygen required by bacteria and other microorganisms in stabilizing decomposable organic matter .

How is BOD removed from wastewater?

Why is BOD removed from wastewater?

BOD is a crucial factor in refining wastewater. The bacteria are important for breaking down substances, however too much BOD can cause unwanted amounts of bacteria. It can also drain receiving waters of oxygen which can kill fish and harm the environment.