Bod and cod definitions relationship

Biochemical oxygen demand - Wikipedia

bod and cod definitions relationship

was found to have the highest mean B.I. of , while the lowest mean B.I. was found to be . treatment plants the BOD/COD correlation should be developed. The objective of this paper is to correlate BOD (Biochemical Oxygen Demand) with COD (Chemical Oxygen Demand) and TOC (Total Organic Carbon). So that . Soluble BOD or COD will always be a fraction of the total unfiltered test. In municipal plants it is very common to have a COD: BOD ratio of , but this should be confirmed through a series of tests and ongoing What does CBOD mean?.

Adsorption as well as entrapment, thus resulting in a more stable immobilized membrane. Such specific Microbial consortium based BOD analytical devices, may find great application in monitoring of the degree of pollutional strength, in a wide variety of Industrial waste water within a very short time.

Consequently, biosensors are now commercially available, but they do have several limitations such as their high maintenance costs, limited run lengths due to the need for reactivation, and the inability to respond to changing quality characteristics as would normally occur in wastewater treatment streams; e. Another important limitation is the uncertainty associated with the calibration function for translating the BOD substitute into the real BOD Rustum et al.

Fluorescent RedOx Indicator[ edit ] A surrogate to BOD5 has been developed using a resazurin derivative which reveals the extent of oxygen uptake by micro-organisms for organic matter mineralization. Software sensor[ edit ] Rustum et al. This will make the use of BOD for on-line process monitoring and control a more plausible proposition.

In comparison to other data-driven modeling paradigms such as multi-layer perceptrons artificial neural networks MLP ANN and classical multi-variate regression analysis, the KSOM is not negatively affected by missing data.

Moreover, time sequencing of data is not a problem when compared to classical time series analysis.

BOD, COD, TOC and TOD – sum parameters in environmental analysis -

Membrane and luminescence[ edit ] Since the publication of a simple, accurate and direct dissolved oxygen analytical procedure by Winkler, [13] the analysis of dissolved oxygen levels for water has been key to the determination of surface water purity and ecological wellness. The Winkler method is still one of only two analytical techniques used to calibrate oxygen electrode meters; the other procedure is based on oxygen solubility at saturation as per Henry's law. Though many researchers have refined the Winkler analysis to dissolved oxygen levels in the low PPB range, the method does not lend itself to automation.

All tanks were operated as weekly renewal feed batch reactors. The seven days detention time of wastewater in the collection pond was taken as a reference exposure time for the batch experiment.

The tanks size, dimension and time of exposure were sufficient to accomplish the simulated wastewater collection pond Mangkoedihardjo, Then replacements of fresh wastewater from the same sources were carried out each week.

After one month of exposure, the hyacinths were harvested and replaced with new ones. This experiment was replicated three times simultaneously and run for two months.

The three parameters were useful to confirm growth conditions during the experiment. Daily observation for evaporation E of wastewater in the tanks without hyacinth and evapotranspiration Et of wastewater in the tanks of hyacinth treatment were carried out by measuring wastewater depletion using a ruler.

Since the surface area of the tank was known then volume of wastewater loss as E and Et could be calculated. In connection with biodegradation, microbial Colony Forming Units CFU were examined weekly by means of general plate count method. Measurement of pH levels in all wastewater were shown to decrease from 7.

DO levels in wastewater without hyacinth were decline from 6. Decreasing DO levels from 6. However, the DO levels were quiet high at the range of temperatures even no mechanical aeration was carried out during the experiment.

Especially in hyacinth treatment the DO was not suppressed into anaerobic condition probably due to the result of photosynthesis during the day by which a portion of produced oxygen was dissolved in wastewater Bich et al.

bod and cod definitions relationship

All the hyacinths were healthy and green during the experiment and most of the plants appeared to grow showing new shoots after a week of exposure.

Therefore the quality parameters of temperature, pH and DO were not limiting conditions for biotic growth. A fluctuation of evaporation was less than evapotranspiration.

Biochemical oxygen demand

It is shown that the presence of hyacinth would result in higher loss of wastewater than without hyacinth. The extent of the microbial population change was determined using the following equation: Therefore microbial colonies in wastewater containing-tanks of hyacinth treatment were shown significant increase. The presence of hyacinth roots were probably brought about increasing CFU that the size and variety of microbial populations were increased in the rhizosphere Olson and Fletcher, Infact the pH s were decline ranging from 1 and 2 levels and DO s were decline about 2 levels.

These suggest that there was a stimulation of microbes by plant root exudates, compounds produced by plants and released from plant roots. Plant exudates include sugars, amino acid s, organic acid s, fatty acid s, sterols, growth factors, nucleotides, flavanones, enzymes and other compounds Shimp et al.

The exudates can also result in alteration of pH and DO which often creating more favorable environments for microbes, regardless of the production of exudates Bich et al. It is shown that even the organic contents of wastewater initially were varied each week due to replacement, however, the trends of BOD and COD were consistent, i.

It is shown for hyacinth treatment that COD losses were significantly higher than without hyacinth. The tremendous amount of COD losses from wastewater, i. Firstly, rhizodegradation of COD in the rhizosphere brought about by co-operation of bioactivity between plant roots and microbes.

The degree of organic pollution which occurs due to an excessive amount of organic matter, has typically been monitored by measuring BOD and COD values in rivers.

A high level of BOD deteriorates river water quality by rapid decomposition of biodegradable organic matter and the subsequent depletion of dissolved oxygen, while COD traditionally represents the total organic matter.

Biodegradability Improvement of Industrial Wastewater Using Hyacinth - SciAlert Responsive Version

However, both concentrations are quantified by the amount of oxygen consumed for a particular chemical oxidation of organic compounds in samples. Enrichment of total nitrogen in urban rivers may result in excessive growth of algae and macrophytes, decreased biodiversity, and odor problems [ 34 ].

bod and cod definitions relationship

There are several limitations of the traditional water quality parameters for use in continuous monitoring. For example, at least five days are required for the completion of the BOD measurements.

The presence of toxic substances may influence the biochemical oxidation, resulting in analytical errors. Potassium dichromate, a typical oxidant for a COD test, cannot completely decompose organic matter in samples, and the degree of the chemical oxidation itself may be affected by organic matter composition and the molecular structures involved [ 5 ].

bod and cod definitions relationship

Therefore, it is necessary to develop more rapid and reliable monitoring techniques to replace the traditional water quality parameter measurements.