Chemical oxygen demand, pollution

The size of most biological reactors is determined by pollution load, for example, kg BOD (biochemical oxygen demand) or COD (chemical oxygen demand) per kg MLVSS (mixed liquor volatile suspended solids) per day in the case of suspended growth type systems, and kg BOD or COD per m3 of media or reactor volume in the case of fixed-film type systems. 

A measure of the total organic material present in slurries can be obtained by determining chemical oxygen demand (COD) or biological oxygen demand (BOD) (3) and the latter measure is used by Water Authorities in relation to the pollution of water courses where oxygen tension in the water is a prime concern. In studies to evaluate aerobic digestion as a means of odour reduction, the dissolved volatile fatty acids are a useful measure of the potential odour nuisance (2). 

With the rapid increase in the nnmber of chemical industries, a great deal of waste-water is produced, which causes pollution and degrades the enviromnent. Many of these industrial wastewaters, particularly the ones, containing phenohc compounds, are well known to be characterized by higher salinity, acidity, chemical oxygen demand (COD) value and low biodegradability, which means that the effluent carmot be treated by the corrventional process [2, 3]. An alternative method of treating such... 

Note pH (within the range of 6.0 to 9.0) BPT incorporates BAT and BCT BPT, best practicable control technology NS, new source performance standards BOD, biochemical oxygen demand TSS, total suspended solids COD, chemical oxygen demand O G, oil and grease BAT, best available technology economically achievable BCT, best conventional pollutant control technology. 

Chemical Oxygen Demand (COD) Means of measuring the pollution strength of domestic and industrial wastes based on the fact that most organic compounds can be oxidized by the action of strong oxidizing agents under acid conditions to carbon dioxide and water. 

Ozonolysis can be applied for assessing the pollution level of potable and wastewaters, by determining the ozone demand in an apparatus including an ozone generator and UVD for measuring the amount of O3 supplied. A correlation can be established between the ozone demand and the chemical oxygen demand, which is a standard method for pollution evaluation. The advantage of the ozonolysis route is its speed (a few minutes for sample... 

This equation assumes that if all the current during electrolysis is used for the oxidation of the initial pollutant and its intermediates, then Vi>OIg = 0 and ICE = 1. When the electrolysis products are soluble in the electrolyte, the ICE can also be calculated from the change in the chemical oxygen demand (COD) [in g 02 dm 3] using the relation ... 

The following is an example of a typical chemical process (in a schematic form) used for the analysis of a wastewater sample in order to determine the presence of organic matter or oxidizable fraction through the measurement of the chemical oxygen demand (COD), a very common parameter in the evaluation of water pollution ... 

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