Oxygen equivalents

COD provides i measure of the oxygen equivalent to that portion of the organic mtitter in i sample that is susceptible to oxidation by a strong chemical oxidant. A higher level of COD can be degraded (neutralized) chemically. The le el of COD. however, automatically reduces with the level of BOD and no further treatment is normally necessary. 

The manufacture of oxygen is described along with that of nitrogen. Both are formed from the liquefaction of air. Oxygen gas is colorless, odorless, and tasteless, but it is slightly blue in the liquid state. Up to 99.995% purity is available commercially. It is commonly used from seamless steel cylinders under 2,000 psi pressure. A 1.5 cu ft cylinder holds 15 lb of oxygen, equivalent to 244 cu ft at standard temperature and pressure. 

Claus propositions were summarized as three statements in his more widely read paper of 1856 42 (1) If several equivalents of ammonia (from two to six) combine with an equivalent of certain metal chlorides, neutral substances are formed, in which the basic property of ammonia has been destroyed and simultaneously the ammonia can be neither detected by the usual methods nor eliminated by double decomposition . (2) If the chlorine in these compounds is replaced by oxygen, strong bases are obtained, whose saturation capacity is always determined by the oxygen equivalents contained in them but not by the number of equivalents of ammonia present in them . (3) The number of equivalents of ammonia entering into these substances is not a random one as is evident from a number of facts, it is determined by the number of equivalents of water contained in the hydrates of the metal oxides which can enter into such compounds along with the ammonia . 

This model places special emphasis on the recovery of reactive metal oxides in the upper layers of the sediment by dissolved oxygen. In other words, the oxidation capacity of dissolved oxygen (DO) is transferred onto metal oxides, which are then buried by further sedimentation. The oxidation capacity is thus shuttled into deeper layers, where it will enhance the anaerobic turnover of organic carbon in sediment layers that could not be maintained by diffusive supply of sulfate alone. A shuttle of oxygen equivalents may also influence the pathways of organic matter decomposition. 

Heat Max Temp (°C) Oxygen (%) Equivalence Ratio 0 Combustion Efficiency... 

Ortiz de Montellano PR, Catalano CE (1985) Epoxidation of styrene by haemoglobin and myoglobin. Transfer of oxygen equivalents to the protein surface. J Biol Chem 260 9265-9271... 

For 1,3,4-thiadiazole, the lower electron supply from the sulfur compared to the oxygen equivalent accounts for the ortho meta para rate ratio in the phenyl ring of 1 3 2 in the 2-phenyl derivative (7.56) no substitution took place at the 5-position (53JPJ701). 

C mol-1) V the volume of the electrolyte (dm3), and 8 is the oxygen equivalent mass (g eq-1). This equation is similar to that proposed by Comninellis and Pulgarin (1991) for the determination of the ICE, although the expression used for the GCE represents an average value between the initial time t and t + At. 

When the waste contains more complex molecules such as compounds refractory to oxidation with OH radicals, as well as in the presence of inorganic ions which can be precursor of long-life oxidants, the Faradic yield cannot be calculated by (8.3) and different alternatives have been proposed. Faouzi and co-worker (Faouzi et al. 2006) proposed a comparison between electrochemical oxidation at BDD anodes and Fenton and Ozone treatments for the removal of dyes a specific parameter OCC (oxygen-equivalent chemical-oxidation capacity) was proposed which is defined as the kg of 02 equivalent to the quantity of oxidant used in each AOP to treat 1 m3 of wastewater. As highlighted by the authors, the parameter OCC may only give information on the chemical efficiency of the oxidants, but it does not give any information related to the real cost of the treatment, as the oxidants can... 

Table 4 Surface relaxations in the outermost atomic layers of the (111) surface (for M on top of O, site), reported for two different metal coverages 6= and 0.25 ML, Surface displacements are calculated as the difference of the ideal (111) surface and the relaxed geometry of the Pd and Pt/Zr02 interfaces. Negative and positive values indicates inwardly and outwardly displacements, respectively. For 0=0.25 ML, O., denotes the surface ion to which an metal atom is bound, while Oj represent the non-bound surface oxygens equivalent notation for the other surface layers. Displacements are given in A.

Because BOD analysis attempts to measure the oxygen equivalent of a given waste, the environment inside the BOD bottle must be conducive to uninhibited bacterial growth. The parameters of importance for maintaining this type of environment are... 

The COD test normally yields higher oxygen equivalent values than those derived using the standard BOD5 test, because more oxygen equivalents can always... 

Chemical oxygen demand (COD)— A measure of the oxygen equivalent content of a given waste obtained by using a chemical such as potassium dichromate to oxidize the organic content of the waste. 

Determination offs,fsi and/ . The formula for microorganisms has been given as C5H7NO2 (Mandt and Bell, 1982). To find the oxygen equivalent of the mass synthesized, /j, react this molecule with oxygen as follows ... 

From this equation, the oxygen equivalent of the mass synthesized is 1.42 mg O2 per mg C5H7NO2. Therefore,/j = 1.42. 

Factor for converting the nitrogen in the wasted sludge to oxygen equivalent... 

Factor for converting nitrogen concentrations to oxygen equivalent Factor that converts the mass of microorganisms in the waste sludge to the equivalent oxygen concentration Acceleration due to gravity... 

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