Chemical oxygen demand characterization

Because of the processes carried out in the plant, the expected compounds in wastewater are formaldehyde, urea, and polymers of these compounds. The global effluent of this kind of factory is characterized by a high chemical oxygen demand (COD) (due mainly to formaldehyde), relatively high values of nitrogen (arising from urea and copolymers) and a low content of phosphorus and inorganic carbon. The main characteristics of the effluent of a resin factory are showed in Table 19.1. 

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... 

Industries dedicated to the treatment of skins are big consumers of water and, as a consequence, big producers of liquid effluents. These effluents are characterized by their high chemical oxygen demand (COD), as well as colors and a high content of salts, oils and fats, and solids, due to the reagents used during the production process. As a result, these effluents have a high pollutant potential and need to be treated before their discharge or elimination. 

Determination of the chemical oxygen demand (COD) characterizing total contents of organic compounds in the condensate was also carried out. 

In order to characterize water quality, the following parameters were measured from the water samples in accordance with Hungarian Standards total organic carbon (TOC), chemical oxygen demand, concentrations of ammonium, nitrite and nitrate ion, iron, manganese, pH, conductivity, m-alkality, turbidity, and heterotroph colony count. 

The large difference between the optimum dose of CI2 determined in this study and that reported by Robeck et al. 21) may result from the amount of CI2 consumed in oxidizing formulating solvents, plus the chlorine demand of the river water which was characterized by a chemical oxygen demand of 5-35 mg/liter and a carbon-chloroform extract of 185-1320 /xg/liter. 

Wastewaters from paper factories containing dyes particularly aniline and sulfur ones are generated from the paper treatment process consisting in the addition of fillers and dyes to the bleached cellulose material. As a result of multi-stage purification of wastewaters from the cellulose plants, there is obtained a low value of BOD (biochemical oxygen demand) - 4 mg/L but COD (chemical oxygen demand) is maintained on the level 75 mg/L. These waste-waters contain a small amormt of suspended matter - 5 mg/L, but they are characterized by intensive colour - 40 mg Pt/L [21]. 

The same relates to the analytical methods, where for anionic, nonionic and cationic surfactants, various colorimetric procedures (MBAS, bismuth active substance(s) (BiAS), and disulfine blue active substance(s) (DSBAS)) were introduced. Since these methods analyse only the loss of surface-activity or primary degradation, other analytical approaches have been employed in the last 10 years in order to characterize the total or ultimate degradation. These include methods such as high performance liquid chromatography (HPLC), gas chromatography (GC) GC/mass spectrometry (MS), and the measurement of total organic carbon (TOC) and chemical oxygen demand (COD). 

Organic Compounds Biochemical Oxygen Demand Chemical Oxygen Demand on Pollution Microbiological Algal and Microbial Toxins Particle Characterization... 

See also Extraction Solid-Phase Extraction Solid-Phase Microextraction. Gas chromatography Overview. Liquid Chromatography Overview. Mass Spectrometry Overview. Water Analysis Seawater - Organic Compounds Seawater - Dissolved Organic Cartxjn Biochemical Oxygen Demand Chemical Oxygen Demand Particle Characterization. 

Data were collected from January 2007 to December 2013. Water samples were taken at Water Treatment Plant Raba and at selected 23 sampling points on water distribution network. Basic quality and operation parameters such as pH, residual chlorine, chlorine dose, chemical oxygen demand, UV absorbance in 272 nm, temperature were tested everyday at water treatment plant, but disinfection by-products parameters are analyzed once a month. Water quality parameters that characterize the process of disinfection by-products formation (such as pH, temperature, UV absorbance in 272 nm, total organic carbon, residual chlorine, chloroform, sum of trihalomethanes) in water pipes were analyzed on average once a month. 

The catalysts studied were characterized using XFA, TEM, XANES, EXAFS, XPS, and liquid nitrogen physisorption methods. The total organic caibon was detected by standard methodology of chemical oxygen demand (COD). 

The discovery of O PtFg was accidental. O PtF was easily made, but its correct characterization probably involved the most difficult work of my entire career. Both of the ions of this salt were then unknown in chemical compounds, and the oxidation of oxygen, demanded of PtFe that it be a one-electron oxidizer of unprecedented power. 

Many sources consist of ill-defined mixtures often characterized only by nonspecific parameters such as chemical or biological oxygen demand, total dissolved or suspended solids, etc. Studies of such effluents usually include toxicity determination of the whole effluent and, if possible, the identification of a component or a property that can be used to study the dispersion of the effluent in receiving waters. 

According to Epolito et al. [19] under typical dyeing conditions, up to 50% of the initial dye concentration remains in the spent dye bath in its hydrolyzed form. Thus after dyeing wastewaters are characterized not only by intensive and difficult colour removal but also by high pH, suspended and dissolved solids, chemical and biochemical oxygen demands. Typical characteristics of raw textile wastewaters are presented in Table 4 [12-14, 20, 21]. 

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