Adsorbable organic chlorine chlorination

You also increase the adsorbable organic chlorine (AOC1), which is difficult to remove, even by ozone and by bank filtration. Thus, quite a bit of unidentified polar compounds is introduced into drinking water, which you can measure with AOC1 and which could have some health effect, and that is the reason why we avoid chlorination even before bank filtration. 

Disinfection by-products (e.g., adsorbable organic halides such as trihalomethanes) are more than 50% decreased compared to equivalent chlorine treatments in standardized AOX test with STABREX3. In practice, disinfection by-products are decreased even further in STABREX applications because less oxidant is required to control the microbial fouling process compared to bromine or chlorine applications. 

The pulp and paper industry is the largest industrial process water user in the U.S.5 In 2000, a typical pulp and paper mill used between 15,140 and 45,420 L (4000 to 12,000 gal) of water per ton of pulp produced. 1 2 3 4 General water pollution concerns for pulp and paper mills are effluent solids, biochemical oxygen demand (BOD), and color. Toxicity concerns historically occurred from the potential presence of chlorinated organic compounds such as dioxins, furans, and others (collectively referred to as adsorbable organic halides, or AOX) in wastewaters after the chlorination/ extraction sequence. With the substitution of chlorine dioxide for chlorine, discharges of the chlorinated compounds have decreased dramatically. 

Analytical methods for 12 chlorinated phenolics and adsorbable organic halides (AOXs). Samples of air emissions and water discharges from each mill must be tested using the laboratory methods included in the rule. The new methods will enable more timely and accurate measurements of releases of these pollutants to the environment and will be used to ensure compliance with air emission and water discharge permit limits... 

Chlorine typically originates from the process feed water (or from air in coastal areas) or as organic chlorine compounds. Chlorine does not adsorb on nickel catalysts, on the contrary any chlorine content in the fresh catalyst will leave the catalyst during operation [389] [391]. A nickel catalyst may even be used for steam reforming of chlorine carbons [129]. However, chlorine is withheld if the catalyst contains alkali. If so, chlorine is reported to deactivate the reforming catalyst [85]. A catalyst with pre-impregnation of chlorine showed less of a decrease in the initial activity than was the case for sulphur [389]. 

AOX adsorbable organic halogen compounds. The total concentration in milligrams per litre, expressed as chlorine, of all halogen compounds (except fluorine) present in a sample of water that are capable of being adsorbed on activated carbon... 

Adsorbable organic Itatides (AOX) and organic chlorine MMIOtHl... 

Frequently, halogenated hydrocarbons in environmental matrices are quantified, in bulk, by a standard analytical procedure for adsorbable organic halogens (AOX). Originally conceived to monitor the formation of chlorinated organic compounds in drinking water, the data derived from environmental characterization have been interpreted as an indicator of anthropogenic... 

Removal of Refractory Organics. Ozone reacts slowly or insignificantly with certain micropoUutants in some source waters such as carbon tetrachloride, trichlorethylene (TCE), and perchlorethylene (PCE), as well as in chlorinated waters, ie, ttihalomethanes, THMs (eg, chloroform and bromoform), and haloacetic acids (HAAs) (eg, trichloroacetic acid). Some removal of these compounds occurs in the ozone contactor as a result of volatilization (115). Air-stripping in a packed column is effective for removing some THMs, but not CHBr. THMs can be adsorbed on granular activated carbon (GAG) but the adsorption efficiency is low. 

Common examples of compounds that are amenable to carbon adsorption are aromatics (benzene, toluene) and chlorinated organics (trichloroethylene, trichloroethane [71-55-6, 75 -(9(9-j5y, tetrachloroethylene, polychlorinated biphenyls (PCBs), DDT /T(9-77-77, pentachlorophenol [87-86-5J. Compounds that are not adsorbed effectively by carbon include ethanol [64-17-5], diethylene glycol [111-46-6], and numerous amines (butylamine [109-73-9, 13952-84-6, 75-64-9], triethanolamine [102-71-6], cyclohexylamine [108-91-8], hexamethylenediamine [108-91-8] (1). Wastewater concentrations that are suitable for carbon adsorption are generally less than 5000 mg/L. 

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