Organic removal

Thickeners. Thickeners are added to remover formulas to increase the viscosity which allows the remover to cling to vertical surfaces. Natural and synthetic polymers are used as thickeners. They are generally dispersed and then caused to swell by the addition of a protic solvent or by adjusting the pH of the remover. When the polymer swells, it causes the viscosity of the mixture to increase. Viscosity is controlled by the amount of thickener added. Common thickeners used in organic removers include hydroxypropylmethylceUulose [9004-65-3], hydroxypropylceUulose [9004-64-2], hydroxyethyl cellulose, and poly(acryHc acid) [9003-01-4]. Thickeners used in aqueous removers include acryHc polymers and latex-type polymers. Some thickeners are not stable in very acidic or very basic environments, so careful selection is important. 

Dehydration of organics (removal of <1% water) generally feasible by molecular sieving, if kinetic diameter of organic >300 pm. 

Approximately one-half of the organics removed are oxidized to CO2 and H2O, and one-half synthesized to biomass. Three to 10 percent of the organics removed result in soluble microbial products (SMP). The SMP is significant because it causes aquatic toxicity. 

As shown in Figure 10, all of the organics removed in the process are either oxidized to CO2 and H2O or synthesized to biomass generally expressed as volatile suspended soHds. As previously noted, a small portion of the organics removed results in SMP products. 

The fraction of the organics removed that result in synthesis varies, depending on nature and biodegradabiUty of the organics in question. A rough estimate is to assume that one-half is oxidized and one-half synthesized. 

The proper selection of polymers for coagulation has a significant impact on organic removal. 

Sand filters vary in sophistication. A simple filter will remove most particles down to 5 pm. Multi-media filters which use sand and anthracite, and possibly a third medium, in discrete layers, can yield very efficient filtration down to 2 pm. Granular activated carbon can be used instead of sand to add some measure of organic removal to the filtration process. The quality produced by any filter depends largely on the efficiency of the backwash. Sand filters in some form provide a satisfactory solution for the majority of water-filtration problems. 

Activated carbon filters remove a wide range of organic matter by adsorption onto the carbon bed. The bed may be derived from a number of different carbon sources, and the correct selection of bed type, capacity, and porosity is a specialized function. Activated carbon may be usefully employed in organic traps, complementing the resin bed, but its capacity and organic removal rate characteristics are flow-dependent. Excessive flows may compromise the rate of adsorption of organic matter. 

Dechlorination requires a much shorter contact time than organics removal (perhaps only 60 seconds at pH levels below 7.0 but 3 minutes at pH over 8.5). The process involves reaction with carbon as well as absorption, such that 1 lb of carbon typically reacts (and is used up) with between 3 and 6 lb of chlorine. 

Liquid face velocity rates (flow rates) for organic removal are usually less than 1 gpm/cu ft, but for chlorine are typically 2 to 3 gpm/cu ft. 

Organic removal using these resins is through a combination of absorption and ion-exchange, typically using strong base anion resin,... 

The formation and dissolution of CaCOa in the ocean plays a significant role in all of these effects (34)- CaCOa is produced by marine organisms at a rate several times the supply rate of CaCOa to the sea from rivers. Thus, for the loss of CaCOa to sediments to match the supply from rivers, most of the CaCOa formed must be redissolved. The balance is maintained through changes in the [COa] content of the deep sea. A lowering of the CO2 concentration of the atmosphere and ocean, for example by increased new production, raises the [COa] ion content of sea water. This in turn creates a mismatch between CaCOa burial and CaCOa supply. CaCOa accumulates faster than it is supplied to the sea. This burial of excess CaCOa in marine sediments draws down the [COa] - concentration of sea water toward the value required for balance between CaCOa loss and gain. In this way, the ocean compensates for organic removal. As a consequence of this compensation process, the CO2 content of the atmosphere would rise back toward its initial value. 

Aujard F. (1997). Effect of vomeronasal organ removal on male sociosexual responses to females in a prosimian primate (Microcebus murinus). Physiol Behav 62, 1003-1008. 

Bean N.J. and Wysocki C.J. (1987). Effects of vomeronasal organ removal in lactating female mice. Ann NY Acad Sci 510, 169-170. 

Beauchamp G.K., Martin I., Wysocki C.J. and Wellington J.L. (1982). Chemoinvestigatory and sexual behavior of male guinea pigs following vomeronasal organ removal. Physiol Behav 29, 329-336. 

Clancy A.N., Macrides F., Singer A. and Agosta W.C. (1984). Male hamster copulatory responses to a high molecular weight fraction of vaginal discharge effects of vomeronasal organ removal. Physiol Behav 33, 653-660. 

Del Cerro M., Chirino R Mayer A.D. and Rosenblatt J.S. (1995). Sex-differences in sensitisation latencies in maternal behavior induced in male and female rats after vomeronasal organ removal. Dev Psychobiol 28, 183 abs. 

Jackson L.M. and Harder J.D. (1996). Vomeronasal organ removal blocks pheromonal induction of estrus in Gray Short-tailed Opossums (Monodelphis domestica). Biol Reprod 54, 506-512. 

Kolunie J. and Stem J. (1995). Maternal aggression in rats — effects of olfactory bulbectomy, ZnS04-induced anosmia, and vomeronasal organ removal. Horm Behav 29, 492-518. 

Meek L., Lee T Rogers E. and Hernandez R. (1994). Effect of vomeronasal organ removal on behavioral estrus and mating latency in female meadow voles (Microtus pennsylvanicus). Biol Reprod 51, 400-404. 

Meredith M. (1986). Vomeronasal organ removal before sexual experience impairs male hamster mating behavior. Physiol Behav 36, 737-743. 

Petrulis A., Peng M. and Johnston R.E. (1999). Effects of vomeronasal organ removal on individual odor discrimination, sex-odor preference, and scent marking by female hamsters. Physiol Behav 66, 73-83. 

Wysocki C.J., Kruczek M., Wysocki L.M. and Lepri J. (1991). Activation of reproduction in nulliparous and primiparous voles is blocked by vomeronasal organ removal. Biol Reprod 45, 611-616. 

Conventional wastewater treatment techniques consist of physical/chemical treatments, including oil separation, dissolved gas flotation, and ammonia distillation (for removal of free cyanides, free sulfides, and ammonia) followed by biological treatment (for organics removal) and residual ammonia nitrification. Almost all residuals from coke-making operations are either recovered as crude byproducts (e.g., as crude coal tar, crude light oil, ammonium sulfate, or other sulfur compounds)... 

This section describes the treatment technologies currently in use to recover or remove wastewater pollutants normally found at coil coating facilities. The treatment processes can be divided into six categories recovery techniques, oil removal, dissolved inorganics removal, cyanide destruction, trace organics removal, and solids removal.5-14 Adoption of specific treatment processes will depend on the following ... 

The use of an attached growth aerobic biofilm reactor to treat leachate is relatively new. Past studies on anaerobic biofilters showed excellent organic removal up to 90%, and the retention time needed to treat high-strength effluent was between 3 and 5 d. The use of aerobic biofilters using... 

Dissected adult female the parasite has been cut longitudinally and the gut and reproductive organs removed to form the characteristic muscle flap . (C) Vesicles forming from a muscle cell after treatment with collagenase the vesicles are then transferred to the experimental chamber, where vesicle-attached patches are formed and single-channel recordings made. 

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