Solids treatment

Zero solids treatment (ZST) is a further enhancement of AVT and MT programs and, as its name suggests, the program employs extensive pre- and post-treatment equipment to ensure the highest possible FW and BW purity. ZST has been employed in the secondary circuits of nuclear-powered SGs as an aid in the prevention of SCC, crevice corrosion, and denting, especially where condenser cooling is effected by the use of brackish or estuarine waters. 

A form of low solids treatment program whereby there is no apparent addition to the total dissolved solids in the BW. 

It has been found that A-tosyl aziridines undergo oxidative addition to palladium complexes to form azapalladacyclobutanes <06JA15415>. Reaction of aziridine 95 with Pd2(dba)3 and 1,10-phenanthroline provides the palladacycle 96 in 45% isolated yield. This compound is an air stable solid. Treatment the palladacycle 96 with catalytic Cul is believed to open the palladacycle to form a copper intermediate, which cyclizes to cyclopentyl alkylpalladium intermediate 97. Loss of Cul then provides the product palladacycle 97 as an air stable solid. Several different aziridines were examined in this reaction. Only a limited set of olefin substituted aziridines provided the azapalladacyclobutanes (e.g. 96). 

Related sulfur-containing derivatives are formed from the reaction of 49 with 2-methyl-2-propanethiol, cyclo-hexanethiol, and 2-propanethiol in toluene at ambient temperature. The resulting tetrameric cyclopentadienyl thiolato complexes [(if-Cp)Mg(/.t3-SR) ]4 (R = Bu, CgFIn, Pr1) are colorless crystalline solids. Treatment of... 

In this process, a vacuum extrusion step (melt treatment) is followed by a continuous SSP (solid treatment). The process starts with PET flakes which are introduced without pre-drying into a ring extruder. The flakes are dried, melted and degassed inside the extruder. A gear pump builds the necessary pressure for melt filtration, where solid particles are removed. After granulation the pellets are fed to a continuous three-step SSP unit [10]. 

Solids. Treatment of mustard agents by the SILVER II process results in the precipitation of silver chloride, which, if not removed, could cause cell plugging. This precipitate is removed from the main circuit in a slurry underflow from hydrocyclones in the anolyte feed stream circuit. Subsequently, this slurry is dewatered in a centrifuge to approximately 50 weight percent AgCl, with the remainder of the slurry consisting of water, nitric acid, silver nitrate, and trace amounts of other materials in the anolyte loop. 

Volatile Treatment. This method of treatment may be used for units operating above 2000 psi (136 atm) drum pressure. In this method, no Solid chemicals are added lo either the boiler 01 pie-boiler cycle. By eliminating solid treatment, the volatile carry-over of solids is eliminated and consequently turbine deposits are avoided. Cycle pH is controlled at 9.0 to 9.5 with a volatile amine such as ammonia. Hydrazine is added as an oxygen scavenger in quantity sufficient to provide a concentration of 20 to 30 ppb at the economizer inlet. 

Perhaps the most persuasive chemical evidence for the existence of the monohydrides of manganese and rhenium is their high-yield conversion to corresponding dihydrides, [H2M(CO)4] , which can be isolated as relatively stable crystalline solids. Treatment of solutions of the trianions in HMPA with 1.6 equivalents of ethanol provided H NMR spectra that showed monohydrides as well as new singlets at 5 - 8.6 and —7.2 ppm due to the dihydrides of manganese and rhenium, respectively. Two equivalents of ethanol or water caused complete conversion of [M(CO)4]3- to the corresponding [H2M(CO)4] . These processes are represented by Eq. (6). 

After removal of the asphaltene fraction, further fractionation of petroleum is also possible by variation of the hydrocarbon solvent. For example, liquehed gases, such as propane and butane, precipitate as much as 50% by weight of the residuum or bitumen. The precipitate is a black, tacky, semisolid material, in contrast to the pentane-precipitated asphaltenes, which are usually brown, amorphous solids. Treatment of the propane precipitate with pentane then yields the insoluble brown, amorphous asphaltenes and soluble, near-black, semisolid resins, which are, as near as can be determined, equivalent to the resins isolated by adsorption techniques. 

A possible explanation for the discrepancy between our findings and those of others must first be sought in terms of both the solid treatment and the purity of the polymerization system. It is generally accepted (3) that an organometallic bond (whether in form of A1—C or Ti—C) is essential for polymerization. The amount of organometallics in a separated solid is very... 

Mixed Bed NHjOH Cycle High pressure steam generators invariably operate on an All Volatile Treatment (AVT) or zero solids treatment which means that any conditioning of the water-steam circuit uses chemicals which do not increase the dissolved solids of the feedwater. One such chemical is ammonia which is dosed to give a feedwater pH of 8.8-9.6 depending upon the materials of construction, and being volatile is returned with the condensate. Polishing... 

N. R Cheremisinoff, Wastewater and Bio solids Treatment Technologies The Comprehensive Reference for Plant Managers and Operators, GI/ABS Publishing, 2002. 

Thermal desorption heats the contaminated soil to desorb and volatilize the contaminants, which are then either recovered or destroyed. This entry discusses the specifics of thermal desorption, including desorption kinetics, soil pretreatment requirements, types of thermal desorption units (TDUs), off-gas treatment, solids treatment, as well as system cost and performance. 

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