Post treatment

Problems sulfur and nitrogen transferred to the products (and coke) Solutions feed hydrotreating, reduction of S, N, Conradson carbon, metals Results higher quality products reduction in pollution better yields of valuable products reduced post-treatment... 

Products excellent properties Kerosene smoke point 25-30 mm Diesel cetane number 55-60 Residue BMCl 15 VI 5= 125 No post-treatment... 

Vol. 1 Polymer Engineering Vol. 2 Filtration Post-Treatment Processes Vol. 3 Multicomponent Diffusion Vol. 4 Transport in Porous Catalysts... 

Secondary Treatments and Uses. Because hardboard products are utilized in a myriad of different ways, the variety of secondary treatments used by customers are practically unlimited. Hardboards are used in furniture, cabinets, paneling, doors, toys, and a host of other uses. Post-treatments may include cutting-to-size, finishing treatments with roU-appHed patterns, melamine overlays, printed paper overlays, paints, and even some extremely durable and water-resistant coatings used in tub and shower linings or other uses where water contact is frequent and extreme. 

The appHcation of this type of conversion coating can be by spray or immersion and is easily tailored to the needs of the user (see Coating processes). The number of stages may vary from two, ie, clean and phosphate then rinse, to as many as five, ie, clean, rinse, phosphate, rinse, and post-treat. The performance requirements dictate the number of operation stages as well as the need for a post-treatment. 

Certain chemical treatments can be employed during the TMP process to achieve improved strength. Sodium sulfite and hydrogen peroxide have been used either for chip pre- or post-treatment of the TMP pulp such pulp is called chemithermomechanical pulp (CTMP). The strength improvements, which may be 50%, are obtained at some sacrifice to yield and opacity. The yields of mechanical pulps are 90—95% the lower yields are associated with chemical treatment. No principal commercial pulps are produced in the next lower yield range, ie, 80—90%. 

Copper-based thermal stabilizers are also effective photostabilizers for nylon. They can be added before polymerization, or the soluble salts (eg, CuSO can be appHed to fibers as part of the finish or to fabrics as post-treatments. The effectiveness of the copper salt—alkah haUde system added to prepolymer in retarding phototendering and photoyeUowing of the resulting spun yam is illustrated in Figure 5. 

The extent of purification depends on the use requirements. Generally, either intense aqueous extractive distillation, or post-treatment by fixed-bed absorption (qv) using activated carbon, molecular sieves (qv), and certain metals on carriers, is employed to improve odor and to remove minor impurities. Essence grade is produced by final distillation in nonferrous, eg, copper, equipment (66). 

Measurable Process Parameters. The RO process is relatively simple ia design. It consists of a feed water source, feed pretreatment, high pressure pump, RO membrane modules, and ia some cases, post-treatment steps. A schematic of the RO process is shown ia Figure 2a. 

Fig. 10. Flow diagram for the setup of a desalination plant employing reverse osmosis, including pre- and post-treatment steps.

Post Treatment. Coated fabrics can be decorated and protected by applying inks and coatings to the surface. Often the finished product is an attempt to simulate the look of leather. This is most common ia upholstery, luggage, and athletic bag constmctions where natural leather is the main competitor, although any number of decorative effects can be created and are used ia produciag products such as waHcoveriag. 

R. J. Wakeman, Filtration Post-Treatment Processes, Elsevier Publishing Co., Amsterdam, 1975. 

Other decoratively plated coatings produced in quantity are copper and copper alloys. Copper-plated hardware for cabinetry, lighting fixtures, household trim, and other uses is protected using a top coat of clear lacquer. Copper plating finishes are available with a variety of post-treatments to simulate antique or mstic appearances. 

Subsequently, biological/physical treatment of leachate with an activated carbon-enhanced sequencing batch bioreactor (PAC-SBR) was analyzed to determine whether the improved treatment by simultaneous adsorption and biodegradation in the SBR would produce an acceptable effluent without post-treatment in the existing granular activated carbon adsorber (Ying et al., 1986). 

Residuals Produced Liquid injection incinerators produce ash which may require application of a post treatment technology prior to disposal. The byproducts from the emission control devices may also require further treatment prior to disposal. 

Residuals Produced The plasma arc process produces ash which may require post treatment to make it suitable for disposal. The wet, scrubber blowdown may require treatment prior to disposal. 

Solidification/Stabilization Processes (Post Treatment Options)... 

For the environmental consultant, an extensive overview of corrective action technologies is provided. Topics covered are the general concepts of corrective action programs, facility investigation principles, treatment technologies for wastes and waste streams, post treatment technologies and engineering considerations for corrective measures implementation. 

Water chlorination is carried out by using both free and combined residuals. The latter involves chlorine application to produce chloramine with natural or added ammonia. Anhydrous ammonia is used if insufficient natural ammonia is present in the wastewater. Although the combined residual is less effective than free chlorine as a disinfectant, its most common application is as a post-treatment following free residual chlorination to provide initial disinfection. 

Pre- or post-treatment with ozone of wastewater may also be applied. Pretreatment with ozone takes place in the presence of biorefractory compounds, as ozone increases the BOD/COD ratio. 

Note The pre- and post-treatment of the chromatograms with the basic tri-ethylamine solution, which can be replaced by an alcoholic solution of sodium hydroxide [1,4] or a phosphate buffer solution pH = 8.0 (c = 0.2 mol/1) [5], serves to stabilize the fluorescence of the amino derivatives [2]. A final spraying with methanolic hydrochloric acid (chci = 5 mol/1) or 70% perchloric acid renders the detection reaction highly specific for histamine [4] and for catecholamines and indolamines [5]. 

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