Odor removal

Odor masking Odor modification Odor perception Odor removal... 

Gas-phase adsorption can also be used when regenerating the adsorbent is not practical. Most of these appHcations are used where the faciHties to effect a regeneration are not justified by the small amount of adsorbent in a single unit. Nonregenerative adsorbents are used in packaging, dual-pane windows, odor removal, and toxic chemical protection. 

H2S or CH the latter always contains associated impurities that have taste and odor. Removal of these gases can be accompHshed by adsorption (qv) with activated carbon (qv) oxidation with chlorine, potassium permanganate, or o2one or aeration. 

Other industries of interest are (1) the manufacturing of spices and flavorings, which may use activated carbon filters to remove odors from their exhaust stream (2) the tanning industry, which uses afterburners or activated carbon for odor removal and wet scrubbers for dust removal and (3) glue and rendering plants, which utilize sodium hypochlorite scrubbers or afterburners to control odorous emissions. 

Figure 6.14 Approximate air supply rate for (human) odor removal (extracted from BS 5925 1980)...

Skunk Odor Removal. Cooperative Extension in Lancaster County, Penn State, http //lancaster.extension.psu.edu/Family/newsletters/HomeLlfeJulAug.htm Skunk Odor... 

Mechanical and biological methods are very effective on a large scale, and physical and chemical methods are used to overcome particular difficulties such as final sterilization, odor removal, removal of inorganic and organic chemicals and breaking oil or fat emulsions. Normally, no electrochemical processes are used [10]. On the other hand, there are particular water and effluent treatment problems where electrochemical solutions are advantageous. Indeed, electrochemistry can be a very attractive idea. It is uniquely clean because (1) electrolysis (reduction/oxidation) takes place via an inert electrode and (2) it uses a mass-free reagent so no additional chemicals are added, which would create secondary streams, which would as it is often the case with conventional procedures, need further treatment, cf. Scheme 10. 

Odor evaluation, in perfumes, 18 379 Odor impacts, air pollution dispersion modeling for, 26 725 Odorous compounds controlling, 10 75 in wastewater, 26 723t Odor panels, 26 724 Odor pollution, 26 669 Odor removal, adsorbents for, 1 611 Odors... 

Efficient odor removal. Requires periodic cleaning and maintenance ... 

Among the new application areas that could become large volume applications are the use of molecular sieves as functional powders, in odor removal, as plastic additives and in composites. The use of zeolites in solid-state applications is highly speculative. If ever practically realized that application would most probably represent a relatively small volume of the total zeolite consumption. 

Function Decolorizing agent taste- and odor-removing agent purification agent in food processing. 

As such, it is used in water treatment to control taste and odors, remove color, and control biological growth. It promotes the removal of iron and manganese species by rendering them insoluble through oxidation ... 

Experience has shown that edible fats and oils flavor and odor removal correlates well with the reduction of FFA. The odor and flavor of an oil with a 0.1 % FFA will be eliminated when the FFA is reduced to 0.01% to 0.03%, assuming a zero peroxide value. Therefore, all commercial deodorization consists of steam stripping the oil for FFA removal. Typical conditions practiced in the United States for the three deodorizer system types are shown in Table 23. The four interrelated operating variables that influence deodorizer design are vacuum, temperature, stripping rate, and retention time at deodorization temperatures. 

FFA removal usually indicates good removal of other more volatile components. Experience has shown that flavor and odor removal correlate well with the FFA reduction. Nevertheless, some differences exist among different oils. Soybean oil, for example, requires less steam than rapeseed oil (0.6-0.8% vs. 0.8-1.2%). This difference is mainly because of the typical rapeseed odor, which is more difficult to remove. In general, oils are easier to deodorize during chemical refining, not only... 

Hansen R.E. Granular Carbon Filters for Taste and Odor Removal. JAWWA 1972, 64, No 3, pp.l76-181. 

The water purification properties of carbon adsorbents have been recognized for more than two millennia, wood chars having been utilized for tins purpose, as early as 200 B.C. [ 1 ]. Modern applications of adsorbents in water supply practice have their roots in the development of public treatment systems in the early 10th century. By the mid 1800 s charcoal was used for taste and odor removal in a number of municipal water plants in England [ 2 ], and more than twenty large scale carbon filtration plants were built and put into operation in the U.S. before the turn of that century [3 ]. 

Alternatives most frequently considered for taste and odor removal include breakpoint chlorination, aeration, ozonation, and oxidation with chlorine dioxide or potassium permanganate. None of these technologies have been found to approach the activated carbon adsorption process iri terms of effective treatment for this particular water quality problem. Another alternative is sorption onto other solids such as bleaching clays, synthetic resins or manganese dioxide. A brief summary of the advantages, disadvantages and cost factors associated with adsorption and alternative treatments for removal of tastes and odors... 

Figure 1 summarizes the most common modes of carbon use in water treatment. While replecement of sand by GAC in conventional filter plants may be satisfactory for taste and odor removal and general organic reduction, there is some concern that the contact time (approximately 8—10 minutes) associated with traditional 304nch deep filter beds may be insufficient for obtaining acceptable removal of to.xic and otherwise potentially hazardous organic substances [12—14 ], and that post-filter contactor columns may therefore be required in some applications. 

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