Solvents pollution

M. M. Mattia Process for Solvent Pollution Control, Chemical Engineering Progress, 66(12) 74-79 (Dec. 1970). 

Outlet solvent pollutant concentration, mole fraction 0.0964... 

Perbellini L, Soave C, Cerpelloni M. Solvent pollution in shoe factories. Med Lav 1992 83(2) 115 19 [abstract only]. 

The epoxy-polyamide system may also provide a base for paper and board coatings applied by rotogravure or roller-coating techniques. It is useful for coating plastics and particularly valuable as a resin system for zinc-rich paints. It may be formulated with exempt solvents specified under Rule 66 (37). Higher solid formulations, particularly those formulated with fatty amido amines, are available. These formulations reduce solvent pollution and allow for higher film builds (37, 38). 

Proton transfer reactions play very important role in chemistry and biochemistry [1-3]. Considerable attention has been focused on the gas phase reactions in the last decades, since they are free of the solvent pollution thus being related to the intrinsic reactivity [4 6]. In particular, investigations of gas-phase acidities and basicities were some of the major undertakings in the field [7,8]. The proton affinity (PA), on the other hand is an interesting thermodynamic property by itself. It gives useful information on the electronic structure of base in question and serves as an indicator of the electrophilic substitution susceptibility of aromatic compounds [9]. It is the aim of this article to describe some recent advances in theoretical calculations of the proton affinities of substituted aromatics. We shall particularly dwell in more detail on the additivity rules, which enable simple and quick estimates of PAs in heavily substituted benzenes and naphthalenes. Some prospects for future developements will be briefly discussed too. 

The next step in selecting greener solvents is to critically evaluate the present solvent use. Many methods for solvent pollution prevention have been developed. 

It is a matter of fact that there are few solvents with properties so unique that they cannot be replaced at an early stage in a product development process. It is also true that the properties which the recoverer depends upon for making separations are not those that the solvent user needs for his product. Cooperation at this early stage is important if the cost to industry s efforts to reduce solvent pollution of the environment is to be minimized. 

In addition to hot-melt adhesives, film or sheet adhesives (88,89) have been used for the same purpose in eliminating solvent pollution. The adhesive-bearing films, such as PSA, can be cut to size and applied between mating surfaces. Curing, if necessary, can be carried out in the usual manner. Thus today, coated film adhesives can be used for large structural parts to replace solvent-borne adhes ives. ... 

As discussed in the Introduction, in addition to hot-melt adhesives, one of the most important forms of adhesives for the future is the waterborne system. In general, an advantage of the waterborne system is that it is free from the solvent-pollution problem. For this reason, we shall describe several new waterborne systems in detail acrylics, modified ethylene-vinyl acetate, polyurethanes, phenolics, epoxies, isocyanates, and tackifiers. Applications of these systems range from PSA s contact adhesives, and laminating adhesives to wood adhesives. 

Adsorption beds designed to stanch solvent pollution from open-top vapor degreasers are similar to but different from adsorption beds used to do the same task for pollution from enclosed vapor degreasers. The former hold substantially more activated carbon, use that adsorbent less efficiently, and never ueat (fortunately) high concenttations of solvent in air. They are also shaped quite differently ... 

If one views Figure 4.41 on an overall basis, one can imderstand that choices have consequences — if one manages fugitive emissions from solvent deaning equipment by directing them to a hlack hole." The main consequence is that solvent pollution of air by solvent is simply and easily exchanged for... 

Outlet solvent pollutant concentration, mole fraction 0.0964 Outlet gas pollutant concentration, mole fraction 1.87447 x 10 ... 

The paint plants of large automotive manufacturers have been a cause of solvent pollution in the major industrialised countries. Control regulations governing the level of emissions from industrial premises which are coming into force in many countries have given direction to the development in automotive finishing of low V.O.C. coatings. 

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