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Developing Wastewater Management Alternatives
Published in Joseph D. Edwards, Industrial Wastewater Treatment, 2019
If the wastewater cannot be discharged because it contains a process chemical that you are using, consider using a different chemical. Change your process to use chemicals which are more acceptable to the regulators. It is the highest priority in pollution prevention and the step you should consider first. For example, you may be using a volatile solvent, like lacquer thinner or methyl ethyl ketone (MEK), to remove water soluble ink from a printing screen. The ink does not contain regulated metals and most has been removed from the screen before taking it to the screen wash sink for final cleaning. The slight ink residue is acceptable to the sewer. The solvent is not. If you switch to a water-soluble cleaning agent that is acceptable to discharge, then you have solved your problem.
INDUSTRIAL ORGANIC SOLVENTS
Published in Nicholas P. Cheremisinoff, Industrial Solvents Handbook, Revised And Expanded, 2003
Diacetone alcohol is available in two grades: a commercial grade containing 15% acetone and an acetone-free grade. Both solvent grades of diacetonc alcohol may acquire a yellow color on aging; both are good solvents for nitrocellulose, cellulose esters, and several other types of resins. The much slower evaporating diacetone alcohol is similar to acetone in its solvency. It is used in brushing-type cellulose ester lacquers to produce hard and brilliant gloss films. Diacetone alcohol is also used as lacquer thinner and in coating compositions for paper and textiles. Mesityl oxide, the unsaturated medium boiling point ketone that is prepared by the dehydration of diacetone alcohol, will darken and form a solid residue on aging. Mesityl oxide is a good solvent for nitrocellulose, cellulose esters, polyvinyl chloride, and vinyl resins. Mesityl oxide is used in lacquers and thinners where its presence lowers solution viscosity and gives the solutions high diluent tolerance for hydrocarbons. Isophorone is an excellent solvent for cellulose esters, nitrocellulose, natural and synthetic resins. Isophorone has a very high aromatic hydrocarbon dilution ratio in nitrocellulose formulations: 5.7 for toluene and 5.1 for xylene. The excellent solvency of isophorone allows the preparation of 45% solids nitrocellulose solutions at room temperatures.
From Circuit Schematics to PCB
Published in Julio Sanchez, Maria P. Canton, Embedded Systems Circuits and Programming, 2017
Julio Sanchez, Maria P. Canton
The etched board should be washed well, first in water and then in lacquer thinner or acetone; either solvent works. It is better to gently rub the board surface with a paper towel soaked in the solvent. Keep in mind that most solvents are flammable and explosive, and also toxic. Once the board is clean, the mounting holes can be drilled using the solder pads as a guide. A small electric drill at high revolutions, such as a Dremmel tool, works well for this operation. The standard drill size for the mounting holes is 0.035″. A #60 drill (0.040″) also works well. Once all the holes are drilled, the components can be mounted from the backside and soldered at the pads.
Estimating evaporation rates and contaminant air concentrations due to small spills of non-ideal aqueous organic solvent mixtures in a controlled environment
Published in Journal of Occupational and Environmental Hygiene, 2023
Spéro Franck Abattan, Patrick Eddy Ryan, Jérôme Lavoué, Stéphane Hallé, Ali Bahloul, Daniel Drolet, Maximilien Debia
The solvents of interest were acetone (ACE), butan-2-one (MEK), methanol (MeOH), propan-2-ol (IPA), and toluene (TOL). These solvents were selected because they cover a wide range of vapor pressures and they are often found in commercial mixtures used in workplaces such as the International Thinner (mixture of butan-2-one and toluene), the Lacquer Thinner (mixture of toluene, methanol, acetone and butan-2-one), and a Global Tech Company aqueous mixture (propan-2-ol and water). Table 1 shows the physical-chemical properties of the solvents. All the values were taken from CNESST chemical substances toxicological repository (CNESST 2022), as several TLV®-TWA (Threshold Limit Values – Time Weighted Average) were taken from the ACGIH booklet (ACGIH®2021). Note that the five solvents used in the study were laboratory grades: ACS grade or optima grade.