Abstract:
The invention provides a method of concentrating a waste liquid produced by development, the method including: obtaining a waste liquid produced by: exposing a planographic printing plate precursor, including: an image recording layer including: an infrared absorbing dye, a polymerization initiator, and a polymerizable compound, and a protective layer on a support, and performing a development process by using a developer liquid that contains an anionic surfactant having a naphthalene skeleton and/or a nonionic surfactant having a naphthalene skeleton in an amount of 1-10% by mass, that contains an organic solvent that has a boiling temperature in a range of 100-300° C. in an amount of 2% by mass or less, and that has a pH of 6.0-9.5; and evaporation-concentrating the waste liquid such that [an amount of the waste liquid after the concentration/an amount of the waste liquid before the concentration] is from 1/10 to 1/2 on a volume basis.
Abstract:
A method of recycling waste liquid from a plate-making process, including: performing a plate-making process using a development replenisher liquid that includes at least one selected from the group consisting of anionic surfactants having a naphthalene skeleton and nonionic surfactants having a naphthalene skeleton at a total content of from 1% by mass to 10% by mass, includes no or not more than 2% by mass of organic solvent having a boiling point of from 100° C. to 300° C., and has a pH of from 10 to 13; concentrating, by evaporating, the discharged plate-making process waste liquid, such that the ratio of the volume of the plate-making process waste liquid after concentration to the volume of the plate-making process waste liquid before concentration is within a range of from 1/10 to 1/2, thereby separating water vapor; and using the obtained regenerated water as diluent water and/or rinse water.