Generally not comparable; comparative and superlative forms are rare and nonstandard.
Translations
The aqueous solution was prepared in the laboratory.
Водный раствор был приготовлен в лаборатории.
Definitions
Relating to, similar to, or containing water; watery. The aqueous solution was clear and colorless, indicating it was mostly water.
Dissolved in water, especially in reference to a solution. The chemist prepared an aqueous solution of salt for the experiment.