"用化学方法吸收" can be translated into English as "absorb by chemical means" or "chemically absorb".
Both expressions convey the idea of using a chemical process or method to achieve absorption. The choice between them may depend on the specific context or the desired level of formality.
"Absorb by chemical means" emphasizes the use of a chemical approach or technique.
"Chemically absorb" is more concise and directly states that the absorption is occurring through a chemical process.