▎ 摘　　要

NOVELTY - A calcium alginate-polyacrylamide-X composite hydrogel comprises X compound selected from silica, polyaniline-silica, graphene oxide, and reduced graphene oxide. USE - A calcium alginate-polyacrylamide-X composite hydrogel for regenerating methyldiethanolamine solution (claimed). ADVANTAGE - The adsorbent allows easily, effectively, and substantially totally removing organic acid anions and heavy metal ions from methyldiethanolamine (MDEA) solution like aqueous MDEA, and can be prepared in a simple, reliable, and efficient manner. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for regenerating methyldiethanolamine solution which involves passing methyldiethanolamine solution through the hydrogel.