Microwave mediated biochar and biochar hydrogel composite synthesis

A biochar-hydrogel composite comprising:

• a hydrogel matrix, a nitrogen source, and a biochar material,
• wherein the hydrogel matrix comprises a porous structure and a surface,
• wherein the biochar material is uniformly dispersed in the hydrogel matrix porous structure and on the hydrogel matrix surface,
• wherein the biochar-hydrogel composite comprises a porous structure with a coarse surface,
• wherein the biochar-hydrogel composite has a water absorption capacity of at least 5%;
• wherein the composite releases at least 20% of nitrogen content after 30 days,
• wherein the hydrogel matrix comprises a first polymeric material and a second polymeric material,
• wherein the first polymeric material consists essentially of polyvinyl alcohol, polyvinyl pyrrolidone, polyalkylene glycols, polyalkylene oxides, hydroxypropyl methacrylate, hydroxyethyl methacrylate, polyacrylamide, copolymers or mixtures thereof;
• wherein the second polymeric material consists essentially of gelatin, chitosan, alginate, gellan gum, cellulose, derivatized celluloses, or any combination thereof;
• and
• wherein the biochar material is derived from a feedstock consisting of biosolid, switchgrass, water oak leaves, or any combination thereof.