▎ 摘　　要

NOVELTY - Preparing device involves adding graphite to the mixed solution of concentrated sulfuric acid and concentrated phosphoric acid, where the volume ratio of sulfuric acid and phosphoric acid is 9:1. The liquid-solid mass ratio of the mixed solution of concentrated sulfuric acid and concentrated phosphoric acid to graphite is 110:1. The potassium permanganate is added to the mixed solution of the stirring reaction, the mass ratio of potassium permanganate and graphite is 3:1, and continue stirred for 1 hour at the above stirring speed and temperature, and then stirred the mixed solution for 12 hours at 50degrees Celsius. The mixed solution is added to deionized water and hydrogen peroxide, stirred slightly and kept, and then centrifuged for 5 minutes at a centrifugal speed of 10000 revolutions/minute using 1 mol/L hydrochloric acid and deionized water. USE - Preparing device for in-situ removal of heavy metals from sludge by electrokinetic coupling of graphene hydrogels. ADVANTAGE - The prepared device shortens treatment time, increase conductivity efficiency, reduce energy consumption, and improve the effect of removing heavy metals in sludge. DETAILED DESCRIPTION - Preparing device involves adding graphite to the mixed solution of concentrated sulfuric acid and concentrated phosphoric acid, where the volume ratio of sulfuric acid and phosphoric acid is 9:1. The liquid-solid mass ratio of the mixed solution of concentrated sulfuric acid and concentrated phosphoric acid to graphite is 110:1. The potassium permanganate is added to the mixed solution of the stirring reaction, the mass ratio of potassium permanganate and graphite is 3:1, and continue stirred for 1 hour at the above stirring speed and temperature, and then stirred the mixed solution for 12 hours at 50degrees Celsius. The mixed solution is added to deionized water and hydrogen peroxide, stirred slightly and kept, and then centrifuged for 5 minutes at a centrifugal speed of 10000 revolutions/minute using 1 mol/L hydrochloric acid and deionized water. The soluble manganese ions are removed, washed the solid precipitate until the upper layer solution is neutral, dried the solid precipitate at 50degrees Celsius, ground, and passed through a 100-mesh sieve to obtain graphene. The graphene is added to deionized water, and the concentration of graphene aqueous solution is 0.5 g/L. The acrylic acid, acrylamide, sodium hydroxide and N,N'-methylenebisacrylamide are added in the graphene aqueous solution. The mass ratio of graphene aqueous solution to acrylic acid, sodium hydroxide, acrylamide and N,N'-methylenebisacrylamide is 625:225:100:55:1, then mixed into a homogeneous solution, added potassium persulfate at 45degrees Celsius, the mass ratio of the liquid mixture to potassium persulfate before adding is 300:1, and kept the reaction at 50degrees Celsius for 6 hours. The obtained solid is washed with deionized water, dried, ground, and passed through a 100-mesh sieve to obtain a graphene hydrogel. The graphene hydrogel is uniformly dispersed and fixed in the middle of the double-layer 800-mesh filter cloth, and the position in contact with the solution is fixed with a plexiglass pressing plate around the filter cloth to obtain a hydrogel fixing device, and combined with the electrodynamic repair device, it constitutes a device for in-situ removal of heavy metals from sludge by electrically coupled graphene hydrogel.