Method for preparing corrosion and scale inhibition adsorbent by taking lignin in papermaking wastewater as raw material

The invention discloses a method for preparing a corrosion and scale inhibition adsorbent by taking lignin in papermaking wastewater as a raw material, wherein the method comprises the following steps: (1) taking alkaline papermaking black liquor, adding a coagulant aid, adding an acid to adjust the pH value, controlling the temperature at 60-70 DEG C, flocculating and layering the waste liquor, filtering, drying, and grinding to obtain lignin; (2) putting the prepared lignin into a beaker, adding Na2SO3 and formaldehyde, then adding NaOH, putting the beaker into a reactor, carrying out a reaction, and after the reaction is finished, cooling and centrifuging to obtain sodium lignin sulfonate; and (3) taking the prepared sodium lignin sulfonate, sequentially adding H2O, organic phosphorus and zinc chloride into the prepared sodium lignin sulfonate, adding an ethanol solution of benzotriazole, putting the mixed solution into the reactor, carrying out a reaction, and cooling to obtain thecorrosion and scale inhi