The invention discloses an amphoteric
sesbania gum coagulant aid and a preparation method and an application method thereof. The amphoteric
sesbania gum coagulant aid is prepared by a series of procedures of dissolving, alkalization, anion treatment, cationization, and amphoteric treatment. The amphoteric
sesbania gum coagulant aid is blended into a solution of which the concentration is 10mg / L in application, and mixed with a polymeric
ferric sulfate solution of which the concentration is 200mg / L to form a combination solution; the PH value of the combination solution is controlled at 7. The amphoteric
sesbania gum coagulant aid disclosed by the invention is prepared from
sesbania gum by cation and anion modification, so that the water
solubility is improved, the compatibility with
electrolyte is improved, and the stability of the
viscosity is increased. The amphoteric
sesbania gum coagulant aid has the advantages of being simple in preparation method, convenient to operate, free of
toxicity, good in coagulation aid effect, high in CODcr (
Chemical Oxygen Demand Cr) removal rate, fast in dirty
settling velocity, and high in
turbidity removal rate. Practice proves that the coagulate effect can be greatly improved when the amphoteric sesbania gum coagulant aid is compounded with the polymeric
ferric sulfate, the coagulation
sedimentation velocity is quickened, alumen ustum is dense, and the CODcr removal rate can be up to 80%.