Effect of Low-Molecule Organic Acids on Soil Adsorption of Fluoride

With the isothermal balance adsorption method,effect of citric acid and oxalic acid on fluoride adsorption by shajiang black soil and fluvio aquic soil was investigated and their possible mechanism verified.The results showed that the effect was significant.(1)When the concentration of the organic acid was low,soil adsorption of fluoride rose with the concentration of the organic acid,and when the concentration of organic acids was high,it dropped with rise in the concentration,and (2)in the presence of the organic acids,soil adsorption of fluoride showed an extremely significant linear positive (or negative) correlationship with balanced fluoride concentration in the soil.