Modified Sponge Iron for Phosphorus Wastewater Treatment
Modified sponge iron was prepared by acid activation.The effects of initial pH,reaction temperature,coexisting anions and other factors on phosphorus removal were discussed.The results showed that the surface of the modified sponge iron after activation by sulfuric acid showed a petal-like or coral-like rough structure,which effectively increased the specific surface area and pore volume.The total phosphorus removal rate of the acid-modified sponge iron was 95%,Which was 19.6%higher than that of the original sponge iron under the conditions of 6 g/L dosage,5 mg/L total phosphorus initial mass concentration and 6 h reaction.The low pH and high temperature were favorable for the adsorption of sponge iron to remove phosphorus,while the coexisting anions such as Cl-and SO42-could accelerate the rate of phosphorus removal,but the inhibition effect of CO32-was more significant.Acid-modified sponge iron has a good continuous phosphorus removal ability,continuous operation for 2 months,phosphorus removal efficiency remains above 68.8%,and no plate knot situation.