The Removal Of Phthalic Acid Esters And Nitrophenol In Water By Potassium Ferrate

Recently there has been increasing concerns on widespread occurrence of endocrinedisrupting chemicals (EDCs) in drinking water. Removing EDCs effectively based on theoriginal water treatment process has become a pressing problem. Potassium ferrate (K2FeO4), ahigh-effective agent in water treatment, has no secondary pollution and multifunction ofoxidization, adsorption, and flocculation coagulation-promotion, which provides a new methodfor the removal of EDCs. The paper presented the preparation, stability and the preservationconditions of K2FeO4, and its degradation of phthalic acid esters (PAEs) and2-sec-butyl-4,6-dinitrophenol (DNBP) under different experimental conditions.The results showed that for the hypochlorite oxidation synthesized K2FeO4, then higherpurity K2FeO4could be obtained and the conversion rate of Fe(III) to Fe(VI) was45.0%whenthe iron source was Fe(NO3)3·9H2O, iron dosing quantity was50%lower than theoretical value,the temperature range was20-30℃and the alkalinity range was10-12mol/L.The stability of K2FeO4was excellent at the pH of10and the temperature of25℃; Theaddition of O3,KI, KClO3and KCl reduced the stability of K2FeO4; While the addition ofNaSiO3and NaClO3improved the stability of K2FeO4; With the preservation conditions forNaClO3of15mmol/L, Na2SiO3of10mmol/L and alkalinity of9mol/L, the decomposition rate ofK2FeO4was16.7%at24th hour.The temperature for degradation of PAEs and DNBP with K2FeO4should be controlledrange of20-30℃and25-35℃respectively; when the pH range of4-7, the degradation of PAEsand DNBP was rapid; The addition of NH4Cl, Na2NO3and NaCl had no influence on thedegradation of PAEs and DNBP; Under the strong acidic condition, the degradation rate of PAEsand DNBP could enhance with the increase of MnCl2concentration.With the temperature at25℃, the pH range of2-10and the concentration of K2FeO4farabove PAEs and DNBP, the degradation of PEAs and DNBP conformed to the first-orderkinetics. And the degradation rate constants, with the change of pH, conformed to Gauss model.