Investigation On The Treatment Of 1,5-Naphthalenedisulfonic Acid Wastewater By Ozone And Fenton Reagent Oxidation

Naphthalene sulfonic acids are important industrial chemicals and widely used in industries such as dyes, pharmaceuticals, agriculture and construction. The produced wastewater is always characterized by good solubility in water, poor biodegradation, high toxicity and teratogenicity. The presence of large amounts of naphthalene sulfonic acids in wastewater has become a serious threat to the security of both environment and humans. Therefore, investigation on the treatment of naphthalene sulfonic compounds of dye and dye intermediate wastewater has attracted wide attention of scholars at home and abroad.In the present work, the simulated wastewater,1,5-Naphthalenedisulfonic Acid solution was treated by ozone, Fenton’s reagent respectively.(1) The degradation of 1,5-Naphthalenedisulfonic Acid by ozone in aqueous was investigated. Fisrtly, The effect of different operational variables on removal efficiency of CODcr, such as the the initial concentration of 1,5-Naphthalenedisulfonic Acid, ozone dosage, reaction temperature, initial pH, were investigated, respectively. Results indicated that the removal rate of CODcr could reach more than 90% after 120min under the reaction conditions of the initial concentration of 1,5-Naphthalenedisulfonic Acid is lmmol/L, ozone dosage 4.21×10-6 mol/s, temperature 25℃, pH 11.0 and under the uniform distribution in the porous core. Secondly, we also dissussed the effect of inorganic ions on the removal efficiency of CODcr of 1,5-Naphthalenedisulfonic Acid with ozone, Results indicated that Na+, Ca2+, Mg2+, Cl-, HCO3-, NO3- have no effect on the ozone system catalytic ability, Fe2+ could enhance the catalytic oxidized ability of ozone, SO42- could inhibit the catalytic oxidized ability of ozone. In addition, the degradation mechanism of 1,5-Naphthalenedisulfonic Acid was investigated. Because the reaction was obviously inhibited by tert-butyl alcohol (TBA), the degradation of 1,5-Naphthalenedisulfonic Acid was OH indirect oxidation mechanism. The mechanism of 1,5-Naphthalenedisulfonic Acid-containing degradation and intermediate product are discussed primarily by ultraviolet spectroscopy, infrared spectroscopy, chemical oxygen demand and total organic carbon analysis. Results indicated that the intermediate products of oxidized 1,5-Naphthalenedisulfonic Acid were small organic molecules, and the ultimate products were H2O,CO2-What is more, BOD5/COD ratio increased from less than 0.1 to 0.4 after 120 min by ozone.(2) The Fenton reagent was used for the treatment of 1,5-Naphthalenedisulfonic Acid. Fisrtly, The effect of different operational variables on removal efficiency of CODcr, such as the dosage of H2O2 and Fe2+, initial pH, reaction temperature, were investigated, respectively. Results indicated that the removal rate of CODcr could reach more than 79% after 30 min under the reaction conditions of the initial concentration of 1,5-Naphthalenedisulfonic Acid was 3mmol/L, H2O2 dosage 55.8mmol/L, Fe2+ dosage 2.79 mmol/L(molar ratio of Fe2+ to H2O2 20:1), pH 3.0-5.0, temperature 25-35℃. Secondly, we also dissussed the effect of inorganic ions on the removal efficiency of CODcr of 1,5-Naphthalenedisulfonic Acid by Fenton reagent. Results indicated that the enhance ability of these ions was:Fe3+< Cu2+, and the inhibition ability of these ions was:SO42-< Cl-< F-< H2PO4-, Na+ and NO3- have no effect on the Fenton’s system catalytic ability. In addition, the degradation mechanism of 1,5-Naphthalenedisulfonic Acid was investigated. Because the reaction was inhibited by tert-butyl alcohol (TBA), the degradation of 1,5-Naphthalenedisulfonic Acid was OH indirect oxidation mechanism and intermediate product are discussed primarily by ultraviolet spectroscopy, chemical oxygen demand and total organic carbon analysis. Results indicated that the intermediate products of oxidized 1,5-Naphthalenedisulfonic Acid were small organic molecules and the ultimate products were H2O, CO2. What is more, BOD5/COD ratio increased from less than 0.1 to 0.35 after 60min by Fenton reagent.