Study On Photodegradation Of 1-Naphthol In Ice

Snow and ice are important components of cold ecosystems as well as of temperate ecosystems in winter and they undoubtedly influence the fate and behaviour of organic pollutants. At present, We have enough knowledge of photochemistry in atmosphere,water and soil, but photochemistry in ice and snow influenced less by temperature belongs to a newer domain.Actually, photochemistry in ice and snow shows equall importance with the photochemistry in atmosphere and water. Preliminary research indicates that the photochemistry reaction of organic pollutants in ice is differ from which in water and atmosphere, some new pollutants are found after photochemistry in ice cause secondary pollution. 1-Naphthol is one of PAHs which is widely used in produce of dye, spice, axunge, medicine and pesticide.It would be significant for environment protection in study of photochemistry of 1-Naphthol in ice.The experimental instrumental of photochemistry is self-made,the light source is high-pressure mercury lamp which is 125W, we studied the photochemistry of 1-Naphthol in two ice systems (UV systems and UV/H2O2 system),the influencing factors and mechanism are investigated also.Experience states clearly:(1)In two systems,the concentration of 1-Naphthol have no change in dark.Lighted exposure for 240min, 1-Naphthol is rapidly degradated,The degraded ration is 50.59%and 71.13% in UV system and UV/H2O2 system. H2O2 can promote the photochemistry reaction of 1-Naphthol in ice.(2) In UV system, In the concentration range of 0.06mol/L～0.6mol/L the degradation rates of 1-Naphthol were decreasing with the increasing of the initial concentrationg of 1-Naphthol. In UV/H2O2 system, In the concentration range of 0.1mol/L～1.0mol/L the degradation rates of 1-Naphthol were inecreasing with the increasing of the initial concentrationg of H2O2.(3) In the pH range of 2~12 it significantly influenced the degradation rates of 1-Naphthol. there was not any difference in the pH value range of 4~8, But the degradation rate was promoted under strong acid and alkaline condition.(4) The degradation rate of 1-Naphthol was different under various luminous intensity. The degradation increased along with the increasing of the luminous intensity.(5) The ions which are coexistence with 1-Naphthol also influcing the degradation of 1-Naphthol. In UV system, The reaction was promoted when Fe2+ was added in the river water when NO2-,NO3-,HCO3-,Fe2+,Mn2+and Fe3+ were added in water. There wasn't any difference when Cl- existed . In UV/H2O2 system, There wasn't any difference when NO2-,NO3-,Cl- existed in ice, The degradation was suppressed when HCO3- existed and promoted when Mn2+ existed. Fe2+and Fe3+ were formed to Fenton reagent with H2O2 when they were added,it can rapidly oxidate 1-Naphthol to other products before Lighted exposure.(6) We found that the degradation of 1-Naphthol was promted when Songhua river water was added.This probably because of the oxidated radical matter in river water can rapidly degradate 1-Naphthol.(7) Change the concentration of DO through untrasound can also influence the photodegradation of 1-Naphthol. the concentration of DO was decreasing with the increasing of untrasoun time. In UV system,The decreasing of DO promoted the 1-Naphthol.In UV/H2O2 system, The decreasing of DO suppressed the photodegradation of 1-Naphthol in 200min,but the degraded ration at 240min had no change.(8) Lighted exposure with a high-pressure mercury lamp which is 125W for 240min , The degraded ration of 1-Naphthol is 50.59%and the degraded ration of TOC is only 6.88% which indicated that 1-Naphthol had not been translated completely into dioxide carbon and water but take reaction between 1-Naphthol molecuars.The products are brown .We choose GS-MS to analysis and determinate the precipitate after centrifuged and enriched. There are 4 products :1-1'-oxibis-Naphthalene; 1,4-Naphthalenedione; 3,4-dihydro-1(2H)- Naphthalenone and 1,2,3,4-tetrahydro- Naphthalene.To sum up, the photodegradation of 1-Naphthol in ice is effect by many fators. 1-Naphthol had not been translated completely into dioxide carbon and water afer Lighted exposure but the products are intermediate products after light exposure. With people paying more attention to the pollutes in ice and the effect on the polar, we study on the photodegradation of 1-Naphthol in ice helpful for us to know the photochemical property and the products of photodegradation in order to deduce the hazard of 1-Naphthol to environment to take effective measures ,it is important for environmental protection.