Study On The Removal And Transformation Of Sucralose-Containing Wastewater By Fe-Carbon Fenton Process

The artificial sweetener sucralose（SUC）is widely used due to its high sweetness and no calories.Numerous recent studies have shown that SUC exists in various aquatic environments.SUC is stable and biologically toxic in the water environment,and the organochlorine in its transformation product has strong biological toxicity and potential harm to the ecological environment,and is an emerging environmental pollutant in water.In order to realize the effective treatment of SUC wastewater,it is necessary to use advanced oxidation method to control the concentration of SUC in the water body;at the same time,the transformation of SUC under the action of hydroxyl radicals（HO·）is explored.This subject can provide method reference and theoretical basis for the treatment of wastewater containing SUC.This topic firstly carried out material characterization and elemental composition analysis of iron-carbon fillers,and at the same time analyzed and measured the quality of sewage to determine the quality of sewage;iron-carbon micro-electrolysis,Fenton oxidation technology and iron-carbon Fenton combined process were used to treat sewage containing SUC.Treatment;four water quality indicators,SUC,CODCr,ammonia nitrogen and DMF were selected for analysis and determination,and the water quality of sewage was dynamically monitored to explore the optimal reaction conditions;the method of chemical reaction kinetics was used to establish a mathematical model to explore the effect of SUC on hydroxyl radical（Variation of the reaction rate under the action of OH）.The main experimental results of this study are as follows:（1）The experimental results of material characterization and elemental analysis of iron-carbon fillers show that the specific surface area of the pores of the iron-carbon filler used in this experiment is Ap=1.2299 m2·g-1,and the specific surface volume Vp=0.00046687 cm3·g-1,the average pore width is 2.36 mm;in the elemental composition of the filler,iron accounts for 36.42%,second only to oxygen.（2）In the iron-carbon micro-electrolysis method,when a piece of iron-carbon filler was added,pH=2,aeration time of 1.5 h,and the second day of the reaction,the removal rate of CODcr was the highest,which was 44.83%;3.0 h,pH=6,the removal rate reached the maximum on the sixth day of the reaction,which was 34.08%.（3）When pH=2,m（FeSO₄）=2.0 g,and the dosage of hydrogen peroxide is V（H₂O₂）=50 ml,the removal rate of CODCr is the highest,which is 50.56%;When pH=4,m（FeSO₄）=5.0 g,and the dosage of hydrogen peroxide was V（H₂O₂）=50 ml,the removal rate was the highest,which was 89.20%.（4）When the reaction pH of Fe-Carbon Fenton method was 4,the concentration of COD reached the lowest,which was 4572.68 mg·L-1,and the removal rate was 47.29%.At pH=7,the concentration of SUC reached the lowest value in the treatment,which was 60.522 mg·L-1,and the removal rate was 35.81%.（5）After mathematical modeling,in theory,removing 1 mol of SUC needs to consume（1.734t/1.032 × 108）×（lnC0-lnCt）mol of H₂O₂,corresponding to 30%of commercially available H₂O₂[（5.78 ×108/t（lnC0-lnCt））]L,where t is the reaction time,C₀ is the initial concentration of SUC,and Ct is the concentration of SUC at the reaction time t.The reaction rate equation model for the reaction of SUC and hydroxyl radical（HO·）is:d[C]/dt=A exp(E_a,obs/RT)C_SUC^0.296C₀^-0.147[OH·]^0.126...