Study On Treatment Of Typical Pollutants In Paper-recycling Wastewater Using Fenton Reaction

China is advancing rapidly in the paper industry.A considerable part of the paper's raw materials are derived from waste paper recycling.The deinking agent added in the process of waste paper recycling releases the ink and additives on the paper into the water.The organic will definitely be harm to the environment if it is not treated.The advanced oxidation technology based on Fenton reaction has strong oxidizing properties and universality for organic matter treatment.Therefore,the Fenton reaction was used in this study to treat typical organic pollutants in paper recycling wastewater,in order to provide reference for practical application.The main components of organic matter of wastewater were determined by gas chromatography-mass spectrometry analysis.Benzophenone?BP?and dibutyl phthalate?DBP?were selected as the experimental object.By studying the degradation of organic pollutants by H₂O₂,Fenton reaction and UV-Fenton reaction,it is known that H₂O₂ has no degradation effect on the two pollutants,while Fenton reaction and UV-Fenton reaction have obvious degradation effect,and the degradation effect of the UV-Fenton reaction is significantly better than that of the Fenton reaction.For using the Fenton reaction to degrade two pollutants,the optimal reaction rate of Fe²⁺and H₂O₂ is 1:6,and the optimal initial pH is 4 by controlled variable experiments.Under the optimal experimental conditions,for the 1mg/L BP solution to be effectively degraded,it is recommended that the initial concentration of Fe²⁺is150?mol/L.The degradation rate of BP is 95.0%at 30 min.For the 1mg/L DBP solution to be effectively degraded,it is recommended that the initial concentration of Fe²⁺is200?mol/L.The degradation rate of DBP is 96.3%at 30 min.For using the UV-Fenton reaction to degrade two pollutants,under the optimal experimental conditions,with 75W Hg lamp emitting UV,for the 1mg/L BP solution to be effectively degraded,it is recommended that the initial concentration of Fe²⁺is50?mol/L.The degradation rate of BP is 93.7%at 30 min.For the 1mg/L DBP solution to be effectively degraded,it is recommended that the initial concentration of Fe²⁺is150?mol/L.The degradation rate of DBP is 95.0%at 30 min.It can be seen that UV increases the reaction rate,reduces the dosage of the reagents,and saves costs.The product analysis of the reaction by LC-MS shows that the carbon-carbon bond of BP broke in the reaction.BP converted to the smaller molecular,and some BP underwent hydroxyl radical addition reaction.DBP mainly breaks the carbon-carbon bond on the branch in the reaction.In addition,the degradation process was fitted by reaction kinetics.It was found that the addition of two pseudo first-order reactions can better simulate the reaction process.In the initial stage of the reaction,the reaction of sufficient amount of Fe²⁺and H₂O₂ led the reaction.Within 5 minutes,Fe²⁺was rapidly consumed and oxidized to Fe³⁺.Thereafter Fe²⁺was reduced to Fe³⁺to produce·OH,and the reduction process was very slow,so the degradation rate of organic pollutants decreased.We treated the mixed pollutant wastewater through the Fenton reaction and the UV-Fenton reaction.The treatment effect is still good.It is considered that the·OH is excessive in the first stage of the reaction,and even if the amount of the pollutant is increased,it can be removed.