| Rubber additives wastewater is characterized by complex organic species and difficult degradation.In this study,the biochemical effluent from a rubber chemicals enterprise in Puyang City was used for advanced treatment of its biochemical effluent by iron-carbon micro-electrolysis,Fenton oxidation and the combination of the two processes to explore the economic and feasible advanced treatment process and its parameters.The effects of individual and combined processes on the degradation of biochemical effluent from rubber additives and their reaction kinetics were compared and studied.The main conclusions of the study are as follows.(1)Iron-carbon micro-electrolysis technology was used to treat the biochemical effluent of rubber additives,and the optimal operating parameters of each influencing factor were obtained by single-factor test:the initial pH was 3,the dosage of iron carbon filler was 125 g/L,and the reaction time was 60 min.At this time,the COD removal rate of the system for the test wastewater was 50.52%,the UV254 content was reduced by 57.66%,and the ammonia nitrogen removal rate reached 40%.The results of the orthogonal test showed that for COD and UV254,pH was the main influencing factor,and the sequence from high to low is:pH,iron carbon filler dosage,reaction time;for ammonia nitrogen,the dosage of iron carbon filler had more influence on its removal effect,and the degree influence of each factor was in the order of iron carbon filler dosage,pH and reaction time.The reaction process of degradation of rubber additives biochemical effluent water by iron-carbon micro-electrolysis system follows the primary reaction kinetics law.(2)The single factor test results of rubber additives biochemical effluent water treated by Fenton advanced oxidation showed that when the initial pH was 4,the dosage of hydrogen peroxide was 5.55 g/L,the mass ratio of FeSO4·7H2O and H2O2 was 1:1,and 60 minutes of reaction,it could remove 81.97%of COD and 85.34%of UV254 from the wastewater,and also remove 60%of total phosphorus.The analysis of the orthogonal test results showed that the order of influence on the removal effect of COD was the dosage of H2O2,the mass ratio of FeSO4·7H2O and H2O2,pH,and reaction time;the order of factors affecting UV254 was the mass ratio of FeSO4·7H2O and H2O2,pH,reaction time and H2O2 dosage;the main factor affecting the removal effect of total phosphorus was pH,and the rest were the mass ratio of FeSO4·7H2O and H2O2,reaction time,and H2O2 dosage in order.The results of Fenton's reagent kinetic study showed that the reaction steps of hydrogen peroxide and ferrous ions were 0.367 and 0.3172,respectively.(3)The combined process flow was determined as iron-carbon micro-electrolysis followed by Fenton oxidation by comparing both experimental effect and cost.The single-factor investigation of H2O2 dosage,initial pH and reaction time resulted in the optimal parameters:the dosage of H2O2 was 1.11 g/L,initial pH of Fenton oxidation was 4,and the pH of the effluent was adjusted back after 60 minutes of reaction.(4)All three processes have degradation effect on the wastewater,among which Fenton oxidation technology has the best COD removal effect,with a COD removal rate of 80.79%;iron-carbon micro-electrolysis can remove 40%of ammonia nitrogen;the combined process has better removal effect on UV254 and total phosphorus with 67%COD removal,and the effluent quality can meet the Class C standard in wastewater quality standards for discharge to municipal sewers(GB/T 31962-2015).The service life of the iron-carbon filler is calculated in half a year,and the operating cost of the combined process is lower than that of the Fenton process alone. |
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