Treatment Of P-nitrophenol Wastewater By Microelectrolysis/Activated Persulfate

Since the 21st century,China's modernization process has been continuously progressing.With the continuous development of industrial and agricultural activities,a large number of highly toxic phenolic substances have entered the environment and formed organic pollution.The research on the treatment of refractory organic phenolic wastewater has also become a recent year.Hot spot in water treatment research,persulfate advanced oxidation method as a new advanced oxidation technology has the advantages of quick effect and short cycle in the treatment of refractory organic phenolic wastewater,and its research level is not deep,in the activation of persulfate There is still good development potential in the field of salt technology and in combination with other wastewater treatment technologies.In this experiment,micro-electrolysis/activated persulfate treatment of refractory p-nitrophenol(PNP)wastewater was carried out,and the purpose of degrading p-nitrophenol in wastewater was achieved by micro-electrolysis in the system and activation of persulfate.The main research contents include:the optimization of micro-electrolytic filler;the influencing factors and reaction kinetics of micro-electrolysis and micro-electrolysis/activated persulfate treatment for p-nitrophenol;the reaction conditions for micro-electrolysis/activated persulfate treatment Study on the reaction rate of phenols.The iron-carbon and iron-copper were used as micro-electrolytic fillers respectively to compare the removal effects of PNP and COD of the two micro-electrolytic combinations under the same conditions.It was found that iron-carbon microelectrolysis using activated carbon as micro-electrolytic filler was better than iron-copper micro-electrolysis.The PNP and COD removal effect is better and the reaction speed is faster.The effects of single factors such as iron and carbon dosage,iron-carbon ratio,initial pH and reaction time on the removal of PNP and COD in the treatment of p-nitrophenol wastewater by iron-carbon microelectrolysis were studied.The optimal treatment conditions for 200mL of 200mg/L simulated p-nitrophenol wastewater are:Fe dosage is 40g/L,iron-carbon ratio is 2:1,pH is 3,reaction time is 120min,PNP at this time The removal rate reached 94.4%and the COD removal rate reached 47.8%.The kinetic model of the degradation of p-nitrophenol wastewater by iron-carbon microelectrolysis was studied.The PNP and COD in the wastewater by micro-electrolysis were consistent with the second-order kinetic model.The reaction rate equation was 1/C-1/C0=kt.The fitting curves were y=0.0008x-0.0095 and y?0.00002x+0.0009,respectively,and the correlation coefficients were R=0.989 and R?0.984,respectively.The single factor pair of sodium persulfate dosage,iron carbon dosage,iron-carbon ratio,initial pH,reaction time and sodium persulfate addition time in the treatment of p-nitrophenol wastewater by micro-electrolysis/activated persulfate method was studied.The effect of PNP and COD removal effects.For 200 mL of 200 mg/L simulated p-nitrophenol wastewater,the dosage of persulfate is 5 mnol/L,the dosage of Fe is 60 g/L,the ratio of iron to carbon is 2:1,the pH is 3,and the reaction time is For 120 min,the sodium persulfate addition time is the reaction condition at the beginning of the reaction,the removal rate of PNP by the micro·electrolysis/activated persulfate method is 98.3%,and the removal rate of COD is 64.3%.On the basis of single factor experiment,the order of influence of micro-electrolysis/activated persulfate method on PNP removal rate was determined by orthogonal test:iron dosage>initial pH>persulfate dosage>iron carbon The optimum reaction conditions were as follows:the persulfate dosage was 5 mmol/L,the iron dosage was 40 mg/L,the iron-carbon ratio was 1:1,and the initial pH was 3.The removal rate of PNP was 98.26%.The order of influence of each reaction factor on COD removal rate was determined as follows:iron dosage>persulfate dosage>iron-carbon ratio>initial pH,the optimal reaction condition was:persulfate dosage 10 mmol/L The iron dosage is 60 mg/L,the iron-carbon ratio is 2:1,and the initial pH is 3.The COD removal rate is 63.67%.The kinetic model of the degradation of p-nitrophenol wastewater by microelectrolysis/activated persulfate method was studied.The PNP and COD of microelectrolysis/activated persulfate degradation of wastewater were consistent with the first-order kinetic model and the second-order kinetic model.The rate equations are lnC-lnC0=-kt and l/C-l/C0=kt respectively,and the fitting curves are y=0.0249x+1.2834 and y=0.00005x+0.0002,respectively,and the correlation coefficients are R?0.989 and R=,respectively.0.975;In the kinetic model of micro-electrolysis/activated persulfate degradation of PNP and COD,the effect of each reaction factor on the reaction rate constant k is different.