| The wastewater from the production of Diazo dinitrophenol（DDNP）has complex composition,high content of organic matter,high chromaticity,high toxicity and poor biodegradability,so it is difficult to treat.In this paper,activated carbon and electrochemical regenerated activated carbon were used as the main materials for advanced treatment of COD and chromaticity in DDNP wastewater.The basic properties of fresh activated carbon（FAC）were characterized and analyzed by means of SEM,EDS,BET and FTIR,and the effects of single factor experiment,FAC dosage,adsorption reaction time of FAC with DDNP production wastewater,p H of DDNP production wastewater and temperature on COD and chromaticity of DDNP production wastewater treated by FAC were carried out.Electrochemical regeneration technology was used to prepare AFAC by electrochemical regeneration technology.RFAC was prepared by electrochemical regeneration technology.The effects of current density（CD）,AFAC regeneration time（AFACRT）,electrolyte type（ET）and electrode spacing（ES）,electrolyte concentration on electrochemical regeneration of activated carbon（Regenerated fresh activated carbon,RFAC）and the enhancement of H2O2on electrochemical regeneration of RFAC were studied by orthogonal experiment.The main conclusions are as follows:The results of analysis and characterization by SEM,EDS,BET and FTIR show that FAC is a kind of material with rich surface pore size,high specific surface area and rich active groups such as-OH and-COOH.The experimental study of single factor conditions shows that when the dosage of FAC is 400g,the contact time between FAC and DDNP production wastewater is 4 days,and the p H=7,reaction temperature of DDNP production wastewater is 30℃,FAC has better removal efficiency of COD and chromaticity of DDNP production wastewater than II,which is 74.3%and 96.8%respectively,which can meet the first-class A standard of the national discharge standard.The orthogonal experimental results of electrochemical regeneration of RFAC show that the best preparation condition of electrochemical regeneration of RFAC is when CD=6,AFACRT=5,ET is Na2CO3,PS=14.The regeneration efficiency of RFAC increases with the increase of the mass concentration of electrolyte Na2CO3.When the mass concentration of Na2CO3is 3%,it has basically reached the adsorption equilibrium,and the treatment efficiency of COD and chromaticity is 73.4%and 92.2%respectively.RFAC can be recycled for 3 times in the treatment of DDNP production wastewater.H2O2has a certain enhancement effect on electrochemical regeneration,and the addition of 2ml 30%H2O2per50m L electrolyte solution in the process of RFAC regeneration is most beneficial to the electrochemical regeneration of AFAC. |
