Research And Application Of A New Type Of Iron Carbon Micro Electrolysis Material

At present,the main sources of iron-carbon micro-electrolysis fillers are waste iron scrap fillers and scrap iron activated carbon fillers or iron scrap fly ash fillers.The earliest uses of micro-electrolysis to treat waste water are basically powdered scraps during the cutting process of cast iron,namely cast iron scrap or iron shavings;with the increasingly prominent passivation of iron filings during the operation of micro-electrolysis,iron powders have emerged.Iron carbon is loaded into the drum in proportion,and the rotation of the drum drives the rotation of the iron powder and iron carbon to treat the micro-electrolytic material of the waste water;along with the continuous development of the micro-electrolysis technology,people add binding agents to the iron powder and iron carbon（For example,clay）is pressed into an oxygen-free sintered structured packing.This paper proposes to improve the iron-carbon micro-electrolysis process and develop a new type of iron-carbon micro-electrolysis material with higher performance than traditional iron filings,using sponge iron as a special iron material,combined with the Fe⁰/O₂ Fenton effect principle developed in recent years.New iron-carbon micro-electrolytic material was used as the source of zero-valent iron.By constructing the Fe⁰/O₂ system,the relevant factors affecting the Fenton effect of the Fe/O₂ system were analyzed and analyzed,and the Fe/O₂system type Fenton was optimized by means of response surface methodology.The effect produces a combination of the best influencing factors for the amount of H₂O₂ and·OH.Combined with the best combination of factors from the response surface,a new type of ferro-carbon micro-electrolytic material was used to degrade the simulated DMAC wastewater,and the degradation effect and degradation kinetics of DMAC were discussed.The degradation mechanism was analyzed by UV spectroscopy.In addition,the novel iron-carbon micro-electrolysis materials and sponge iron+activated carbon materials were used to simulate the degradation of DMAC wastewater from Fe/O₂ system Fenton effect,degradation treatment effect and degradation reaction kinetics.The main conclusions are as follows:（1）The iron-based material and bentonite with a mass ratio of 25 to 35:1 were pulverized and mixed and granulated into pellets,which were then added to the reactor for reduction and roasting to obtain spherical iron-based functional monomers.Afterwards,the mass ratio of 15to 20:1 iron-based functional monomer and powdered manganese dioxide are added to the polyurethane,epoxy resin and acrylate acetone dissolved in a ratio of 10:3:1.Add a certain amount of triethylenetetramine,fully mix for 30min,then vacuum dry at a temperature of70-80°C to obtain a ferromanganese precursor;finally place the ferromanganese precursor in a reaction vessel at a temperature of 80-150°C.Roasting for 30-60min,calcining at180-300°C for 1h,baking at 500-800°C for 2h,cooling to room temperature,new iron-carbon micro-electrolytic material is obtained.（2）Through the physical properties and morphological characterization of the new iron-carbon materials,the apparent density is 1052 kg/m³,the true density is 2120 kg/m³,the water absorption is 26%,and the porosity is 50%;The surface of the carbon material is rough,many tiny and relatively large pores exist at the same time,and the internal structure is loose.（3）After comparison and optimization of H₂O₂ determination methods,the determination of H₂O₂ is 0.225 mmol/L titanium salt,and the best absorbance is measured with a 10 mm cuvette at 384 nm after 10 min of color development.The comparison and optimization of the determination methods of·OH showed that when the sampling time was30 min,the corresponding absorbance value reached the maximum;（4）The Fenton reaction in the Fe⁰/O₂ system is easier to perform under acidic conditions;the amount of Fe²⁺,H₂O₂,and·OH produced tends to decrease slowly with the increase of the particle size of the iron-carbon material;With increasing dosage,the amount of Fe²⁺,H₂O₂,and·OH produced by the Fe/O₂ system is also greater,and the effect is best when the amount of Fe/C material is equal to 130 g/L;the system produces H₂O₂,·OH,and Fe²⁺.The amount decreases as the particle size increases,reaching a maximum when the stirring speed is 100r/min;（5）Response surface optimization was used to determine that the amount of H₂O₂produced by the Fe/O₂ system based on pH value,addition of iron-carbon material,and stirring speed was:pH>dosing of iron-carbon material>stirring Speed;The effect on the amount of·OH produced by the Fe/O₂ system is:pH>stirring speed>dosing of iron-carbon material.Through the analysis of the response surface map and the corresponding contour plots and parallel verification experiments,it can be seen that the amount of H₂O₂ and·OH produced by the Fe/O₂ system can reach the prediction standard.The experimental values are consistent with the predicted values,and the H₂O₂ and·OH reach the maximum value.The optimum combination factors are:pH 4.62,iron-carbon material dosage 138.36 g/L,stirring speed 104.17 r/min.（6）The corresponding removal rates of DMAC simulated wastewater with three different concentrations of 125mg/L,260mg/L,and 500mg/L were 31.08%,33.77%,and35.12%,respectively;the corresponding initial concentrations were obtained.The removal rate of the removal rate is not very large,but the removal rate of the wastewater with higher initial concentration is relatively high at the end of the reaction;the pseudo first-order kinetics and pseudo-second-order kinetics are used to simulate the degradation of DMAC simulated wastewater by the new iron-carbon material.It is known that the novel iron-carbon materials are more prone to pseudo-first-order reaction kinetics in the degradation of DMAC simulated wastewater;through the UV spectrum analysis of the degradation of DMAC simulated wastewater,it can be seen that DMAC simulated wastewater appears at the wavelengths of196 nm,220 nm,and 340 nm.The absorption peak was found.At the end of the reaction,the absorption peaks at 196 nm and 220 nm disappeared as a whole,while the absorption peak at340 nm showed a significant decrease.The analysis suggests that it may be DMAC—CH₃,C=O,and-NH-.The other groups are destroyed.（7）The amount of Fe²⁺,H₂O₂,and·OH produced by the new type of iron-carbon material was greater than that of sponge iron+activated carbon;the removal rates of DMAC from the two materials were 33.77%and 35.32%,respectively,resulting in a new type of iron-carbon material and sponge iron+activated carbon At the same time,the removal rate of DMAC waste water was not much different.The treatment effect of sponge iron+activated carbon was slightly better than that of new iron-carbon material.（8）After treating the actual chemical wastewater from a chemical industry institute in Gansu Province as the object of treatment,the water quality requirements are met after the Fe-carbon micro-electrolysis+Fenton+coagulation+biochemical+coagulation+Fe-C Fenton+Fenton depth treatment.Sewage discharged into the"B-grade"indicator in the Urban Sewage Water Quality Standards（CJ343-2010）.That is,the major pollution indicator COD is reduced to less than 500mg/L,and the treated wastewater is discharged into the urban sewer network.