Study On Fabrication Of CGFM For Color Removal In Hypersaline And Acidic Dye Wastewater

Dye wastewater has high chromaticity,high concentration of organic matter,complex components,many refractory substances,and contains a large amount of inorganic salts and sulfides,which is difficult to be treated.Especially for strong acidic azo dyes,they need to be dyed in an acidic bath,and neutral salts are added to slow down the dyeing process.The treatment of the hypersaline and acidic dye wastewater generated from them needs to be urgently addressed.In this study,coal gasification fine slag with fine particle size and rich pore structure was used as the carbon source.Coal gasification fine slag based micro-electrolytic material(CGFM)was prepared and applied to the decolorization of hypersaline and acidic dye wastewater.It was in line with the concept of sustainable development to treat waste with waste.CGFM was prepared by high-temperature calcination.The macroscopic morphology under different particle sizes and physicochemical properties under different calcination procedures of CGFM were characterized.The preparation conditions of CGFM was optimized considering the decolorization on Brilliant Crocein.There were acid-soluble components in the coal gasification fine slag,which could mitigate the acidity of wastewater,reduce the dissolution rate of iron,and slow down the formation of the passivation layer.The acid resistance and durability of CGFM in acidic wastewater were improved.When the ratio of iron to slag was 1:1,the roasting procedure was 800℃ for 1 h,and the particle size was 4 mm,CGFM demonstrated the optimal application effect on wastewater for abundant quantity of primary batteries,good adsorption,strong wear resistance,and high reactivity.The decolorization mechanism of Brilliant Crocein by CGFM in acidic wastewater was studied.Under acidic conditions,CGFM exhibited excellent decolorization on Brilliant Crocein.Through the detection and analysis of the surface changes,ionic states in the solution,and degradation products of CGFM,it was found that microelectrolysis has different reaction mechanisms for Brilliant Crocein under different initial p H.At the initial p H of 2,the micro-electrolysis system was in a better reaction environment.The production of free radicals catalyzed by the dissolved divalent iron ions is involved in the oxidative decolorization process of pollutants.At the later stage of the reaction,the metal hydrolytic polymer played the performance of flocculation and adsorption.The coupling of multiple action mechanisms enhanced the decolorization of CGFM on Brilliant Crocein with less loss and no passivation and hardening.Under the action of electrochemistry,the azo double bonds of Brilliant Crocein were reduced and broken down into small molecules,resulting in the formation of a large number of phenolic substances,greatly improving the biodegradability of wastewater.The decolorization behavior of CGFM in hypersaline and acidic dye wastewater was studied.When the initial p H was 2,the dosage was 40 g/L,the aeration rate was0.5 L/min,and the salt content was 2 g/L,and the reaction time was 120 min,the decolorization rate could reach 86.48% significantly.The B/C value increased from0.249 to 1.373,significantly improving the biodegradability.The removal efficiency and reaction rate constants were fitting to the second order kinetic model.The application of CGFM in actual wastewater was excellent.The absorption peak intensity of chromogenic groups was significantly reduced,COD was reduced from 21820 mg/L to 10540 mg/L,and the B/C value was increased from 0.375 to 0.734.Compared with activated carbon,it was more advantageous to choose coal gasification fine slag as carbon source to treat hypersaline and acidic dye wastewater for less loss,low cost,and good results.The reusability of CGFM was excellent.While CGFM was repeatedly used ten times to treat hypersaline and acidic dye wastewater,the decolorization was satisfactory with less loss and stable spherical structure.To sum up,choosing coal gasification fine slag as the carbon source for CGFM can effectively remove the chromaticity and organic matter,improve the biodegradability,and significantly reduce the pressure in subsequent treatment stages when treating hypersaline and acidic dye wastewater.The multi-component of coal gasification fine slag has improved the physical and chemical properties of microelectrolytic materials,significantly reduced the consumption rate of micro-electrolytic materials,extended the service life of the materials,coupled adsorptionelectrochemistry-flocculation,enhanced the effect of the action,and controlled the hardening and passivation problems caused by ions oxide precipitation.The treatment of actual wastewater presents strong promotion and application value of CGFM.This thesis has 57 figures,2 tables and 120 references.