Removal Of Organic Agents From Phosphate Flotation Wastewater

In this paper,the removal of organic matter from flotation wastewater of a phosphate mine in Guizhou was studied.The main minerals in phosphate rock are fluorapatite,quartz and dolomite.Through grinding and flotation tests,the flotation wastewater was recycled.With the increase of the number of cycles,the content of organic matter in wastewater increases gradually,the grade of P₂O₅ in concentrate decreases gradually,and the recovery rate changes insignificantly.Therefore,it is necessary to treat the organic matter in flotation wastewater.In order to remove organic matter from simulated wastewater by adsorption method,activated carbon,fly ash and charcoal were used to investigate the effects of adsorbent dosage,pH,adsorption time and temperature on the removal of organic matter from simulated wastewater.When SEW and SEA were treated with activated carbon,the removal rates were 84.7%and 67.1%,respectively,at the dosage of 2g·L^-1.When fly ash was used to treat SEW and SEA,it was found that new calcium aluminosilicate?feldspar?is formed after charcoal is roasted at 350?,and the network structure was increased.The roasted fly ash below-0.048 mm has better adsorption effect.In the treatment of SEW and SEA,the removal rates were 73.7%and 63.97%with the dosage of 50 g·L^-11 and 40 g·L^-1,respectively.The removal rate of SEW and SEA was 63.17%when the amount of charcoal was 35 g·L^-1,and 30g·L^-1.The removal rate of SEA did not increase significantly,and the removal rate was 58.78%.With the increase of temperature,the removal rate decreases gradually.Removal of organic matter from simulated wastewater by coagulation sedimentation process.When SEW was treated,the amount of PAC and PAFC was suitable at 7 g·L^-1,and the removal rates were 17.69%and 22.43%,respectively.When SEA was treated,the appropriate amount of PAC was 7 g·L^-1,with a removal rate of 19.42%,and the appropriate amount of PAFC was 5 g·L^-1,with a removal rate of 25.31%.pH had little effect on the removal rates of SEW and SEA.Removal of organic matter from simulated wastewater by oxidation process.The removal rate of CMD-1 was 27.32%and that of CMD-2 was 14.98%when treating SEW,and that of CMD-1 was 24 g·L^-11 with 53.98%and that of CMD-2 with 20 g·L^-1with 30.84%.In contrast,CMD-1 has a better removal effect on organic matter.When SEW was treated,the removal rate first increased and then decreased with the increase of pH.With the increase of pH,the removal rate of SEA increased gradually.The neutral condition was better when SEW was treated,and the alkaline condition was better when SEA was treated.With the increase of temperature,the removal rate decreases gradually.Study on the mechanism of SEA adsorption by activated carbon.Box-Behnken module was used for orthogonal test.The interaction between activated carbon dosage and SEA concentration was significant,while the interaction between pH,activated carbon dosage and SEA concentration was not significant.XRD analysis showed that activated carbon was amorphous sample,which contained silica and graphite;scanning electron microscopy showed that activated carbon adsorbed SEA,the surface became smooth and the adsorption effect was better;FTIR analysis showed that activated carbon adsorbed SEA;Zeta potential of activated carbon decreased with the increase of pH in solution,and the stability of the system decreased first and then increased.The BET specific surface area of the original activated carbon is 650.4405m2·g^-1,mainly the adsorption of SEA by the micropore of activated carbon.XPS was used to determine the binding energy of SEA adsorbed on activated carbon surface at different acidity and alkalinity.The adsorption isotherms conform to Langmuir and Freundlich isotherms.The negative values of?H^?and?S^?obtained from thermodynamic analysis and?G^?of SEA indicate that adsorption is a spontaneous process.C80 microcalorimeter analysis showed that the adsorption was exothermic reaction,and the reaction heat was-16.611 J·g^-1,-19.564 J·g^-11 and-27.64 J·g^-1,respectively.In adsorption kinetics,the adsorption conformed to pseudo-second-order kinetic model?R²>0.99?,Bangham pore diffusion model?R²>0.92?and W-M kinetic model?R²>0.94?.The activation energy of activated carbon for SEA adsorption is E_a=27.96 kJ·mol^-1,which belongs to physical adsorption.