Remediation Of Sulfanilic Acid Wastewater With Activation Of Persulfate Based On Iron/copper Nanocomposite And Heat

sulfanilic acid（4-SA）is the most representative of sulfonated aromatic amine.It is widely used into dye production,printing,dyeing auxiliaries,spices,food coloring,medicine and pesticide,and it also is intermediate of azo dye anaerobic decolorization.It is a common environmental pollutant and is harmful to human body.However,because its structure is stable,soluble in water,and has the characteristics of xenobiotic,it is difficult to biodegrade.it is necessary finding a new method of disposing 4-SA.Advanced oxidation technologies（AOPs）as efficient organic pollutants treatment technologies development and progress gradually,iron and copper base nanomaterials heterogeneous activation persulfate system for its excellent activation performance and magnetic characteristics of the recycling has gained a lot of attention.Three different kinds of iron and copper based composites were prepared by different structures,which may have different activation of sulfate:Spinel structure copper ferrite（CuFe₂O₄）;Nano-sized copper oxide coated by nano-Fe₃O₄（CuO@Fe₃O₄）and Hierarchically fusiform CuO microstructure decorated by Fe₃O₄（Fe₃O₄/hf-CuO）.There are a lot of characterization have been done of iron/copper nanocomposite like CuFe₂O₄,CuO@Fe₃O₄ and Fe₃O₄/hf-CuO and then used all of them to activate PS removal 4-SA.The result illustrated that 1g L^-1 Fe₃O₄/hf-CuO could remove 100 mg L^-1 of 4-SA under condition:temperture=30 ^oC,pH=3-9±0.2,PS=20 mg L^-1 and degradation efficiency could reach to 95%in 4 hours.Fe₃O₄/hf-CuO is the best nanocomposite of three because of the highly degradation efficiency in the widely p H range by using less nanocomposite to degrade more 4-SA.Then reasearch illustrated that it conforms to the pseudo-first-order kinetics,the kinetic constant is 0.0352 min^-1.SO₄^·-was the most important radical in degradation and TOC consequence shows that it could not completely mineralize 4-SA,so it has to be completely mineralize using further experiment.Thermal activation of PS technology has a good efficiency and the removal rate of TOC is higher.Therefore,the efficacy of the treatment on aminobensulfonic acid is studied.In the heat activated system,50 mg L^-1of 4-SA could be completely mineralized in 4 hours under condition:temperature=60^oC,pH=7±0.2,PS=20 mmol L^-1.Reaction conforms pseudo-first-order kinetics and the kinetic constant is 0.0274min^-1.SO₄^·-was the most important radical in degradation.After that,using heat combined with Fe₃O₄/hf-CuO to activate PS to remove 4-SA.Result illustrated that4-SA in heat activation system,Fe₃O₄/hf-CuO activation system and Fe₃O₄/hf-CuO and heat co-activation system could totally be degraded.TOC removal efficiency of heat activation system,Fe₃O₄/hf-CuO activation system and Fe₃O₄/hf-CuO and heat co-activation system was 59.58%,39.18%and 97.62%respectively,which means Fe₃O₄/hf-CuO and heat co-activation system could mineralize more TOC of 4-SA.It illustrated Fe₃O₄/hf-CuO and heat co-activation system is efficient and feasible.