Study On Green Treatment Of Wastewater Containing 1-Amino-2-Naphthol-4-Sulfonic Acid And Wastewater Containing Ammonia

Naphthalene sulfonic acid wastewater mainly comes from the production process of dyes.The wastewater characterized with high color,strong acidity and difficult to degrade naturally.For this kind of wastewater,this paper took 1-amino-2-naphthol-4-sulfonic acid（1,2,4-acid）wastewater as the research object.Ammonia-containing wastewater mainly comes from the process of coal and petroleum processing.Usually,the content of ammonia is relatively high.The large amount of ammonia in water not only causes eutrophication of water,but also has some toxic and side effects on human and aquatic animals and plants.In addition,ammonia can be oxidized into nitrogen oxides（NO and NO₂）could contribute to acid rain,photochemical smog and haze,which pose harm to human health.In this paper,trioctylamine（TOA）was used as complexing agent,methyl isobutyl ketone（MIBK）and kerosene were used as diluents to extract 1,2,4-acid from wastewater.The effects of diluent type,TOA concentration,temperature and pH on partition coefficient（D）were discussed.The results showed that TOA(1.41 mol·kg^-1)+MIBK could obtain the best extraction（D=76）at 25℃and pH=1.1.After that,the extractant was regenerated by stripping method and distillation method respectively.The composition of the original extractant and regenerated extractant were analyzed by GC-MS.It was determined that stripping could regenerate extractant.The distillation process was simulated using Aspen Plus to prove its feasibility in the process of extractant regeneration.the microscopic law of the extraction of 1,2,4-acid from wastewater by TOA was further understood by studying the extraction mechanism.The extraction mechanism was explored step by step by using UV-vis,FT-IR and ¹H NMR,respectively.The results show that in the process of complex extraction of 1,2,4-acid,the complexes between TOA and 1,2,4-acid were formed by ion association,which resulted in the transfer of 1,2,4-acid from aqueous phase to organic phase.The green treatment of ammonia-containing wastewater was achieved by wet catalytic oxidation（CWAO）.The ionic liquid polymers（PILs）containing ionic liquid and ethylene glycol dimethacrylate（EGDMA）was used as support and the gold（Au）and ruthenium（Ru）were used as active sites to prepare supported catalysts.The catalyst and catalyst support were characterized by scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）and transmission electron microscopy（TEM）.The results show that there was a certain interaction between the active metal and the catalyst support.This interaction facilitates the stable and uniform dispersion of the metal nanoparticles on the catalyst support,and the interaction site between the Au and the catalyst support was denser than Ru.TEM results show that this relatively strong interaction causes Au to aggregate on the support to form larger nanoparticles（4.5 nm）,while Ru nanoparticles have a relatively smaller particle size（2.5 nm）.Catalytic experiments show that PILs-NTf₂ supported Au or Ru has high activity and selectivity for oxidation of ammonia to N₂ under mild conditions.Due to the aggregation of Au on the support to form larger nanoparticles,the conversion of Ru/PILs-NTf₂（⁹5%）was better than that of Au/PILs-NTf₂（⁸3%）at any temperature and pressure.For selection to N₂,the Ru/PILs-NTf₂ catalyst was evidently affected by temperature and pressure,whereas the Au/PILs-NTf₂ catalyst was hardly affected.And the selectivity of Ru/PILs-NTf2 catalyst to N₂（⁹0%）was slightly lower than that of Au/PILs-NTf2 catalyst（⁹8%）.