Research On Treatment Of Sodium Phenolate Wastewater From Coal Processing By ESIX Technology

With the development of Chinese social economy,the problem of industrial pollution has become increasingly prominent.Among them,the treatment of industrial wastewater has become an urgent global environmental problem.Above all,industrial phenol-containing wastewater from coal processing has received extensive attention because of its serious hazards and wide sources.Recently,the traditional methods for phenol-containing wastewater treatment mainly include extraction,steam distillation,adsorption,membrane separation technology,advanced oxidation,biological method and other technologies.However,the traditional treatment methods have various disadvantages,such as high energy consumption,high chemical consumption,and secondary pollution,which bring inconvenience to the subsequent treatment.Therefore,it is of great significance to develop a new type of phenol-containing wastewater treatment technology with low energy consumption and environmental protection.Electrochemically switched ion exchange(ESIX)technology as an efficient,economical and eco-friendly method for ion separation and recovery that could not only realize the removal of the target ions in the solution,but also achieve the regeneration of the electroactive material by electrochemical effect.Taking advantage of the high-salt characteristic of the phenol-containing wastewater,the ESIX system can recover the salt ions and separate the phenol from the wastewater under the electrochemical application.In this paper,the ESIX system is applied in the field of phenol-containing wastewater treatment.The working mechanism of this ESIX system,the influences of applied potential and initial sodium phenoxide concentration on the performance,and the energy consumption in the series operation were investigated in high-concentration phenol-containing wastewater.The operating parameters,treatment effects and energy consumption of the ESIX system with?-Mn O₂ electrode were studied in low-concentration phenol-containing wastewater.First,the application of ESIX system in the treatment of high-concentration phenol-containing wastewater was studied.Fe HCF as an electroactive material was prepared by hydrothermal method.And the morphological structure,crystal form and electrochemical properties of Fe HCF materials were analyzed by SEM,XRD,CV,EIS,EQCM.Meanwhile,the principle of the ESIX system was investigated.The influences of applied potential and initial sodium phenoxide concentration on the performance,and the energy consumption in the series operation were investigated.Characterization found that the Fe HCF coated electrode with large interstitial sites in the rigid open framework was fabricated for the insertion/extraction of Na⁺ions.Through comparison and selection,it is found that under the best operating conditions,more than 79%of phenol could be removed with energy consumption of 9.677 Wh/mol,and NaOH solution with a p H of 12.84 was generated with energy consumption of 2.083 Wh/mol.Secondly,the application of ESIX system in the treatment of low concentration phenol wastewater was studied.The?-Mn O₂ obtained by etching the precursor material,Na Mn₂O₄,were analyzed by SEM,XRD,CV,EIS and other characterization methods to inspect the morphological structure and electrochemical performance.Furthermore,the influences of applied potential and initial sodium phenoxide concentration on the performance,and the stability of the ESIX system in low concentration phenol-containing wastewater were investigated.The results show that-1.0 V is the optimum applied voltage,and the ESIX system has outstanding treatment effect on low concentration phenol-containing wastewater.Furthermore,over 97.2%Na⁺and 89.2%phenol were separated and the electrochemical stability of the?-Mn O₂ electrode was achieved.Excellent.In this study,the ESIX system with the Fe HCF coated electrode driven by low potential at normal pressure and temperature(NPT)with low cost not only could separate and recover Na⁺from wastewater to produce NaOH,but also can remove phenol from wastewater.It is expected to be used in the treatment of industrial coking wastewater with no secondary pollution,high stability and low energy consumption.Phenol-containing wastewater from coal chemical industry is characterized by a wide range of concentration gradients.The ESIX system with the?-Mn O₂ electrode has shown excellent results in the treatment of low concentration phenol-containing wastewater.