Research On Removal Efficiency Of Organic Matter In Concentrated Salt Water From Coal Chemical Industry

In recent years,with the rapid development of China's economy,energy demand is increasing,thus driving the rapid development of coal chemica l industry.However,the coal chemical industry has produced a large number of toxic and refractory wastewater,the current water resources and environmental situation brought great pressure,so the realization of coal chemical industry wastewater "zero emissions" is the development of coal chemical industry,the external needs and external requirements,the key point And the difficulty is the treatment of coal chemical salt water,resulting in high cost of crystallization of salt treatment,improper handling will leave environmental risks.Therefore,it is very important to reduce the concentration of organic matter in coal salt and to realize the standard and content of organic matter in the salt salt.It is very important to realize the salt separation and resource utilization of coal chemical salt water industry.This paper studies this problem.Firstly,from the coal Erdos Energy Chemical corporation on-site recovery of coal chemical concentrates brine tube nanofiltration membrane effluent GC/MS analysis results show that concentrated brine mainly contains toluene aroma compounds and long chain alkanes,and a small amount Esters and naphthalenes and other organic matter.Based on the water quality conditions,this paper studied the effects of co-crystallization catalyzed ozone oxidation and granular activated carbon adsorption on the deep processing of coal chemical concentrates.Secondly,the catalytic ozone oxidation system was studied in detail,including:?1?Preparation of co-crystallization catalyst,the catalyst characterization was carried out and the problems such as catalyst poisoning,scaling and catalyst stability were studied.?2?The optimization conditions of the operation conditions were as follows: O₃ dosage rate 2.0mg/min,catalyst dosage 2.0g/L,pH value and temperature were raw water quality conditions.?3?with toluene and octane water,found that organic matter will not make the catalyst poisoning;and then NaCl and deionized water distribution,found that high concentrations of NaCl wi ll affect the catalyst activity and adsorption performance.?4?It is speculated that the mechanism of catalytic ozone oxidation is analyzed,and that the production of ·OH is caused by the e-migration between the different valence states of the oxides in the co-crystallization catalyst.The catalytic oxidation process is an indirect oxidation of hydroxyl radicals,a variety of oxidation reaction synergies.In addition,chloride ions lead to the formation of inert intermediates,the termination of ozone cha in decomposition,reducing the effect of oxidation system.Finally,the adsorption technology of granular activated carbon is studied in detail.?1?The optimum flow rate is 8.0m/h,the optimum adsorption time is 2h,the dosage of activated carbon is 2.0g/L,the pH 3,temperature 25?.For the best adsorption pH,taking into account the practical engineering applications,this study with Na OH modified activated carbon can maintain the best adsorption pH of 7 or so.The adsorption isotherm of activated carbon to toluene,octane and undecane was simulated by Langmuir model at the same time.The results showed that the correlation of the model was better.?2?The analysis of the effect of high salt ion showed that the salt was adsorbed on the GAC and occupied th e GAC surface active site,and its adsorption capacity was decreased when NaCl concentration was low.With the increase of salt concentration,a large amount of ions produced a charge shielding effect,the repulsive force between molecules decreased,and t he adsorption was improved.In addition,the high concentration of NaCl in the solution will produce salting-out effect,reduce the solubility of organic matter in the adsorption system,and promote its transfer on the surface of GAC.?3?The regenerated activated carbon was regenerated by thermal regeneration method.The results showed that the adsorption stability of recycled carbon was better.?4?The adsorption kinetics of activated carbon was studied with toluene,octane and undecane.It was found that the adsorption of toluene was more suitable than pseudo-second-order kinetics model.The diffusion equation of octane and undecane was better.The heterogeneous catalytic ozonation system and the granular activated carbon adsorption system established in this paper can quickly and efficiently remove the refractory organic matter in the coal chemical concentrated brine,greatly improve the quality of the subsequent production of crystalline salt,for the realization of coal chemical wastewater "zero emissions" Larger practical application value.