| Triazole nitrile is a new and highly effective herbicide in recent years,and the triazole nitrile waste water produced in the production process is a kind of refractory nitrogenous heterocyclic wastewater.The main characteristics of such wastewater are:1)high salt content and high COD concentration;2)complex organic compounds;3)biological toxicity;4)difficult to degrade.At present,one or more kinds of effective pretreatment are adopted to treat this kind of wastewater at home and abroad.This kind of wastewater is pretreated to fully degrade or separate the biologically toxic components in wastewater,and then degrade with biological method.This paper deals with the actual wastewater produced by Xianghe company in the process of production of triazole nitrile,according to the characteristics of water quality,high salinity and heterocyclic compound containing triazole,using the activated carbon to adsorb the heterocycle wastewater.The regeneration of activated carbon was studied and the best regeneration methods and regeneration conditions were studied.Finally the effective sodium hypochlorite oxidation method for the treatment of high concentration of triazole heterocyclic wastewater was investigated.The water samples were analyzed by UV visible spectrophotometry and high performance liquid chromatography.The activated carbon was characterized by SEM,BET and BJH.The main research work is as follows:1.Optimum adsorption conditions of activated carbon for actual wastewater:Under normal temperature,pH=1.41,the amount of activated carbon is 1.25g,the adsorption time is 3h,COD and target pollutant removal rate are 66%,95.9%.The activated carbon was characterized by SEM,BET and BJH,and the results showed that the activated carbon could adsorb the actual wastewater well.The cyclic adsorption of activated carbon showed that the adsorption capacity of activated carbon was large,it is 1.648g/g.Activated carbon has good adsorption selectivity for nitrogen-containing heterocyclic compounds,adsorption of activated carbon on Actual wastewater can preferentially adsorb nitrogen heterocyclic compounds and enrich heterocyclic compounds containing nitrogen.2.Microwave has good regeneration effect on activated carbon,in the experiment of electrochemical regeneration of activated carbon,when the concentration of NaCl which is electrolyte is 4 g/L,the voltage is 10 V,the plate spacing is 2 cm,the electrolyte initial pH is 1.4 and the electrolysis regeneration time was 2 h,the optimum regeneration rate of activated carbon was 52.4%;Experiment on regeneration of activated carbon by water phase heat method,when the initial solution is 100ml,the saturated activated carbon is 1.25g,pH=13.03,pyretic stroke,the regeneration time is 2min,the optimum regeneration rate of activated carbon was 72.67%.compared with electrochemical and water phase heat method,The regeneration of activated carbon by microwave method has the advantages of short regeneration time,high regeneration rate of activated carbon and small amount of waste water.HPLC was used to analyze the desorption solution and adsorption solution of activated carbon obtained by microwave regeneration for first,third,sixth times.Under microwave field,activated carbon can be regenerated many times,and its regeneration performance is stable.3.Chloros oxide regenerated wastewater with microwave.40ml regeneration wastewater,heating 3h at 85 C,at this point,the optimum oxidation efficiency rite of direct treatment of regenerated wastewater with sodium hypochlo was 67.10%;40ml regeneration wastewater,pH=13.01,6min oxidation by medium fire,at this point,the optimum oxidation efficiency of microwave assisted sodium hypochlorite is 91.13%,Compared with sodium hypochlorite direct oxidation method,the microwave assisted hypochlorite process has the advantages of shorter time consuming,higher oxidation efficiency and higher oxidation efficiency as high as 91.13%.Therefore,microwave assisted sodium hypochlorite treatment of wastewater is economical and feasible. |
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