Experimental Study On The Treatment Of Chinese Patent Medicine Alcohol Precipitation Wastewater By Anaerobic Digestion + Simultaneous Nitrification And Denitrification

In the production wastewater of Chinese patent medicines,the alcohol precipitation wastewater has high organic concentration,strong bioinhibition,and a large proportion of pollution load.Reasonable disposal of this wastewater can reduce the operating load and treatment burden of the subsequent comprehensive treatment unit,and will have good environmental benefits.Among the wastewater biochemical treatment technologies,anaerobic digestion is an ideal technology for treating wastewater with high organic concentration,simultaneous nitrification and denitrification has the advantages of low energy consumption and carbon saving.Combining the two technologies will have good research prospects.This subject taked the alcohol precipitation wastewater produced in the process of making Ganmaoling granules and Banlangen granules from raw materials such as trigeminal bitter and isatis root as the research object,and used anaerobic digestion+simultaneous nitrification and denitrification process to treat this wastewater.The overall treatment efficiency of the process was investigated through long-term commissioning and operation,the main composition changes of wastewater were analyzed by spectral detection technology,and the microbial community structure of each unit was studied by 16S r RNA high-throughput sequencing.The main conclusions are as follows:（1）The anaerobic digestion unit was inoculated with anaerobic granular sludge,and stably operated with the influent volume load of 10 kg COD/（m³·d）and 0.19 kg TN/（m³·d）after 220 days debugged.The simultaneous nitrification and denitrification unit was inoculated with aerobic activated sludge,and stably operated with the influent volume load of 1.0 kg COD/（m³·d）and 0.07 kg TN/（m³·d）after 219 days debugged.（2）The overall operation processing efficiency of the anaerobic digestion+simultaneous nitrification and denitrification process was stable,the COD concentration of the influent was 21000 mg/L,the COD removal rate was 97%,the TN concentration of the influent was 400 mg/L,the TN removal rate was 85%,the NH₄⁺-N concentration of the influent was 200 mg/L,the NH₄⁺-N removal rate was96%,the lignin concentration of the influent was 1800 mg/L,the lignin removal rate was 75%,and the acute toxicity concentration of the influent was 150 mg/L,the acute toxicity removal rate was 7%.（3）The analysis results of Excitation-Emission-Matrix Spectra,Fourier transform infrared spectroscopy,and Ultraviolet-visible absorption spectroscopy showed that the wastewater contained alkanes,olefins,phenols,alcohols,amines,halogenated hydrocarbons,unsaturated organics,aromatic compounds and humic acids.And the dissolved organic matter in wastewater was mainly contributed by humic acids.（4）After treated by each unit,the three-dimensional fluorescence peak intensity of the wastewater was reduced 86%,and the standard volume of fluorescence area integration was reduced 78%,which indicated the humic acids was degraded.The stretching vibration peaks of aromatic compounds in the effluent of each unit appeared peak split,which indicated the acute toxicity and aromaticity of wastewater tended to decrease.The molecular weight parameter value in the ultraviolet region was increased,which indicated the removal effect of macromolecular organic matter in wastewater was remarkable.（5）Methanothrix,Methanobacterium,Bacteroides,Sphaerochaeta,Aminivibri were the mainly microorganisms in the anaerobic digestion unit,with a relative abundance of 21.88%.The relative abundance of Rhodococcus,Nitrosomonas,Hyphomicrobium,Candidatus＿Kuenenia were reached to 3.96%,which involved in the degradation of aromatic compounds,nitrification,denitrification,and anammox.The genera of Deinococcus-Thermus were evolution emerged in the system,which used toxic substances as the me Tableolic substrates.（6）Bacteroides,Saccharofermentans,Trichococcus were the mainly microorganisms in the simultaneous nitrification and denitrification unit,with a relative abundance of 16.09%.The relative abundance of Nitrosomonas,Nitrospira and Nannocystis were reached to 8.15%,which involved in the nitrification process.The relative abundance of Hydrogenophaga,Thermomonas,Mesorhizobium,Flavobacterium and Arenimonas were reached to 12.65%,which involved in the denitrification process.The genera of Acinetobacter,Thauera and Novosphingobium were evolution emerged in the system,which have the functions of both the degradation of aromatic pollutants and denitrification.