Study On The Treatment Of Maltol Production Wastewater By Aeration Biofilter Process

Organic wastewater with high chemical oxygen demand(COD)and high ammonia nitrogen has strong toxicity and "tri-causal" characteristics,in which organic compounds are structurally stable and can enter the environment through various pathways,causing adverse effects on the ecological environment and human health,so it is important to find an efficient and economic solution.In recent years,biological methods have been widely used to treat industrial wastewater,among which biomanganese oxides generated by extracellular oxidation of manganese by manganese oxidizing bacteria can be used to treat hard-to-degrade organic wastewater because of its strong adsorption and oxidation properties.In this paper,we firstly investigated the degradation effect of biomanganese oxide on monocyclic organic aniline and the effect on the surface structure of manganese sand,and further investigated the degradation efficiency of maltol production wastewater in a pilot system established on this basis,and analyzed the changes of microbial community during the operation.The following conclusions were drawn:The adsorption efficiency of natural manganese sand was investigated for aniline,and the degradation effect of biomanganese oxide on aniline and ammonia nitrogen was also studied.The adsorption effect of natural manganese sand on aniline reached the maximum adsorption rate of 82% within 4 h,and then gradually tended to saturate within 10 h;in the presence of biomanganese oxide,aniline at a concentration of 100mg/L was almost completely removed within 1h,and also had a certain degradation effect on ammonia nitrogen;the surface structure of manganese sand under the influence of biomanganese oxide changed,and compared with the original sample,the microscopic surface of manganese sand obviously The surface structure of manganese sand under the influence of biomanganese oxide changed,and the microscopic surface of manganese sand became more smooth and more microporous compared with the original sample.The degradation efficiency and operational factors of the pilot-scale aeration biofilter process on maltol production wastewater were studied.The COD concentration in the wastewater was maintained at 100-300 mg/L and ammonia nitrogen concentration at 10-20 mg/L;after the process treatment,the COD effluent concentration was maintained at 40-60 mg/L with a removal rate of more than 60%,and the ammonia nitrogen effluent concentration was at 1-5 mg/L with a removal rate of more than 80%.The changes of microbial communities in the nitrifying aeration biofilter(N-BAF)and carbon oxidation bioaeration filter(C-BAF)during the operation of the aeration biofilter(BAF)system were investigated.the degradation of ammonia nitrogen in the N-BAF filter was obvious,which was mainly composed of nitrifying bacteria(Nitrosomonas,Methylotenera,etc.),;in the C-BAF Biomanganese oxides(Pseudomonas Pseudomonas)and bacteria of the phylum Aspergillus achieved efficient degradation of COD.The site situation of invasion by foreign organisms during operation seriously damaged the original microbial community,resulting in a decrease in microbial community abundance,and the invaded bacteria on the level of the biotope phylum were mainly Aspergillus,Bacteroidetes and other unclassified bacteria,accounting for46.92%,14.42% and 10.91%.The combined physical-chemical-biological method was used to treat such situations,and the results showed that the treated COD removal rate was close to 40% and ammonia nitrogen removal rate was close to 80%,and the system returned to normal operation.