Research And Development Of A New Fermentation Bed Sewage Treatment System And Microbial Diversity In The System

With the increasing scale of pig raising,the pollution discharge of pig farms is increasing and the pollution to the environment is becoming more and more serious.In this study,a new type of pig fermentation bed sewage treatment system was developed from the source,which combined with microbial fermentation bed treatment and natural evaporation,using microorganism to quickly absorb the organic matter in sewage,and use the natural evaporation principle to evaporate the water in sewage and achieve the goal of zero emission.In order to further study the performance of the system in production practice.In this study,the effect of source emission reduction and sewage treatment capacity of the system was studied,and high throughput sequencing technology was used to study the dominant microorganisms in the fermentation bed.The concrete results are as follows:1.the water dispenser of the traditional piggery was optimized.The water bowl with the water level valve was replaced by the traditional duck mouth water dispenser.The average water consumption of the three stages in the piglets,the medium pigs and the big pigs was 3.9L/(head.d),4.1L/(head d)and 4.4L/(head d)respectively.The water consumption of the whole production stage was 366.7m3,which was far superior in water saving.In the traditional piggery,the purpose of reducing effluent from the source is realized,which is conducive to the subsequent treatment of sewage.2.through the optimization of the leaking dung floor and the use of automatic shaving machine,the excrement of the excrement is only 307.2t during the whole feeding process,and the discharge amount of a traditional piggery in a breeding period can reach about 1000 t,which makes the whole discharge of the green piggery only 20% left and right of the traditional piggery.3.the study found that the capacity of the new fermentation bed sewage treatment system to treat sewage was the lowest in December,and the highest in July.In December,the daily handling capacity was 2.3 tons,compared with 9.2 tons in July.The total amount of treatment is about 2000 tons in the year.4.to investigate the microbial diversity and dominant bacteria in the system.9 samples were obtained from the surface,middle and deep layer of the fermented bed with the "five point sampling method",for the surface(1-1,1-2,1-3),the middle layer(2-1,2-2,2-3),and the deep(3-1,3-2,3-3).The total DNA of the mattress material was extracted,and the total DNA of the mattress material was used as the template.The 16 SrDNA gene V3-V4 hypervariable region of the bacteria was amplified by PCR,and the ITS1-ITS2 region of the fungus was amplified by PCR.The PCR product was sent to Shanghai Meiji biological medicine technology Co.,Ltd.for 16 SrRNA gene fragment amplification and high throughput sequencing.Through sequence analysis and sequence analysis,species classification and OUT cluster analysis were carried out.The results are as follows:(1)the microbial diversity in the middle layer of the fermentation bed is much higher than that of the surface and deep layer,and the diversity and abundance of the bacteria are much higher than that of the fungi.(2)the bacteria belonging to 24 doors,43 classes,95 orders,197 families,390 genera,529 species,and the average 45.96% of the Proteobacteria(Proteus)and the average of 28.79%(pseudo bacilli)are the dominant bacteria in the fermentation bed.(3)fungi belong to 18 genera,15 families,11 orders,11 orders,6 classes,and 18 genera.The dominant flora was Ascomycota(cystis)with an average of 59.18% and Zopfiella(62.34%).The above results show that by the design of the source reduction,the water consumption and discharge of the piggery are reduced,and the treatment capacity of the sewage can also fully meet the 1500 pig farms of a year.In terms of microbial diversity,the results showed that there were differences in microbial richness,diversity,similarity and dominant flora at different depths.