Study On Start-up Performance And Biological Characteristics Of A Self-cleaning Activated Bio-filter

With the development of social urbanization, the requirements of sewage treatment were more and more strict, however, the index of some municipal wastewater treatment plant effluent couldn’t satisfy the A standard of GB 18918-2002. Self-cleaning activated bio-filter had broad application prospects in terms of advanced denitrification, which owed to its small footprint and easy performance. This paper compared the natural start-up and the artificially seeding sludge start-up of Self-cleaning activated bio-filter,researched the pollutants removal efficiency of Self-cleaning activated bio-filter operational phase impacting by filtration rate and the amount of carbon source supplement, and established a calculation model for the rate of internal voids of the bio-filter. The Phenom scanning electron microscope was used to observe the biofilm on the filter surface and Matlab software was used to calculate the fractal box dimension of the biofilm on the filter surface. High-throughput sequencing was used to research the microorganism structure. The following is the main content of subject study.(1)During 28 d period of natural start-up, the highest removal rate of COD was 17.50% and the lowest was 2.17%;the highest removal rate of TN was 9.84% and the lowest was 1.38%;the highest removal rate of TP was 22.76% and the lowest was 1.87%. During 7 days period of the start-up of artificially seeding sludge, the removal rate of COD reached 48.60%, the removal rate of TN reached 52.60% and the removal rate of TP reached 46.32%. During the period of function artificially seeding sludge. The best biochemical reaction time was 18 min. When ethanol was used as the carbon source, the amount of carbon source added to 30ml/m3 was appropriate.(2) The three point sample from the Self-cleaning activated bio-filter filter layer measured biomass were 1.6×106cfu/mL, 40.3×106cfu/mL, 56.1×106cfu/mL. The fractal box dimension of the three point sample was 2.1376,2.1425,2.1431. The fractal box dimension is a linear relationship between the Pair value of biomass.(3)In the middle of the Self-cleaning activated bio-filter filter layer. The biomass of Phosphorus bacteria was 8.9×106 cfu/mL and the biomass of Denitrification bacteria was 2.426×106 cfu/mL. From the point of view of the family and genus level, the Comamonadaceae contains bacteria which have a denitrification capability and the Hydrogenophaga contains bacteria which have a anaerobic nitrate respiratory function became the dominant families and genera in the Self-cleaning activated bio-filter.Diversity of the biological community in self-cleaning activated bio-filter is less than the diversity of the biological community in the biological pool.