Optimization of construction parameters of glass pumice sequencing batch biofilm reactor and study on denitrification performance of aquaculture wastewater

【Objective】The denitrification performance of glass pumice constructed sequencing batch biofilm reactor(SBBR) in aquaculture sewage was studied,which provided model and data reference of an efficient and low-cost carrier choice for biofilm treatment of aquaculture sewage. 【Method】The SBBR was constructed with glass pumice as the carrier,using aquaculture pond sediment to hang film,and the pore size(3-8,2-3,1-2 and 0.1-1.0 mm),particle size(10-20,20-30and 30-50 mm) and filling rate(20%,30% and 40%) of the glass pumice were optimized for the optimal construction parameters of the SBBR. Taking zeolite,volcanic stone,activated carbon,and SiO2 particles as controls,the volatile suspended solid(VSS) and extracellular polymeric substances(EPS) of each carrier material were compared,the adsorption capacity of different materials for more hydrophobic proteins was compared. 【Result】The SBBR constructed with 1-2 mm pore size,10-20 mm particle size,and 20% filling rate had the best nitrogen removal performance. On day 30,the removal rates of ammonia nitrogen,nitrous nitrogen and total nitrogen concentration could reach(90.61±0.30)% and(99.45±0.08)% and(94.04±0.14)%,the content of VSS on glass pumice was 3.87±0.11 g/L,and the content of EPS was 80.99±0.05 mg/g-VSS,which were significantly higher than other groups(P<0.05,the same below),and EPS had a higher protein/polysaccharide(PN/PS) ratio,which was conducive to the formation of biofilms. In the adsorption experiment of nitrogen-removing bacteria,glass pumice adsorbed(58.08±0.15)% of bovine serum albumin(BSA),which was significantly higher than that of zeolite(41.72±0.40)%,volcanic rock(25.34±0.53)%,activated carbon(20.68±0.13)% and Si O2 particles(15.56±0.38)%. 【Conclusion】The application of SBBR constructed with glass pumice in aquaculture sewage treatment has good denitrification ability,and excellent adsorption capacity of nitrogen removal bacteria,which is a good carrier material for biofilm technology to repair aquaculture sewage.