Nitrogen and phosphorus treatment of marine wastewater by a laboratory-scale sequencing batch reactor with eco-friendly marine high-efficiency sediment

摘要

We screened and identified a NH3-N-removing bacterial strain, Bacillus sp. KGN1, and a removing strain, Vibrio sp. KGP1, from 960 indigenous marine isolates from seawater and marine sediment from Tongyeong, South Korea. We developed eco-friendly high-efficiency marine sludge (eco-HEMS), and inoculated these marine bacterial strains into the marine sediment. A laboratory-scale sequencing batch reactor (SBR) system using the eco-HEMS for marine wastewater from land-based fish farms improved the treatment performance as indicated by 88.2% removal efficiency (RE) of total nitrogen (initial: 5.6mg/L) and 90.6% RE of total phosphorus (initial: 1.2mg/L) under the optimal operation conditions (food and microorganism (F/M) ratio, 0.35g SCODCr/g mixed liquor volatile suspended solids (MLVSS)boldd/bold; dissolved oxygen (DO) 1.00.2mg/L; hydraulic retention time (HRT), 6.6h; solids retention time (SRT), 12 d). The following kinetic parameters were obtained: cell yield (Y), 0.29g MLVSS/g SCODCr; specific growth rate (mu), 0.06d(-1); specific nitrification rate (SNR), 0.49mg NH3-N/g MLVSSboldh/bold; specific denitrification rate (SDNR), 0.005mg g MLVSSboldh/bold. The nitrogen- and phosphorus-removing bacterial strains comprised 18.4% of distribution rate in the microbial community of eco-HEMS under the optimal operation conditions. Therefore, eco-HEMS effectively removed nitrogen and phosphorus from highly saline marine wastewater from land-based fish farms with improving SNR, SDNR, and SPUR values in more diverse microbial communities.