Enrichment and agent preparation of Gordonia for denitrifying phosphorus removal

Abstract:

[Background] Adding microbial inoculum is an important means to enhance the efficiency of biological treatment, and denitrification is a key step in nitrogen and phosphorus removal from wastewater. However, there are few reports on denitrifying microbial agents. [Objective] To acclimate efficient denitrifying phosphorus accumulating organism (DPAO), make the denitrifying agent, and enhance the agent performance. [Methods] The DPAO was rapidly enriched by two-phase method, and strain NC1-1 with high-efficiency nitrogen and phosphorus removal was screened out and identified. The bacterial powder was prepared with NC1-1 strain, and the effect of the powder on wastewater treatment in A²SBR system was studied. [Results] DPAO was enriched successfully after 36 days. Strain NC1-1 was identified as Gordonia, with the nitrogen and phosphorus removal rates of 89.46% and 91.68%, respectively. The bacterial powder was successfully prepared with the wheat bran-to-corn flour ratio of 85%:15%, NC1-1 inoculum volume of 20 mL, and fermentation broth volume of 20 mL. The removal rates of total phosphorus (TP) and NO₃⁻-N in the A²SBR system supplemented with the bacterial powder at a dosage of 10% were 12.06% and 11.52%, respectively, higher than those in the A²SBR system without the bacterial powder. [Conclusion] The adding of NC1-1 enhanced the pollutant removal efficiency of A²SBR system. The research outcome provides a theoretical basis for the further study of DPAO agent.

Key words:denitrifying phosphorus accumulating organism;A²SBR;Gordonia;bacterial powder