Denitrification performance and microbial communities of solid-phase denitrifying reactors using poly (butylene...

Area of Science:

• Environmental Science
• Microbiology
• Materials Science

Background:

• Aquaculture wastewater poses environmental challenges due to high nitrate levels.
• Solid-phase denitrification (SPD) offers a promising approach for nitrate removal.
• Developing efficient and sustainable materials for SPD is crucial.

Purpose of the Study:

• To evaluate the denitrification performance of poly (butylene succinate)/bamboo powder composite in SPD systems.
• To investigate the impact of varying salinity conditions on denitrification efficiency.
• To analyze the material degradation and microbial community dynamics during the process.

Main Methods:

• Utilized synthetic aquaculture wastewater with salinities of 0‰ and 25‰.
• Operated SPD systems packed with the composite material for 200 days.
• Conducted morphological, spectroscopic, and microbial community analyses.

Main Results:

• Achieved maximum denitrification rates of 0.22 kg NO₃^--N m^-3 d^-1 (0‰) and 0.34 kg NO₃^--N m^-3 d^-1 (25‰).
• Observed minimal nitrite accumulation and low dissolved organic carbon (DOC) release (<15 mg/L).
• Confirmed composite degradation and identified dominant bacterial (Acidovorax, Simplicispira) and fungal (Aspergillus) genera.

Conclusions:

• Poly (butylene succinate)/bamboo powder composite is effective for aquaculture nitrate removal via SPD.
• The composite supports robust microbial communities, facilitating denitrification under different salinities.
• This approach offers a potential strategy for DOC control and cost reduction in aquaculture wastewater treatment.