[Gaseous phenol removal in a bio-trickling filter]

Area of Science:

• Environmental microbiology
• Biotechnology
• Wastewater treatment

Background:

• Phenol is a common industrial pollutant.
• Bio-trickling filters (BTFs) are effective for treating organic pollutants.

Purpose of the Study:

• To evaluate the performance of a BTF for phenol removal.
• To identify optimal operating conditions for phenol degradation.
• To characterize the microbial community and degradation pathway.

Main Methods:

• Experimental operation of a BTF.
• Optimization of residence time, pH, and spray density.
• Microbial community analysis using PCR-DGGE and 16S rDNA sequencing.
• Gas chromatography-mass spectrometry (GC-MS) for intermediate detection.

Main Results:

• High phenol removal efficiency (99.5% peak, 98% long-term).
• Optimal conditions: 20.6 s residence time, pH 7.0, 1.67 m(3) x (m(2) x h)(-1) spray density.
• Identified key bacteria: Polaromonas sp., Acinetobacter sp., Acidovorax sp., Veillonella parvula, Corynebacterium sp.
• Detected pyruvic acid as a phenol biodegradation intermediate.

Conclusions:

• BTFs are highly efficient for phenol removal.
• Specific operating parameters enhance degradation.
• Identified microbial consortia and a potential biodegradation pathway contribute to phenol removal.