Anaerobic sequencing batch reactor as initiating stage in complete pentachlorophenol biodegradation

Area of Science:

• Environmental microbiology
• Bioreactor engineering
• Wastewater treatment

Background:

• Pentachlorophenol (PCP) is a persistent organic pollutant requiring effective remediation strategies.
• Anaerobic biodegradation offers a promising approach for PCP removal from contaminated environments.
• Sequential batch reactors (SBRs) are versatile systems for biological wastewater treatment.

Purpose of the Study:

• To detail the technological and microbiological aspects of PCP biodegradation in an anaerobic sequencing batch reactor (AnSBR).
• To evaluate the impact of sludge adaptation, concentration, and PCP levels on biodegradation efficiency.
• To model the PCP degradation process and analyze effluent quality and sludge structural changes.

Main Methods:

• Utilized a two-reactor system, focusing on the first anaerobic sequencing batch reactor (AnSBR).
• Investigated two distinct sludge adaptation strategies for pentachlorophenol (PCP) detoxification.
• Monitored PCP degradation rates, effluent chemical oxygen demand (COD) and suspended solids (SS), and sludge microstructure.

Main Results:

• Demonstrated the influence of sludge concentration and adaptation methods on PCP biodegradation rates.
• Determined the minimum retention time required for PCP degradation based on initial PCP concentrations.
• Observed changes in sludge micro- and macrostructure during the acclimatization process, correlating with degradation efficiency.

Conclusions:

• The study provides critical insights into optimizing AnSBR performance for PCP removal.
• Understanding sludge behavior and process parameters is essential for effective bioremediation of PCP-contaminated water.
• The findings contribute to the development of robust biological treatment systems for recalcitrant organic pollutants.