Nitrifying biomass can retain its acclimation to 2,4,6-trichlorophenol

Area of Science:

• Environmental microbiology
• Wastewater treatment technologies
• Bioremediation

Background:

• Municipal wastewater treatment plants often receive industrial wastewater containing inhibitory organic chemicals like chlorinated phenols.
• Nitrification, a key step in aerobic biological treatment, is highly sensitive to inhibition by chlorinated phenols, impacting treatment efficiency.

Purpose of the Study:

• To investigate the acclimation of nitrifying biomass to 2,4,6-trichlorophenol (TCP).
• To assess the retained nitrification and TCP biodegradation capabilities of acclimated biomass.
• To evaluate the stability of TCP resistance in acclimated biomass over time and sub-culturing.

Main Methods:

• Acclimation of normal activated sludge to 2,4,6-trichlorophenol (TCP).
• Comparative analysis of nitrification kinetics and TCP removal rates between acclimated and normal biomass.
• Assessment of biomass performance after prolonged periods without TCP exposure and during sub-culturing.
• High-throughput sequencing to identify bacterial communities in acclimated biomass.

Main Results:

• Acclimated biomass exhibited over 2-fold faster nitrification kinetics and effective TCP removal compared to normal biomass.
• Even after two months without TCP, acclimated biomass maintained significant nitrification (0.325 mM/h vs 0.165 mM/h) and TCP removal (0.049 mM/h vs 0.001 mM/h).
• Resistance to TCP inhibition persisted for at least 5 generations of sub-culturing without TCP exposure.

Conclusions:

• Nitrifying biomass can be effectively acclimated to tolerate and degrade 2,4,6-trichlorophenol.
• Acclimated biomass demonstrates robust and stable resistance to TCP inhibition, retaining functionality over extended periods and multiple generations.
• This acclimation strategy holds promise for enhancing the resilience of biological wastewater treatment processes facing inhibitory organic pollutants.