Physiologic impact of 2-chlorophenol on denitrification process in mixture with different electron sources

Area of Science:

• Environmental Microbiology
• Biotechnology
• Environmental Chemistry

Background:

• The presence of chlorinated phenols like 2-chlorophenol (2-CP) can inhibit microbial processes in wastewater treatment.
• Denitrification is a crucial process for removing nitrogen from wastewater, and its efficiency can be affected by various organic compounds.

Purpose of the Study:

• To investigate the physiological and kinetic behavior of sludge during denitrification in the presence and absence of 2-chlorophenol (2-CP).
• To evaluate the influence of different electron donors (phenol, glucose, acetate) on the denitrification process when 2-CP is present.

Main Methods:

• Batch assays were conducted to monitor denitrification under varying conditions.
• Key parameters measured included nitrate and substrate consumption efficiencies, specific consumption rates, and product yields (N2 gas, bicarbonate).

Main Results:

• 2-CP significantly decreased phenol consumption efficiency and specific consumption rates, but denitrification still occurred.
• Denitrification performance with glucose was largely unaffected by 2-CP, though specific glucose consumption rate increased.
• Acetate consumption efficiency remained high with 2-CP, but specific acetate consumption rate increased, while nitrate consumption rate decreased.

Conclusions:

• The effect of 2-CP on denitrification is dependent on the type and concentration of the electron donor used.
• Understanding these substrate-specific effects is vital for optimizing wastewater treatment bioreactors handling 2-CP.
• The study provides valuable physiological and kinetic data for managing denitrification in the presence of 2-CP.