Modelling PAHs removal in activated sludge process: effect of disintegration.

Area of Science:

• Environmental Science
• Environmental Engineering
• Biotechnology

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are persistent organic pollutants found in wastewater.
• Activated sludge processes are commonly used for wastewater treatment but can be limited in PAH removal.
• Sludge disintegration methods are being explored to enhance pollutant removal.

Purpose of the Study:

• To evaluate the impact of sludge disintegration on PAH removal in activated sludge systems.
• To investigate the role of dissolved and colloidal matter (DCM) in PAH removal after disintegration.
• To develop a model for predicting PAH availability and degradation influenced by sludge disintegration.

Main Methods:

• Utilized two laboratory-scale bioreactors, one with and one without a sonication disintegration system.
• Performed mass balances to quantify PAH removal efficiencies.
• Developed and applied a model to assess DCM content and its effect on PAH degradation.

Main Results:

• Sludge disintegration significantly improved overall PAH removal, particularly for higher molecular weight PAHs.
• Disintegration led to an increase in dissolved and colloidal matter (DCM) content.
• The developed model effectively predicted improved PAH degradation trends and identified DCM as the primary driver.

Conclusions:

• Sludge disintegration is an effective strategy for enhancing PAH removal in activated sludge.
• Increased DCM following disintegration is the key factor improving PAH availability and apparent degradation.
• The developed model provides valuable insights into the mechanisms of PAH removal enhancement.