Adopting primary plastic trickling filters as a solution for enhanced nitrification

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Wastewater Management

Background:

• Sewage treatment works (STW) face pressure to optimize performance and reduce energy consumption.
• Conventional trickling filter processes (CTFP) are established but can be enhanced.
• Energy-intensive alternatives like submerged aerated filters (SAF) are common but costly.

Purpose of the Study:

• To explore the practicability of integrating a cross flow structured plastic media (CFSP) trickling filter (TF) ahead of an existing CTFP.
• To demonstrate the viability of this configuration using an empirical multispecies TF model.
• To assess the potential for enhanced nitrification and reduced energy use.

Main Methods:

• Utilized a process configuration selection matrix to evaluate the hypothetical setup.
• Employed an empirical multispecies trickling filter model to simulate performance.
• Simulated prior removals of biochemical oxygen demand (BOD) to predict nitrification enhancement.

Main Results:

• Predicted enhanced nitrification performance of the CTFP due to prior BOD removal.
• Model simulations indicated 50-80% BOD removals could lead to 40-70% reductions in effluent ammoniacal nitrogen (NH4-N).
• The proposed configuration showed potential to replace energy-intensive alternatives like SAF.

Conclusions:

• Integrating a CFSP trickling filter ahead of a CTFP is a viable and low-energy strategy.
• This configuration maximizes existing assets while improving nitrification robustness.
• The approach offers significant reductions in effluent ammoniacal nitrogen and energy consumption.