Towards a continuous two-phase partitioning bioreactor for xenobiotic removal

Area of Science:

• Environmental Engineering
• Biotechnology
• Chemical Engineering

Background:

• Wastewater treatment often faces challenges with persistent organic pollutants like 4-chlorophenol.
• Continuous two-phase partitioning bioreactors (C-TPPB) offer a promising approach for efficient pollutant removal.

Purpose of the Study:

• To investigate the removal of 4-chlorophenol from contaminated water using a C-TPPB system incorporating Hytrel 8206 polymer tubing.
• To evaluate the mass transfer characteristics and overall efficiency of the bioreactor under various operating conditions.

Main Methods:

• A simulated C-TPPB was designed with coiled Hytrel 8206 tubing for pollutant diffusion.
• Wastewater containing 4-chlorophenol flowed through the tubing, with removal occurring in the aqueous bioreactor phase.
• Experiments were conducted varying influent concentrations (500-1500 mgL⁻¹) and hydraulic retention times (4-8h).

Main Results:

• Overall mass transfer coefficients ranged from 1.7-3.5×10⁻⁷ ms⁻¹, indicating efficient pollutant diffusion through the tubing.
• Removal efficiencies for 4-chlorophenol in the tubing wastewater stream consistently exceeded 96%.
• The Hytrel tubing enhanced system stability by buffering increases in organic loading.

Conclusions:

• The C-TPPB system with Hytrel tubing is highly effective for removing 4-chlorophenol, achieving removal efficiencies up to 99%.
• Mass transfer rates were comparable to biological removal rates, confirming the system's efficiency.
• The integrated system demonstrates robust performance and improved stability for treating contaminated water.