3D printed, plastic photocatalytic flow reactors for water purification

Area of Science:

• Materials Science and Engineering
• Chemical Engineering
• Environmental Science

Background:

• 3D printing offers rapid, cost-effective prototyping and is emerging as a scalable advanced manufacturing process.
• Photocatalytic reactors are crucial for degrading pollutants in aqueous solutions.
• Developing efficient and scalable photocatalytic reactor designs is essential for environmental remediation.

Purpose of the Study:

• To design and evaluate two lab-scale, 3D printed plastic, fixed-film, flow-through photocatalytic reactors.
• To compare the performance of a baffled reactor (Reactor B) against an unbaffled reactor (Reactor A) in photocatalytic degradation.
• To assess the efficiency and scalability of 3D printed photocatalytic reactors for water treatment applications.

Main Methods:

• Fabrication of two sinusoidal, 3D printed plastic reactors (Reactor A: no baffles, Reactor B: with baffles) using a P25 TiO2/polylactic acid (PLA) coating.
• Photocatalytic degradation of aqueous solutions of methylene blue (MB) and phenol (PhOH) under UVA irradiation.
• Evaluation of reactor performance based on degradation rates, dependence on flow rate, photonic efficiency, and photocatalytic space-time yields (PSTY).

Main Results:

• Both reactors demonstrated repeatable photocatalytic activity for MB and PhOH degradation without significant loss of performance.
• Reactor B, with baffles, exhibited significantly lower flow rate dependence in MB degradation compared to Reactor A, attributed to enhanced lateral mixing.
• Photonic efficiencies for Reactor A were 0.025% (MB) and 0.052% (PhOH); PSTYs were 0.98 × 10⁻⁴ and 1.49 × 10⁻⁴ m³ solution·m⁻³ reactor⁻¹·day⁻¹·kW⁻¹, respectively.

Conclusions:

• This study presents the first all-plastic, 3D printed photocatalytic reactor, showcasing the advantages of 3D printing for prototyping advanced manufacturing processes.
• The baffled design (Reactor B) improves reactor performance by enhancing flow dynamics, leading to more efficient photocatalysis.
• The scalability of 3D printing suggests significant potential for developing advanced, customized photocatalytic reactors for various environmental applications.