Additive Manufacturing for Contaminants: Ammonia Removal Using 3D Printed Polymer-Zeolite Composites

The diverse suite of contaminants released to the environment requires creative solutions. This research identifies novel application of additive manufacturing to rapidly prototype functional composite structures to adsorb contaminants. Ammonia contamination of water from natural and anthropogenic sources is common. Granular zeolite removes ammonia from water but is not easy to deploy and retrieve from environmental media. This work employed a 3D printer to customize deployable and retrievable devices that remove ammonia from water. Twin screw compounding of zeolite into polylactic acid (PLA) provided printable composites (≈16 wt % zeolite). Simple placement of the printed structures in vials containing ammonia contaminated water (1.2− 12.2 mg/L) significantly reduced concentrations (40−60%) under static water conditions relevant to bioassays or anoxic conditions. Surficial abrasion of composite surfaces may facilitate additional ammonia removal. Normalization to zeolite mass indicated printed PLA-zeolite composites performed comparably to free zeolite. Most ammonia removal occurred within 48 h, with diminishing benefit with longer exposure. This first-principles research demonstrated 3D printed devices remove ammonia from water. There is potential for future benefit through rapid prototyping to optimize efficacy via geometric complexity, higher filler loadings, uptake kinetics studies, and different filler−polymer pairings for additional contaminants.