An article published on August 2, 2017 in the peer-reviewed journal Green Chemistry reported on a cost effective solution to remove bisphenol A (BPA, CAS 80-05-7) from water. BPA is used in the production of polycarbonate plastic (PC) and epoxy resins, and can be found in applications such as DVDs, CDs, eyeglass lenses, thermal receipts, and food packaging. Due to its high production volume, BPA is ubiquitous in the environment, entering waterways via industrial waste streams or landfill runoff. BPA is a recognized human endocrine disruptor (FPF reported) and therefore a public health concern.
Yusuf Onundi and colleagues from the University of Auckland, New Zealand, Carnegie Mellon University, and Oregon State University, both U.S., developed a group of catalysts called TAML activators (tetra-organic-amido-N macrocyclic ligand complexes). These small molecules mimic oxidizing enzymes and, in combination with hydrogen peroxide (H2O2), were shown to effectively remove BPA from water. At pH 8.5, TAML/H2O2 added to BPA-contaminated water (10,000 µg/L) resulted in a >99% reduction of BPA within 30 minutes. BPA assembled into oligomers which precipitated out of the water. At this near neutral pH, normally found in wastewater treatment, “the oligomers could be filtered and disposed of in a BPA water treatment facility,” suggested Terrence Collins, senior author of the study. Very notably, the researchers found that oligomerization of the BPA molecules was non-reversible. Further, the researchers tested the TAML/H2O2-treated water in yeast estrogen screens (YES) and zebrafish developmental assays and found no estrogen activity or abnormalities. At pH 11, TAML/H2O2 added to BPA-contaminated water (34,244 µg/L) achieved a >99.9% reduction of BPA within 15 minutes. At this pH, the catalyst destroyed the BPA molecules and no oligomerization occurred.
Collins concluded: “Because TAML/hydrogen peroxide treatment eliminates BPA from water so easily at concentrations that are similar to a variety of waste streams including paper plant processing solutions and landfill leachate, assuming the lab studies transfer to the real world, we can now offer a new and simple procedure for reducing BPA exposures worldwide.”
Science Daily (August 2, 2017). “Catalysts efficiently and rapidly remove BPA from water.”
Brian Bienkowski (August 2, 2017). “BPA breakthrough: New treatment takes controversial chemical out of water.” Environmental Health News
Rebecca Campbell (August 25, 2017). “Scientists spend a decade perfecting BPA removal method.” Chemistry World
Onundi, Y. et al. (2017). “A multidisciplinary investigation of the technical and environmental performances of TAML/peroxide elimination of bisphenol A compounds from water: Destruction, oligomerisation, mechanism, end product toxicity, and applications.” Green Chemistry (published August 2, 2017).