Bisphenols are monomers used in the production of polycarbonate plastics and epoxy resins, which are used in many applications, including food contact materials. Among them, bisphenol A (BPA) is the most extensively used and studied compound due to its well-documented toxicological effects, including genotoxicity, endocrine disruption, reproductive toxicity, cytotoxicity and neurotoxicity. In response to these risks, in April 2023, the European Food Safety Authority (EFSA) significantly lowered the Tolerable Daily Intake (TDI) for BPA from 4 µg/kg body weight per day to 0.2 ng/kg body weight per day. Moreover, the EU has banned the use of BPA in food contact materials as of December 2024. Even before these regulatory changes, the industry had already been actively seeking compounds with reduced or no toxic effects that can replace BPA while maintaining its desired chemical properties. One such alternative is tetramethyl bisphenol F diglycidyl ether (TMBPF-DGE), a derivative of 4,4′-methylenebis-(2,6-dimethylphenol) (TMBPF), produced by the Sherwin-Williams Company (USA). While TMBPF, a potential BPA substitute, exhibits similar cytotoxicity to BPA, it has a lower impact on the endocrine and reproductive systems. In addition, its biodegradation kinetics have already been studied. In this work, I focus on the related, newly synthesized compound TMBPF-DGE, examining its removal and degradation kinetics via photochemical and biological processes.
Photochemical removal was assessed in drinking water and treated wastewater effluent at an initial concentration of 200 ng/L using a laboratory photochemical reactor equipped with a low-pressure Hg-UV lamp (λ = 254 nm), with a maximum irradiation time of 120 min. Biological removal was studied in a synthetic wastewater effluent inoculated with activated sludge from a municipal wastewater treatment plant, at an initial TMBPF-DGE concentration of 0.1 mg/L. At set intervals, samples were extracted using solid-phase extraction and analysed by LC-MS/MS following method optimization and validation. Assuming first-order kinetics, degradation rate constants and half-lives were determined.
Photochemical treatment removed 98 % of TMBPF-DGE in drinking water and 94 % in synthetic effluent after 120 mins. During biological removal, levels of TMBPF-DGE fell below the LOQ after 48 hrs. These findings demonstrate that TMBPF-DGE can be effectively removed from aqueous environments by biological and photochemical processes. However, further research is needed to identify and assess the toxicity of transformation products.
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