Welter Júlia Bitencourt, da Silva Salatiel Wohlmuth, Schneider Daniela Eduarda, Rodrigues Marco Antônio Siqueira, Ferreira Jane Zoppas
Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Engenharia de Minas, Metalúrgica e de Materiais (PPGE3M), Av. Bento Gonçalves, 9500, Porto Alegre, RS, Brazil.
UFRGS - Instituto de Pesquisas Hidráulicas (IPH), Programa de Pós-Graduação em Recursos Hídricos e Saneamento Ambiental, Av. Bento Gonçalves, 9500, Porto Alegre, RS, Brazil.
Chemosphere. 2020 Jun;248:126062. doi: 10.1016/j.chemosphere.2020.126062. Epub 2020 Jan 31.
Glucocorticoids are widely used to treat a variety of diseases. Consequently, these compounds have been found in water and wastewater matrix. Despite studies have proven its toxicity, just a few works investigate techniques to degrade and mineralize them. To solve this issue, this work presents the degradation and mineralization of prednisone (PRED) by electrochemical advanced oxidation (EAO) using a boron-doped diamond supported on niobium (Nb/BDD) anode in synthetic and real wastewater. Cyclic voltammetry (CV) was performed to investigate the PRED oxidation mechanisms. CV suggest that PRED will be oxidized via HO and other oxidants generated from the ions present in the liquid matrix (SO, SO, HClO, ClO etc.). Different EAO conditions as initial pH (3, 7 and 11) and applied current densities (5, 10 and 20 mA cm) were evaluated. The best result was obtained at alkaline pH (11) and a current density of 20 mA cm, achieving 78% of degradation and 42% of mineralization. Using the best conditions, the EAO was applied as a polishing treatment stage to remove PRED from a biological pre-treated municipal wastewater spiked with PRED. The results indicate that EAO applied in the real matrix provides better results than the synthetic solution, probably associated with the presence of ions that can be electrochemically converted into oxidant species, resulting in higher kinetic constant, mineralization current efficiency and lower energetic consumption. Therefore, the EAO process without the addition of chemicals has proven to be an effective alternative as a tertiary treatment of municipal wastewater contaminated with PRED.
糖皮质激素被广泛用于治疗多种疾病。因此，在水和废水基质中发现了这些化合物。尽管研究已证明其毒性，但仅有少数研究探讨了降解和矿化它们的技术。为了解决这个问题，本研究展示了在合成废水和实际废水中，使用负载在铌（Nb/BDD）阳极上的硼掺杂金刚石通过电化学高级氧化（EAO）对泼尼松（PRED）进行降解和矿化。通过循环伏安法（CV）研究PRED的氧化机制。CV表明PRED将通过HO以及液体基质中存在的离子（SO、SO、HClO、ClO等）产生的其他氧化剂被氧化。评估了不同的EAO条件，如初始pH值（3、7和11）和施加的电流密度（5、10和20 mA/cm）。在碱性pH值（11）和20 mA/cm的电流密度下获得了最佳结果，实现了78%的降解率和42%的矿化率。在最佳条件下，将EAO用作抛光处理阶段，以从添加了PRED的生物预处理城市废水中去除PRED。结果表明，在实际基质中应用EAO比在合成溶液中效果更好，这可能与可电化学转化为氧化物种的离子的存在有关，从而导致更高的动力学常数、矿化电流效率和更低的能量消耗。因此，不添加化学药剂的EAO工艺已被证明是处理受PRED污染的城市废水的有效三级处理替代方法。
