Laboratório Associado de Sensores E Materiais, Instituto Nacional de Pesquisas Espaciais (INPE), Av. Dos Astronautas, São José Dos Campos, SP, 1758, 12227 010, Brazil.
Electrochemical & Environmental Engineering Lab, TEQUIMA Research Group - Edificio Enrique Costa Novella, Campus Universitario S/N, 13071, Ciudad Real, Spain.
Environ Sci Pollut Res Int. 2023 Nov;30(55):117871-117880. doi: 10.1007/s11356-023-30407-w. Epub 2023 Oct 24.
In this work, a new coating of boron-doped diamond ultra-nanocrystalline (U-NBDD), tailored to prevent massive formation of perchlorates during disinfection, is evaluated as electrode for the reclaiming of treated secondary wastewater by the electrochemically assisted disinfection process. Results obtained are compared to those obtained by using a standard electrode (STD) that was evaluated as a standard in previous research showing outstanding performance for this application. First tests were carried out to evaluate the chlorine speciation obtained after the electrolysis of synthetic chloride solutions at two different ranges of current densities. Concentrations of hypochlorite obtained using the U-NBDD anode at 25 mA cm were 1.5-fold higher, outperforming STD anode; however, at 300 mA cm, an overturn on the behavior of anodes occurs where the amount of hypochlorite produced on STD anode was 1.5-fold higher. Importantly, at low current density the formation of chlorates and perchlorates is null using U-NBDD. Then, the disinfection of the real effluent of the secondary clarifier of a municipal wastewater treatment facility is assessed, where inactivation of Escherichia coli is achieved at low charge applied per volume electrolyzed (0.08 A h L) at 25 mA cm using the U-NBDD. These findings demonstrate the appropriateness of the strategy followed in this work to obtain safer electro-disinfection technologies for the reclaiming of treated wastewater.
在这项工作中，评估了一种新的硼掺杂金刚石超纳米晶（U-NBDD）涂层，旨在防止消毒过程中高氯酸根的大量形成，作为通过电化学辅助消毒过程回收处理后的二级废水的电极。将获得的结果与使用标准电极（STD）获得的结果进行了比较，该标准电极在先前的研究中被评估为该应用的标准，表现出出色的性能。首先进行了测试，以评估在两种不同电流密度范围内电解合成氯化物溶液后获得的氯的形态。使用 U-NBDD 阳极在 25 mA cm 下获得的次氯酸盐浓度高 1.5 倍，优于 STD 阳极；然而，在 300 mA cm 下，阳极的行为发生了逆转，STD 阳极产生的次氯酸盐量高 1.5 倍。重要的是，在低电流密度下，U-NBDD 不会形成氯酸盐和高氯酸盐。然后，评估了市政污水处理厂二级澄清池的实际废水的消毒情况，在 25 mA cm 下使用 U-NBDD 以每电解体积施加的低电荷量（0.08 A h L）实现大肠杆菌的失活。这些发现证明了本工作中采用的策略是合理的，可获得更安全的电消毒技术，用于回收处理后的废水。
