Departamento de Química da Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - Universidade de São Paulo, Ribeirão Preto 14.040-901, Brazil; Instituto Federal de Educação, Ciência e Tecnologia do Triângulo Mineiro, Uberaba 38.064-790, Brazil.
Departamento de Química da Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - Universidade de São Paulo, Ribeirão Preto 14.040-901, Brazil.
Sci Total Environ. 2023 Jan 10;855:158816. doi: 10.1016/j.scitotenv.2022.158816. Epub 2022 Sep 15.
This study aims to develop a cheap method for the evaluation of quality of water or the assessment of the treatment of water by chemical oxygen demand (COD) measurements throughout the use of the HSV color model in digital devices. A free application installed on a smartphone was used for analyzing the images in which the colors were acquired before to be quantified. The proposed method was also validated by the standard and spectrophotometric methods, demonstrating that no significant statistical differences were attained (average accuracy of 97 %). With these results, the utilization of this smartphone-based method for COD analysis was used/evaluated, for first time, by treating electrochemically a real water matrix with substantial organic and salts content using BDD and Pt/Ti anodes. Aiming to understand the performance of both anodes, bulk experiments were performed under real pH by applying current densities (j) of 15, 30, and 60 mA cm. COD abatement results (which were achieved with this novel smart water security solution) clearly showed that different organic matter removal efficiencies were achieved, depending on the electrocatalytic material used as well as the applied current density (42 %, 45 %, and 85 % for Ti/Pt while 93 %, 97 % and total degradation for BDD by applying 15, 30, and 60 mA cm, respectively). However, when the persulfate-mediated oxidation approach was used, with the addition of 2 or 4 g NaSO L, COD removal efficiencies were enhanced, obtaining total degradation with 4 g NaSO L and by applying 15 mA cm. Finally, this smartphone imaging-based method provides a simple and rapid method for the evaluation of COD during the use of electrochemical remediation technology, developing and decentralizing analytics technologies for smart water solutions which play a key role in achieving the Sustainable Development Goal 6 (SDG6).
本研究旨在开发一种廉价的方法，通过在数字设备中使用 HSV 颜色模型来评估水的质量或评估水的处理效果，通过化学需氧量 (COD) 测量。智能手机上安装的免费应用程序用于分析获取颜色之前的图像。所提出的方法还通过标准和分光光度法进行了验证，证明没有达到显著的统计学差异（平均准确率为 97%）。有了这些结果，首次利用基于智能手机的 COD 分析方法，使用 BDD 和 Pt/Ti 阳极对含有大量有机物和盐分的实际水基质进行电化学处理。为了了解两个阳极的性能，在实际 pH 下进行了体积实验，施加的电流密度 (j) 为 15、30 和 60 mA cm。COD 去除结果（使用这种新型智能水安全解决方案实现）清楚地表明，根据所使用的电催化材料和施加的电流密度，实现了不同的有机物去除效率（Ti/Pt 为 42%、45%和 85%，而 BDD 为 93%、97%和完全降解，分别施加 15、30 和 60 mA cm）。然而，当使用过硫酸盐介导的氧化方法，并添加 2 或 4 g NaSO L 时，COD 去除效率得到提高，通过添加 4 g NaSO L 和施加 15 mA cm 获得完全降解。最后，这种基于智能手机成像的方法为电化学修复技术使用过程中 COD 的评估提供了一种简单快速的方法，为智能水解决方案开发和分散分析技术，这对于实现可持续发展目标 6（SDG6）起着关键作用。
