Instituto de Química, Universidade Federal de Uberlândia, Uberlândia 38400-902, Brazil.
Faculdade de Ciências Naturais e Exactas, Universidade Save, Chongoene 0301-01, Mozambique.
Molecules. 2022 Aug 27;27(17):5521. doi: 10.3390/molecules27175521.
Benzophenone-3, fipronil and propylparaben are micropollutants that are potential threats to ecosystems and have been detected in aquatic environments. However, studies involving the investigation of new technologies aiming at their elimination from these matrices, such as advanced oxidation processes, remain scarce. In this study, different iron complexes (FeCit, FeEDTA, FeEDDS and FeNTA) were evaluated for the degradation of a mixture of these micropollutants (100 µg L−1 each) spiked in municipal wastewater treatment plant (MWWTP) effluent at pH 6.9 by solar photo-Fenton. Operational parameters (iron and H2O2 concentration and Fe/L molar ratio) were optimized for each complex. Degradation efficiencies improved significantly by increasing the concentration of iron complexes (1:1 Fe/L) from 12.5 to 100 µmol L−1 for FeEDDS, FeEDTA and FeNTA. The maximum degradation reached with FeCit for all iron concentrations was limited to 30%. Different Fe/L molar ratios were required to maximize the degradation efficiency for each ligand: 1:1 for FeNTA and FeEDTA, 1:3 for FeEDDS and 1:5 for FeCit. Considering the best Fe/L molar ratios, higher degradation rates were reached using 5.9 mmol L−1 H2O2 for FeNTA and FeEDTA compared to 1.5 and 2.9 mmol L−1 H2O2 for FeEDDS and FeCit, respectively. Acute toxicity to Canton S. strain D. melanogaster flies reduced significantly after treatment for all iron complexes, indicating the formation of low-toxicity by-products. FeNTA was considered the best iron complex source in terms of the kinetic constant (0.10 > 0.063 > 0.051 > 0.036 min−1 for FeCit, FeNTA, FeEDTA and FeEDDS, respectively), organic carbon input and cost-benefit (USD 327 m−3 > USD 20 m−3 > USD 16 m−3 > USD 13 m−3 for FeEDDS, FeCit, FeEDTA and FeNTA, respectively) when compared to the other tested complexes.
二苯甲酮-3、氟虫腈和丙基对羟基苯甲酸酯是潜在的生态系统威胁物质，已在水生环境中被检出。然而，涉及到研究旨在从这些基质中去除这些污染物的新技术的研究仍然很少，例如高级氧化工艺。在这项研究中，评估了不同的铁络合物（FeCit、FeEDTA、FeEDDS 和 FeNTA）在 pH 值为 6.9 的市政污水处理厂（MWWTP）出水时，对这三种微污染物（每种浓度为 100μg/L）混合物的降解效果。优化了每种络合物的操作参数（铁和 H2O2 的浓度和 Fe/L 的摩尔比）。通过增加铁络合物的浓度（从 12.5 增加到 100μmol/L），FeEDDS、FeEDTA 和 FeNTA 的降解效率显著提高。对于所有的铁浓度，FeCit 的最大降解率都被限制在 30%以内。对于每个配体，需要不同的 Fe/L 摩尔比才能使降解效率最大化：FeNTA 和 FeEDTA 为 1:1，FeEDDS 为 1:3，FeCit 为 1:5。考虑到最佳的 Fe/L 摩尔比，使用 5.9mmol/L H2O2 时，FeNTA 和 FeEDTA 的降解速率更高，而 FeEDDS 和 FeCit 分别需要 1.5mmol/L 和 2.9mmol/L H2O2。对于所有的铁络合物，处理后对坎特 S. 黑腹果蝇的急性毒性显著降低，表明形成了低毒性的副产物。就动力学常数（FeCit、FeNTA、FeEDTA 和 FeEDDS 分别为 0.10 > 0.063 > 0.051 > 0.036 min-1）、有机碳投入和成本效益（FeEDDS、FeCit、FeEDTA 和 FeNTA 分别为 USD 327 m-3 > USD 20 m-3 > USD 16 m-3 > USD 13 m-3）而言，FeNTA 被认为是最好的铁络合物来源。
