Ferreira Matheus Almeida, Brandão Cristina Celia Silveira, Ginoris Yovanka Pérez
Environmental Technology and Water Resources Postgraduate Program, Department of Civil and Environmental Engineering, University of Brasília, Brasília 70910-900, Brazil.
Toxins (Basel). 2024 Dec 12;16(12):536. doi: 10.3390/toxins16120536.
The frequency and intensity of harmful cyanobacterial blooms have increased in the last decades, posing a risk to public health since conventional water treatments do not effectively remove extracellular cyanotoxins. Consequently, advanced technologies such as the Fenton process are required to ensure water safety. The cyanotoxin cylindrospermopsin (CYN) demands special attention, as it is abundant in the extracellular fraction and has a high toxicological potential. Hence, this study aimed to assess the application of the Fenton process for the oxidation of CYN spiked in natural water from Paranoá Lake (Brasília, Brazil). The HO/Fe(II) molar ratio was evaluated from 0.2 to 3.4, with an optimum molar ratio of 0.4, achieving a CYN degradation efficiency of 97.8% when using 100 µM of HO and 250 µM of Fe(II). The CYN degradation efficiency, using 75 µM of HO and 187.5 µM of Fe(II), decreased by increasing the initial pH (from 96.2% at pH 2 to 23.0% at pH 9) and the initial CYN concentration (from 93.7% at 0.05 µM of CYN to 85.0% at 0.2 µM of CYN). At the optimum HO/Fe(II) molar ratio of 0.4, the hydroxy radical scavengers tested (124.3 µM C of algogenic organic matter, 5 mg L of humic acid, and 513.3 µM of methanol) did not considerably affect the CYN degradation, reaching a maximum CYN degradation reduction from 98.3% to 82.2%.
在过去几十年中，有害蓝藻水华的频率和强度有所增加，由于传统水处理方法无法有效去除细胞外蓝藻毒素，这对公众健康构成了风险。因此，需要采用如芬顿法等先进技术来确保水安全。蓝藻毒素柱孢藻毒素（CYN）需要特别关注，因为它在细胞外部分含量丰富且具有很高的毒理学潜力。因此，本研究旨在评估芬顿法对巴西巴西利亚帕拉诺阿湖天然水中添加的CYN的氧化作用。评估了HO/Fe(II)摩尔比从0.2到3.4的情况，最佳摩尔比为0.4，当使用100µM的HO和250µM的Fe(II)时，CYN降解效率达到97.8%。使用75µM的HO和187.5µM的Fe(II)时，CYN降解效率会随着初始pH值（从pH2时的96.2%降至pH9时的23.0%）和初始CYN浓度（从0.05µM的CYN时的93.7%降至0.2µM的CYN时的85.0%）的增加而降低。在最佳HO/Fe(II)摩尔比为0.4时，所测试的羟基自由基清除剂（124.3µM C的藻源有机物、5mg/L的腐殖酸和513.3µM的甲醇）对CYN降解没有显著影响，CYN降解最大降低率从98.3%降至82.2%。
