Department of Medicine Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, via S. Allende 1, 84081 Baronissi, SA, Italy.
Department of Chemistry and Biology, University of Salerno, via Giovanni Paolo II 132, 84084 Fisciano, SA, Italy.
Sci Total Environ. 2021 May 1;767:144395. doi: 10.1016/j.scitotenv.2020.144395. Epub 2020 Dec 29.
In this work permaleic acid (PMA) was investigated as possible disinfecting agent and compared to peracetic acid (PAA) in real tap water and wastewater. Preliminary tests in lysogeny broth (LB) were also performed. PMA was synthesized from maleic anhydride and hydrogen peroxide and, for the first time, its antimicrobial activity was evaluated with respect to the growth inhibition of E. coli. The effect of the pH and bivalent ions, typically occurring in real water matrices (namely, Mg and Ca), was also investigated. pKa values for PMA were calculated for the first time by DFT calculations. The concentration of bivalent ions strongly affected disinfection efficiency with PMA (Ca=0.33 mgL and Mg=0.35 mgL: 100% E. coli reduction > log 5; Ca=13.3 mg L and Mg=25.6 mg L: E. coli reduction < log 1, after 60 min), and such results were supported by DFT modelling outcomes (pKa of PMA 7.3) and disinfection tests in presence of EDTA chelating agent. More alkaline pH conditions drastically decreased PMA disinfection (pH = 5: > log 5 E.coli reduction; pH = 9: < log 1 E.coli reduction, after 60 min). PMA disinfection efficiency is strongly affected by the target water quality, the concentration of metal bivalent ions and the initial pH.
在这项工作中，我们研究了过氧马来酸（PMA）作为可能的消毒剂，并将其与过氧乙酸（PAA）在实际自来水和废水中进行了比较。还在溶菌肉汤（LB）中进行了初步测试。PMA 是由马来酸酐和过氧化氢合成的，这是首次评估其在抑制大肠杆菌生长方面的抗菌活性。还研究了 pH 值和二价离子（即在实际水基质中通常存在的 Mg 和 Ca）的影响。首次通过 DFT 计算计算了 PMA 的 pKa 值。二价离子的浓度强烈影响 PMA 的消毒效率（Ca=0.33mgL 和 Mg=0.35mgL：100%大肠杆菌减少>log5；Ca=13.3mgL 和 Mg=25.6mgL：大肠杆菌减少<log1，60 分钟后），并且这些结果得到了 DFT 建模结果（PMA 的 pKa 为 7.3）和 EDTA 螯合剂存在下的消毒测试的支持。更碱性的 pH 值条件大大降低了 PMA 的消毒效果（pH=5：>log5 大肠杆菌减少；pH=9：<log1 大肠杆菌减少，60 分钟后）。PMA 的消毒效率受目标水质、二价金属离子浓度和初始 pH 值的强烈影响。
