This study evaluates 9 biocides as disinfectants against microbiological contaminants, specifically, microalgae and E. coli, while assessing their safety and environmental impact. Specifically, the biocide effectiveness and corresponding generation of halogenated compounds is assessed in a real contaminated groundwater receiving acidic leachate from a phosphogypsum landfill. Oxidizing agents are investigated, namely, hypochlorite, peracetic acid, hydrogen peroxide, chlorine dioxide, and persulfate, together with electrophilic biocides, namely, 2,2-dibromo-2-cyanoacetamide and (chloro-) methylisothiazolinone. In addition, a novel disinfection approach is assessed by applying reducing agents, namely, sulfite and metabisulfite. The disinfection mechanism and the formation of halogenated compounds are discussed on the basis of the mode of action and of the molecular structure of each biocide. Overall, the results show that an optimal dosage of the biocides exists to minimize the formation of harmful compounds in water while maximizing disinfection, especially for hypochlorite and peracetic acid. This dosage was between 0.03 mM and 0.15 mM depending on the biocide. The safety of electrophilic biocides is found to be associated to their molecular structure rather than their mode of action. Hydrogen peroxide, MIT, and metabisulfite are the most promising disinfectants in the contaminated groundwater matrix of interest since no halogenated by-products are detected upon successful disinfection, while they are able to completely inactivate bacteria and remove over the 80% of microalgae in the selected matrix. In particular, metabisulfite represents a highly promising biocide, owing to its low environmental and health impacts, as well as economic feasibility (estimated reagent cost ~0.002 € per cubic meter of treated water).

这项研究评估了9种杀菌剂作为针对微生物污染物（尤其是微藻和大肠杆菌）的消毒剂，同时评估其安全性和环境影响。具体而言，在从磷石膏填埋场接收酸性浸出液的真实受污染地下水中评估了杀生物剂的有效性和相应的卤代化合物生成。研究了氧化剂，即次氯酸盐，过乙酸，过氧化氢，二氧化氯和过硫酸盐，以及亲电子杀生物剂，即2,2-二溴-2-氰基乙酰胺和（氯-）甲基异噻唑啉酮。另外，通过施用还原剂，即亚硫酸盐和偏亚硫酸氢盐，评估了一种新颖的消毒方法。根据作用方式和每种杀生物剂的分子结构，讨论了其消毒机理和卤代化合物的形成。总体，结果表明，存在最佳剂量的杀生物剂，可最大程度地减少水中有害化合物的生成，同时最大程度地提高消毒效果，尤其是对于次氯酸盐和过乙酸而言。取决于杀生物剂，该剂量在0.03mM至0.15mM之间。发现亲电子杀生物剂的安全性与其分子结构而不是其作用方式有关。过氧化氢，麻省理工学院和焦亚硫酸盐是受污染地下水基质中最有希望的消毒剂，因为成功消毒后未检测到卤化副产物，同时它们能够完全灭活细菌并去除所选藻类中80％以上的微藻类。矩阵。尤其是，亚硫酸氢盐由于对环境和健康的影响小，因此具有很高的应用前景，