{"title":"Enhanced inactivation of Aspergillus niger biofilms by the combination of UV-LEDs with chlorine-based disinfectants","authors":"","doi":"10.1016/j.watres.2024.122451","DOIUrl":null,"url":null,"abstract":"<div><p>The presence of pathogenic fungal biofilms in drinking water distribution systems poses significant challenges in maintaining the safety of drinking water. This research delved into the formation of <em>Aspergillus niger</em> (<em>A. niger</em>) biofilms and evaluated their susceptibility to inactivation using combinations of ultraviolet light emitting diodes (UV-LEDs) with chlorine-based disinfectants, including UV-LEDs/chlorine (Cl<sub>2</sub>), UV-LEDs/chlorine dioxide (ClO<sub>2</sub>), and UV-LEDs/chloramine (NH<sub>2</sub>Cl) at 265 nm, 280 nm and 265/280 nm. Results indicated that <em>A. niger</em> biofilms reached initial maturity within 24 h, with matured three-dimensional filamentous structures and conidiospores by 96 h. UV-LEDs combined with chlorine-based disinfectants enhanced <em>A. niger</em> biofilm inactivation compared to UV-LEDs alone and low-pressure UV combined with chlorine-based disinfectants. At an UV fluence of 400 mJ/cm<sup>2</sup>, log reductions of UV<sub>265</sub>, UV<sub>280</sub>, and UV<sub>265/280</sub> combined with chlorine-based disinfectants were 2.95-fold, 3.20-fold, and 2.38-fold higher than that of UV<sub>265</sub>, UV<sub>280</sub>, and UV<sub>265/280</sub>, respectively. During the inactivation, <em>A. niger</em> biofilm cells experienced increased membrane permeability and intracellular reactive oxygen species levels, resulting in cellular apoptosis. Extracellular polymeric substances contributed to the higher resistance of biofilms. Regarding electrical energy consumption, the order was: UV-LEDs/ClO<sub>2</sub> > UV-LEDs/NH<sub>2</sub>Cl > UV-LEDs/Cl<sub>2</sub>. These findings provide insights into the effective utilization of UV-LEDs for fungal biofilm disinfection.</p></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":null,"pages":null},"PeriodicalIF":11.4000,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0043135424013502","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
The presence of pathogenic fungal biofilms in drinking water distribution systems poses significant challenges in maintaining the safety of drinking water. This research delved into the formation of Aspergillus niger (A. niger) biofilms and evaluated their susceptibility to inactivation using combinations of ultraviolet light emitting diodes (UV-LEDs) with chlorine-based disinfectants, including UV-LEDs/chlorine (Cl2), UV-LEDs/chlorine dioxide (ClO2), and UV-LEDs/chloramine (NH2Cl) at 265 nm, 280 nm and 265/280 nm. Results indicated that A. niger biofilms reached initial maturity within 24 h, with matured three-dimensional filamentous structures and conidiospores by 96 h. UV-LEDs combined with chlorine-based disinfectants enhanced A. niger biofilm inactivation compared to UV-LEDs alone and low-pressure UV combined with chlorine-based disinfectants. At an UV fluence of 400 mJ/cm2, log reductions of UV265, UV280, and UV265/280 combined with chlorine-based disinfectants were 2.95-fold, 3.20-fold, and 2.38-fold higher than that of UV265, UV280, and UV265/280, respectively. During the inactivation, A. niger biofilm cells experienced increased membrane permeability and intracellular reactive oxygen species levels, resulting in cellular apoptosis. Extracellular polymeric substances contributed to the higher resistance of biofilms. Regarding electrical energy consumption, the order was: UV-LEDs/ClO2 > UV-LEDs/NH2Cl > UV-LEDs/Cl2. These findings provide insights into the effective utilization of UV-LEDs for fungal biofilm disinfection.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.