TiO2-based photocatalytic disinfection of microbes in aqueous media: A review.
TL;DR: It is believed that the combined application of disinfection and decontamination will greatly enhance the utilization of TiO2 photocatalyst as a potential alternative to conventional methods of water purification.
About: This article is published in Environmental Research.The article was published on 2017-04-01. It has received 325 citations till now. The article focuses on the topics: Portable water purification.
Citations
More filters
TL;DR: In this article, the main advancements in overcoming the barriers accompanied by pure ZnO and the criteria for fabrication of effective visible-light-responsive (ZnO-based) photocatalysts are reviewed.
697 citations
TL;DR: Given the appealing merits of heterogeneous photocatalytic disinfection of viruses, there is no doubt that this technology will be an impressively active research field and a source of comfort and confidence to humans in battling against viruses.
400 citations
TL;DR: This review summarises the opportunities and future directions of research in the heterogeneous Fenton catalysis and insights to the zero-valent iron and its capacity to remove a wide range of organic pollutants, heavy metals and bacterial contamination are discussed.
334 citations
TL;DR: This review is the first to comprehensively summarize the progress in design and antimicrobial performance of g-C3N4-based photocatalysts for water disinfection and microbial control, involving not only bacteria but also viruses and microalgae.
283 citations
TL;DR: A review of the latest advances in the synthesis of VLA photocatalysts using a variety of synthetic methods, including conventional photocatalyst modification with doping agents, heterostructure or composite formation, π-conjugated architecture coupling and exploration of multi-component oxides is presented in this paper.
270 citations
References
More filters
TL;DR: This paper reviews major key points in the generation of reactive oxygen species in bacteria, defense mechanisms and genetic responses to oxidative stress, with special attention to oxidative damage to proteins.
Abstract: The advent of O2 in the atmosphere was among the first major pollution
events occurred on earth. The reaction between ferrous iron, very abundant in the
reductive early atmosphere, and oxygen results in the formation of harmful superoxide
and hydroxyl radicals, which affect all macromolecules (DNA, lipids and proteins).
Living organisms have to build up mechanisms to protect themselves against oxidative
stress, with enzymes such as catalase and superoxide dismutase, small proteins like
thioredoxin and glutaredoxin, and molecules such as glutathione. Bacterial genetic
responses to oxidative stress are controlled by two major transcriptional regulators
(OxyR and SoxRS). This paper reviews major key points in the generation of reactive
oxygen species in bacteria, defense mechanisms and genetic responses to oxidative
stress. Special attention is paid to the oxidative damage to proteins.
1,384 citations
"TiO2-based photocatalytic disinfect..." refers methods in this paper
...According to Daels et al. (2015), TiO2-functionalized membranes were found to successfully inactivate 76% of the overall bacteria colonies in 6 h. Likewise, the disinfection of bacteria such as Pseudomonas aeruginosin has also been attempted by employing Ag-TiO2 as a photocatalyst (G Li et al.,…...
[...]
TL;DR: Comparison with other practical candidate fecal indicators shows that E. coli is far superior overall, and under most circumstances it is possible to design a monitoring program that permits public health protection at a modest cost.
Abstract: Public health protection requires an indicator of fecal pollution. It is not necessary to analyse drinking water for all pathogens. Escherichia coli is found in all mammal faeces at concentrations of 10 log 9(-1), but it does not multiply appreciably in the environment. In the 1890s, it was chosen as the biological indicator of water treatment safety. Because of method deficiencies, E. coli surrogates such as the 'fecal coliform' and total coliforms tests were developed and became part of drinking water regulations. With the advent of the Defined Substrate Technology in the late 1980s, it became possible to analyse drinking water directly for E. coli (and, simultaneously, total coliforms) inexpensively and simply. Accordingly, E. coli was re-inserted in the drinking water regulations. E. coli survives in drinking water for between 4 and 12 weeks, depending on environmental conditions (temperature, microflora, etc.). Bacteria and viruses are approximately equally oxidant-sensitive, but parasites are less so. Under the conditions in distribution systems, E. coli will be much more long-lived. Therefore, under most circumstances it is possible to design a monitoring program that permits public health protection at a modest cost. Drinking water regulations currently require infrequent monitoring which may not adequately detect intermittent contamination events; however, it is cost-effective to markedly increase testing with E. coli to better protect the public's health. Comparison with other practical candidate fecal indicators shows that E. coli is far superior overall.
861 citations
"TiO2-based photocatalytic disinfect..." refers background in this paper
...For instance, among a wide range of bacteria, E. coli coliform is recognized as an indicator of unhygienic water, as its presence generally reflects fecal contamination of water (Edberg et al., 2000)....
[...]
...coli coliform is recognized as an indicator of unhygienic water, as its presence generally reflects fecal contamination of water (Edberg et al., 2000)....
[...]
TL;DR: The imperative need to boost research and innovation for new and cost-effective treatment technologies, in line with the uptake, mode of action and consequences of each emerging contaminant, is demonstrated.
859 citations
"TiO2-based photocatalytic disinfect..." refers background in this paper
...Major impediments to safe drinking water are due to the presence of emerging pollutants including pesticides, drugs, and dyes (Gavrilescu et al., 2015; Reddy et al., 2015)....
[...]
TL;DR: A review of the fundamental disinfection mechanisms of photocatalysis and the models used to fit the disinfection process is presented in this paper, where the theoretical development of a mechanistic model for photocatalytic disinfection based on lipid peroxidation is explored with due consideration to the interaction between microbes and photocatalyst particles.
Abstract: This paper is a review of the fundamental disinfection mechanisms of photocatalysis and the models used to fit the disinfection process. Photocatalysis is an attractive technology for water treatment largely due to its potential to utilize solar energy directly and achieve both disinfection and chemical detoxification. Many papers have been published on photocatalytic disinfection, but there is still considerable debate on disinfection mechanisms and a general lack of mechanistic models for the process. The fundamental photocatalytic disinfection mechanisms as they relate to the inactivation of bacteria are comprehensively surveyed here. The process of lipid peroxidation of membrane fatty acids, particularly polyunsaturated fatty acids, is gaining momentum in the literature. In recent papers, an increasing number of researchers are paying close attention to the products of lipid peroxidation. The mathematical models, empirical and mechanistic, used to fit the disinfection process have also been thoroughly reviewed. In this regard, most of the proposed models are empirical in nature and rooted in traditional chemical disinfection principles, which are often not representative of the heterogeneous photocatalytic process. The theoretical development of a mechanistic model for photocatalytic disinfection based on lipid peroxidation is explored with due consideration to the interaction between microbes and photocatalyst particles. The extensive literature on autooxidation of lipids in such fields as biology and medicine is informative to the development of the model.
548 citations
"TiO2-based photocatalytic disinfect..." refers background in this paper
...For instance, among a wide range of bacteria, E. coli coliform is recognized as an indicator of unhygienic water, as its presence generally reflects fecal contamination of water (Edberg et al., 2000)....
[...]
TL;DR: The effects of pollutants on the cellular biochemistry of microalgae and the biochemical mechanisms thatmicroalgae use to detoxify or modify pollutants are reviewed and the potential uses ofMicroalgae as bioindicator species as an early sentinel in polluted sites are evaluated.
480 citations