共查询到20条相似文献,搜索用时 31 毫秒
1.
Janine S. Cardoso‐Rurr Juliana Patro de Paiva Ivan G. Paulino‐Lima Tatiana A.M. de Alencar Claudia A.S. Lage Alvaro C. Leito 《Photochemistry and photobiology》2019,95(2):618-626
Rational use of water is a major challenge for governments and global organizations, with easy and inexpensive interventions being sought by communities that are not supplied with drinking water. In this context, solar disinfection (SODIS) has shown great efficiency for water disinfection. To speed up the process and improve inactivation, we studied the effects of methylene blue (MB) as a photodynamic agent because of its ability to absorb visible light (red wavelength) and generate singlet oxygen as a reactive species, thereby inactivating bacteria and viruses present in water. In this study, samples of clean mineral water were artificially contaminated with Gram‐positive (Staphylococcus epidermidis or Deinococcus radiodurans) or with Gram‐negative strains (Escherichia coli or Salmonella typhimurium) and exposed to traditional SODIS or to MB‐SODIS. A lethal synergistic effect was observed when cultures were illuminated in the presence of MB. The obtained results indicate that bacterial inactivation can be achieved in a much shorter time when using MB associated with SODIS treatment. Therefore, this technique was able to provide safe water for consumption through the inactivation of microorganisms in general, including pathogens and some strains resistant to the traditional SODIS procedure, thus allowing its use in areas usually less exposed to sunlight. 相似文献
2.
Disinfection of drinking water contaminated with Cryptosporidium parvum oocysts under natural sunlight and using the photocatalyst TiO2 总被引:1,自引:0,他引:1
Méndez-Hermida F Ares-Mazás E McGuigan KG Boyle M Sichel C Fernández-Ibáñez P 《Journal of photochemistry and photobiology. B, Biology》2007,88(2-3):105-111
The results of a batch-process solar disinfection (SODIS) and solar photocatalytic disinfection (SPCDIS) on drinking water contaminated with Cryptosporidium are reported. Cryptosporidium parvum oocyst suspensions were exposed to natural sunlight in Southern Spain and the oocyst viability was evaluated using two vital dyes [4',6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI)]. SODIS exposures (strong sunlight) of 8 and 12h reduced oocyst viability from 98% (+/-1.3%) to 11.7% (+/-0.9%) and 0.3% (+/-0.33%), respectively. SODIS reactors fitted with flexible plastic inserts coated with TiO2 powder (SPCDIS) were found to be more effective than those which were not. After 8 and 16 h of overcast and cloudy solar irradiance conditions, SPCDIS reduced oocyst viability from 98.3% (+/-0.3%) to 37.7% (+/-2.6%) and 11.7% (+/-0.7%), respectively, versus to that achieved using SODIS of 81.3% (+/-1.6%) and 36.0% (+/-1.0%), respectively. These results confirm that solar disinfection of drinking water can be an effective household intervention against Cryptosporidium contamination. 相似文献
3.
Navntoft C Ubomba-Jaswa E McGuigan KG Fernández-Ibáñez P 《Journal of photochemistry and photobiology. B, Biology》2008,93(3):155-161
Inactivation kinetics are reported for suspensions of Escherichia coli in well-water using compound parabolic collector (CPC) mirrors to enhance the efficiency of solar disinfection (SODIS) for batch reactors under real, solar radiation (cloudy and cloudless) conditions. On clear days, the system with CPC reflectors achieved complete inactivation (more than 5-log unit reduction in bacterial population to below the detection limit of 4CFU/mL) one hour sooner than the system fitted with no CPC. On cloudy days, only systems fitted with CPCs achieved complete inactivation. Degradation of the mirrors under field conditions was also evaluated. The reflectivity of CPC systems that had been in use outdoors for at least 3 years deteriorated in a non-homogeneous fashion. Reflectivity values for these older systems were found to vary between 27% and 72% compared to uniform values of 87% for new CPC systems. The use of CPC has been proven to be a good technological enhancement to inactivate bacteria under real conditions in clear and cloudy days. A comparison between enhancing optics and thermal effect is also discussed. 相似文献
4.
Chikako Nishigori Nozomi Yamano Makoto Kunisada Aiko Nishiaki-Sawada Hiroyuki Ohashi Tatsushi Igarashi 《Photochemistry and photobiology》2023,99(2):335-343
Life on earth has constantly coped with the impact of solar radiation, especially solar ultraviolet radiation (solar UV). Various biological mechanisms protect us from solar UV. New devices emitting shorter wavelengths UV-C, i.e. <254 nm emitted by conventional UV germicidal lamps, have emerged. These shorter wavelength UV-C emitting devices are useful for various purposes, including microorganism inactivation. However, as solar UV-C does not reach the earth surface, biological impacts of UV-C has been studied using 254 nm germicidal lamps, and those using shorter wavelength UV-C is rarely known. To balance the utility and risk of UV-C, the biological effect of these new UV-C emitting devices must be investigated. In addition, our knowledge of biological impacts of the wavelength-dependent entire UV (100–400 nm) must be enhanced. In this review, we briefly summarize the biological impacts of shorter wavelength UV-C. Mechanisms of UV-C-induced cellular damage and factors affecting the microorganism inactivation efficiency of UV-C have been discussed. In addition, we theoretically estimate the probable photocarcinogenic action spectrum of shorter wavelength UV-C. We propose that increasing the knowledge on UV-C will facilitate the adoption of shorter wavelength UV-C emitting new devices in an optimal and appropriate manner. 相似文献
5.
A review of cyanobacteria and cyanotoxins removal/inactivation in drinking water treatment 总被引:2,自引:0,他引:2
Judy A. Westrick David C. Szlag Benjamin J. Southwell James Sinclair 《Analytical and bioanalytical chemistry》2010,397(5):1705-1714
This review focuses on the efficiency of different water treatment processes for the removal of cyanotoxins from potable water.
Although several investigators have studied full-scale drinking water processes to determine the efficiency of cyanotoxin
inactivation, many of the studies were based on ancillary practice. In this context, “ancillary practice” refers to the removal
or inactivation of cyanotoxins by standard daily operational procedures and without a contingency operational plan utilizing
specific treatment barriers. In this review, “auxiliary practice” refers to the implementation of inactivation/removal treatment
barriers or operational changes explicitly designed to minimize risk from toxin-forming algae and their toxins to make potable
water. Furthermore, the best drinking water treatment practices are based on extension of the multibarrier approach to remove
cyanotoxins from water. Cyanotoxins are considered natural contaminants that occur worldwide and specific classes of cyanotoxins
have shown regional prevalence. For example, freshwaters in the Americas often show high concentrations of microcystin, anatoxin-a,
and cylindrospermopsin, whereas Australian water sources often show high concentrations of microcystin, cylindrospermopsin,
and saxitoxins. Other less frequently reported cyanotoxins include lyngbyatoxin A, debromoaplysiatoxin, and β-N-methylamino-l-alanine. This review focuses on the commonly used unit processes and treatment trains to reduce the toxicity of four classes
of cyanotoxins: the microcystins, cylindrospermopsin, anatoxin-a, and saxitoxins. The goal of this review is to inform the
reader of how each unit process participates in a treatment train and how an auxiliary multibarrier approach to water treatment
can provide safer water for the consumer. 相似文献
6.
Vartika Srivastava Manukonda Suresh Kumar Puthiya Veetil Nidheesh Carlos A. Martínez-Huitle 《Current Opinion in Electrochemistry》2021
Use of robust and safe water disinfection technologies which are inexpensive and energy-efficient are need of the hour to combat the problem of inadequate access of safe and clean drinking water. Energy and chemically intensive water treatment technologies warrant the need for a safe and environmentally sound treatment technology. Electrochemical disinfection or electrodisinfection (ED) is experiencing a great resurgence among the scientific communities owing to its novel use of electrode materials and electric current in an inexpensive and energy-efficient way for achieving the inactivation of microorganisms. Among the various electrodes used in the ED, boron-doped diamonds emerge as a sustainable alternate for their ability to electro generate strong potent oxidants which result in effective pathogen control in drinking water. ED for disinfecting waters occurs via generation of the reactive species which act in the bacterial inactivation mechanisms. In this mini-review, a critical discussion on the fundamentals and applications of promising electrochemical methods using boron-doped diamond anodes (namely electrochemical oxidation), evidencing their advantages for the remediation of drinking water infected with waterborne agents, is given. 相似文献
7.
We critically investigate the claim put forward by Sagripanti and Lytle ([2007] Photochem. Photobiol. 83, 1278-1282) that inactivation of influenza A virus by solar radiation can explain the seasonality of influenza epidemics. We correct an error in the Sagripanti and Lytle paper and show that changes in relative humidity and temperature affect influenza virus inactivation as strongly as variation in solar radiation. Furthermore, it appears unlikely that transmission in outdoor settings plays an important role during influenza outbreaks, because influenza A virus is sensitive to a wide range of environmental factors. 相似文献
8.
Wei-Tao QIU Yong-Chao HUANG Zi-Long WANG Shuang XIAO Hong-Bing JI Ye-Xiang TONG 《物理化学学报》2017,33(1):80-102
Photoelectrochemical water splitting is to utilize collected photo-generated carrier for direct water cleavage for hydrogen production. It is a system combining photoconversion and energy storage since converted solar energy is stored as high energy-density hydrogen gas. According to intrinsic properties and band bending situation of a photoelectrode, hydrogen tends to be released at photocathode while oxygen at photoanode. In a tandem photoelectrochemical chemical cell, current passing through one electrode must equals that through another and electrode with lower conversion rate will limit efficiency of the whole device. Therefore, it is also of research interest to look into the common strategies for enhancing the conversion rate at photoanode. Although up to 15% of solar-to-hydrogen efficiency can be estimated according to some semiconductor for solar assisted water splitting, practical conversion ability of state-of-the-art photoanode has yet to approach that theoretical limit. Five major steps happen in a full water splitting reaction at a semiconductor surface:light harvesting with electron excitations, separated electron-hole pairs transferring to two opposite ends due to band bending, electron/hole injection through semiconductor-electrolyte interface into water, recombination process and mass transfer of products/reactants. They are closely related to different proposed parameters for solar water splitting evaluation and this review will first help to give a fast glance at those evaluation parameters and then summarize on several major adopted strategies towards high-efficiency oxygen evolution at photoanode surface. Those strategies and thereby optimized evaluation parameter are shown, in order to disclose the importance of modifying different steps for a photoanode with enhanced output. 相似文献
9.
Gernot Renger 《Angewandte Chemie (International ed. in English)》1987,26(7):643-660
The cleavage of water by solar radiation into dioxygen and metabolically bound hydrogen during photosynthesis is of central importance for the existence of higher forms of life on earth. The realization of this process in biological organisms made possible the use of the earth's huge water reservoir for the exploitation of solar energy and, at the same time, led to the creation of an aerobic atmosphere. The dioxygen thereby formed is a powerful oxidant which permits an energetically highly efficient nutrient turnover. In recent years considerable progress has been made in understanding the functional and structural organization of photosynthetic water splitting. This article attempts to give a review of our current state of knowledge with special emphasis on the oxidation of water to O2 in biological systems. 相似文献
10.
Disinfection and Mechanistic Insights of Escherichia coli in Water by Bismuth Oxyhalide Photocatalysis 下载免费PDF全文
Ilana Sherman Yoram Gerchman Yoel Sasson Hani Gnayem Hadas Mamane 《Photochemistry and photobiology》2016,92(6):826-834
This study demonstrates the potential of a new BiOCl0.875Br0.125 photocatalyst to disinfect Escherichia coli in water under simulated solar irradiation. Photocatalytic efficiency was examined for different photocatalyst loadings, solar wavelengths, exposure times, photocatalyst concentration × contact time (Ct) concept and with the use of scavengers. To elucidate the inactivation mechanism, we examined DNA damage, membrane damage, lipid peroxidation and protein release. Both photolysis and photocatalysis were negligible under visible irradiation, but enhanced photocatalytic activity was observed under solar UVA (λ > 320 nm) and UVB (λ > 280 nm), with 1.5 and 3.6 log inactivation, respectively, after 40 min of irradiation. The log inactivation vs Ct curve for E. coli by UVA/BiOCl0.875Br0.125 was fairly linear, with Ct = 10 g L?1 × min, resulting in 2 log inactivation. Photocatalytic treatment led to membrane damage, but without lipid peroxidation. Accordingly, protein was released from the cells after UVA or UVA/BiOCl0.875Br0.125 treatment. Photocatalysis also increased endonuclease‐sensitive sites vs photolysis alone, by an unknown mechanism. Finally, E. coli inactivation was not influenced by the addition of tert‐butanol or l ‐histidine, implying that neither hydroxyl radicals nor singlet oxygen reactive species are involved in the inactivation process. 相似文献
11.
水资源短缺是世界长期面临的问题,当前全球80多个国家的约15亿人口面临淡水不足,其中26个国家的3亿人口完全生活在缺水状态。近年来,人们开发了新型太阳能界面水蒸发材料和技术,能够利用高效光热材料吸收太阳能转化为热能,实现大量的、快速的水蒸发,冷凝后收集便得到洁净水,是一种高效、绿色、低成本水处理和解决水资源短缺的方法。石墨烯三维组装体材料的物理和化学性质优异,光热转化效率高,同时其太阳光吸收率高,内部微纳孔道丰富,具有良好的水传输通道,表面水蒸发面积大,在太阳光照射下能够实现超高的水蒸发速率,在光热水处理方面展现了巨大的科学研究意义和实用价值。本文将综述石墨烯三维组装体的制备及光热水处理方面的研究进展,包括石墨烯三维结构组装体制备方法,其光热水蒸发性能,总结了石墨烯三维结构组装体在光热水蒸发及水处理方面的应用,最后分析了石墨烯三维结构组装体光热水处理面临的问题及展望。 相似文献
12.
Hanxue Liang Qihua Liao Nan Chen Yuan Liang Guiqin Lv Panpan Zhang Bing Lu Liangti Qu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(52):19217-19222
Solar‐driven interfacial water evaporation yield is severely limited by the low efficiency of solar thermal energy. Herein, the injection control technique (ICT) achieves a capillary water state in rGO foam and effectively adjusts the water motion mode therein. Forming an appropriate amount of capillary water in the 3D graphene foam can greatly increase the vapor escape channel, by ensuring that the micrometer‐sized pore channels do not become completely blocked by water and by exposing as much evaporation area as possible while preventing solar heat from being used to heat excess water. The rate of solar steam generation can reach up to 2.40 kg m?2 h?1 under solar illumination of 1 kW m?2, among the best values reported. In addition, solar thermal efficiency approaching 100 % is achieved. This work enhances solar water‐evaporation performance and promotes the application of solar‐driven evaporation systems made of carbon‐based materials. 相似文献
13.
Clarification of how water affects the photovoltaic performance of perovskite solar cells is one of the major challenges to successfully develop a large-scale low-cost fabrication process. Many authors have reported beneficial effects of moisture during the fabrication of perovskite solar cells (PSCs), such as enhanced crystallinity, photoluminescence and photovoltage. However, the highest power conversion efficiency reported until this date was obtained under completely dry atmosphere conditions, avoiding the presence of water during perovskite formulation and preserving the damage caused by moisture exposure with encapsulation techniques. This apparent contradiction makes patent the necessity of an extensive clarification to establish the conditions in which water represents a beneficial or harmful factor in the development of high efficiency and stable perovskite devices. In this review, we summarized the effects of water, both as an additive into the perovskite formulation as an additive and as moisture exposure during fabrication. We discuss in depth the structural and chemical effects, analysing also the photovoltaic consequences during operation conditions. As a final input, we remark a useful method to perform high efficiency PSCs under different lab ambient conditions and highlight the latest advances in hydrophobic devices and encapsulation techniques. 相似文献
14.
Over the past five years, an important development in the area of self-assembling containers has been the increase in interest in those containers that function in aqueous solution. This progress is a reflection of a similar trend within supramolecular chemistry in general, and is driven in part by the need to address issues and challenges within the biological sciences, as well as a desire to develop new strategies for greener chemistries carried out in water. It is also an opportunity to learn more about fundamental topics such as the hydrophobic effect. In this critical review we discuss progress in aqueous-based self-assembling container molecules since 2005 (177 references). 相似文献
15.
利用光热材料的太阳能水蒸发技术是一种绿色、 环保地解决淡水资源短缺的重要技术, 但光热材料的制备成本、 蒸发效率和热损失等因素限制了其推广应用. 本文采用一锅法制备了聚乙烯醇载银海绵(AgNPs/PVA)太阳能界面蒸发器, 并研究了AgNPs含量对AgNPs/PVA在太阳能驱动水蒸发过程中光热性能的影响. 研究结果表明, 当AgNPs的质量为PVA的10%时, 制备的AgNPs/PVA在1 kW/m 2的太阳光强度下具有最优的蒸发速率, 水蒸发速率可达1.62 kg?m ?2?h ?1, 为纯水(0.42 kg?m ?2?h ?1)的3.9倍. 本文制备的AgNPs/PVA具有制备工艺简单、 亲水性能优良和蒸发性能良好的特点, 在太阳能驱动水蒸发领域具有较大的应用前景. 相似文献
16.
面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。 相似文献
17.
光电化学水分解电池能够将太阳能直接转化为氢能,是一种理想的太阳能利用方式. p-n叠层电池具有理论转换效率高、成本低廉、材料选择灵活等优势,被认为是最有潜力的一类光电化学水分解电池. 然而,目前这类叠层电池的太阳能转化效率还不高,主要原因是单个电极的效率太低. 本文介绍了几种提高光电极分解水性能的方法--减小光生载流子的体相复合、表面复合以及抑制背反应等,同时综述了国内外关于几种p型半导体光阴极的研究进展,如Si、InP、CuIn1-x GaxS(Se)2、Cu2ZnSnS4等. 通过总结,作者提出一种p-Cu2ZnSnS4(CuIn1-xGaxS(Se)2)/n-Ta3N5(Fe2O3) 组装方式,有望获得高效低成本叠层光电化学水分解电池. 相似文献
18.
19.
Cristina Jimnez-Holgado Paola Calza Debora Fabbri Federica Dal Bello Claudio Medana Vasilios Sakkas 《Molecules (Basel, Switzerland)》2021,26(17)
This study investigated the direct and indirect photochemical degradation of citalopram (CIT), a selective serotonin reuptake inhibitor (SSRI), under natural and artificial solar radiation. Experiments were conducted in a variety of different operating conditions including Milli-Q (MQ) water and natural waters (lake water and municipal WWT effluent), as well as in the presence of natural water constituents (organic matter, nitrate and bicarbonate). Results showed that indirect photolysis can be an important degradation process in the aquatic environment since citalopram photo-transformation in the natural waters was accelerated in comparison to MQ water both under natural and simulated solar irradiation. In addition, to investigate the decontamination of water from citalopram, TiO2-mediated photocatalytic degradation was carried out and the attention was given to mineralization and toxicity evaluation together with the identification of by-products. The photocatalytic process gave rise to the formation of transformation products, and 11 of them were identified by HPLC-HRMS, whereas the complete mineralization was almost achieved after 5 h of irradiation. The assessment of toxicity of the treated solutions was performed by Microtox bioassay (Vibrio fischeri) and in silico tests showing that citalopram photo-transformation involved the formation of harmful compounds. 相似文献