scholarly journals The Pathway towards Photoelectrocatalytic Water Disinfection: Review and Prospects of a Powerful Sustainable Tool

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 921
Author(s):  
Sergi Garcia-Segura ◽  
Omotayo A. Arotiba ◽  
Enric Brillas
Keyword(s):  
Synergistic Effects ◽  
Low Cost ◽  
Water Disinfection ◽  
Bacterial Inactivation ◽  
Sustainable Development Goal ◽  
E Coli ◽  
Light Delivery ◽  
System Requirements ◽  
Photo Electrode ◽  
Nanostructure Control

Photoelectrocatalysis is a hybrid photon/electron-driven process that benefits from the synergistic effects of both processes to enhance and stabilize the generation of disinfecting oxidants. Photoelectrocatalysis is an easy to operate technology that can be scaled-up or scaled-down for various water treatment applications as low-cost decentralized systems. This review article describes the fundamentals of photoelectrocatalysis, applied to water disinfection to ensure access to clean water for all as a sustainable development goal. Advances in reactor engineering design that integrate light-delivery and electrochemical system requirements are presented, with a description of photo-electrode material advances, including doping, nano-decoration, and nanostructure control. Disinfection and cell inactivation are described using different model microorganisms such as E. coli, Mycobacteria, Legionella, etc., as well the fungus Candida parapsilosis, with relevant figures of merit. The key advances in the elucidation of bacterial inactivation mechanisms by photoelectrocatalytic treatments are presented and knowledge gaps identified. Finally, prospects and further research needs are outlined, to define the pathway towards the future of photoelectrocatalytic disinfection technologies.

scholarly journals Bacterial Disinfection by CuFe2O4 Nanoparticles Enhanced by NH2OH: A Mechanistic Study

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 18 ◽  
Author(s):  
Yu Gu ◽  
Furen Xiao ◽  
Liumin Luo ◽  
Xiaoyu Zhou ◽  
Xiaodong Zhou ◽  
...  
Keyword(s):  
Water Treatment ◽  
Noble Metals ◽  
Low Cost ◽  
Water Disinfection ◽  
Mechanistic Study ◽  
Copper Ferrite ◽  
Bacterial Inactivation ◽  
E Coli ◽  
Reactive Oxygen Species Content ◽  
Current Water

Many disinfection technologies have emerged recently in water treatment industry, which are designed to inactivate water pathogens with extraordinary efficiency and minimum side effects and costs. Current disinfection processes, including chlorination, ozonation, UV irradiation, and so on, have their inherent drawbacks, and have been proven ineffective under certain scenarios. Bacterial inactivation by noble metals has been traditionally used, and copper is an ideal candidate as a bactericidal agent owing to its high abundance and low cost. Building on previous findings, we explored the bactericidal efficiency of Cu(I) and attempted to develop it into a novel water disinfection platform. Nanosized copper ferrite was synthesized, and it was reduced by hydroxylamine to form surface bound Cu(I) species. Our results showed that the generated Cu(I) on copper ferrite surface could inactivate E. coli at a much higher efficiency than Cu(II) species. Elevated reactive oxygen species’ content inside the cell primarily accounted for the strong bactericidal role of Cu(I), which may eventually lead to enhanced oxidative stress towards cell membrane, DNA, and functional proteins. The developed platform in this study is promising to be integrated into current water treatment industry.

scholarly journals Design of a cost-effective electrochlorination system for point-of-use water treatment

2020 ◽  
Vol 26 (5) ◽  
pp. 200437-0
Author(s):  
Mainak Bhattacharya ◽  
Koyel Bandyopadhyay ◽  
Anirban Gupta
Keyword(s):  
Water Treatment ◽  
Continuous Flow ◽  
Low Cost ◽  
Developed Countries ◽  
Water Disinfection ◽  
Residual Chlorine ◽  
Waterborne Diseases ◽  
Bacterial Inactivation ◽  
Treatment Unit ◽  
Continuous Flow Reactors

Bacteriological contamination in drinking water is known to be responsible for the spread of various waterborne diseases. Although chlorine is frequently used as disinfectant in water treatment, low-cost disinfecting technologies in the villages of developing and under-developed countries are not yet successfully implemented. This study contributed in designing a simple and inexpensive water disinfection unit to produce chlorine from the naturally available dissolved chloride of groundwater by electrochlorination, using inert and cheap graphite electrodes. Laboratory-based experiments were performed in both batch and continuous flow reactors to study the effect of time, current, electro charge loading (ECL), and surface area of electrodes in chlorine generation and bacterial inactivation. Controlled experiments in continuous mode in the absence of chlorine further indicated the possibility of partial inactivation of bacteria under the influence of the electric field. Finally, a treatment unit with drilled anodes, and undrilled cathode electrodes, in continuous flow set-up was installed in four schools of four different villages in West Bengal, India. An average residual chlorine concentration and removal efficiency of total coliform in the designed systems were determined as 0.3 ± 0.07 mg/L, and 98.4% ± 1.6%, respectively.

scholarly journals Photocatalytic water disinfection by simple and low-cost monolithic and heterojunction ceramic wafers

2015 ◽  
Vol 14 (6) ◽  
pp. 1190-1196 ◽  
Author(s):  
Neel M. Makwana ◽  
Rachael Hazael ◽  
Paul F. McMillan ◽  
Jawwad A. Darr
Keyword(s):  
Low Cost ◽  
Water Disinfection ◽  
Bacterial Inactivation ◽  
Charged Species

Ceramic wafers prepared by a simple, low-cost method, are investigated for photocatalytic water disinfection. Heterojunction wafers were able to sustain the formation of charged species responsible for bacterial inactivation.

Water Disinfection Using Fe3+ and N-Doped 3SnO2/TiO2 Thin Films Coated on Glass Fibers

2010 ◽  
Vol 148-149 ◽  
pp. 1501-1506 ◽  
Author(s):  
Lek Sikong ◽  
Peerawas Kongsong ◽  
Vishnu Rachpech
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Glass Fibers ◽  
Composite Films ◽  
Water Disinfection ◽  
Blue Dye ◽  
Tio2 Films ◽  
Methylene Blue Dye ◽  
Bacterial Inactivation ◽  
E Coli

The water disinfection efficiency of Fe3+ and N-doped 3SnO2/TiO2 composite and undoped films was investigated. The water containing E. coli with an initial concentration of 103 CFU/ml was treated by a photocatalytic reactor filled with 60 g of glass fibers coated with the catalytic films for 1-5 circulated cycles. The number of survival bacteria after treatment was evaluated with spread plate techniques. Furthermore, the photocatalytic reaction on degradation of methylene blue dye solution was also investigated in order to observe the correlation between the result of bacteria inactivation of the prepared films and that of photocatalytic activity on methylene blue degradation. It reveals that N-doping in the TiO2 composite films results in shifting absorption wavelength towards visible light, narrowing the energy band gap and acts as photo-generated electrons trapping site, leading to retardation of the electrons-holes recombination, while Fe3+ doping has a main effect on hindrance of anatase crystal growth of the composite films. Therefore, 20N/3SnO2/TiO2 composite thin film exhibits greater photocatalytic activity and disinfection efficiency than those of undoped and Fe3+ doped TiO2 films. It was found that the bacterial inactivation of the prepared films correlates closely to photocatalytic activity performed by degradation of methylene blue dye solution. The 20N/3SnO2/TiO2 composite film can kill E. coli 97% within 5 cycled water treatment (~93 min) while Fe3+/3SnO2/TiO2, undoped TiO2 and UV alone can kill only 62, 65 and 58%, respectively. The 20N/3SnO2/TiO2 films coated on glass fibers are expect to be applied as an antibacterial photocatalyst for water purification.

scholarly journals Robust immobilization of anionic silver nanoparticles on cellulose filter paper toward a low-cost point-of-use water disinfection system with improved anti-biofouling properties

RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 4873-4882
Author(s):  
Gongyan Liu ◽  
Ruiquan Yu ◽  
Jing Jiang ◽  
Zhuang Ding ◽  
Jing Ma ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Filter Paper ◽  
Low Cost ◽  
Water Disinfection ◽  
Point Of Use ◽  
Cellulose Filter

Point-of-use water disinfection by GA@AgNPs-LA-FP.

scholarly journals Performance of silver-coated red soil nanocomposites in water disinfection

2018 ◽  
Vol 54 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Ebrahim Mahmoudi ◽  
Farid Moeinpour
Keyword(s):  
Contact Time ◽  
Elimination Rate ◽  
Red Soil ◽  
Water Disinfection ◽  
Box Behnken Design ◽  
E Coli ◽  
Surface Response Method ◽  
Research Findings ◽  
Response Method ◽  
Bacterial Effect

Abstract The present research studied the anti-bacterial effect of silver-coated red soil nanoparticles on Gram-negative bacteria Escherichia coli (E. coli) from water. The effects of disinfectant concentration (0.02, 0.05 and 0.1 g/mL), contact time (10, 20 and 30 minutes) and bacteria number (102, 104 and 106 CFU/mL) have been also investigated. To obtain important factors, the interactions between factors and optimal experimental design in surface response method were used based on Box-Behnken design. According to the research findings, the system is efficient in eliminating E. coli. The results showed that E. coli elimination efficiency intensified through increasing the amount of disinfectant from 0.02 to 0.1 g/mL. Expanding contact time from 10 minutes to 30 minutes also heightened the E. coli elimination rate. R2 for E. coli elimination is 0.9956 indicating a good agreement between model experimental data and forecasting data.

Microwave Synthesis of Nanosilver Colloidal Suspension for Anti-Bacterial Coating

2011 ◽  
Vol 356-360 ◽  
pp. 277-282 ◽  
Author(s):  
Hsi Chi Yang ◽  
Jung Pin Wang ◽  
Chien Te Hsieh
Keyword(s):  
Microwave Irradiation ◽  
Colloidal Suspension ◽  
Bacterial Inactivation ◽  
Narrow Size Distribution ◽  
E Coli ◽  
Microwave Assisted ◽  
Reaction Solution ◽  
Escherchia Coli ◽  
Ag Crystallites ◽  
Heating Up

This article reports a microwave-assisted route to synthesize nanosilver colloidal suspension and to deposit silver nanoparticles onto activated carbon fabrics (ACFs). The properties of the nanosilver suspension are characterized in terms of bacterial inactivation and growth inhibition. The metallic Ag nanocrystals with narrow size distribution are uniformly dispersed onto ACFs under the microwave irradiation of 1 min. Microwave irradiation is capable of heating up the reaction solution homogeneously, inducing uniform nucleation and rapid crystal growth to form the Ag crystallites. This work aims to elucidate how as-grown Ag nanoparticles affect the inactivation of Escherchia coli (E. coli) and how Ag-ACF surface inhibits the bacterial growth. The Ag colloidal suspension offers superior anti-bacterial ability against E. coli cells at a low concentration of 20 mg/L. Thus, the study has established a simple, efficient and effective process in the synthesis of both Ag colloidal suspension and Ag-ACF composite.

scholarly journals Improved CUT&RUN chromatin profiling and analysis tools

2019 ◽  
Author(s):  
Michael P. Meers ◽  
Terri Bryson ◽  
Steven Henikoff
Keyword(s):  
Fusion Protein ◽  
High Efficiency ◽  
Low Cost ◽  
Protein A ◽  
Micrococcal Nuclease ◽  
Permeabilized Cells ◽  
E Coli ◽  
Carry Over ◽  
Chromatin Profiling ◽  
Premature Release

AbstractWe previously described a novel alternative to Chromatin Immunoprecipitation, Cleavage Under Targets & Release Using Nuclease (CUT&RUN), in which unfixed permeabilized cells are incubated with antibody, followed by binding of a Protein A-Micrococcal Nuclease (pA/MNase) fusion protein (1). Upon activation of tethered MNase, the bound complex is excised and released into the supernatant for DNA extraction and sequencing. Here we introduce four enhancements to CUT&RUN: 1) a hybrid Protein A-Protein G-MNase construct that expands antibody compatibility and simplifies purification; 2) a modified digestion protocol that inhibits premature release of the nuclease-bound complex; 3) a calibration strategy based on carry-over of E. coli DNA introduced with the fusion protein; and 4) a novel peak-calling strategy customized for the low-background profiles obtained using CUT&RUN. These new features, coupled with the previously described low-cost, high efficiency, high reproducibility and high-throughput capability of CUT&RUN make it the method of choice for routine epigenomic profiling.

scholarly journals Bacterial Cell Inactivation Using a Single-Frequency Batch-Type Ultrasound Device

2021 ◽  
Vol 6 (1) ◽  
pp. 65-80
Author(s):  
Poetro Sambegoro ◽  
Maya Fitriyanti ◽  
Bentang Arief Budiman ◽  
Kamarisima Kamarisima ◽  
Sekar Wangi Arraudah Baliwangi ◽  
...  
Keyword(s):  
Bacterial Cell ◽  
Treatment Time ◽  
Low Cost ◽  
Single Frequency ◽  
Bacterial Cells ◽  
Cell Inactivation ◽  
E Coli ◽  
Commercial System ◽  
Ultrasound Device ◽  
Frequency Ultrasound

Ultrasound technology employs cavitation to generate high-pressure soundwaves to disrupt bacterial cells. This study reveals the effectiveness of a single frequency ultrasound device for bacterial cell inactivation. A low-cost ultrasound device having a single frequency, i.e. 22 kHz for lab-scale application, was developed first, and the prototype was mechanically designed and analyzed using the finite-element method to assure the targeted natural frequency could be achieved. The prototype was then tested inactivating bacterial cells, Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), in a simple medium and a food system, and the results were then compared to a commercial system. A treatment time of up to 15 minutes was able to reduce E. coli and B. subtilis cells by 3.3 log and 2.8 log, respectively, and these results were similar to those of the commercial system. The effectiveness of bacterial cell inactivation using the developed single-frequency ultrasound device is then discussed. The findings are useful for designing low-cost ultrasound devices for application in the food industry.

scholarly journals A Simple Method to Create Superhydrophobic Aluminium Surfaces

2012 ◽  
Vol 706-709 ◽  
pp. 2874-2879 ◽  
Author(s):  
R. Jafari ◽  
Masoud Farzaneh
Keyword(s):  
Contact Angle ◽  
Stearic Acid ◽  
Synergistic Effects ◽  
Low Cost ◽  
Contact Angle Hysteresis ◽  
Spray Coating ◽  
Superhydrophobic Surfaces ◽  
Water Contact ◽  
Simple Method ◽  
Static Contact

Superhydrophobic surfaces were prepared using a very simple and low-cost method by spray coating. A high static water contact angle of about 154° was obtained by deposition of stearic acid on an aluminium alloy. However, this coating demonstrated a high contact angle hysteresis (~ 30º). On the other hand, superhydrophobic surfaces with a static contact angle of about 162º and 158º, and a low contact angle hysteresis of about 3º and 5º were respectively obtained by incorporating nanoparticles of SiO2and CaCO3in stearic acid. The excellent resulting hydrophobicity is attributed to the synergistic effects of micro/nanoroughness and low surface energy. A study of the wettability of these surfaces at temperatures ranging from 20 to-10 °C showed that the superhydrophobic surface becomes rather hydrophobic at supercooled temperatures.

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