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

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.

Download Full-text

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

Environmental Engineering Research ◽

10.4491/eer.2020.437 ◽

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.

Download Full-text

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

Catalysts ◽

10.3390/catal11080921 ◽

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.

Download Full-text

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

Nanomaterials ◽

10.3390/nano10010018 ◽

2019 ◽

Vol 10 (1) ◽

pp. 18 ◽

Cited By ~ 1

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.

Download Full-text

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 ◽

10.1039/d0ra09152a ◽

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.

Download Full-text

Assessment of a low-cost, point-of-use, ultraviolet water disinfection technology

Journal of Water and Health ◽

10.2166/wh.2007.015 ◽

2007 ◽

Vol 6 (1) ◽

pp. 53-65 ◽

Cited By ~ 29

Author(s):

Sarah A. Brownell ◽

Alicia R. Chakrabarti ◽

Forest M. Kaser ◽

Lloyd G. Connelly ◽

Rachel L. Peletz ◽

...

Keyword(s):

Rural Communities ◽

Residence Time ◽

Low Cost ◽

Plug Flow ◽

Field Studies ◽

Water Disinfection ◽

Galvanized Steel ◽

Hydraulic Residence Time ◽

Biological Assays ◽

Point Of Use

We describe a point-of-use (POU) ultraviolet (UV) disinfection technology, the UV Tube, which can be made with locally available resources around the world for under $50 US. Laboratory and field studies were conducted to characterize the UV Tube's performance when treating a flowrate of 5 L/min. Based on biological assays with MS2 coliphage, the UV Tube delivered an average fluence of 900±80 J/m2 (95% CI) in water with an absorption coefficient of 0.01 cm−1. The residence time distribution in the UV Tube was characterized as plug flow with dispersion (Peclet Number = 19.7) and a mean hydraulic residence time of 36 s. Undesirable compounds were leached or produced from UV Tubes constructed with unlined ABS, PVC, or a galvanized steel liner. Lining the PVC pipe with stainless steel, however, prevented production of regulated halogenated organics. A small field study in two rural communities in Baja California Sur demonstrated that the UV Tube reduced E. coli concentrations to less than 1/100 ml in 65 out of 70 samples. Based on these results, we conclude that the UV Tube is a promising technology for treating household drinking water at the point of use.

Download Full-text

A low-cost solution to rural water disinfection

IEEE Engineering in Medicine and Biology Magazine ◽

10.1109/memb.2006.1636349 ◽

2006 ◽

Vol 25 (3) ◽

pp. 36-37

Author(s):

C. Taflin

Keyword(s):

Low Cost ◽

Water Disinfection ◽

Rural Water

Download Full-text

Advanced Oxidation Process Based Water Disinfection- the Microbiology Beyond Bacterial Inactivation

10.20944/preprints202008.0291.v1 ◽

2020 ◽

Author(s):

Habeeb Rahman A.P ◽

Amrita Mishra ◽

Cecilia Stålsby Lundborg ◽

Suraj Kumar Tripathy

Keyword(s):

Advanced Oxidation Process ◽

Advanced Oxidation ◽

Vital Role ◽

Water Disinfection ◽

Resistant Bacteria ◽

Successful Implementation ◽

Bacterial Inactivation ◽

Bacterial Survival ◽

Bacterial Adaptation ◽

Hostile Environments

Different water treatment regiments are revealed to have potential in enriching antibiotic resistant bacteria (ARB). Advanced oxidation processes (AOPs) based disinfection techniques have been studied widely in the recent times due to their advantages over conventional treatment methods. However, bacterial response and adaptations against the hostile environments of AOPs is not clearly understood yet. Based on the existing knowledge on the ways in which bacteria surpass the antibiotic treatment, here we propose few important aspects of bacterial adaptation which could be true for AOPs as well since both antibiotics and AOPs generate reactive oxygen species (ROS) during their modes of action. We discuss the plausible role of ROS in the selection of ARB and bacterial heterogeneity as a strategy to bypass the lethal action of AOPs. Understanding bacterial adaptation during disinfection plays a vital role in devising strategies to outclass the bacterial survival. Hence, more importance should be given to such studies in the near future for the successful implementation of AOPs.

Download Full-text