Can solar driven processes effectively control antibiotic resistance and cytotoxicity during drinking water treatment?
Antibiotics, antibiotic resistant bacteria and antibiotic resistant genes have been detected in various aquatic environments because of the disposal of both treated and untreated wastewater. Their occurrence in water is a threat for human and animal health worldwide because they can promote antibiotic resistance (AR) spread, thus reducing the therapeutic potential of antibiotics against human and animal pathogens. The lack of groundwater sources in several geographical area worldwide make surface water the best alternative option for producing drinking water. But, because of the higher risk of contamination compared to groundwater, surface water should be properly treated and/or disinfected before potable use.
Fig. 1. Solar reactor for water treatment
Water disinfection may be a possible solution to minimize AR spread but conventional processes, such as chlorination, result in the formation of dangerous disinfection by-products (DBPs). As matter of fact, chlorine reacts with organic matter and other precursors to form regulated and emerging carcinogenic DBPs (e.g., trihalomethanes). Epidemiological studies have shown that consumption or exposure to DBPs concentrations above the maximum containment level in water can be associated with problems of liver, kidney, the central nervous system and increased risks of bladder, and colorectal cancers.
In order to find effective disinfection processes, alternative to chlorination, in this study oxidants/catalysts were coupled with UV radiation (H2O2/UV, TiO2/UV and N-TiO2/UV) (also known as Advanced Oxidation Processes (AOPs)), to be compared with chlorination in the inactivation of an AR Escherichia coli (E. coli) strain in surface water. In AOPs, UV artificial light can be replaced with sunlight thus saving energy costs and making solar driven AOPs a feasible and attractive option to produce drinking water in small communities (Fig. 1).
Fig. 2. Inactivation of AR E. coli strain by H2O2/UV, UV and H2O2
In this work sunlight was simulated by a special UV lamp to address experimental need. Under the investigated conditions, chlorination (1.0 mg L-1) was the faster process (2.5 min) to achieve total inactivation of the initial bacterial density. Among AOPs, H2O2/UV resulted in the best inactivation rate: total inactivation was achieved in 45 min treatment (Fig. 2). Moreover, in spite chlorination of surface water results in the formation of toxic by-products (among which chloroform), cytotoxicity tests did not show significant differences between the two investigated processes. Accordingly, further studies need to show that these new disinfection processes are a reliable alternative to chlorination.
Luigi Rizzo
University of Salerno, Department of Civil Engineering, 84084 Fisciano (SA), Italy
Publication
Surface water disinfection by chlorination and advanced oxidation processes: Inactivation of an antibiotic resistant E. coli strain and cytotoxicity evaluation.
Miranda AC, Lepretti M, Rizzo L, Caputo I, Vaiano V, Sacco O, Lopes WS, Sannino D
Sci Total Environ. 2016 Jun 1
Related Articles:
 | Microalgae-based wastewater treatment for nutrients recovery The world may face deficits of water supplies in the decades ahead, for both potable water and water for irrigation, due to human population growth, droughts and floods due to… |
 | Carbapenem-resistant Enterobacteriaceae: fighting mutants Antibiotic resistance occurs when bacteria causing an infection survive after being exposed to a drug that, under normal conditions, would kill it or inhibit its growth. As a result, this… |
 | Monitoring of the consumption of new psychoactive… Licit and illicit drug use monitoring is an important subject for public health. Almost every substance that people consume is excreted as parent compound and as metabolites via urine and… |
 | Campylobacter antimicrobial resistance in dogs and humans Campylobacteriosis has been the most frequently reported zoonotic disease in humans in Europe since 2005, and the annual number of notified campylobacteriosis cases has increased in many European countries in… |
 | A new procedure to accurately define Nitrate… The Nitrates Directive of the European Union (91/676/EEC) aims to reduce and prevent water pollution caused by nitrates from agricultural sources. It establishes that water resources should be considered polluted… |
 | Ferrate technology: an innovative solution for… Sewers might be out of sight, but they play a huge role in shaping the well-being of a society. They quietly carry away all the wastewater from our homes, businesses,… |
Leave a Reply
You must be logged in to post a comment.