Showing papers by "Pedro J. J. Alvarez published in 2014"
TL;DR: Extracellular DNA in sediment is a major ARG reservoir that could facilitate antibiotic resistance propagation, and chromosomally encoded 16S rRNA genes were undetectable after 8 weeks, suggesting higher persistence of plasmid-borne ARGs in river sediment.
Abstract: The propagation of antibiotic resistance genes (ARGs) represents a global threat to both human health and food security. Assessment of ARG reservoirs and persistence is therefore critical for devising and evaluating strategies to mitigate ARG propagation. This study developed a novel, internal standard method to extract extracellular DNA (eDNA) and intracellular DNA (iDNA) from water and sediments, and applied it to determine the partitioning of ARGs in the Haihe River basin in China, which drains an area of intensive antibiotic use. The concentration of eDNA was higher than iDNA in sediment samples, likely due to the enhanced persistence of eDNA when associated with clay particles and organic matter. Concentrations of sul1, sul2, tetW, and tetT antibiotic resistance genes were significantly higher in sediment than in water, and were present at higher concentrations as eDNA than as iDNA in sediment. Whereas ARGs (frequently located on plasmid DNA) were detected for over 20 weeks, chromosomally encoded 16S rRNA genes were undetectable after 8 weeks, suggesting higher persistence of plasmid-borne ARGs in river sediment. Transformation of indigenous bacteria with added extracellular ARG (i.e., kanamycin resistance genes) was also observed. Therefore, this study shows that extracellular DNA in sediment is a major ARG reservoir that could facilitate antibiotic resistance propagation.
325 citations
TL;DR: It is demonstrated that extracellular polymeric substances produced by bacteria constitute a permeability barrier with reducing constituents that mitigate the antibacterial activity of silver ions (Ag(+)).
Abstract: Whereas the antimicrobial mechanisms of silver have been extensively studied and exploited for numerous applications, little is known about the associated bacterial adaptation and defense mechanisms that could hinder disinfection efficacy or mitigate unintended impacts to microbial ecosystem services associated with silver release to the environment Here, we demonstrate that extracellular polymeric substances (EPS) produced by bacteria constitute a permeability barrier with reducing constituents that mitigate the antibacterial activity of silver ions (Ag(+)) Specifically, manipulation of EPS in Escherichia coli suspensions (eg, removal of EPS attached to cells by sonication/centrifugation or addition of EPS at 200 mg L(-1)) demonstrated its critical role in hindering intracellular silver penetration and enhancing cell growth in the presence of Ag(+) (up to 019 mg L(-1)) High-resolution transmission electron microscopy (HRTEM) combined with X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectrometry (EDS) analyses showed that Ag(+) was reduced to silver nanoparticles (AgNPs; 10-30 nm in diameter) that were immobilized within the EPS matrix Fourier transform infrared (FTIR) and (13)C nuclear magnetic resonance (NMR) spectra suggest that Ag(+) reduction to AgNPs by the hemiacetal groups of sugars in EPS contributed to immobilization Accordingly, the amount and composition of EPS produced have important implications on the bactericidal efficacy and potential environmental impacts of Ag(+)
233 citations
TL;DR: The accumulation of AuNPs in the plasmodesma of the phloem complex in root cells clearly suggests ease of transport between cells and translocation throughout the whole plant, inferring the potential for entry and transfer in food webs.
Abstract: Poplar plants (Populus deltoides × nigra, DN-34) were used as a model to explore vegetative uptake of commercially available gold nanoparticles (AuNPs) and their subsequent translocation and transport into plant cells. AuNPs were directly taken up and translocated from hydroponic solution to poplar roots, stems and leaves. Total gold concentrations in leaves of plants treated with 15, 25 and 50 nm AuNPs at exposure concentrations of 498±50.5, 247±94.5 and 263±157 ng/mL in solutions were: 0.023±0.006, 0.0218±0.004 and 0.005±0.0003 µg/g dry weight, respectively, which accounted for 0.05, 0.10 and 0.03%, respectively, of the total gold mass added. The presence of total gold in plant tissues was measured by inductively coupled plasma mass spectrometry, while AuNPs were observed by transmission electron microscopy in plant tissues. In solution, AuNPs were distinguished from Au(III) ions by membrane separation and centrifugation. AuNPs behaved conservatively inside the plants and were not dissolved into gold ions. On the other hand, Au(III) ions were taken up and reduced into AuNPs inside whole plants. AuNPs were observed in the cytoplasm and various organelles of root and leaf cells. A distinct change in color from yellow to pink was observed as Au(III) ions were reduced and precipitated in hydroponic solution. The accumulation of AuNPs in the plasmodesma of the phloem complex in root cells clearly suggests ease of transport between cells and translocation throughout the whole plant, inferring the potential for entry and transfer in food webs.
179 citations
TL;DR: Overall, although released Ag(+) is known to be the critical effector of the antimicrobial activity of AgNPs, the nanoparticles apparently deliveredAg(+) to bacteria more effectively and exerted more pronounced microbial population shifts that would hinder some wastewater treatment processes.
163 citations
TL;DR: NDM-1 genes prevailed through several treatment units (including disinfection by chlorination) in two WWTPs in northern China, raising the possibility of propagation to indigenous bacteria.
Abstract: The New Delhi metallo-β-lactamase (NDM-1) increases bacterial resistance to a broad range of antibiotics, and bacteria that produce it can cause infections that are very difficult to treat, thus posing great risks to human health. This paper addresses the occurrence of NDM-1 genes through different processes in wastewater treatment plants (WWTPs). NDM-1 genes prevailed through several treatment units (including disinfection by chlorination) in two WWTPs in northern China. Significant NDM-1 gene levels were present in the effluent discharged from both WWTPs (from 1316 ± 232 to 1431 ± 247 copies/mL, representing from 4.4 to 93.2%, respectively, of influent levels). NDM-1 genes were present at much higher concentrations in dewatered waste sludge that is applied to soils [(4.06 ± 0.98) × 107 to (6.21 ± 2.23) × 107 copies/g of dry weight], raising the possibility of propagation to indigenous bacteria. This concern was validated by a conjugation experiment with Haihe River sediment not harboring NDM-1 genes at ...
142 citations
TL;DR: The results underscore the importance of considering the effect of background constituents in the selection of photocatalysts and in the design of AOPs for emerging applications in tertiary treatment of wastewater effluent and disinfection of natural waters.
138 citations
TL;DR: The variation in regional water issues associated with shale gas development in the U.S. and the approaches of various states in mitigating these impacts are highlighted.
Abstract: The unconventional fossil fuel industry is expected to expand dramatically in coming decades as conventional reserves wane. Minimizing the environmental impacts of this energy transition requires a contextualized understanding of the unique regional issues that shale gas development poses. This manuscript highlights the variation in regional water issues associated with shale gas development in the U.S. and the approaches of various states in mitigating these impacts. The manuscript also explores opportunities for emerging international shale plays to leverage the diverse experiences of U.S. states in formulating development strategies that minimize water-related impacts within their environmental, cultural, and political ecosystem.
118 citations
TL;DR: The results suggest that oxygen-containing surface functionalities do not necessarily facilitate the biodegradation of carbonaceous nanomaterials, as is commonly assumed.
Abstract: The transformation of engineered nanomaterials in the environment can significantly affect their transport, fate, bioavailability, and toxicity. Little is known about the biotransformation potential of single-walled carbon nanotubes (SWNTs). In this study, we compared the enzymatic transformation of SWNTs and oxidized (carboxylated) SWNTs (O-SWNTs) using three ligninolytic enzymes: lignin peroxidase, manganese peroxidase (MnP), and laccase. Only MnP was capable of transforming SWNTs, as determined by Raman spectroscopy, near-infrared spectroscopy, and transmission electron microscopy. Interestingly, MnP degraded SWNTs but not O-SWNTs. The recalcitrance of O-SWNTs to enzymatic transformation is likely attributable to the binding of Mn2+ by their surface carboxyl groups at the enzyme binding site, which inhibits critical steps in the MnP catalytic cycle (i.e., Mn2+ oxidation and Mn3+ dissociation from the enzyme). Our results suggest that oxygen-containing surface functionalities do not necessarily facilita...
65 citations
TL;DR: The results highlight the importance of coating properties in the rate and extent to which nanoparticles are assimilated by plants and potentially introduced into food webs.
Abstract: Manipulation of the organic coatings of nanoparticles such as quantum dots (QDs) to enhance specific applications may also affect their interaction and uptake by different organisms. In this study, poplar trees (Populus deltoides × nigra) were exposed hydroponically to 50-nM CdSe/CdZnS QDs coated with cationic polyethylenimine (PEI) (35.3 ± 6.6 nm) or poly(ethylene glycol) of anionic poly(acrylic acid) (PAA-EG) (19.5 ± 7.2 nm) to discern how coating charge affects nanoparticle uptake, translocation, and transformation within woody plants. Uptake of cationic PEI-QDs was 10 times faster despite their larger hydrodynamic size and higher extent of aggregation (17 times larger than PAA-EG-QDs after 11-day incubation in the hydroponic medium), possibly due to electrostatic attraction to the negatively charged root cell wall. QDs cores aggregated upon root uptake, and their translocation to poplar shoots (negligible for PAA-EG-QDs and 0.7 ng Cd/mg stem for PEI-QDs) was likely limited by the endodermis. After 2-d...
50 citations
TL;DR: Results suggest that this novel catabolic biomarker (thmA/dxmA) has great potential for the rapid assessment of the performance of natural attenuation or bioremediation of dioxane plumes.
Abstract: Dioxane (dioxane) is a cocontaminant of emerging concern at thousands of sites impacted by chlorinated solvents, and there is an urgent need to assess site-specific dioxane biodegradation capabilities. In this study, a primer/probe set was developed to target bacterial genes encoding the large hydroxylase subunit of a putative tetrahydrofuran/dioxane monooxygenase (an enzyme proposed to initiate dioxane catabolism), using TaqMan (5'-nuclease) chemistry. This effort relied on multiple-sequence alignment of the four thmA/dxmA genes available on the National Center for Biotechnology Information database. The probe targets conserved regions surrounding the active site, thus allowing detection of multiple dioxane degraders. Real-time polymerase chain reaction using reference strain genomic DNA demonstrated the high selectivity (no false positives) and sensitivity of this probe (7000−8000 copies/g of soil). Microcosm tests prepared with groundwater samples from 16 monitoring wells at five different dioxane-impacted sites showed that enrichment of this catabolic gene (up to 114-fold) was significantly correlated with the amount of dioxane degraded. A significant correlation was also found between biodegradation rates and the abundance of thmA/dxmA genes. In contrast, 16S rRNA gene copy numbers (a measure of total bacteria) were neither sensitive nor reliable indicators of dioxane biodegradation activity. Overall, these results suggest that this novel catabolic biomarker (thmA/dxmA) has great potential for the rapid assessment of the performance of natural attenuation or bioremediation of dioxane plumes.
49 citations
TL;DR: Using microtiter plate and quantitative reverse transcriptase polymerase chain reaction assays, it is shown that sub-millimolar concentrations of nickel and cadmium inhibit biofilm formation by the bacterium Burkholderia multivorans through the inhibition of acyl-homoserine lactone quorum sensing.
TL;DR: In this article, the authors show that the microbial abundance and diversity in flowback waters decrease shortly after hydraulic fracturing, with Clostridia, a class that includes spore-forming microorganisms, becoming dominant.
Abstract: Microorganisms can cause detrimental effects in shale gas production, such as reservoir souring, plugging, equipment corrosion, and a decrease in hydrocarbon production volume and quality, thus representing a multi-billion-dollar problem. Prefracturing fluids, drilling mud, and impoundment water likely introduce deleterious microorganisms into shale gas reservoirs. Conditions within the reservoir generally select for halotolerant anaerobic microorganisms. Microbial abundance and diversity in flowback waters decrease shortly after hydraulic fracturing, with Clostridia, a class that includes spore-forming microorganisms, becoming dominant. The rapid microbial community successions observed suggest biocides are not fully effective, and more targeted treatment strategies are needed. At the impoundment level, microbial control strategies should consider biocide rotation, seasonal loading adjustments, and biocide pulse dosing. In shale plays where souring is common, stable 34S/32S isotope analysis to identify a...
TL;DR: Both 5 nm and 35’nm AgNPs decreased the diversity of AOB, as indicated by denaturing gradient gel electrophoresis with ammonia monooxygenase gene (amoA) primers, although some unknown Nitrosomonas species were relatively resistant to AgNps.
Abstract: Nitrification is known as one of the most sensitive processes affected when activated sludge is exposed to antimicrobial silver nanoparticles (AgNPs). The impact of AgNPs and their released silver ions (Ag+) on the abundance, activity, and diversity of different nitrifying bacteria in wastewater treatment plants (WWTPs), however, is poorly understood. The present study investigated the impacts of 2 sizes of AgNPs (5 nm and 35 nm) and Ag+ ions on the nitrifier community in activated sludge, including both ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). Ammonia-oxidizing bacteria were more sensitive to AgNPs than the NOB; a 5-d and 7-d exposure of activated sludge to 35 nm AgNPs (40 ppm) significantly reduced AOB abundance to 24% and 19%, respectively. This finding was confirmed further by a decrease in activated sludge ammonia oxidation activity measured by 14C-labeled bicarbonate uptake. In contrast, neither AgNPs (up to 40 ppm) nor Ag+ (1 ppm) affected the abundance of NOB. Both 5 nm and 35 nm AgNPs decreased the diversity of AOB, as indicated by denaturing gradient gel electrophoresis with ammonia monooxygenase gene (amoA) primers, although some unknown Nitrosomonas species were relatively resistant to AgNPs. The generally greater resistance of NOB than AOB to AgNPs suggests that the accumulation of bacteriostatic nitrite in WWTPs is unlikely to be exacerbated due to the accidental or incidental release of AgNPs. Environ Toxicol Chem 2014;33:2234–2239. © 2014 SETAC
TL;DR: Simulations show that current approaches to manage the vapor intrusion risk for conventional fuel released might need to be modified when dealing with some high ethanol blend fuel (i.e., E20 up to E95) releases.
Abstract: Ethanol-blended fuel releases usually stimulate methanogenesis in the subsurface, which could pose an explosion risk if methane accumulates in a confined space above the ground where ignitable conditions exist. Ethanol-derived methane may also increase the vapor intrusion potential of toxic fuel hydrocarbons by stimulating the depletion of oxygen by methanotrophs, and thus inhibiting aerobic biodegradation of hydrocarbon vapors. To assess these processes, a three-dimensional numerical vapor intrusion model was used to simulate the degradation, migration, and intrusion pathway of methane and benzene under different site conditions. Simulations show that methane is unlikely to build up to pose an explosion hazard (5% v/v) if diffusion is the only mass transport mechanism through the deeper vadose zone. However, if methanogenic activity near the source zone is sufficiently high to cause advective gas transport, then the methane indoor concentration may exceed the flammable threshold under simulated conditions. During subsurface migration, methane biodegradation could consume soil oxygen that would otherwise be available to support hydrocarbon degradation, and increase the vapor intrusion potential for benzene. Vapor intrusion would also be exacerbated if methanogenic activity results in sufficiently high pressure to cause advective gas transport in the unsaturated zone. Overall, our simulations show that current approaches to manage the vapor intrusion risk for conventional fuel released might need to be modified when dealing with some high ethanol blend fuel (i.e., E20 up to E95) releases.
TL;DR: In this paper, a magnetically recyclable photosensitizing system for harnessing solar energy for water treatment and disinfection is reported, which comprises C60 aminofullerene as a sensitizer for singlet oxygenation and functionalized mesoporous silica (msu-f SiO2) encapsulating magnetite nanoparticles (msu-SiO2/mag) as magnetically separable host.
TL;DR: The accumulation of anaerobic metabolites acetate and hydrogen that could hinder the thermodynamic feasibility of BTEX and PAH biotransformations under fermentative/methanogenic conditions was apparently alleviated by the growing predominance of Methanosarcina.
Abstract: A controlled field experiment was con- ducted to assess the potential for fermentative-meth- anogenic biostimulation (by ammonium-acetate injection) to enhance biodegradation of benzene, toluene, ethylbenzene and xylenes (BTEX) as well as polycyclic aromatic hydrocarbons (PAHs) in groundwater contaminated with biodiesel B20 (20:80 v/v soybean biodiesel and diesel). Changes in micro- bial community structure were assessed by pyrose- quencing 16S rRNA analyses. BTEX and PAH removal began 0.7 year following the release, concomitantly with the increase in the relative abun- dance of Desulfitobacterium and Geobacter spp. (from 5 to 52.7 % and 15.8 to 37.3 % of total Bacteria 16S rRNA, respectively), which are known to anaerobi- cally degrade hydrocarbons. The accumulation of anaerobic metabolites acetate and hydrogen that could hinder the thermodynamic feasibility of BTEX and PAH biotransformations under fermentative/methano- genic conditions was apparently alleviated by the growing predominance of Methanosarcina. This sug- gests the importance of microbial population shifts that enrich microorganisms capable of interacting syntrophically to enhance the feasibility of fermenta- tive-methanogenic bioremediation of biodiesel blend releases.
TL;DR: Compared with (smaller) nanodots, nanorods resulted in relatively low bioaccumulation, acute toxicity, and damage to spermatozoa and the tested organs, which underscores that toxicity of metallic nanomaterials could not be solely predicted based either on their elemental composition or on the amount of ions released before receptor intake.
Abstract: Cadmium sulfide (CdS) nanomaterials (such as CdS nanodots or nanorods) are widely used in optical, electronic, and biological applications. Large-scale production and use of these materials will likely result in accidental and incidental releases, which raise concerns about their potential environmental and human-health impacts. Most studies on toxicity of Cd-containing nanomaterials have focused on nanodots, and the relative toxicity of Cd-containing nanorods is not well understood. Here, we compared genotoxicity and cytotoxicity of CdS nanorods (30-50 nm diameter, 500-1100 nm length) and cubic CdS nanodots (3-5 nm) in mice by examining total cadmium accumulation in organs, acute toxicity, DNA damage, spermatozoon viability and abnormality, kidney and liver damage, and oxidative stress. Compared with (smaller) nanodots, nanorods resulted in relatively low bioaccumulation, acute toxicity, and damage to spermatozoa and the tested organs. Differences in toxicity between CdS nanodots and nanorods could not be fully explained by differences in their metal ion (Cd2+) release patterns, based on control tests with mice gavaged with dissolved CdCl2 at equivalent concentrations. This underscores that toxicity of metallic nanomaterials could not be solely predicted based either on their elemental composition or on the amount of ions released before receptor intake. Particle morphology (including size) may also need to be considered.
TL;DR: In this paper, a library of Escherichia coli gene-deletion mutants was used to show that clones lacking sodB (coding for oxidative stress protection), lon (protein damage repair), or cusR (metal efflux pump) are quite sensitive to silver (with 7.3, 5.3 and 1.1% of cells surviving, respectively), compared with 90.4% survival for wild-type E. coli, after 6-h exposure to 8 mg/L AgNO3.
Abstract: Bacterial adaptation and defense mechanisms against silver are poorly understood at the genetic level. A library of Escherichia coli gene-deletion mutants was used to show that clones lacking sodB (coding for oxidative stress protection), lon (protein damage repair), or cusR (metal efflux pump) are quite sensitive to silver (with 7.3 ± 9.1%, 5.3 ± 1.8%, and 0.4 ± 0.1% of cells surviving, respectively, compared with 90.1 ± 5.4% survival for wild-type E. coli, after 6-h exposure to 8 mg/L AgNO3), suggesting the importance of the coded functions as defense mechanisms. Mutants lacking pgaB or wcaD, which code for production of extracellular polymeric substances (EPS), also showed significant (p < 0.05) sensitivity to silver exposure (23.4 ± 16.2% and 23.1 ± 32.6% survival, respectively). Transmission electron microscopy (TEM) with scanning TEM/energy-dispersive X-ray spectroscopy analysis showed accumulation of silver nanoparticles within EPS, suggesting that EPS serve as a protective barrier that also immobilizes dissolved silver as silver nanoparticles. Environ Toxicol Chem 2014;33:993–997. © 2014 SETAC
TL;DR: The chemical ecology of biofilms is reviewed and mechanisms whereby signal manipulation can be used to promote or control bioFilms are proposed.
Abstract: In their natural environment, bacteria and other microorganisms typically grow as surface-adherent biofilm communities. Cell signal processes, including quorum signaling, are now recognized as being intimately involved in the development and function of biofilms. In contrast to their planktonic (unattached) counterparts, bacteria within biofilms are notoriously resistant to many traditional antimicrobial agents and so represent a major challenge in industry and medicine. Although biofilms impact many human activities, they actually represent an ancient mode of bacterial growth as shown in the fossil record. Consequently, many aquatic organisms have evolved strategies involving signal manipulation to control or co-exist with biofilms. Here, we review the chemical ecology of biofilms and propose mechanisms whereby signal manipulation can be used to promote or control biofilms.
TL;DR: The recombination-assisted megaprimer (RAM) as mentioned in this paper was proposed to enhance the success rate of restriction-free cloning by using exponential amplification coupled with homologous end-joining.
TL;DR: In this paper, the authors investigated how municipal solid waste (MSW) composition influences the heating value and air pollution for the co-combustion of coal with MSW using five MSW composition scenarios, four of which were derived by a reduction of plastics, organics, paper, or a combination thereof.
Abstract: Use of municipal solid waste (MSW) as fuel for electricity generation reduces landfill disposal and can mitigate air quality degradation associated with combustion of conventional fossil fuels. Co-combustion is a waste-to-energy technology that can use MSW and coal as co-fuels, offering potential energy recovery and reduced air emissions. This research discerns how MSW composition influences the heating value and air pollution for the co-combustion of coal with MSW using five MSW composition scenarios, four of which were derived by a reduction of plastics, organics, paper, or a combination thereof, as compared to the national average MSW composition. Numerous combustion products could be evaluated; this study focused on five high impact air combustion products: SO2, CO, CO2, NO, and NO2. The moisture content was varied from ∼10% (considered dry) to 40% (average MSW moisture). AspenPlus software was used for the deterministic simulation modeling of incineration (MSW only) and parallel co-firing (co-combust...
TL;DR: The present study shows that strong interactions between some munitions constituents and nanomaterials following environmental release are likely and time-dependent binding has implications for the bioavailability, migration, transport, and fate of munitions constituents in the environment.
Abstract: There is an increasing likelihood of interactions between nanomaterials and munitions constituents in the environment resulting from the use of nanomaterials as additives to energetic formulations and potential contact in waste streams from production facilities and runoff from training ranges. The purpose of the present research was to determine the ability of nano-aluminum oxide (Al2O3) and multiwalled carbon nanotubes (MWCNTs) to adsorb the munitions constituents cyclotrimethylenetrinitramine (RDX) and tungsten (W) from aqueous solution as a first step in determining the long-term exposure, transport, and bioavailability implications of such interactions. The results indicate significant adsorption of RDX by MWCNTs and of W by nano-Al2O3 (but not between W and MWCNT or RDX and nano-Al2O3). Kinetic sorption and desorption investigations indicated that the most sorption occurs nearly instantaneously (<5 min), with a relatively slower, secondary binding leading to statistically significant but relatively smaller increases in adsorption over 30 d. The RDX sorption that occurred during the initial interaction was irreversible, with long-term, reversible sorption likely the result of a secondary interaction; as interaction time increased, however, the portion of W irreversibly sorbed onto nano-Al2O3 also increased. The present study shows that strong interactions between some munitions constituents and nanomaterials following environmental release are likely. Time-dependent binding has implications for the bioavailability, migration, transport, and fate of munitions constituents in the environment. Environ Toxicol Chem 2014;33:1035–1042. © 2014 SETAC
01 Jan 2014
TL;DR: Several natural and engineered nanomaterials, such as silver (nAg), titanium oxide (TiO), and carbon nanotubes (CNT), are known to have antibacterial properties and are under consideration as disinfecting agents for water treatment systems as mentioned in this paper.
Abstract: Several natural and engineered nanomaterials, such as silver (nAg), titanium oxide (TiO,), and carbon nanotubes (CNT), are known to have antibacterial properties and are under consideration as disinfecting agents for water treatment systems. Their antimicrobial mechanisms are diverse, including photocatalytic production of reactive oxygen species (ROS) that inactivate viruses and cleave DNA, disruption of the structural integrity of the bacterial cell envelope resulting in leakage of intracellular components, arid interruption of energy transduction. In order for a material to be used for water disinfection, it must exhibit potent antimicrobial activity while remaining harmless to humans at relevant doses. However, other factors can also hinder its viability as a disinfectant. For suspended nanoparticles, these factors include the presence of salts that promote coagulation and precipitation, natural organic matter that coats or sorbs on nanoparticles and reduces their bioavailability, and competing species that consume ROS. Similarly, the efficacy of antimicrobial coatings can be compromised by the deposition of debris (e.g., soluble microbial products, inorganic precipitates, or dead cells) that occlude antimicrobial surface sites and facilitate biofilm formation. Another potential limitation is the need to retain and recycle the nanoparticles to reduce cost and avoid potential health and environmental impacts. Despite these limitations, antimicrobial nanoparticles could overcome critical challenges associated with traditional chemical disinfectants (e.g., free chlorine and ozone) such as harmful disinfection by-products and short-lived reactivity, and they could enhance existing technologies such as ultraviolet inactivation of viruses, solar disinfection of bacteria, and biofouling prone membrane filtration. Furthermore, a potential growth in demand for decentralized or point-of use water treatment and reuse systems will likely stimulate further research and commercialization of nanoparticles to enhance water disinfection applications.