Co-localized Crassostrea virginica and Crassostrea ariakensis oysters differ in bioaccumulation, retention and depuration of microbial indicators and human enteropathogens.

Aims: To evaluate the bioaccumulation, retention and depuration rates of nine pathogens and surrogates when two oyster species were co-localized in tanks of seawater.

Methods And Results: Crassostrea ariakensis (n = 52) and Crassostrea virginica (n = 52) were exposed to five virus types, two protozoan and two microsporidian species for 24 h. Oysters were then placed in depuration tanks, and subsets were removed and analysed for micro-organisms at weekly intervals.

Data gaps in evidence-based research on small water enterprises in developing countries.

Small water enterprises (SWEs) are water delivery operations that predominantly provide water at the community level. SWEs operate beyond the reach of piped water systems, selling water to households throughout the world. Their ubiquity in the developing world and access to vulnerable populations suggests that these small-scale water vendors may prove valuable in improving potable water availability.

Pretreatment for low pressure membranes in water treatment: a review.

The application of low pressure membranes (LPMs) to drinking water treatment and wastewater reuse has undergone accelerated development in the past decade. Integration of pretreatment with LPM filtration has been widely employed at full scale to reduce membrane fouling and/or increase the removal of certain aquatic contaminants. In principle, pretreatment of source water can impact membrane filtration in three ways: altering contaminant size distributions, changing mutual affinities of contaminants or their affinities to membrane surfaces, and suppressing undesirable microbial growth or removing biodegradable contaminants.

Meta-analysis of mass balances examining chemical fate during wastewater treatment.

Mass balances are an instructive means for investigating the fate of chemicals during wastewater treatment. In addition to the aqueous-phase removal efficiency (phi), they can inform on chemical partitioning, transformation, and persistence, as well as on the chemical loading to streams and soils receiving, respectively, treated effluent and digested sewage sludge (biosolids). Release rates computed on a per-capita basis can serve to extrapolate findings to a larger scale.

Fate of triclosan and evidence for reductive dechlorination of triclocarban in estuarine sediments.

The biocides triclosan and triclocarban are wastewater contaminants whose occurrence and fate in estuarine sediments remain unexplored. We examined contaminant profiles in 137Cs/7Be-dated sediment cores taken near wastewater treatment plants in the Chesapeake Bay watershed (CB), Maryland and Jamaica Bay(JB), New York. In JB, biocide occurrences tracked the time course of biocide usage and wastewater treatment strategies employed, first appearing in the 1950s (triclocarban) and 1960s (triclosan), and peaking in the late 1960s and 1970s (24 +/- 0.

Ab initio and in situ comparison of caffeine, triclosan, and triclocarban as indicators of sewage-derived microbes in surface waters.

Three organic wastewater compounds (OWCs) were evaluated in theory and practice for their potential to trace sewage-derived microbial contaminants in surface waters. The underlying hypothesis was that hydrophobic OWCs outperform caffeine as a chemical tracer, due to their sorptive association with suspended microorganisms representing particulate organic carbon (POC). Modeling from first principles (ab initio) of OWC sorption to POC under environmental conditions suggested an increasing predictive power: caffeine (0.

Unified membrane fouling index for low pressure membrane filtration of natural waters: principles and methodology.

Membrane filtration is considered an important technology that can contribute to the sustainability of water supplies. However, its continued development necessitates the establishment of proper techniques for the assessment of membrane fouling. Unified Membrane Fouling Index (UMFI) was developed in this study in order to quantify and assess the fouling of low-pressure membranes (LPM) observed at various scales of water treatment.

Natural organic matter fouling of low-pressure, hollow-fiber membranes: Effects of NOM source and hydrodynamic conditions.

Effects of natural organic matter (NOM) source and hydrodynamic conditions on both hydraulically reversible and irreversible fouling of low-pressure, hollow-fiber (LPHF) membranes were systematically investigated using representative sources of natural waters and wastewater effluents. It was found that NOM source plays a primary role in determining the fouling of these membranes. Increase in permeate flux promoted membrane fouling, but to a lesser extent than NOM source.

Bacterial community analysis of shallow groundwater undergoing sequential anaerobic and aerobic chloroethene biotransformation.

At Department of Energy Site 300, beneficial hydrocarbon cocontaminants and favorable subsurface conditions facilitate sequential reductive dechlorination of trichloroethene (TCE) and rapid oxidation of the resultant cis-dichloroethene (cis-DCE) upon periodic oxygen influx. We assessed the geochemistry and microbial community of groundwater from across the site. Removal of cis-DCE was shown to coincide with oxygen influx in hydrocarbon-containing groundwater near the source area.

Partitioning, persistence, and accumulation in digested sludge of the topical antiseptic triclocarban during wastewater treatment.

The topical antiseptic agent triclocarban (TCC) is a common additive in many antimicrobial household consumables, including soaps and other personal care products. Long-term usage of the mass-produced compound and a lack of understanding of its fate during sewage treatment motivated the present mass balance analysis conducted at a typical U.S.

Mass balance assessment of triclosan removal during conventional sewage treatment.

The antimicrobial agent triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS) is a member of a larger group of polychlorinated binuclear aromatic compounds frequently associated with adverse environmental and human health effects. Whereas the structure and function of TCS would suggest significant resistance to biotransformation, biological wastewater treatment currently is considered the principal destructive mechanism limiting dispersal of and environmental contamination with this compound. We explored the persistence of TCS in a typical full-scale activated sludge US sewage treatment plant using a mass balance approach in conjunction with isotope dilution liquid chromatography electrospray ionization mass spectrometry (ID-LC-ESI-MS) for accurate quantification.

Detection of triclocarban and two co-contaminating chlorocarbanilides in US aquatic environments using isotope dilution liquid chromatography tandem mass spectrometry.

The antimicrobial compound triclocarban (TCC; 3,4,4'-trichlorocarbanilide; CAS# 101-20-2) is a high-production-volume chemical, recently suggested to cause widespread contamination of US water resources. To test this hypothesis, we developed an isotope dilution liquid chromatography electrospray ionization tandem mass spectrometry method for ultratrace analysis of TCC (0.9 ng/L detection limit) and analyzed low-volume water samples (200 mL) along with primary sludge samples from across the United States.

Detection of norovirus capsid protein in authentic standards and in stool extracts by matrix-assisted laser desorption ionization and nanospray mass spectrometry.

Mass spectrometry (MS) represents a rapid technique for the identification of microbial monocultures, and its adaptation to the detection of pathogens in real-world samples is a public health and homeland security priority. Norovirus, a leading cause of gastroenteritis in the world, is difficult to monitor because it cannot be cultured outside the human body. The detection of norovirus capsid protein was explored using three common MS-based methods: scanning of intact proteins, peptide mass fingerprinting, and peptide sequencing.

Sorption and bioreduction of hexavalent uranium at a military facility by the Chesapeake Bay.

Directly adjacent to the Chesapeake Bay lies the Aberdeen Proving Ground, a U.S. Army facility where testing of armor-piercing ammunitions has resulted in the deposition of >70,000 kg of depleted uranium (DU) to local soils and sediments.

Reduction of infectivity of schistosome cercariae by application of cercaricidal oil to water.

Schistosomiasis continues to plague populations living in disease-endemic areas, and exposure to infective cercariae results in more than 200 million cases worldwide. Laboratory experiments were conducted to test whether a cercaricidal film applied directly to the water surface can reduce viability of cercariae. A distillate from inexpensive cedarwood oil enriched for cedrol in a mixed oil fraction was formulated (1:5) with the surfactant Tween 80.

Identification and phenotypic characterization of Sphingomonas wittichii strain RW1 by peptide mass fingerprinting using matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Mass spectrometry is a potentially attractive means of monitoring the survival and efficacy of bioaugmentation agents, such as the dioxin-mineralizing bacterium Sphingomonas wittichii strain RW1. The biotransformation activity of RW1 phenotypes is determined primarily by the presence and concentration of the dioxin dioxygenase, an enzyme initiating the degradation of both dibenzo-p-dioxin and dibenzofuran (DF). We explored the possibility of identifying and characterizing putative cultures of RW1 by peptide mass fingerprinting (PMF) targeting this characteristic phenotypic biomarker.

Analysis of triclocarban in aquatic samples by liquid chromatography electrospray ionization mass spectrometry.

Triclocarban, N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea, is a polychlorinated phenyl urea pesticide, marketed under the trademark TCC and used primarily as an antibacterial additive in personal care products. Despite its extensive use over several decades, environmental occurrence data on TCC are scarce. This is due in part to a lack of analytical techniques offering the desired sensitivity, selectivity, affordability, and ease of use.