Transport of chemical and microbial compounds from known wastewater discharges: potential for use as indicators of human fecal contamination

Degradation and acute toxicity removal of the antidepressant Fluoxetine (Prozac(®)) in aqueous systems by electron beam irradiation

Electron beam irradiation (EBI) has been considered an advanced technology for the treatment of water and wastewater, whereas very few previous investigations reported its use for removing pharmaceutical pollutants. In this study, the degradation of fluoxetine (FLX), an antidepressant marketed as Prozac(®), was investigated by using EBI at FLX initial concentration of 19.4 ± 0.2 mg L(-1). More than 90 % FLX degradation was achieved at 0.5 kGy, with FLX below the detection limit (0.012 mg L(-1)) at doses higher than 2.5 kGy. The elucidation of organic byproducts performed using direct injection mass spectrometry, along with the results of ion chromatography, indicated hydroxylation of FLX molecules with release of fluoride and nitrate anions. Nevertheless, about 80 % of the total organic carbon concentration remained even for 7.5 kGy or higher doses. The decreases in acute toxicity achieved 86.8 and 9.6 % for Daphnia similis and Vibrio fischeri after EBI exposure at 5 kGy, respectively. These results suggest that EBI could be an alternative to eliminate FLX and to decrease residual toxicity from wastewater generated in pharmaceutical formulation facilities, although further investigation is needed for correlating the FLX degradation mechanism with the toxicity results.

The occurrence of PAHs and faecal sterols in Dublin Bay and their influence on sedimentary microbial communities

The source, concentration, and potential impact of sewage discharge and incomplete organic matter (OM) combustion on sedimentary microbial populations were assessed in Dublin Bay, Ireland. Polycyclic aromatic hydrocarbons (PAHs) and faecal steroids were investigated in 30 surface sediment stations in the bay. Phospholipid fatty acid (PLFA) content at each station was used to identify and quantify the broad microbial groups present and the impact of particle size, total organic carbon (%TOC), total hydrogen (%H) and total nitrogen (%N) was also considered. Faecal sterols were found to be highest in areas with historical point sources of sewage discharge. PAH distribution was more strongly associated with areas of deposition containing high %silt and %clay content, suggesting that PAHs are from diffuse sources such as rainwater run-off and atmospheric deposition. The PAHs ranged from 12 to 3072ng/g, with 10 stations exceeding the suggested effect range low (ERL) for PAHs in marine sediments. PAH isomer pair ratios and sterol ratios were used to determine the source and extent of pollution. PLFAs were not impacted by sediment type or water depth but were strongly correlated to, and influenced by PAH and sewage levels. Certain biomarkers such as 10Me16:0, i17:0 and a17:0 were closely associated with PAH polluted sediments, while 16:1ω9, 16:1ω7c, Cy17:0, 18:1ω6, i16:0 and 15:0 all have strong positive correlations with faecal sterols. Overall, the results show that sedimentary microbial communities are impacted by anthropogenic pollution.

Complex mixtures, complex responses: Assessing pharmaceutical mixtures using field and laboratory approaches

Pharmaceuticals are present in low concentrations (<100 ng/L) in most municipal wastewater effluents but may be elevated locally because of factors such as input from pharmaceutical formulation facilities. Using existing concentration data, the authors assessed pharmaceuticals in laboratory exposures of fathead minnows (Pimephales promelas) and added environmental complexity through effluent exposures. In the laboratory, larval and mature minnows were exposed to a simple opioid mixture (hydrocodone, methadone, and oxycodone), an opioid agonist (tramadol), a muscle relaxant (methocarbamol), a simple antidepressant mixture (fluoxetine, paroxetine, venlafaxine), a sleep aid (temazepam), or a complex mixture of all compounds. Larval minnow response to effluent exposure was not consistent. The 2010 exposures resulted in shorter exposed minnow larvae, whereas the larvae exposed in 2012 exhibited altered escape behavior. Mature minnows exhibited altered hepatosomatic indices, with the strongest effects in females and in mixture exposures. In addition, laboratory-exposed, mature male minnows exposed to all pharmaceuticals (except the selective serotonin reuptake inhibitor mixture) defended nest sites less rigorously than fish in the control group. Tramadol or antidepressant mixture exposure resulted in increased splenic T lymphocytes. Only male minnows exposed to whole effluent responded with increased plasma vitellogenin concentrations. Female minnows exposed to pharmaceuticals (except the opioid mixture) had larger livers, likely as a compensatory result of greater prominence of vacuoles in liver hepatocytes. The observed alteration of apical endpoints central to sustaining fish populations confirms that effluents containing waste streams from pharmaceutical formulation facilities can adversely impact fish populations but that the effects may not be temporally consistent. The present study highlights the importance of including diverse biological endpoints spanning levels of biological organization and life stages when assessing contaminant interactions.

Are insect repellents toxic to freshwater insects? A case study using caddisflies exposed to DEET

Stream ecosystems face ever-increasing pressures by the presence of emergent contaminants, such as, personal care products. N, N-diethyl-3-methylbenzamide (DEET) is a synthetic insect repellent that is being found in surface waters environments in concentrations up to 33.4 μg/L. Information concerning DEET's toxicity in the aquatic environment is still limited and focused only on its acute effects on model species. Our main objective was to assess the effects of DEET exposure to a caddisfly non-target species using sub-lethal endpoints. For that, we chose Sericostoma vittatum, an important shredder in Portuguese freshwaters that has been already used in different ecotoxicological assays. Besides acute tests, S. vittatum were exposed during 6 days to a gradient of DEET concentrations (8, 18 and 40.5 mg/L) to assess effects on feeding behaviour and biochemical responses, such as, lipid peroxidation levels (LPO), catalase and acetylcholinesterase (AChE) activities, and also assess effects on energy reserves and consumption. Acute tests revealed a 48 h-LC50 of 80.12 mg/L and DEET exposure caused feeding inhibition with a LOEC of 36.80 mg/L. Concerning the biochemical responses, DEET caused no effects in LPO nor on catalase activity. A non-significant decrease in AChE activity was observed. Regarding energetic reserves, exposure to DEET caused a significant reduction in S. vittatum carbohydrates levels. These results add important information for the risk assessment of insect repellents in the aquatic environment and suggest that reported environmental concentrations of DEET are not toxic to non-target freshwater insects.

Evaluating the extent of pharmaceuticals in surface waters of the United States using a National-scale Rivers and Streams Assessment survey

To assess the potential exposure of aquatic ecosystems to active pharmaceutical ingredients, the authors conducted a national-scale, probability-based statistical survey of the occurrence of these compounds in surface waters of the United States. The survey included 182 sampling sites and targeted rivers with close proximity to urban areas. The 46 analytes reported represent many classes of active pharmaceutical ingredients (APIs), including antibiotics, diuretics, antihypertensives, anticonvulsants, and antidepressants. Of the 46 analytes, 37 were detected in at least 1 sampling location. Sulfamethoxazole (an antibiotic) was the most frequently detected compound, being measured in 141 of the 182 surface waters surveyed at concentrations ranging up to 570 ng/L. Ten of the compounds were detected in 20% or more of the sampling sites. Weighted means of the analytical measurements are used with the statistical survey design and analysis to provide national estimates of the extent of contamination for these APIs in the nation's urban rivers. Published 2015 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US Government work and as such, is in the public domain in the United States of America.

Responses of the aquatic midge Chironomus riparius to DEET exposure

N,N-diethyl-3-methylbenzamide (DEET) is the active ingredient of many commercial insect repellents. Despite being detected worldwide in effluents, surface water and groundwater, there is still limited information on DEET's toxicity toward non-target aquatic invertebrates. Thus, our main objective was to assess the effects of DEET in the life cycle of Chironomus riparius and assess its biochemical effects. Laboratory assays showed that DEET reduced developmental rates (reduced larval growth, delayed emergence) of C. riparius larvae and also caused a decrease in the size of adult midges. Concerning the biochemical responses, a short exposure to DEET caused no effects in lipid peroxidation, despite the significant inhibition of catalase and glutathione-S-transferase activities and of total glutathione contents. Moreover, inhibition of acetylcholinesterase activity was also observed showing neurotoxic effects. Environmental risk assessment of insect repellents is needed. Our results showed moderate toxicity of DEET toward C. riparius, however, due to their mode of action, indirect ecological effects of DEET and of other insect repellents cannot be excluded and should be evaluated.

Occurrence, distribution, and sources of antimicrobials in a mixed-use watershed

The release into the environment of antimicrobial compounds from both human and agricultural sources is a growing global concern. The Grand River watershed, the largest mixed-use watershed in southern Ontario, receives runoff from intensive animal production as well as municipal wastewater effluents from a rapidly increasing human population. A survey of surface waters and wastewater effluents was conducted across the watershed to assess the occurrence and distribution of several antimicrobials (i.e., trimethoprim, sulfamethoxazole, sulfamethazine, lincomycin, and monensin) and chemical indicators (i.e., ammonia, nitrate, ibuprofen, venlafaxine, atrazine) and to characterize exposure levels. The human antimicrobials trimethoprim and sulfamethoxazole were detected in the urban areas of the main channel at mean concentrations of 8 ± 7 ng/L and 31 ± 24 ng/L, respectively, but at much lower concentrations in the agricultural tributaries. In contrast, the veterinary antimicrobial sulfamethazine was detected at a mean concentration of 11 ± 9 ng/L in the main channel, and at a much higher concentration in the agricultural tributaries. Lincomycin was detected in only two river samples and not in the effluents while monensin was not detected in all samples. The herbicide atrazine was detected at very low concentrations in the surface waters of both the tributaries and the main channel. The concentrations of the antimicrobials and chemical indicators generally increased downstream of the confluences with agricultural tributaries and effluent outfalls. In the wastewater effluents, the concentrations of trimethoprim, sulfamethoxazole, ibuprofen, and venlafaxine decreased with increasing treatment levels (i.e., secondary to tertiary) as indicated by ammonia/nitrate concentrations. There was a strong correlation among trimethoprim, sulfamethoxazole, and venlafaxine in the main channel and in the wastewater effluents. While the environmental concentrations of antimicrobials in the watershed are low relative to toxicity thresholds, their persistence in the environment may be an important consideration in defining strategies for future water management.

A high-precision sampling scheme to assess persistence and transport characteristics of micropollutants in rivers

Increasing numbers of organic micropollutants are emitted into rivers via municipal wastewaters. Due to their persistence many pollutants pass wastewater treatment plants without substantial removal. Transport and fate of pollutants in receiving waters and export to downstream ecosystems is not well understood. In particular, a better knowledge of processes governing their environmental behavior is needed. Although a lot of data are available concerning the ubiquitous presence of micropollutants in rivers, accurate data on transport and removal rates are lacking. In this paper, a mass balance approach is presented, which is based on the Lagrangian sampling scheme, but extended to account for precise transport velocities and mixing along river stretches. The calculated mass balances allow accurate quantification of pollutants' reactivity along river segments. This is demonstrated for representative members of important groups of micropollutants, e.g. pharmaceuticals, musk fragrances, flame retardants, and pesticides. A model-aided analysis of the measured data series gives insight into the temporal dynamics of removal processes. The occurrence of different removal mechanisms such as photooxidation, microbial degradation, and volatilization is discussed. The results demonstrate, that removal processes are highly variable in time and space and this has to be considered for future studies. The high precision sampling scheme presented could be a powerful tool for quantifying removal processes under different boundary conditions and in river segments with contrasting properties.

The occurrence and fate of tetracyclines in two pharmaceutical wastewater treatment plants of Northern China

Several parameters of the method, solid-phase extraction (SPE)-ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS), were optimized to investigate the presence and partitioning of 18 antibiotics (including sulfonamides, tetracyclines, quinolones, macrolides, and β-lactams) during various processing stages at two typical pharmaceutical wastewater treatment plants (PWWTPs) in northern China. Oxytetracycline (OTC), chlortetracycline (CTC), and tetracycline (TC) were all detected in each stage of both PWWTPs. Antibiotics were largely removed through biological units of both PWWTPs, with removal efficiencies of 62.0 to 78.3%. Mass balance analyses indicated that degradation (44.8-53.7% for PWWTP1 and 40.1-59.6% for PWWTP2) was the major mechanism responsible for the removal of tetracyclines, whereas the contribution of sorption by sludge (12.6-20.0% for PWWTP1 and 18.7-33.5% for PWWTP2) was less significant for the investigated pharmaceuticals. Although there was significant removal of tetracyclines through PWWTPs, large amounts of tetracyclines were still discharged through the effluent (up to 32.0 ± 6.0 mg L(-1)) and dewatered sludge (up to 5,481.1 ± 123.0 mg kg(-1)), which increased the risk of selecting for antibiotic resistance in the receiving water and soil environments.

Seasonal and spatial variations of PPCP occurrence, removal and mass loading in three wastewater treatment plants located in different urbanization areas in Xiamen, China

The occurrence and fate of 48 pharmaceuticals and personal care products (PPCPs) in three wastewater treatment plants (WWTPs) located in different urbanization areas in Xiamen, China was investigated over one year. Results showed that PPCPs were widely detected, but the major PPCPs in the influent, effluent, and sludge were different. Spatial and seasonal variations of PPCP levels in the influent and sludge were observed. The removal efficiencies for most PPCPs were similar among the three WWTPs, although they employed different biological treatment processes. Furthermore, the mass loadings per inhabitant of most pharmaceuticals had a positive correlation with the urbanization levels, indicating that most pharmaceutical usage was higher in the urban core compared to the suburban zones. The total mass loadings of all the 48 PPCPs in the effluent and waste sludge showed close proportions, which suggested the importance of proper waste sludge disposal to prevent a large quantity of PPCPs from entering the environment.

Occurrence and distribution pattern of acidic pharmaceuticals in surface water, wastewater, and sediment of the Msunduzi River, Kwazulu-Natal, South Africa

The paucity of information on the occurrence of pharmaceuticals in the environment in African countries led the authors to investigate 8 acidic pharmaceuticals (4 antipyretics, 3 antibiotics, and 1 lipid regulator) in wastewater, surface water, and sediments from the Msunduzi River in the province of KwaZulu-Natal, South Africa, using solid-phase extraction (SPE) and liquid chromatography-mass spectrometry (LC/MS). The method recoveries, limits of detection (LOD), and limits of quantification were determined. The method recoveries were 58.4% to 103%, and the LODs ranged between 1.16 ng/L and 29.1 ng/L for water and between 0.58 ng/g and 14.5 ng/g for sediment. The drugs were all present in wastewater and in most of the surface water and sediment samples. Aspirin was the most abundant pharmaceutical observed, 118 ± 0.82 μg/L in wastewater influent, and the most observed antibiotic was nalidixic acid (25.2-29.9 μg/L in wastewater); bezafibrate was the least observed. The distribution pattern of the antipyretic in water indicates more impact in suburban sites. The solid-liquid partitioning of the pharmaceuticals between sediment and water, measured as the distribution coefficient (log KD ) gave an average accumulation magnitude of 10× to 32× in sediments than in water. The downstream distribution patterns for both water and sediment indicate discharge contributions from wastewater, agricultural activities, domestic waste disposal, and possible sewer system leakages. Although concentrations of the pharmaceuticals were comparable with those obtained from some other countries, the contamination of the present study site with pharmaceuticals has been over time and continues at present, making effective management and control necessary.

Fecal Sterol and Runoff Analysis for Nonpoint Source Tracking

Fecal pollution source identification is needed to quantify risk, target installation of source controls, and assess performance of best management practices in impaired surface waters. Sterol analysis is a chemical method for fecal source tracking that allows for differentiation between several fecal pollution sources. The objectives of this study were to use these chemical tracers for quantifying human fecal inputs in a mixed-land-use watershed without point sources of pollution and to determine the relationship between land use and sterol ratios. Fecal sterol analysis was performed on bed and suspended sediment from impaired streams. Human fecal signatures were found at sites with sewer overflow and septic inputs. Different sterol ratios used to indicate human fecal pollution varied in their sensitivity. Next, geospatial data was used to determine the runoff volumes associated with each land-use category in the watersheds. Fecal sterol ratios were compared between sampling locations and correlations were tested between ratio values and percentage of runoff for a given land-use category. Correlation was not observed between percentage of runoff from developed land and any of the five tested human-indicating sterol ratios in streambed sediments, confirming that human fecal inputs were not evenly distributed across the urban landscape. Several practical considerations for adopting this chemical method for microbial source tracking in small watersheds are discussed. Results indicate that sterol analysis is useful for identifying the location of human fecal nonpoint-source inputs.

Acute toxicity assessment of N,N-diethyl-m-toluamide (DEET) on the oxygen flux of the dinoflagellate Gymnodinium instriatum

Despite the ubiquitous occurrence of N,N-diethyl-m-toluamide (DEET) in aquatic systems, assessments evaluating the toxicity of DEET on phytoplankton species are summed to a single study on a unicellular green alga. In particular, the toxicological effects of DEET in dinoflagellates are unknown. In this study, we employed the mixotrophic dinoflagellate Gymnodinium instriatum as a study system to evaluate acute effects of DEET on the oxygen flux of laboratory cultures. This study reports an inhibitory reaction model of DEET described by the equation y = 4.99x(0.54), where y represents the percent inhibition of oxygen flux and x represents DEET concentration in mg L(−1) (r(2) = 0.98). Based on this model, the effective concentration of DEET needed to reduce O2 flux by 50% (EC50) for this species was found to be at 72.9 mg L(−1). The reported EC50 is more than five times lower than the EC50 reported previously for the unicellular green algae Chlorella protothecoides. This study raises the question of the potential toxicological effects of DEET in dinoflagellates, in particular those populations inhabiting systems characterized by low water circulation such as enclosed bays and lagoons.

Research trends on emerging environment pollutants – a review

Concern for the natural environment increasingly devotes more attention to growing potential hazards resulting from the release of various substances. Currently, one of the main problems associated with environmental pollution is the derivation of organic compounds from wastewater. Substances derived from sewage leaks into the environment in the form of a multicomponent mixtures often enhances the toxic effects caused by these compounds. While analyzing the reports in the literature of the last two decades it can be seen that substantial efforts are devoted to the determination of selected trace contaminants present in wastewater. Among the most marked there are endocrine disrupting compounds, residues of pharmaceuticals and personal care products, plastics and sunscreens. Recently, a new group of compounds joined the aforementioned contaminants, namely drugs, whose legality and availability is increasing every year. Exposure to these type of compounds, named in the literature as emerging contaminants (ECs), involves, among others, such effects as hormonal imbalance, reduction of the survivability of aquatic organisms and reproductive problems. This paper provides a review of the types of emerging organic groundwater contaminants (EGCs) which are beginning to be found in the natural environment in many countries all around the world.

Fecal pollution source tracking toolbox for identification, evaluation and characterization of fecal contamination in receiving urban surface waters and groundwater

The quality of surface waters/groundwater of a geographical region can be affected by anthropogenic activities, land use patterns and fecal pollution sources from humans and animals. Therefore, the development of an efficient fecal pollution source tracking toolbox for identifying the origin of the fecal pollution sources in surface waters/groundwater is especially helpful for improving management efforts and remediation actions of water resources in a more cost-effective and efficient manner. This review summarizes the updated knowledge on the use of fecal pollution source tracking markers for detecting, evaluating and characterizing fecal pollution sources in receiving surface waters and groundwater. The suitability of using chemical markers (i.e. fecal sterols, fluorescent whitening agents, pharmaceuticals and personal care products, and artificial sweeteners) and/or microbial markers (e.g. F+RNA coliphages, enteric viruses, and host-specific anaerobic bacterial 16S rDNA genetic markers) for tracking fecal pollution sources in receiving water bodies is discussed. In addition, this review also provides a comprehensive approach, which is based on the detection ratios (DR), detection frequencies (DF), and fate of potential microbial and chemical markers. DR and DF are considered as the key criteria for selecting appropriate markers for identifying and evaluating the impacts of fecal contamination in surface waters/groundwater.

Spoilt for choice: A critical review on the chemical and biological assessment of current wastewater treatment technologies

The knowledge we have gained in recent years on the presence and effects of compounds discharged by wastewater treatment plants (WWTPs) brings us to a point where we must question the appropriateness of current water quality evaluation methodologies. An increasing number of anthropogenic chemicals is detected in treated wastewater and there is increasing evidence of adverse environmental effects related to WWTP discharges. It has thus become clear that new strategies are needed to assess overall quality of conventional and advanced treated wastewaters. There is an urgent need for multidisciplinary approaches combining expertise from engineering, analytical and environmental chemistry, (eco)toxicology, and microbiology. This review summarizes the current approaches used to assess treated wastewater quality from the chemical and ecotoxicological perspective. Discussed chemical approaches include target, non-target and suspect analysis, sum parameters, identification and monitoring of transformation products, computational modeling as well as effect directed analysis and toxicity identification evaluation. The discussed ecotoxicological methodologies encompass in vitro testing (cytotoxicity, genotoxicity, mutagenicity, endocrine disruption, adaptive stress response activation, toxicogenomics) and in vivo tests (single and multi species, biomonitoring). We critically discuss the benefits and limitations of the different methodologies reviewed. Additionally, we provide an overview of the current state of research regarding the chemical and ecotoxicological evaluation of conventional as well as the most widely used advanced wastewater treatment technologies, i.e., ozonation, advanced oxidation processes, chlorination, activated carbon, and membrane filtration. In particular, possible directions for future research activities in this area are provided.

Stability and removal of atorvastatin, rosuvastatin and simvastatin from wastewater

Atorvastatin (ATO), rosuvastatin (RST) and simvastatin (SIM) are commonly used drugs that belong to the statin family (lowering human blood cholesterol levels) and have been detected as contaminants in natural waters. Stability and removal of ATO, RST and SIM from spiked wastewater produced at the Al-Quds University campus were investigated. All three statins were found to undergo degradation in wastewater (activated sludge). The degradation reactions of the three drugs in wastewater at room temperature follow first-order kinetics with rate constants of 2.2 × 10⁻⁷ s⁻¹ (ATO), 1.8 × 10⁻⁷ s⁻¹ (RST) and 1.8 × 10⁻⁶ s⁻¹ (SIM), which are larger than those obtained in pure water under the same conditions, 1.9 × 10⁻⁸ s⁻¹ (ATO), 2.2 × 10⁻⁸ s⁻¹ (RST) and 6.2 × 10⁻⁷ s⁻¹ (SIM). Degradation products were identified by LC-MS and LC/MS/MS. The overall performance of the wastewater treatment plant (WWTP) installed in the Al-Quds University campus towards the removal of these drugs was assessed showing that more than 90% of spiked ATO, RST and SIM were removed. In order to evaluate the efficiency of alternative removal methods to replace ultra-filtration membranes, adsorption isotherms for the three statins were investigated using both activated carbon and clay-micelle complex as adsorbents. The batch adsorption isotherms for the three statins were found to fit the Langmuir equation, with a larger number of adsorption sites and binding affinity for micelle-clay composite compared with activated carbon and filtration experiments of the three statins and their corresponding metabolites demonstrated a more efficient removal by micelle-clay filters.

Investigating landfill leachate as a source of trace organic pollutants

Landfill leachate samples (n=11) were collected from five USA municipal solid waste (MSW) landfills and analyzed for ten trace organic pollutants that are commonly detected in surface and municipal wastewater effluents (viz., carbamazepine, DEET, fluoxetine, gemfibrozil, PFOA, PFOS, primidone, sucralose, sulfamethoxazole and trimethoprim). Carbamazepine, DEET, PFOA and primidone were detected in all leachate samples analyzed and gemfibrozil was detected in samples from four of the five-landfill sites. The contaminants found in the highest concentrations were DEET (6900-143000 ng L(-1)) and sucralose (<10-621000 ng L(-1)). Several compounds were not detected (fluoxetine) or detected infrequently (sulfamethoxazole, trimethoprim and PFOS). Using the average mass of DEET in leachate amongst the five landfills and scaling the mass release from the five test landfills to the USA population of landfills, an order of magnitude estimate is that over 10000 kg DEET yr(-1) may be released in leachate. Some pharmaceuticals have similar annual mean discharges to one another, with the estimated annual discharge of carbamazepine, gemfibrozil, primidone equating to 53, 151 and 128 kg year(-1). To the authors knowledge, this is the first time that primidone has been included in a landfill leachate study. While the estimates developed in this study are order of magnitude, the values do suggest the need for further research to better quantify the amount of chemicals sent to wastewater treatment facilities with landfill leachate, potential impacts on treatment processes and the significance of landfill leachate as a source of surface water contamination.

Assessment of ichthyotoxicity and anthropogenic contamination in the surface waters of Kenting National Park, Taiwan

Millions of tourists visit Kenting National Park (KNP) in southern Taiwan every year, causing great amount of sewage discharges in this area. This study aimed to assess the impact of sewage on KNP surface waters using zebrafish embryo-larval bioassays combined with chemical analyses of pharmaceuticals and personal care products (PPCPs). Surface water samples were collected monthly from May to October in 2010. During the monthly bioassays, zebrafish embryos were exposed to the water samples for 144 h. Hatchability, embryonic heart rate, larval survival rate, and deformities were recorded. Larval swimming behavior was also digitally quantified at the end of exposure. Significant decreases in hatchability and larval survival rate were observed at all sites. Both hatchability and larval survival rate were negatively correlated with nitrite and ammonia concentrations in the water. The field water had little effect on embryonic heart rate and morphology. However, lower swimming speeds and activity levels were observed in the larvae, suggesting neurobehavioral toxicity of the surface waters. The general detection frequency of the 28 target PPCPs was 75%. High levels of some PPCPs, particularly caffeine, N,N-diethyl-3-methylbenzamide (DEET), and nonylphenol, were measured in the water samples. Our results show that surface waters in KNP have been strongly impacted by human activities, resulting in lethal and behavioral toxicities in developing fish.

Caffeine as an indicator of human fecal contamination in the Sinos River: a preliminary study

The preservation of hydric resources is directly related to fecal contamination monitoring, in order to allow the development of strategies for the management of polluting sources. In the present study, twenty-five water samples from six water public supply collection sites were used for the evaluation of the presence of caffeine, total and fecal coliforms. Caffeine was detected in all samples, with concentrations ranging from 0.15 ng mL-1 to 16.72 ng mL-1. Total coliforms were detected in all samples, with concentrations in the range of 52 NMP/100 mL to higher than 24196 NMP/100 mL, whether the concentration range for fecal coliforms was in the range of below 1 NMP/100 mL to 7800 NMP/100 mL. No significant correlation was found between total coliforms and caffeine concentrations (rs = 0.35, p = 0.09). However, a moderate correlation between fecal coliforms and caffeine concentrations was found (rs = 0.412, p <0.05), probably indicating a human source for these bacteria. Caffeine determination in water may be a useful strategy to evaluate water contamination by human fecal waste.

Correlation of trace contaminants to wastewater management practices in small watersheds

Ten low-order streams draining headwater catchments within the East Fork Little Miami Watershed were evaluated throughout one year for the presence of six steroidal hormones, the antibiotic sulfamethoxazole, the antimicrobials triclosan and triclocarban, and the artificial sweetener sucralose. The wastewater management practices in the catchments included septic systems, sanitary sewers, a combination of both, and a parkland with no treatment systems. The concentrations and detection frequencies of sucralose showed a significant positive correlation with the septic density in each catchment. A similar relationship was found for sulfamethoxazole. Both sucralose and sulfamethoxazole are hydrophilic and unlikely to be removed effectively by sorption during septic treatment. The concentrations and detection frequencies of the antimicrobials were also positively correlated with septic density. The presence of the antimicrobials in the streams indicates that although they are hydrophobic, removal during septic treatment was incomplete. The target analytes that correlated with septic density were also detected in stream samples collected below a wastewater treatment plant located within the same watershed. The steroidal hormone estrone was the most frequently detected analyte at all sites. However, the estrone concentrations and detection frequencies did not correlate with the septic density due to multiple non-point sources.

Attenuation of trace organic compounds (TOrCs) in bioelectrochemical systems

Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are two types of microbial bioelectrochemical systems (BESs) that use microorganisms to convert chemical energy in wastewaters into useful energy products such as (bio)electricity (MFC) or hydrogen gas (MEC). These two systems were evaluated for their capacity to attenuate trace organic compounds (TOrCs), commonly found in municipal wastewater, under closed circuit (current generation) and open circuit (no current generation) conditions, using acetate as the carbon source. A biocide was used to evaluate attenuation in terms of biotransformation versus sorption. The difference in attenuation observed before and after addition of the biocide represented biotransformation, while attenuation after addition of a biocide primarily indicated sorption. Attenuation of TOrCs was similar in MFCs and MECs for eight different TOrCs, except for caffeine and trimethoprim where slightly higher attenuation was observed in MECs. Electric current generation did not enhance attenuation of the TOrCs except for caffeine, which showed slightly higher attenuation under closed circuit conditions in both MFCs and MECs. Substantial sorption of the TOrCs occurred to the biofilm-covered electrodes, but no consistent trend could be identified regarding the physico-chemical properties of the TOrCs tested and the extent of sorption. The octanol-water distribution coefficient at pH 7.4 (log DpH 7.4) appeared to be a reasonable predictor for sorption of some of the compounds (carbamazepine, atrazine, tris(2-chloroethyl) phosphate and diphenhydramine) but not for others (N,N-Diethyl-meta-toluamide). Atenolol also showed high levels of sorption despite being the most hydrophilic in the suite of compounds studied (log DpH 7.4 = -1.99). Though BESs do not show any inherent advantages over conventional wastewater treatment, with respect to TOrC removal, overall removals in BESs are similar to that reported for conventional wastewater systems, implying the possibility of using BESs for energy production in wastewater treatment without adversely impacting TOrC attenuations.

Occurrence, bioaccumulation and risk assessment of lipophilic pharmaceutically active compounds in the downstream rivers of sewage treatment plants

The occurrence, bioaccumulation and risk assessment of lipophilic pharmaceutically active compounds (LPhACs), such as antibiotics (roxithromycin, erythromycin and ketoconazole), anti-inflammatories (ibuprofen and diclofenac), β-blockers (propranolol), antiepileptics (carbamazepine) and steroid hormones (17α-ethinylestradiol), were investigated in the downstream rivers of sewage treatment plants in Nanjing, China. The results indicate that these LPhACs were widely detected in the surface water and fish samples, with the mean concentrations of the total LPhACs (ΣLPhACs) being in the range of 15.4 and 384.5 ng/L and 3.0 and 128.4 ng/g (wet weight), respectively. The bioaccumulation of the ΣLPhACs in wild fish tissues was generally in the order the liver>brain>gill>muscle. Among the target LPhACs, however, an interspecies difference in tissue distribution was evident for erythromycin. The bioaccumulation factors of LPhACs in the liver and brain, the two major targeted storage sites for toxicants, exhibited an obvious negative correlation with the aquatic concentrations (P<0.05). Finally, risk quotients posed by pharmaceuticals were assessed by comprehensive and comparative methods for different aquatic organisms (algae, daphnids and fish). The overall relative order of susceptibility was estimated to be algae>daphnids>fish. However, the results indicate that diclofenac, ibuprofen and 17α-ethinylestradiol each posed chronic risks for high trophic level organisms (fish). In all of the risk assessments, erythromycin was found to be the most harmful for the most sensitive algae group. In this work, however, the total BAF and toxicological interactions of pharmaceuticals were not performed due to the lack of metabolite information and combined toxicity data, which represents a major hindrance to the effective risk assessment of pharmaceuticals.

Contamination of stormwater by wastewater: a review of detection methods

Even in separate sewer systems, wastewater may find its way into the receiving waters through stormwater sewers. The main reasons for this are cross-connections, illicit connections, overflows and leakages through broken sewers. Such discharges may affect receiving water quality and increase risks to public health and aquatic organisms. Detecting wastewater contamination and locating its points of ingress into storm sewer systems can be a challenging task, which should be addressed using proper methods and indicator parameters. A number of detection methods have already been proposed in this area, yet there is a lack of a general overview of such methods. This literature review summarizes and evaluates the methods used for detecting wastewater in stormwater, including those recently developed. The advantages, weaknesses and limitations of individual methods are discussed. It is concluded that while no single method can as yet produce results in a precise, fast and inexpensive way, the use of human waste specific chemical and microbiological markers, and their innovative sampling, offer the way forward. Guidance for selecting the most effective combinations of detection methods, under specific conditions, is also provided.

Emerging contaminants in urban groundwater sources in Africa

The occurrence of emerging organic contaminants within the aquatic environment in Africa is currently unknown. This study provides early insights by characterising a broad range of emerging organic contaminants (n > 1000) in groundwater sources in Kabwe, Zambia. Groundwater samples were obtained during both the dry and wet seasons from a selection of deep boreholes and shallow wells completed within the bedrock and overlying superficial aquifers, respectively. Groundwater sources were distributed across the city to encompass peri-urban, lower cost housing, higher cost housing, and industrial land uses. The insect repellent DEET was ubiquitous within groundwater at concentrations up to 1.8 μg/L. Other compounds (n = 26) were detected in less than 15% of the sources and included the bactericide triclosan (up to 0.03 μg/L), chlorination by-products - trihalomethanes (up to 50 μg/L), and the surfactant 2,4,7,9-tetramethyl-5-decyne-4,7-diol (up to 0.6 μg/L). Emerging contaminants were most prevalent in shallow wells sited in low cost housing areas. This is attributed to localised vulnerability associated with inadequate well protection, sanitation, and household waste disposal. The five-fold increase in median DEET concentration following the onset of the seasonal rains highlights that more mobile compounds can rapidly migrate from the surface to the aquifer suggesting the aquifer is more vulnerable than previously considered. Furthermore it suggests DEET is potentially useful as a wastewater tracer in Africa. There was a general absence of personal care products, life-style compounds, and pharmaceuticals which are commonly detected in the aquatic environment in the developed world. This perhaps reflects some degree of attenuation within the subsurface, but could also be a result of the current limited use of products containing emerging contaminants by locals due to unaffordability and unavailability. As development and population increases in Africa, it is likely a wider-range of emerging contaminants will be released into the environment.

Pepper mild mottle virus as an indicator and a tracer of fecal pollution in water environments: comparative evaluation with wastewater-tracer pharmaceuticals in Hanoi, Vietnam

We analyzed pepper mild mottle virus (PMMoV) in 36 samples taken from surface water, wastewater, groundwater, tap water and bottled water in Hanoi, Vietnam. We then compared the occurrence and fates of PMMoV with pharmaceuticals and personal care products (PPCPs), which are known wastewater tracers. PMMoV was detected in 94% of the surface water samples (ponds, water from irrigated farmlands and rivers) and in all the wastewater samples. The PMMoV concentration ranged from 5.5×10(6)-7.2×10(6)copies/L in wastewater treatment plant (WWTP) influents, 6.5×10(5)-8.5×10(5)copies/L in WWTP effluents and 1.0×10(4)-1.8×10(6)copies/L in surface water. Among the sixty PPCPs analyzed, caffeine and carbamazepine had high detection rates in surface water (100% and 88%, respectively). In surface water, the concentration ratio of PMMoV to caffeine remained unchanged than that in WWTP influents, suggesting that the persistence of PMMoV in surface water was comparable to that of caffeine. The persistence and the large concentration ratio of PMMoV in WWTP influents to the method detection limit would account for its ubiquitous detection in surface water. In comparison, human enteric viruses (HEV) were less frequently detected (18-59%) than PMMoV in surface water, probably because of their faster decay. Together with the reported high human feces-specificity, our results suggested that PMMoV is useful as a sensitive fecal indicator for evaluating the potential occurrence of pathogenic viruses in surface water. Moreover, PMMoV can be useful as a moderately conservative fecal tracer for specifically tracking fecal pollution of surface water. PMMoV was detected in 38% of the groundwater samples at low concentrations (up to 19copies/L). PMMoV was not detected in the tap water and bottled water samples. In groundwater, tap water and bottled water samples, the occurrence of PPCPs and HEV disagreed with that of PMMoV, suggesting that PMMoV is not suitable as an indicator or a tracer in those waters.

Occurrence and removal of transformation products of PPCPs and illicit drugs in wastewaters: a review

Pharmaceuticals and personal care products (PPCPs) along with illicit drugs (IDs) are newly recognized classes of environmental pollutants and are receiving considerable attention because of their environmental impacts: frequent occurrence, persistence and risk to aquatic life and humans. However, relatively little information is often available with regard to their possible biotic and abiotic transformation products (TPs). This lack of knowledge has resulted in a substantial amount of ongoing effort to develop methods and approaches that would assess their occurrence, degradability potential elimination mechanisms and efficiencies in sewage treatment plants as well as environmental and human health risks. In this article, an extensive literature survey was performed in order to present the current stage of knowledge and progress made in the occurrence of TPs of PPCPs and IDs in raw and treated wastewaters. Apart from the TPs resulting from structural transformations of the parent compound in the aquatic environment or in technological treatment facilities (e.g. sewage and drinking water treatment plants), free metabolites and drug conjugates formed during human metabolism have also been included in this review as they are also released into the aquatic environment through wastewaters. Their concentration levels were reported in influents and effluents of WWTPs, hospital effluents and their removals in the treatment plants were discussed. Finally, information on the toxicity of TPs has been compiled when available.

Presence and effects of pharmaceutical and personal care products on the Baca National Wildlife Refuge, Colorado

Pharmaceuticals and personal care products (PPCPs) have raised concerns due to their potential effects to aquatic organisms. These chemicals appear in mixtures at very low concentrations thus making their detection and quantification difficult. Polar organic chemical integrative samplers (POCIS) concentrate trace levels of chemicals over time increasing method sensitivity and thus represent a cost-effective screening tool for biomonitoring studies. The Baca National Wildlife Refuge (BNWR), Colorado, is home for several endemic fish species, including Rio Grande chub (Gila pandora). The objectives of this study were to (1) determine the types and concentrations of PPCPs in the Refuge, (2) compare and contrast two methods (grab and POCIS) for the quantification of PPCPs from surface water, and (3) determine effects due to PPCP exposure in fish. Between 2011 and 2013, 141 PPCPs were quantified using a combination of grab samples and POCIS. Although no PPCPs were detected from the grab samples, high concentrations of N,N-Diethyl-meta-toluamide (DEET) and triclosan were detected in all fish sampling sites with POCIS. Fathead minnows (Pimephales promelas) and Rio Grande chubs of both sexes were collected in 2011 and 2012. Several biological responses were observed in both species from creeks contaminated with PPCPs; however the presence of PPCPs in the reference site did not allow for valid data comparison and interpretation. We conclude that POCIS is a sensitive method for the detection and quantification of PPCPs and for identification of reference sites and that appropriate "reference" sites need to be identified at the BNWR for follow-up studies with native fish.

Spatial and temporal variation in de facto wastewater reuse in drinking water systems across the U.S.A

De facto potable reuse occurs when treated wastewater is discharged into surface waters upstream of potable drinking water treatment plant (DWTP) intakes. Wastewater treatment plant (WWTP) discharges may pose water quality risks at the downstream DWTP, but additional flow aids in providing a reliable water supply source. In this work de facto reuse is analyzed for 2056 surface water intakes serving 1210 DWTPs across the U.S.A. that serve greater than 10,000 people, covering approximately 82% of the nation’s population. An ArcGIS model is developed to assess spatial relationships between DWTPs and WWTPs, with a python script designed to perform a network analysis by hydrologic region. A high frequency of de facto reuse occurrence was observed; 50% of the DWTP intakes are potentially impacted by upstream WWTP discharges. However, the magnitude of de facto reuse was seen to be relatively low, where 50% of the impacted intakes contained less than 1% treated municipal wastewater under average streamflow conditions. De facto reuse increased greatly under low streamflow conditions (modeled by Q95), with 32 of the 80 sites yielding at least 50% treated wastewater, this portion of the analysis is limited to sites where stream gauge data was readily available.

Retention in treated wastewater affects survival and deposition of Staphylococcus aureus and Escherichia coli in sand columns

The fate and transport of pathogenic bacteria from wastewater treatment facilities in the Earth's subsurface have attracted extensive concern over recent decades, while the impact of treated-wastewater chemistry on bacterial viability and transport behavior remains unclear. The influence of retention time in effluent from a full-scale municipal wastewater treatment plant on the survival and deposition of Staphylococcus aureus and Escherichia coli strains in sand columns was investigated in this paper. In comparison to the bacteria cultivated in nutrient-rich growth media, retention in treated wastewater significantly reduced the viability of all strains. Bacterial surface properties, e.g., zeta potential, hydrophobicity, and surface charges, varied dramatically in treated wastewater, though no universal trend was found for different strains. Retention in treated wastewater effluent resulted in changes in bacterial deposition in sand columns. Longer retention periods in treated wastewater decreased bacterial deposition rates for the strains evaluated and elevated the transport potential in sand columns. We suggest that the wastewater quality should be taken into account in estimating the fate of pathogenic bacteria discharged from wastewater treatment facilities and the risks they pose in the aquatic environment.

Persistence of pharmaceuticals in effluent-dominated surface waters

Pharmaceutical fate in surface water depends on a combination of physical and chemical processes, but currently, little information is available on cumulative dissipation rates in effluent-dominated receiving waters. In this study, dissipation rates were calculated for pharmaceutical compounds in two streams receiving municipal wastewater effluents using results from passive samplers. Seventeen pharmaceuticals were detected at the two sampling locations, and first-order dissipation rates were found to range between 0.03 and -0.02 h, indicating that some compounds were conserved, while others rapidly dissipated over several kilometers downstream of the source.

Are fecal stanols suitable to record and identify a pulse of human fecal contamination in short-term exposed shellfish? A microcosm study

In this study, the capacity of oysters to bioaccumulate fecal stanols and to record a source-specific fingerprint was investigated by the short-term contamination of seawater microcosms containing oysters with a human effluent. Contaminated oysters bioaccumulated the typical fecal stanols coprostanol and 24-ethylcoprostanol and their bioaccumulation kinetics were similar to that of the Fecal Indicator Bacteria Escherichia coli used in European legislation. Although stanol fingerprints of contaminated water allowed the identification of the human specific fingerprint, this was not the case for oysters. This discrepancy is attributed to (i) high concentrations of endogenous cholestanol and sitostanol, responsible for "unbalanced" stanol fingerprints, (ii) different accumulation/depuration kinetics of fecal coprostanol and 24-ethylcoprostanol and (iii) the limits of the analytical pathway used. These results show that fecal stanols bioaccumulated by oysters are useful to record fecal contamination but the usefulness of stanol fingerprints to identify specific sources of contamination in shellfish currently seems limited.

Role of primary substrate composition and concentration on attenuation of trace organic chemicals in managed aquifer recharge systems

This study was undertaken to investigate the role of primary substrate composition and concentration on the attenuation of biodegradable emerging trace organic chemicals (TOrCs) in simulated managed aquifer recharge (MAR) systems. Four sets of soil columns were established in the laboratory, each receiving synthetic feed solutions comprising different ratios and concentrations of peptone-yeast and humic acid as the primary substrate to investigate the effect on removal of six TOrCs (atenolol, caffeine, diclofenac, gemfibrozil, primidone, and trimethoprim). Based on abiotic control experiments, adsorption was not identified as a significant attenuation mechanism for primidone, gemfibrozil and diclofenac. Caffeine, atenolol and trimethoprim displayed initial adsorptive losses, however, adsorption coefficients derived from batch tests confirmed that adsorption was limited and in the long-term experiment, biodegradation was the dominant attenuation process. Within a travel time of 16 h, caffeine - an easily degradable compound exhibited removal exceeding 75% regardless of composition or concentration of the primary substrate. Primidone - a poorly degradable compound, showed no removal in any column regardless of the nature of the primary substrate. The composition and concentration of the primary substrate, however, had an effect on attenuation of moderately degradable TOrCs, such as atenolol, gemfibrozil and diclofenac, with the primary substrate composition seeming to have a larger impact on TOrC attenuation than its concentration. When the primary substrate consisted mainly of refractory substrate (humic acid), higher removal of the moderately degradable TOrCs was observed. The microbial communities in the columns receiving more refractory carbon, were noted to be more diverse and hence likely able to express a wider range of enzymes, which were more suitable for TOrC transformation. The effect of the primary substrate on microbial community composition, diversity and gene expression potential confirmed its influence on TOrC degradation.

The impact of land use on microbial surface water pollution

Our knowledge relating to water contamination from point and diffuse sources has increased in recent years and there have been many studies undertaken focusing on effluent from sewage plants or combined sewer overflows. However, there is still only a limited amount of microbial data on non-point sources leading to diffuse pollution of surface waters. In this study, the concentrations of several indicator micro-organisms and pathogens in the upper reaches of a river system were examined over a period of 16 months. In addition to bacteria, diffuse pollution caused by Giardia lamblia and Cryptosporidium spp. was analysed. A single land use type predestined to cause high concentrations of all microbial parameters could not be identified. The influence of different land use types varies between microbial species. The microbial concentration in river water cannot be explained by stable non-point effluent concentrations from different land use types. There is variation in the ranking of the potential of different land use types resulting in surface water contamination with regard to minimum, median and maximum effects. These differences between median and maximum impact indicate that small-scale events like spreading manure substantially influence the general contamination potential of a land use type and may cause increasing micro-organism concentrations in the river water by mobilisation during the next rainfall event.

Distribution and ecological risk of antibiotics in a typical effluent-receiving river (Wangyang River) in north China

In this study, the occurrence and distribution of sixteen antibiotics belonging to four groups in surface water, sediment and groundwater samples from the Wangyang River (WYR), a typical river receiving sewage discharges were investigated. Laboratory analyses revealed that antibiotics were widely distributed in the studied area. The aqueous samples were unavoidably contaminated with antibiotics, and the target antibiotics present in high levels were oxytetracycline, tetracycline, chlortetracycline, ofloxacin, sulfamethoxazole, and trimethoprim, with maximum concentrations of the individual contaminant at 3.6×10(5), 9.7×10(3), 6.9×10(4), 1.2×10(4), 4.8×10(3), and 1.1×10(3) ng L(-1), respectively. Oxytetracycline, tetracycline, ciprofloxacin and roxithromycin were the most frequently detected compounds in sediment samples, with maximum concentrations of the individual contaminant at 1.6×10(5), 1.7×10(4), 2.1×10(3) and 2.5×10(3) ng g(-1), respectively. The results also revealed that the high intensity of aquaculture activities could contribute to the increasing levels of antibiotics in the area. According to the ratios of measured environmental concentration (MEC) to predicted no-effect concentration (PNEC), chlortetracycline, tetracycline, ofloxacin, ciprofloxacin, erythromycin-H2O and sulfamethoxazole may present possible environmental risk to Pseudokirchneriella subcapitata, Synechococcus leopoliensis and M. aeruginosa. Attention should be given to the long-term ecological effects caused by the continuous discharge of antibiotics in the WYR area.

Riverbank filtration potential of pharmaceuticals in a wastewater-impacted stream

Pharmaceutical contamination of shallow groundwater is a substantial concern in effluent-dominated streams, due to high aqueous mobility, designed bioactivity, and effluent-driven hydraulic gradients. In October and December 2012, effluent contributed approximately 99% and 71%, respectively, to downstream flow in Fourmile Creek, Iowa, USA. Strong hydrologic connectivity was observed between surface-water and shallow-groundwater. Carbamazepine, sulfamethoxazole, and immunologically-related compounds were detected in groundwater at greater than 0.02 μg L(-1) at distances up to 6 m from the stream bank. Direct aqueous-injection HPLC-MS/MS revealed 43% and 55% of 110 total pharmaceutical analytes in surface-water samples in October and December, respectively, with 16% and 6%, respectively, detected in groundwater approximately 20 m from the stream bank. The results demonstrate the importance of effluent discharge as a driver of local hydrologic conditions in an effluent-impacted stream and thus as a fundamental control on surface-water to groundwater transport of effluent-derived pharmaceutical contaminants.

Sequencing human mitochondrial hypervariable region II as a molecular fingerprint for environmental waters

To protect environmental water from human fecal contamination, authorities must be able to unambiguously identify the source of the contamination. Current identification methods focus on tracking fecal bacteria associated with the human gut, but many of these bacterial indicators also thrive in the environment and in other mammalian hosts. Mitochondrial DNA could solve this problem by serving as a human-specific marker for fecal contamination. Here we show that the human mitochondrial hypervariable region II can function as a molecular fingerprint for human contamination in an urban watershed impacted by combined sewer overflows. We present high-throughput sequencing analysis of hypervariable region II for spatial resolution of the contaminated sites and assessment of the population diversity of the impacting regions. We propose that human mitochondrial DNA from public waste streams may serve as a tool for identifying waste sources definitively, analyzing population diversity, and conducting other anthropological investigations.

Pharmaceuticals and personal care products in a mesoscale subtropical watershed and their application as sewage markers

This study comprehensively analyzed 23 classes of 51 pharmaceuticals and personal care products (PPCPs) in the two major prongs of Jiulong River and its estuary in southeast China, where the levels of the targeted PPCPs were mostly unknown. For both Jiulong River and its estuary, nine PPCPs were detected with 100% detection frequencies including two anti-inflammatory and analgesic drugs (ketoprofen and diclofenac acid), a stimulant (caffeine), a plasticizer (bisphenol A), two preservatives (methyl paraben and propyl paraben), two antimicrobials (triclosan and triclocarban) and a β-blocks (metoprolol), among which bisphenol A and caffeine accounted for more than 60% in concentrations. PPCPs generally had higher concentrations in dry season than normal season and wet season, while certain PPCPs, such as UV filters, showed higher concentrations in wet season, which were presumed to be related to their usage patterns. The concentrations of PPCPs were significantly correlated to several quality parameters of the surface water. The selected sewage markers were also used to track sewage in the studied river and the ratios of easily removed markers and conservative markers were used to identify the contribution of raw or treated sewage input. From our result, Jiulong River and its estuary were likely polluted by potential discharge of raw sewage.

Distributions of polycyclic musk fragrance in wastewater treatment plant (WWTP) effluents and sludges in the United States

The polycyclic musks, AHTN and HHCB are fragrance ingredients widely used in consumer products. A monitoring campaign was conducted and collected grab effluent and sludge samples at 40 wastewater treatment plants (WWTP) across the United States to understand their occurrence and statistical distribution in these matrices. AHTN concentration in effluent ranged from <0.05 μg/L (LOQ) to 0.44 μg/L with a mean and standard deviation of 0.18 ± 0.11 μg/L. HHCB concentrations in effluent ranged from 0.45 to 4.79 μg/L with a mean of 1.86 ± 1.01 μg/L. AHTN concentrations in sludge ranged from 0.65 to 15.0mg/kg dw (dry weight) with a mean and standard deviation being 3.69 ± 2.57 mg/kg dw, while HHCB sludge concentrations were between 4.1 and 91 mg/kg with a mean of 34.0 ± 23.1mg/kg dw. Measured concentrations of AHTN and HHCB were significantly correlated with each other in both effluent and sludge. The concentrations of HHCB in both effluent and sludge were approximately an order of magnitude higher than those for AHTN, consistent with 2011 usage levels. The highest measured effluent concentrations for both AHTN and HHCB were below their respective freshwater PNECs (predicted no effect concentrations), indicating a negligible risk to biological communities below WWTPs, even in the absence of upstream dilution. Moreover, the large number of effluents and sludges sampled provides a statistical distribution of loadings that can be used to develop more extensive probabilistic exposure assessments for WWTP mixing zones and sludge amended soils.

Acute and chronic environmental effects of clandestine methamphetamine waste

The illicit manufacture of methamphetamine (MAP) produces substantial amounts of hazardous waste that is dumped illegally. This study presents the first environmental evaluation of waste produced from illicit MAP manufacture. Chemical oxygen demand (COD) was measured to assess immediate oxygen depletion effects. A mixture of five waste components (10mg/L/chemical) was found to have a COD (130 mg/L) higher than the European Union wastewater discharge regulations (125 mg/L). Two environmental partition coefficients, K(OW) and K(OC), were measured for several chemicals identified in MAP waste. Experimental values were input into a computer fugacity model (EPI Suite™) to estimate environmental fate. Experimental log K(OW) values ranged from -0.98 to 4.91, which were in accordance with computer estimated values. Experimental K(OC) values ranged from 11 to 72, which were much lower than the default computer values. The experimental fugacity model for discharge to water estimates that waste components will remain in the water compartment for 15 to 37 days. Using a combination of laboratory experimentation and computer modelling, the environmental fate of MAP waste products was estimated. While fugacity models using experimental and computational values were very similar, default computer models should not take the place of laboratory experimentation.

Assessment of iron chelates efficiency for photo-Fenton at neutral pH

In this study, homogeneous photo-Fenton like at neutral pH was applied to remove sulfamethoxazole from water. The process was performed using different chelating agents in order to solubilize iron in a neutral water solution. The chelating agents tested were: ethylenediaminetetraacetic acid (EDTA); nitrilotriacetic acid (NTA); oxalic acid (OA) and tartaric acid (TA). The iron leaching was monitored over reaction time to evaluate the chelates stability and their resistance to HO· and UV-A radiation. Chelates of EDTA and NTA presented more stability than OA and TA, which also confirmed their higher efficiency. Total Organic Carbon (TOC) analyses were also performed to evaluate the contribution in terms of solution contamination related to the use of chelating agents. The better properties of biodegradability in respect of EDTA combined with better efficiency in terms of microcontaminant removal and the smallest TOC contribution indicate that NTA could represent a useful option to perform photo-Fenton processes at neutral pH.

Caffeine as an indicator of estrogenic activity in source water

Caffeine has already been used as an indicator of anthropogenic impacts, especially the ones related to the disposal of sewage in water bodies. In this work, the presence of caffeine has been correlated with the estrogenic activity of water samples measured using the BLYES assay. After testing 96 surface water samples, it was concluded that caffeine can be used to prioritize samples to be tested for estrogenic activity in water quality programs evaluating emerging contaminants with endocrine disruptor activity.

Tetracycline accumulates in Iberis sempervirens L. through apoplastic transport inducing oxidative stress and growth inhibition

Environmental antibiotic contamination is due mainly to improper and illegal disposal of these molecules that, yet pharmacologically active, are excreted by humans and animals. These compounds contaminate soil, water and plants. Many studies have reported the bioaccumulation of antibiotics in plants and their negative effects on photosynthesis, cell growth and oxidative balance. Therefore, the principal objective of this paper was the study of antibiotic accumulation sites in plants and its uptake modality. Iberis sempervirens L., grown in soil and in agar in the presence or absence of tetracycline, were used as a model system. Using confocal and transmission electron microscopy, we demonstrated that tetracycline was absorbed and propagated in plants through apoplastic transport and also accumulated in intercellular spaces. Tetracycline was rarely detected inside cells (in cytoplasm and mitochondria where, coherent to its pharmacological activity, it probably affected ribosomes), except in stomata. Moreover, we verified and clarified further the phytotoxic effects of tetracycline on plants. We observed that the antibiotic induced a large reduction in plant growth and development and inhibition of photosynthetic activity. As tetracycline may lead to oxidative stress in plants, plant cells tried to balance this disequilibrium by increasing the amount and activity of some endogenous enzyme antioxidant agents (superoxide dismutase 1 and catalase) and levels of antiradical secondary metabolites.

Screening and analysis of 940 organic micro-pollutants in river sediments in Vietnam using an automated identification and quantification database system for GC-MS

In order to obtain a detailed picture of pollution by organic micro-pollutants in Vietnamese rivers, 940 semi-volatile organic compounds in river sediments collected from four major cities were examined by a comprehensive gas chromatography-mass spectrometry-database. The number of detected chemicals at each site ranged from 49 to 158 (median 96 out of 940) with 185 analytes detected at least once in the survey. The substances detected with high frequency (over 80%) and high concentrations were n-alkanes, phthalates, sterols and PAHs. For most substances, sediments from metropolitan areas (Hanoi and Ho Chi Minh City) were more heavily contaminated than those in rural and suburban areas. Sterols were observed in nearly 100% of sediments at extremely high concentrations, suggesting that the studied rivers were contaminated by sewage. Pyrethroids (permethrin-1 and -2) were the most dominant insecticides found in inner canals of Hanoi and Ho Chi Minh City. Deltamethrin was only detected at a site in Hanoi at an elevated concentration. This reflects that pyrethroids are used for the protection of private and public health rather than for agriculture. p,p'-DDE and p,p'-DDD were the dominant members of the DDT family of chemicals detected, indicating no recent inputs of DDTs in the study areas. PCBs residues were lower than those in other Asian countries, which suggest historically much lower use of PCBs in Vietnam. PAHs pollution in urban areas is caused by the runoff of petroleum products and vehicle exhaust gases, whereas in rural and suburban areas, the combustion of fossil fuels and biomass is major sources of PAHs. Overall, the study confirmed that rivers in Vietnam were heavily polluted mainly by domestic wastewater.

Dissipation of Three Veterinary Antimicrobials in Beef Cattle Feedlot Manure Stockpiled over Winter

Dissipation of veterinary antimicrobials is known to occur during aerated windrow composting of beef cattle manure. However, it is unclear if a similar dissipation occurs during stockpiling. Chlortetracycline, tylosin, and sulfamethazine are three of the most commonly used veterinary antimicrobials in beef cattle production in western Canada. Their dissipation in stockpiled manure was investigated over 140 d during winter in Alberta, Canada. Beef cattle housed in pens were administered 44 mg of chlortetracycline kg feed (dry weight), 44 mg of chlortetracycline + 44 mg sulfamethazine kg feed, 11 mg of tylosin kg feed, or feed without antimicrobials (control). Manure samples were extracted using pressurized liquid extraction, and the extracts were analyzed for chlortetracycline, sulfamethazine, and tylosin by LC-MS-MS. Dissipation of all three antimicrobials in the manure was explained by exponential decay kinetics. Times for 50% dissipation (DT) were 1.8 ± 0.1 d for chlortetracycline alone or 6.0 ± 0.8 d when mixed with sulfamethazine, 20.8 ± 3.8 d for sulfamethazine, and 4.7 ± 1.2 d for tylosin. After 77 d, <1% of initial chlortetracycline and <2% of sulfamethazine remained. Tylosin residues were more variable, decreasing to approximately 12% of initial levels after 28 d, with 20% present after 77 d and 13% after 140 d. Temperatures within stockpiles reached maximum values within 6 d of establishment and varied with location (bottom, 62.5°C; middle, 63.8°C; and top, 42.9°C). Antimicrobials in the manure did not inhibit microbial activity, as indicated by temperature and mass losses of carbon (C) and nitrogen (N). The C/N ratio in the manure decreased over the stockpiling period, indicating decomposition of manure to a more stable state. Dissipation of excreted residues with DT values 1.8 to 20.8 d showed that stockpiling can be as effective as windrow composting in mitigating the transfer of these three veterinary antimicrobials into the environment during land application of processed manure.