Mobility of contaminants of emerging concern in soil column experiments.

In this study, laboratory column experiments under water saturated conditions were conducted for over 35 days to investigate the transport of nine pharmaceuticals (nadolol, sulfamethizole, sulfamethoxazole, sulfamethoxypyridazine, carbamazepine, ibuprofen, diclofenac, hydrochlorothiazide, and gemfibrozil) and four artificial sweeteners (acesulfame, saccharin, cyclamate, and sucralose) in two soils (S and C) with similar organic carbon content (between 0.8 and 1.1%) and pH (7.90 and 7.25) but different texture (58.3 and 85.5% of silt+clay, respectively). Ibuprofen and artificial sweeteners reached maximum concentrations at the outlet of the columns and showed a homogenous vertical profile in the aqueous phase, with the same concentration in all sampling ports under flow percolation conditions. Regarding carbamazepine and hydrochlorothiazide, apparent retardation was observed for both and was attributed to sorption. Nadolol, a positively charged beta-blocker, did not show any apparent breakthrough. After 35 days, the columns were washed using tap water for over one week. Soils were then analyzed at different depths and vertical concentration profiles were plotted. Overall, highest concentrations were measured in the top most layers for contaminants in the soil column with higher clay content (C), whereas vertical profiles were more uniform in that with lower clay content (S).

Tracing Urban Wastewater Contaminants into the Atlantic Ocean by Nontarget Screening.

Oceans are the ultimate sink for many of the over 100 million man-made substances. Until now, monitoring was limited to a reduced number of targeted persistent organic pollutants, reaching open waters mainly via atmospheric deposition. However, the composition and fate of the thousands of pollutants reaching the marine environment though wastewater discharges from coastal sources remain largely unexplored. By combining a newly developed nontarget screening (NTS) workflow and high-resolution mass spectrometry (HRMS), we have identified over 500 sewage-derived contaminants occurring in the ocean. Samples from the NE Atlantic contained this anthropogenic imprint at distances over 50 km from the coastline and >500 m depth, beyond the continental margin. The range of identified compounds spans from pharmaceuticals and personal care products to food additives and industrial chemicals, including several that have never been reported in the environment, as they escaped conventional targeted analytical methods. Predicting the effects of the continuous input of this chemical "cocktail" on marine ecosystems is a formidable challenge, since 40% of the detected compounds lack information regarding their use and ecotoxicity.

Sorption and degradation of contaminants of emerging concern in soils under aerobic and anaerobic conditions.

Large quantities of contaminants of emerging concern (CECs) are susceptible of entering the terrestrial environments through the application of recycled wastewater, manures, and biosolids, resulting in their progressive contamination and possible long-term effects over terrestrial species. Many studies on the environmental fate of CECs focus on aquatic environments and/or wastewater treatment plants, but little is still known about their behavior at environmentally relevant concentrations in agricultural soils. In this study, we evaluated the adsorption and degradation of nine different pharmaceuticals (nadolol, sulfamethizole, sulfamethoxazole, sulfamethopyridazone, carbamazepine, ibuprofen, diclofenac, hydrochlorothiazide, and gemfibrozil) and four artificial sweeteners (acesulfame, saccharin, cyclamate, and sucralose) in two soils under aerobic and anaerobic conditions. The sorption of target compounds in soils fitted well to a Freundlich isotherm model and was relatively low (Kf < 200 L kg-1). Sorption was highest for cyclamate (Kf = 162 L kg-1) and acesulfame (Kf = 156 L kg-1), while lowest sorption coefficients were measured for ibuprofen (Kf = 1-7 L kg-1). All target compounds (except for carbamazepine) were susceptible to microbial degradation under aerobic conditions, with half-lives ranging from 1 to 18 days. Degradation occurred at a higher rate under aerobic conditions for most contaminants, but they were relatively persistent under anaerobic conditions. For instance, over 90% of the initial amount of spiked nadolol was degraded in aerobic soils after 4 days of incubation, while only 18-24% was lost in absence of oxygen after 1 month, resulting in t1/2 values between 95 and 103 days. The degradation behavior of the target compounds varied in relation to soil and compound physicochemical properties as well as the microbial activities (e.g., 220 ppm of CH4 were produced in anaerobic experiments) and aeration of the tested soils. Overall, the poor adsorption and relative persistence of sucralose and carbamazepine suggests that both may be used as potential tracers for soil and groundwater contamination.

Removal of personal care products (PCPs) in wastewater and sludge treatment and their occurrence in receiving soils.

Clean water is one of the main resources for key activities such as agriculture, power generation, and public and industrial supplies. However, once wastewater generated by these activities is released into the environment, it may represent a potential risk to ecosystems and even human health depending on the presence of certain types and levels of contaminants. This study is focused on personal care products (PCPs), a class of contaminants of emerging concern (CECs) which includes commonly used cosmetic and personal hygiene products (e.g., fragrances, UV filters, antimicrobials, surfactants, among others), and their comparison with legacy contaminants such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). We have monitored the concentrations of up to 66 target compounds in influent and effluent wastewater, sludge, and compost samples from a wastewater treatment plant (WWTP) at Jerez de la Frontera (SW Spain) over a 1-year period. Almost half of the target compounds (44%) were frequently detected in influent wastewater samples, with prevalence of synthetic fragrances and higher abundance of UV filters during warmer periods. Due to their relatively poor removal efficiencies (<70%), 30 target compounds were always detected in the final effluent. The highest levels here were observed for an UV filter (octocrylene) and three synthetic fragrances (traseolide, OTNE, and galaxolide), showing maximum concentrations of 4-7 µg L-1 and 12-95 µg g-1 in the dissolved and particulate fractions, respectively. Concentrations of these compounds increased in sludge, being up to 365 µg g-1 for some fragrances and showing negligible decrease after anaerobic digestion. Windrow composting of this sludge, however, resulted in an efficient removal (up to 100%) for most analytes. On the other hand, levels between <1 and 651 ng g-1 were measured in soils columns (0-150 cm) at the WWTP gardens irrigated with effluent wastewater. The occurrence of PCPs in these soils seemed to be heavily influenced by temperature, as maximum concentrations were measured in colder months, indicating a higher rate of microbial activity degradation and/or volatilization during warmer months.

Disturbance of ecological habitat distribution driven by a chemical barrier of domestic and agricultural discharges: An experimental approach to test habitat fragmentation.

Contamination is an important factor for determining the pattern of habitat selection by organisms. Since many organisms are able to move from contaminated to more favorable habitats, we aimed to: (i) verify if the contamination along the river Guadalete (Spain) could generate a chemical barrier, restricting the displacement of freshwater shrimps (Atyaephyra desmarestii) and (ii) discriminate the role of the contaminants concerning the preference response by the shrimps. A. desmarestii was experimentally tested in a multi-compartmented, non-forced exposure system, simulating the spatial arrangement of the samples just like their distribution in the environment. Water and sediment samples were chemically characterized by analyses of 98 chemical compounds and 19 inorganic elements. Shrimps selected the less contaminated water and sediment samples, with two marked preference patterns: (i) upstream displacement avoiding the sample located at the point of pollutant discharges and those samples downstream from this point and (ii) fragmentation of the population with spatial isolation of the upstream and downstream populations. The preference was related to the avoidance of artificial sweeteners, flame retardants, fragrances, PAHs, PCBs, pesticides, UV filters and some inorganic elements. The threat of contamination was related to its potential to isolate populations due to the chemical fragmentation of their habitat.

Chemical and microbiological characterization of cruise vessel wastewater discharges under repair conditions.

Cruise ship wastewater discharges are pollution sources towards the marine environment that are poorly characterized. In this study, wastewater samples from cruise ships have been obtained during repair works in a shipyard. Different organic pollutants have been analyzed and their concentrations were similar to those in urban wastewaters for pharmaceuticals and fragrances, but higher for UV filters and PAHs. For the first time, cypermethrin, a pesticide highly toxic towards aquatic species, was found at relevant concentrations (>1 µg L^-1). The faecal microorganisms were for all parameters higher than 10^4 CFU 100 mL^-1, which together with the presence of antibiotic compounds in wastewater (e.g., triclosan), could potentially lead to the generation of antibiotic resistance bacteria (ARB). The historical position of cruise ships, determined from the Automatic Identification System (AIS), were used to define the time ships were underway, at port, or in repair. From ship's passenger and crew load, and from estimates of discharges the total volume of wastewater produced by these ships (371,000 m^3 year^-1) and the average flow (0.15 ±â€¯0.03 m^3crew^-1 day^-1) were calculated.

Sources and trends of artificial sweeteners in coastal waters in the bay of Cadiz (NE Atlantic).

This is the first comprehensive study on the input, occurrence, and distribution of artificial sweeteners (ASs) in coastal wastewater treatment plants (WWTPs) and their receiving coastal waters. Acesulfame (ACE), aspartame (ASP), cyclamate (CYC), saccharine (SAC), and sucralose (SUC) were monitored for 6 months in Cadiz Bay (SW Spain). ASP was always detected at <0.1 µg L-1 and removal efficiencies were >90% for SAC and CYC. Higher ACE removal efficiencies were observed during warmer months. Persistence of ACE and SUC was observed in both WWTPs and their receiving coastal surface waters, where values up to 0.6 and 3 µg L-1 were measured, respectively. The highest concentrations were measured in a sewage-impacted estuary located in the north of the bay, where conservative behavior was confirmed. The source specificity and recalcitrance of ACE and SUC make them suitable for being used as sewage-pollution markers in coastal environments.

Monitoring the occurrence of pharmaceuticals in soils irrigated with reclaimed wastewater.

The use of reclaimed wastewater for irrigation is foreseen as a possible strategy to mitigate the pressure on water resources in dry regions. However, there is the risk of potential accumulation of contaminants of emerging concern (CECs) in the edaphic environment, their percolation and consequently contamination of aquifers. In the present study, we measured the levels of a wide range of commonly used pharmaceutically active compounds (PhACs) in sewage from a local wastewater treatment plant (WWTP) and in soils irrigated with treated wastewater. Analysis of target compounds showed total concentrations between 73 and 372 µg L-1 in WWTP influents, and from 3 to 41 µg L-1 in effluents. The total concentrations of PhACs detected in surface soil samples were in the range of 2 and 15 ng g-1, with predominance of analgesics and anti-inflammatories (maximum concentration = 10.05 ng g-1), followed by antibiotics and psychiatric drugs (maximum concentration = 5.45 ng g-1 and 3.78 ng g-1, respectively). Both effluent samples and irrigated soils shared similar compositional patterns, with compounds such as hydrochlorothiazide and diclofenac being predominant. Additionally, PhACs were also detected in soil samples at a depth of 150 cm, indicating that these chemical undergo leaching associated with heavy-rain episodes. Their occurrence in soils was affected by temperature too, as maximum concentrations were measured in colder months (up to 14 ng g-1), indicating higher persistence at lower temperatures. Finally, the ecotoxicological risk of PhACs in soil was evaluated by calculating their risk quotients (RQs). The risk was very low as RQ values ranged between <0.01 and 0.07. However, this initial assessment could be improved by future works on toxicity using specific terrestrial organisms.

Occurrence, distribution and environmental risk of pharmaceutically active compounds (PhACs) in coastal and ocean waters from the Gulf of Cadiz (SW Spain).

In this study, we have evaluated the occurrence and distribution of 78 pharmaceuticals in different aquatic marine environments from the Gulf of Cadiz (SW Spain) for the first time. The obtained results revealed that pharmaceuticals were present in seawater at total concentrations ranging 61-2133 and 16-189ngL-1 in coastal and oceanic transects, respectively. Potential marine pollution hotspots were observed in enclosed or semi-enclosed water bodies (Cadiz Bay), showing concentrations that were one or two orders of magnitude higher than in the open ocean. The presence of these chemicals in local sewage treatment plants (STPs), one of the main contamination sources, was also assessed, revealing total concentrations of up to 23µgL-1 in effluents. PhACs with the highest detection frequencies and concentrations in the sampling region were analgesics and anti-inflammatories followed by antibiotics in the case of samples from Cadiz Bay or caffeine in oceanic seawater samples. Risk quotients, expressed as ratios between the measured environmental concentration (MEC) and the predicted no-effect concentrations (PNEC) were higher than 1 for two compounds (gemfibrozil and ofloxacin) in effluent of Jerez de la Frontera sewage treatment plant (STP). No high environmental risk was detected in both coastal and oceanic sampling areas, although the information available about the effects of these chemicals on marine biota is still very limited and negative effects on non-target species cannot be discarded.

Determining the distribution of pharmaceutically active compounds (PhACs) in soils and sediments by pressurized hot water extraction (PHWE).

The occurrence of pharmaceutically active compounds (PhACs) in the environment may pose a potential risk for humans and ecosystems. Wastewater treatment plants (WWTPs) are recognized as one of the main sources of these chemicals into both aquatic and terrestrial environments. The objectives of the study were to determine the presence of a wide variety of PhACs (n = 45) in sewage-impacted sediments and soils from the Guadalete River basin (SW Spain) by developing and applying an environmentally friendly multi-residue method based on pressurized hot water extraction (PHWE). Different parameters were optimized, including extraction temperature, pH, solvents, and clean-up. Extraction recoveries were analyte dependent, varying between 50% and 140% for most of the analytes when using pure water as extraction solvent at 100 °C. Determination of PhACs was performed by ultra-high performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS), enabling method detection (mLODs) and quantification (mLOQs) limits between <0.01 and 0.83 ng g-1 and from 0.02 to 2.75 ng g-1, respectively. Regarding the sampling area, 14 out of 45 target compounds were detected in soils and sediments. Analgesic/anti-inflammatories was the therapeutic group most commonly detected, reaching concentrations up to 20 ng g-1.