Fate of β-blocker human pharmaceuticals in surface water: Comparison of measured and simulated concentrations in the Glatt Valley Watershed, Switzerland

This study focused on the occurrence and fate of four β-blockers (atenolol, sotalol, metoprolol, propranolol) in wastewater and surface water. Measured concentrations were compared with predicted concentrations using an implementation of the geo-referenced model GREAT-ER for the Glatt Valley Watershed (Switzerland). Particularly, the question was addressed how measured and simulated data could complement each other for the exposure assessment of human pharmaceuticals and other micropollutants entering surface water through wastewater treatment plants (WWTP).Concentrations in the Glatt River ranged from <LOQ to 83 ng L⁻¹ with the highest concentrations found for atenolol. Higher loads were measured on days with combined sewer overflow events during high flow conditions.GREAT-ER was able to predict spatially resolved river concentrations based on average consumption and excretion data, removal in wastewater treatment plants (WWTPs) and dissipation and degradation processes in surface water within a factor of 2. These results indicate that modelling might be sufficient to estimate daily average exposure concentrations for compounds that are either recalcitrant or whose degradation and sorption behaviour can be predicted with confidence based on laboratory experiments. Chemical measurements, in contrast, should be reserved for assessing point sources, investigating mechanisms which lead to short-term temporal fluctuations in compound loads, and determining in-situ degradation rates in conjunction with modelling.     

Occurrence of several acidic drugs in sewage treatment plants in Switzerland and risk assessment

The occurrence and fate of five acidic drugs (Mefenamic acid, Ibuprofen, Ketoprofen, Diclofenac and Clofibric acid) were analysed in three sewage treatment plants (STP) over 4-7 consecutive days. The results point out that the five substances were persistent in wastewater effluents after municipal wastewater treatment. At the most, half of Mefenamic acid was eliminated. Ibuprofen was well removed (80%) by one sewage treatment plant. The removal of Ibuprofen is dependent on the residence time of wastewater in the STPs. A long raining period induce an important decrease of removal of Ibuprofen and Ketoprofen. Removal rates showed a great variability according to sewage treatment plants and types of treatments (e.g. biological, physico-chemical). The concentrations of Ibuprofen, Mefenamic acid and Diclofenac were relatively high in the effluents (150-2000 ng/l), showing a potential contamination of surface water. An environmental risk assessment is presented. Mefenamic acid seems to present a risk for the aquatic environment, with a ratio PEC/PNEC higher than one.     

Elimination of beta-blockers in sewage treatment plants

beta-Blockers are used to treat high blood pressure as well as patients recovering from heart attacks. In several studies, they were detected in surface water, thus indicating incomplete degradability of these substances in sewage treatment plants (STPs). In this study, we determined the sorption coefficients (K(D)) and degradation rates of the four beta-blockers sotalol, atenolol, metoprolol and propranolol in sludge from an STP operating with municipal wastewater. The sorption coefficients (K(D), standard deviations in brackets) were determined as 0.04(+/-0.035), 0.04(+/-0.033), 0.00(+/-0.023) and 0.32(+/-0.058) Lg(-1)(COD), and the pseudo-first-order degradation rate constants were estimated to be 0.29(+/-0.02), 0.69(+/-0.05), 0.58(+/-0.05) and 0.39(+/-0.07) Ld(-1)g(-1)(COD) for sotalol, atenolol, metoprolol and propranolol, respectively. These values translate into a typical elimination in STPs (sludge concentrations of 4g(COD)L(-1) and a hydraulic retention time of 6h) of 25%, 37%, 44% and 50% for sotalol, propranolol, metoprolol and atenolol, respectively. These results are also confirmed by measurements in two municipal STPs for atenolol, sotalol and propranolol. The estimated eliminations are slightly too high for metoprolol.     

Organic contaminant behavior during rapid infiltration of secondary wastewater at the phoenix 23rd avenue project

Movement of trace organic pollutants during rapid infiltration of secondary wastewater for groundwater recharge was studied at the 23rd Avenue Rapid Infiltration Project in Phoenix, Arizona. Samples of the wastewater applied to the spreading basins and of renovated water taken from monitoring wells were characterized for priority pollutants and other specific organic compounds using gas chromatography/mass spectrometry. The concentrations of organic constituents were affected by volatilization, biodegradation and sorption processes. Nonhalogenated aliphatics and aromatic hydrocarbons exhibited concentration decreases of 50–99% during soil percolation. Halogenated organic compounds were generally removed to a lesser extent. Concentrations of trichloroethylene, tetrachloroethylene, and pentachloroanisole appeared to be significantly higher in the renovated water than in the basin water, reasons for this behavior remain unclear. Many organic contaminants were detected in the groundwater indicating such systems should be designed to localize contamination of the aquifer. Chlorination of the wastewater had no significant effect on concentrations and types of trace organic compounds.     

Occurrence, partition and removal of pharmaceuticals in sewage water and sludge during wastewater treatment

During 8 sampling campaigns carried out over a period of two years, 72 samples, including influent and effluent wastewater, and sludge samples from three conventional wastewater treatment plants (WWTPs), were analyzed to assess the occurrence and fate of 43 pharmaceutical compounds. The selected pharmaceuticals belong to different therapeutic classes, i.e. non-steroidal anti-inflammatory drugs, lipid modifying agents (fibrates and statins), psychiatric drugs (benzodiazepine derivative drugs and antiepileptics), histamine H2-receptor antagonists, antibacterials for systemic use, beta blocking agents, beta-agonists, diuretics, angiotensin converting enzyme (ACE) inhibitors and anti-diabetics. The obtained results showed the presence of 32 target compounds in wastewater influent and 29 in effluent, in concentrations ranging from low ng/L to a few μg/L (e.g. NSAIDs). The analysis of sludge samples showed that 21 pharmaceuticals accumulated in sewage sludge from all three WWTPs in concentrations up to 100 ng/g. This indicates that even good removal rates obtained in aqueous phase (i.e. comparison of influent and effluent wastewater concentrations) do not imply degradation to the same extent. For this reason, the overall removal was estimated as a sum of all the losses of a parent compound produces by different mechanisms of chemical and physical transformation, biodegradation and sorption to solid matter. The target compounds showed very different removal rates and no logical pattern in behaviour even if they belong to the same therapeutic groups. What is clear is that the elimination of most of the substances is incomplete and improvements of the wastewater treatment and subsequent treatments of the produced sludge are required to prevent the introduction of these micro-pollutants in the environment.     

Occurrence and removal of N-nitrosamines in wastewater treatment plants

The presence of nitrosamines in wastewater might pose a risk to water resources even in countries where chlorination or chloramination are hardly used for water disinfection. We studied the variation of concentrations and removal efficiencies of eight N-nitrosamines among 21 full-scale sewage treatment plants (STPs) in Switzerland and temporal variations at one of these plants. N-nitrosodimethylamine (NDMA) was the predominant compound in STP primary effluents with median concentrations in the range of 5-20 ng/L, but peak concentrations up to 1 μg/L. N-nitrosomorpholine (NMOR) was abundant in all plants at concentrations of 5-30 ng/L, other nitrosamines occurred at a lower number of plants at similar levels. From concentrations in urine samples and domestic wastewater we estimated that human excretion accounted for levels of <5 ng/L of NDMA and <1 ng/L of the other nitrosamines in municipal wastewater, additional domestic sources for <5 ng/L of NMOR. Levels above this domestic background are probably caused by industrial or commercial discharges, which results in highly variable concentrations in sewage. Aqueous removal efficiencies in activated sludge treatment were in general above 40% for NMOR and above 60% for the other nitrosamines, but could be lower if concentrations were below 8-15 ng/L in primary effluent. We hypothesize that substrate competition in the cometabolic degradation explains the occurrence of such threshold concentrations. An additional sand filtration step resulted in a further removal of nitrosamines from secondary effluents even at low concentrations. Concentrations released to surface waters were largely below 10 ng/L, suggesting a low impact on Swiss water resources and drinking water generation considering the generally high environmental dilution and possible degradation. However, local impacts in case a larger fraction of wastewater is present cannot be ruled out.     

A simple method for the measurement of organic iodine in wastewater and surface water

Total adsorbable organic iodine (TAOI) has been used as a surrogate parameter for X-ray contrast media in municipal wastewater. Available methods require specialized equipment for pyrolyzing these compounds to convert the covalently bound iodine into iodide, which is then measured by ion chromatography. In this study we describe a simple method for liberating iodide from these compounds with Cu(II) and hydrogen peroxide. Concentrations of TAOI were measured in wastewater effluent, surface waters that were expected to be impacted by wastewater, and unimpacted surface waters. TAOI concentrations ranged between 1.9 and 16.3 microg/L I in wastewater with a median of 6.5 microg/L I. The lowest TAOI concentrations consistently were detected in a wastewater treatment plant that apparently had few hospitals within its collection area. In comparison, TAOI concentrations in surface water that was unimpacted by sewage were between 0.3 and 3.5 microg/L I. TAOI concentrations in surface waters that were impacted by sewage were consistent with the expected conservative behavior of TAOI.     

Predicted environmental concentrations of cocaine and benzoylecgonine in a model environmental system

A Mackay-type level II fugacity model has been used to predict the behaviour and final concentrations of cocaine (COC) and its main metabolite benzoylecgonine (BE) in a regional environmental system defined according to the European guidelines on Risk Assessment. The model takes into account the initial COC intake, partial degradation of the parent compound to BE, treatment of wastewater and environmental fate of these substances. Predicted environmental concentrations (PECs) lie in the ng L⁻¹ level, with the exception of the air compartment, where the concentrations are negligible. PECs in the water phase are in accordance with measured experimental concentrations in different European rivers. This case study shows that a simple level II fugacity model is suitable enough for modelling the environmental fate of high water soluble and low volatile organic compounds such as pharmaceuticals and personal care products.     

Occurrence, oral exposure and risk assessment of volatile organic compounds in drinking water for Izmir

Concentrations of volatile organic compounds (VOCs) were measured in the drinking water in Province of Izmir, Turkey, and associated health risks due to ingestion of these compounds were investigated using population weighted random samples. A total of 100 houses were visited in different districts of Izmir and drinking water samples were collected from consumers' drinking water source. Questionnaires were administered to one participant in each house to determine demographics and drinking water consumption rates. Oral exposure and risks were estimated for each participant and Izmir population by deterministic and probabilistic approaches, respectively. The four trihalomethane (THM) species (i.e., chloroform, bromodichloromethane, dibromochloromethane, and bromoform), benzene, toluene, p-xylene, and naphthalene were the most frequently detected VOCs with concentrations ranging from below detection limit to 35 microg/l. The risk estimates were found to be less than the values reported in the literature with few exceptions. Noncarcinogenic risks attributable to ingestion of VOCs for Izmir population were negligible, whereas the mean carcinogenic risk estimates for bromodichloromethane and dibromochloromethane were above the de minimis level of one in a million (10(-6)). For all VOCs, the concentrations measured in metropolitan area were greater than those in other districts. All THM species were detected in higher concentrations in tap water, whereas nontap water contained more benzene, toluene, p-xylene, and naphthalene. Therefore, the concentrations of the latter four compounds and associated risks increased with increasing income and education level since bottled water was used in larger proportions within these subgroups. The results of this study showed that oral exposure to drinking water contaminants and associated risks may be higher than the acceptable levels even if the concentrations fall below the standards.     

Antagonistic Action of Fe and Mn in Mediterranean-Type Plants Irrigated with Wastewater Effluents Following Biological Treatment

The present study examined the ability of certain Mediterranean plants to absorb Mn ++ when irrigated with wastewater effluents following treatment, the relative absorption of Fe ++ and Mn ++ , as well as the endurance of such plants to high Mn ++ concentrations in the water used for their irrigation. The experimental plants used in the study were Olea europaea , Nerium oleander and Geranium sp . These plants were irrigated with secondary treatment wastewater effluents, with water commonly used for irrigation in the area, and with water enriched with high concentrations of Mn ++ . The results showed that irrigation of the plants with wastewater treatment effluents resulted in slightly elevated concentrations of Mn ++ and Fe ++ in the leaves, the roots, and in the soil. On the contrary, irrigation with water enriched with high concentrations of Mn ++ (as high as 1000 mg/L) resulted in correspondingly high Mn ++ concentrations in the plants under study. The accumulation of Mn ++ was much higher in the roots than in the leaves of these plants. In the case of Mn ++ enriched water irrigation, the corresponding concentrations of Fe ++ in the roots, in the leaves, and in the soil indicated the existence of strong antagonism between these two elements. All plants exhibited tolerance to high concentrations of Mn ++ .     

Pharmaceutical compounds in the wastewater process stream in Northwest Ohio

In order to add to the current state of knowledge regarding occurrence and fate of Pharmaceutical and Personal Care Products (PPCP's) in the environment, influent, effluent and biosolids from three wastewater treatment facilities in Northwest Ohio, USA, and a stream containing effluent discharge from a rural treatment facility were analyzed. The three WWTP facilities vary in size and in community served, but are all Class B facilities. One facility was sampled multiple times in order to assess temporal variability. Twenty compounds including several classes of antibiotics, acidic pharmaceuticals, and prescribed medications were analyzed using ultrasonication extraction, SPE cleanup and liquid chromatography-electrospray ionization tandem mass spectrometry. The highest number of compounds and the greatest concentrations were found in the influent from the largest and most industrial WWTP facility. Short-term temporal variability was minimal at this facility. Many compounds, such as clarithromycin, salicylic acid and gemfibrizol were found at concentrations more than one order of magnitude higher than found in the effluent samples. Effluent waters contained elevated levels of carbamazepine, clindamycin and sulfamethoxazole. Differences in composition and concentration of effluent waters between facilities existed. Biosolid samples from two different facilities were very similar in PPCP composition, although concentrations varied. Ciprofloxacin was found in biosolids at concentrations (up to 46 mug/kg dry mass) lower than values reported elsewhere. Diclofenac survived the WWTP process and was found to persist in stream water incorporating effluent discharge. The low variability within one plant, as compared to the variability found among different wastewater treatment plants locally and in the literature is likely due to differences in population, PPCP usage, plant operations and/or local environment. These data are presented here for comparison with this emerging set of environmental compounds of concern.     

Occurrence of emerging contaminants, priority substances (2008/105/CE) and heavy metals in treated wastewater and groundwater at Depurbaix facility (Barcelona, Spain)

The presence of 170 pharmaceuticals, personal care products, priority substances according to the 2008/105EU Directive and four metals (Cd, Ni, Hg, Pb) have been investigated at the Llobregat delta, south of Barcelona (Spain). In the area, reclaimed water is destined to satisfy environmental uses, irrigation and the construction of a hydraulic barrier against seawater intrusion in the deep aquifer of the delta. A monitoring survey was undertaken of water samples from a tertiary wastewater treatment plant (Depurbaix), treated waste water with an additional treatment of ultrafiltration, reverse osmosis, and UV disinfection (WWATP, for the hydraulic barrier injection). Groundwater samples from the aquifer receiving recharge were also investigated. The pharmaceutical group of substances was detected in sampled waters at concentrations rarely exceeding a few μg/L, among the compounds Caffeine, Nicotine and Galaxolide (musk fragrance) were found to be present in more than 60% of the samples. Diuron was the only priority substance detected. The four metals were always present in a variable concentration. After the WWATP treatment the majority of analytes are removed from tertiary treated wastewater or their concentration is reduced below 0.1 μg/L. Monitoring revealed a widespread occurrence of analysed compounds in groundwater. Among them Codeine (analgesic), Ibuprofen (anti-inflammatory), Iopamidol, Iopromide (contrast agent) and Paraxanthine (metabolite of caffeine) have only been detected in groundwater, and are not present in water currently being injected in the deep aquifer.     

Kinetics of aqueous chlorination of some pharmaceuticals and their elimination from water matrices

Apparent rate constants for the reactions of four selected pharmaceutical compounds (metoprolol, naproxen, amoxicillin, and phenacetin) with chlorine in ultra-pure (UP) water were determined as a function of the pH. It was found that amoxicillin (in the whole pH range 3-12), and naproxen (in the low pH range 2-4) presented high reaction rates, while naproxen (in the pH range 5-9), and phenacetin and metoprolol (in the pH range 2.5-12 for phenacetin, and 3-10 for metoprolol) followed intermediate and slow reaction rates. A mechanism is proposed for the chlorination reaction, which allowed the evaluation of the intrinsic rate constants for the elementary reactions of the ionized and un-ionized species of each selected pharmaceutical with chlorine. An excellent agreement is obtained between experimental and calculated rate constants by this mechanism.The elimination of these substances in several waters (a groundwater, a surface water from a public reservoir, and two effluents from municipal wastewater treatment plants) was also investigated at neutral pH. The efficiency of the chlorination process with respect to the pharmaceuticals elimination and the formation THMs was also established. It is generally observed that the increasing presence of organic and inorganic matter in the water matrices demand more oxidant agent (chlorine), and therefore, less chlorine is available for the oxidation of these compounds. Finally, half-life times and oxidant exposures (CT) required for the removal of 99% of the four pharmaceuticals are also evaluated. These parameters are useful for the establishment of safety chlorine doses in oxidation or disinfection stages of pharmaceuticals in treatment plants.     

A comparison of human pharmaceutical concentrations in raw municipal wastewater and yellowwater

Currently, many articles report on pharmaceutical residues detected in various compartments of the environment. A major pathway into the aquatic environment is municipal wastewater. This article discusses the relevance of yellowwater (urine) as pharmaceutical source within this wastewater stream. Literature data about concentrations of 28 pharmaceutical residues detected in raw wastewater are compared to their theoretically calculated concentrations in urine. The study shows that these pharmaceuticals and their metabolites are excreted predominantly via urine although some substances show reasonable excretion via faeces. It is demonstrated that the influence of pharmacokinetic activities is one important issue affecting the presence of pharmaceuticals in the aquatic environment. Nevertheless, only a weak correlation between concentrations of pharmaceuticals calculated in yellowwater and analysed in raw wastewater was observed. This is due to environmental effects taking place between the excretion of urine and the entrance of sewerage into the wastewater treatment plant. The data show that urine separation and separate handling/treatment of this wastewater stream represents a promising approach to protect the aquatic environment safely from human pharmaceuticals.     

On-line titration of volatile fatty acids for the process control of anaerobic digestion plants.

The on-line titration of volatile fatty acids (VFA) was found to be a reliable method to measure the substrate (metabolite) concentration without the use of expensive analytical devices. A measurement cell was designed that ensures stable long-term operation, high throughputs and copes with both very low and very high VFA concentrations. Using synthetic textile wastewater, a recalibration of the pH probe was necessary only twice a week. A good reproducibility of the VFA concentrations was determined and standard deviations were below +/- 1% of the measured concentration. Changing salt concentrations of the wastewater in the range of 2.5-150 gl(-1) NaCl did not influence the determined VFA concentration significantly. The method was suitable to control the hydraulic retention time in an acidic phase reactor and to determine the acidification rates of wastewater compounds in batch experiments.     

Assessing risk to human health from tropical leafy vegetables grown on contaminated urban soils

Fifteen tropical leafy vegetable types were sampled from farmers' gardens situated on nine contaminated sites used to grow vegetables for commercial or subsistence consumption in and around Kampala City, Uganda. Trace metal concentrations in soils were highly variable and originated from irrigation with wastewater, effluent discharge from industry and dumping of solid waste. Metal concentrations in the edible shoots of vegetables also differed greatly between, and within, sites. Gynandropsis gynandra consistently accumulated the highest Cd, Pb and Cu concentrations, while Amaranthus dubius accumulated the highest Zn concentration. Cadmium uptake from soils with contrasting sources and severity of contamination was consistently lowest in Cucurbita maxima and Vigna unguiculata, suggesting these species were most able to restrict Cd uptake from contaminated soil. Concentrations of Pb and Cr were consistently greater in unwashed, than in washed, vegetables, in marked contrast to Cd, Ni and Zn. The risk to human health, expressed as a ‘hazard quotient’ (HQ_M), was generally greatest for Cd, followed successively by Pb, Zn, Ni and Cu. Nevertheless, it was apparent that urban cultivation of leafy vegetables could be safely pursued on most sites, subject to site-specific assessment of soil metal burden, judicious choice of vegetable types and adoption of washing in clean water prior to cooking.     

Urinary excretion rates of natural estrogens and androgens from humans, and their occurrence and fate in the environment: A review

Endocrine disrupting compounds (EDCs) are pollutants with estrogenic or androgenic activities at very low concentrations and are emerging as a major concern for water quality. For sewage of municipal wastewater treatment plants in cities, one of the most important sources of EDCs are natural estrogens and natural androgens (NEAs) excreted from humans. Therefore, estrogenic/androgenic potencies or relative binding affinity of the NEAs were first outlined from different sources, and data of urinary excretion rates of NEAs were summarized. To evaluate their estrogenic activities, their excretion rates of estrogen equivalent (EEQ) or testosterone (T) equivalent (TEQ) were also calculated. Based on our summary, the total excretion rates of EEQ by estrone (E1), 17β-estradiol (E2), and estriol (E3) only accounted for 66-82% of the total excretion rate of EEQ among four different groups, and the other corresponding natural estrogens contributed 18-34%, which meant that some of the other natural estrogens may also exist in wastewater with high estrogenic activities. Based on the contribution ratio of individual androgens to the total excretion rate of TEQ, five out of 12 natural androgens, T, dihydrotestosterone (DHT), androsterone (AD), 5β-androstanediol (β-ADL), and androstenediol (ANL) were evaluated as the priority natural androgens, which may exist in wastewater with high androgenic activities. Published data on occurrence and fate of the NEAs including natural estrogen conjugates in the environment were also summarized here.     

Contaminant levels,source strengths,and ventilation rates in California retail stores

This field study measured ventilation rates and indoor air quality in 21 visits to retail stores in California. Three types of stores, such as grocery, furniture/hardware stores, and apparel, were sampled. Ventilation rates measured using a tracer gas decay method exceeded the minimum requirement of California's Title 24 Standard in all but one store. Concentrations of volatile organic compounds (VOCs), ozone, and carbon dioxide measured indoors and outdoors were analyzed. Even though there was adequate ventilation according to standard, concentrations of formaldehyde and acetaldehyde exceeded the most stringent chronic health guidelines in many of the sampled stores. The whole‐building emission rates of VOCs were estimated from the measured ventilation rates and the concentrations measured indoor and outdoor. Estimated formaldehyde emission rates suggest that retail stores would need to ventilate at levels far exceeding the current Title 24 requirement to lower indoor concentrations below California's stringent formaldehyde reference level. Given the high costs of providing ventilation, effective source control is an attractive alternative.     

Influence of irrigation with lagooned urban wastewater on chemical and microbiological soil parameters in a citrus orchard under Mediterranean condition

The reduced availability of water resources in semi-arid Mediterranean regions requires an efficient use of supply sources. Urban wastewater, after treatment to minimise health hazards, may constitute an important resource for irrigation in areas characterised by intensive agriculture. These considerations have motivated an investigation (during the irrigation season 1996) of the dynamics of microbial biomass in the soil of a citrus orchard in eastern Sicily, which has been irrigated for 15 years with lagooned urban wastewater, to evaluate the effects of this practice on soil fertility. The analyses of parameters regarding soil microbial biomass (microbial carbon and microbial nitrogen, soluble carbon and nitrogen, cumulative respiration, respiratory quotient and enzymatic activity in the soil) have confirmed that the evolution of soil microflora is directly conditioned by the type of water used for irrigation and climatic conditions. Just before the beginning of the irrigation season (May), microbial biomass carbon (MBC), soluble C, cumulative respiration and enzymatic activity were significantly higher in the soil irrigated with wastewater with respect to the same soil irrigated with 'clear' water; the qCO2 was significantly lower. In June, after 1 month of irrigation, both soils showed an increase of all microbial parameters except for enzymatic activity and qCO2 which showed a significant reduction. In September, at the end of the irrigation period, there was a decrease of almost all investigated parameters in both plots, which was more evident in the soil irrigated with 'clear' water. The microbial biomass of the soil irrigated with wastewater, during the irrigation period, did not undergo any negative effects, having an evolution analogous to the plot irrigated with 'clear' water. The use of lagooned wastewater after three lustrums has shown, particularly in the dry season, an increase in quantity of easily available nutrients, with an improvement of the metabolic efficiency of soil microflora coupled with a more marked activity of total hydrolase and phosphatases. The variations of the parameters related to the soil microflora were strongly influenced by the seasonal climatic trend.