Occurrence of synthetic musks in Korean sewage sludges

Six polycyclic musks (PCMs) and five nitro musks (NMs) were analyzed in dewatered sludge samples from 13 municipal, 4 livestock and 1 pharmaceutical wastewater treatment plants (WWTPs) in South Korea. 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB; Galaxolide^®, Abbalide^®), and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN; Tonalide^®, Fixolide^®) were the two predominant PCMs in the sludge samples, at concentrations ranging from 0.52 to 82.0 mg/kg dry weight (dw) and 0.12 to 28.8 mg/kg (dw), respectively, suggesting the extensive use of these two PCMs in South Korea. Hierarchical cluster analysis (HCA) revealed the different usage patterns of PCMs between livestock cultivating farm and household. The levels of HHCB and AHTN in the effluent discharged from the WWTPs were lower than the threshold effect levels derived for fish, suggesting low potential risks to aquatic organisms. Nevertheless, the calculated discharge of synthetic musks (SMs) from sludge in each target WWTP ranged from 36 to 10,961 g/d. These results indicate the necessity of conducting monitoring studies in marine ecosystems due to ocean disposal of sludge, particularly focused on the two prevailing PCMs.     

Polycyclic musk fragrances in different environmental compartments in Berlin (Germany)

The aim of this study was to obtain data about the contamination of different environmental compartments (102 surface water samples, 59 sediment samples and 165 eel samples) by polycyclic musks (HHCB, AHTN, ADBI, AHMI, and ATII) within the framework of an exposure monitoring program. Results for HHCB (Galaxolide) gave the following mean values in areas strongly polluted with sewage: surface water 1.59 micrograms l-1; sediment 0.92 mg kg-1 d.w. and eel 1513 micrograms kg-1 f.w. (in the edible portion) (6471 micrograms kg-1 lipid). The following average concentrations were found in waters hardly contaminated with sewage: surface water 0.07 microgram l-1, sediment < 0.02 mg kg-1 and eel 52 micrograms kg-1 f.w. (445 micrograms kg-1 lipid). Mean concentrations of 6.85 micrograms l-1 (maximum: 13.3 micrograms/l) could be measured at sewage treatment plants' outlets. It could be shown that these polycyclics are highly suited to use as indicators of the degree of contamination of waters with organic substances originating from sewage. A mean bioconcentration factor (BCF) on wet weight of 862 (HHCB) and 1069 (AHTN) for the transfer from water to eel under natural conditions could be calculated. The corresponding BCF-values based on the lipid content of eel were 3504 (HHCB) and 5017 (AHTN).     

Fate and removal of polycyclic musks, UV filters and biocides during wastewater treatment

The fate of polycyclic musks (PCMs) (HHCB, AHTN, ADBI, AHDI, ATII, DPMI), UV filters (3-(4-methylbenzylidene) camphor, 4-MBC; octyl-methoxycinnamate, OMC; octocrylene, OC; octyl-triazone, OT) and biocides (permethrin, carbendazim) during wastewater treatment was studied on a full-scale plant. Average influent concentrations of OMC, HHCB, OC, AHTN, 4-MBC and OT were at 20070, 4420, 1680, 1430, 960 and 720 ng L(-1), respectively. The other PCMs, permethrin and carbendazim ranged between < limits of quantification and 670 ng L(-1). Concentrations in the water line decreased significantly for most compounds. Removal rates for PCMs ranged from 72% to 86%, for UV filters from 92% to >99% and were at 92% and 37% for permethrin and carbendazim, respectively. Removal during wastewater treatment was mainly driven by sorption onto solids and biodegradation. For anaerobic sludge digestion, elimination of PCMs, OMC and the biocides was observed.     

A rapid method to measure the solid-water distribution coefficient (Kd) for pharmaceuticals and musk fragrances in sewage sludge

Pharmaceuticals and personal care products are omnipresent in wastewater world-wide. In order to predict their sorption quantities onto sludge in wastewater treatment plants (WWTPs), the solid-water distribution coefficients (Kd values) of selected pharmaceuticals (antiphlogistics, estrogens, lipid regulators, anti-epileptic and cytostatic agents) and polycyclic musk fragrances (HHCB, AHTN) were determined in primary and secondary sludges taken from a German municipal WWTP. For the Kd determination, batches of primary and secondary sludge slurries were spiked with the respective target compounds and slowly stirred under defined conditions (e.g. an argon atmosphere). Finally, the water and solid sludge phases were analysed. The Kd values of pharmaceuticals ranged from <1 to 500 L kg(-1), while those for the polycyclic musk fragrances AHTN and HHCB proved to be up to 5300 and 4900 L kg(-1), respectively. The primary and secondary sludge showed significant differences for some pharmaceuticals such as Diclofenac and Cyclophosphamide due to the different pH and composition of the two sludges. The removal rate from the water phase caused by sorption in a WWTP can be reasonably predicted on the basis of the Kd values.     

Seasonal occurrence and behavior of synthetic musks (SMs) during wastewater treatment process in Shanghai, China

Synthetic musks (SMs), as a group of the widely used fragrance ingredients, are not completely removed from the wastewater treatment plant (WWTP). Although the increasing concerns have been focused on the removal and fate of these compounds in WWTP, little is known related to SMs removal mechanism with the seasonal variation, especially, the detail removal contribution of bioreactor in different seasons. In this study, in order to clearly understand the complicated behavior of SMs during wastewater treatment process, we determined four synthetic musks, galaxolide (HHCB), tonalide (AHTN), musk xylene (MX) and musk ketone (MK) in a domestic WWTP in Shanghai, China during four seasons (with the particular interests on the seasonal contribution of individual bio-unit). Operating temperature combined other seasonal elements (e.g. illumination, biomass and bioactivity) render influences on the elimination of SMs in different treatment units, particular in the bioreactor. The results showed that the higher operating temperature would benefit the elimination of SMs. The overall mass loss of total SMs during the wastewater treatment process were as high as 131.7 g d^− 1 (28.3 g d^− 1 loss in bioreactor) in summer followed by 109.1 g d^− 1 (29.8 g d^− 1 loss in bioreactor) in fall. Contributions of individual bio-unit (anaerobic, anoxic and oxic unit) to the total SMs elimination in bioreactor were seasonal fluctuated, e.g. the anoxic unit made a remarkable contribution (almost 90%) in fall, whereas there were nearly equivalent contributions of three bio-units in summer.     

Occurrence and reductions of pharmaceuticals and personal care products and estrogens by municipal wastewater treatment plants in Ontario, Canada

Over the last ten years there have been reports of pharmaceuticals and personal care product (PPCP) residuals in municipal wastewater treatment plant (WWTP) effluents. The principle goal of this study was specifically to expand and in some cases establish a Canadian database for the presence of selected acidic drugs, triclosan, polycyclic musks, and selected estrogens in MWWTP influent and effluent. The impact of treatment configuration (e.g. lagoons, conventional activated sludge (CAS), and CAS followed by media filtration (CAS+filtration)) was also examined. For CAS systems, the most prevalent treatment type, the effect of operating temperature and SRT was evaluated. Selected PPCPs included ten acidic pharmaceuticals (i.e. a group of pharmaceuticals that are extractable at a pH of 2 or less), triclosan, five polycyclic musks and two estrogens. The pharmaceuticals and musks were selected on the basis of levels of use in Canada; reported aquatic toxicity effects; and the ability to analyze for the compounds at low levels. Twelve MWWTPs discharging into the Thames River, the second largest river in southwestern Ontario, were surveyed. The only common characteristic of acidic drugs is their extraction pH as they differ in their intended biological function and chemical structure. Many organics degraded by WWTP processes benefit from warm temperatures and long SRTs so the impact of these variables warranted additional attention. Influent concentrations and reductions for acidic drugs reported by this study were compared to other Canadian studies, when available, and European investigations. The data of this study seems consistent with other reports. Ten acidic drugs were considered by this study. Three were consistently present at non-quantifiable levels (e.g. CLF, FNP and FNF). Additionally, one analyte, SYL, presented results that were so inconsistent that the values were not analysed. The remaining six acidic pharmaceuticals were placed into three categories. IBU and NPX members of the first category had consistently high reductions. At the level of reduction achieved (i.e. median reduction of greater than 93%) and any effect of treatment type or operating characteristics would be subtle and non-discernable given the analytical noise. In the second group are KTP and IND, and definitive comments are difficult to make on the impact of treatment type and operational considerations due to a sparse data set (i.e. many influent values were at non-quantifiable concentrations). Median reductions were in the 23% to 44% range. In the last category are GMF and DCF which have median reductions of 66% and -34%, respectively. Several negative reduction values in the data set (i.e. twelve of twenty six sampling events) suggest that DCF may be deconjugated under certain conditions. This warrants further evaluation when analytical methods for measuring human metabolites of DCF are available. For both GMF and DCF, reduction does not appear to be strongly influenced by SRTs up to 15 days, while SRTs over 30 days were associated with more frequent non-quantifiable effluent levels of DCF. This would suggest that better treatment would be provided by lagoons and CAS systems with extended aeration. Preliminary data suggests that temperature does not play a strong role in the reduction of these compounds. Triclosan (TCL) was detected at concentrations of 0.01-4.01 microg/L in influent samples and 0.01-0.324 microg/L in effluent samples. Reduction of TCL ranged from 74% to 98%. Lagoon treatment seems to be the best TCL reduction as it was present in the influent and effluent at quantifiable and non-quantifiable concentrations, respectively, on nine of nine sampling occasions. Influent and reduction values of five polycyclic musks (e.g. ADBI, AHMI, ATII, HHCB, and AHTN) were examined over the course of this study. AHMI was predominantly present at non-quantifiable concentrations. HHCB and AHTN were present at the highest concentrations. A comparison between Canadian values and those of European studies indicate that in general polycyclic musk concentrations in Canadian MWWTP effluents are 5-10 times lower. More extensive European and Canadian databases would be useful in confirming this initial observation. Median reductions for the five remaining musks range between 37% and 65% in CAS systems. CAS+filtration systems would be expected to have higher reductions if musks were bound to the effluent solids. This trend is not apparent but this may be due to the small size of the data set. In lagoon systems, musk reduction for HHCB and AHTN are approximately 98-99%. For ADBI and ATII musk, there are no numerical reduction values as most often the effluent concentration was non-quantifiable. In some instances, both the influent and effluent concentrations were non-quantifiable. The hormones 17-beta-estradiol (E2) and estrone (E1) were detected at concentrations of 0.006 to 0.014 and 0.016 to 0.049 microg/L, respectively. E2 was not detected in any effluent samples (<0.005 microg/L) whereas E1 was detected in effluent samples from CAS treatment plants (median of 0.008 microg/L), and in one sample from lagoons. These data demonstrate that there are detectable levels of PPCPs entering Canadian waterways at trace levels, and that only some of these compounds are being reduced in a significant proportion by municipal wastewater treatment processes.     

Occurrence of phthalates and musk fragrances in indoor air and dust from apartments and kindergartens in Berlin (Germany)

In this study, the occurrence of persistent environmental contaminants room air samples from 59 apartments and 74 kindergartens in Berlin were tested in 2000 and 2001 for the presence of phthalates and musk fragrances (polycyclic musks in particular). These substances were also measured in household dust from 30 apartments. The aim of the study was to measure exposure levels in typical central borough apartments, kindergartens and estimate their effects on health. Of phthalates, dibutyl phthalate had the highest concentrations in room air, with median values of 1083 ng/m(3) in apartments and 1188 ng/m(3) in kindergartens. With around 80% of all values, the main phthalate in house dust was diethylhexyl phthalate, with median values of 703 mg/kg (range: 231-1763 mg/kg). No statistically significant correlation could be found between air and dust concentration. Musk compounds were detected in the indoor air of kindergartens with median values of 101 ng/m(3) [1,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclopenta-(g) 2-benzopyrane (HHCB)] and 44 ng/m(3) [7-acetyl-1,1,3,4,4,6-hexamethyl-tetraline (AHTN)] and maximum concentrations of up to 299 and 107 ng/m(3) respectively. In household dust HHCB and AHTN were detected in 63 and 83% of the samples with median values of 0.7 and 0.9 mg/kg (Maximum: 11.4 and 3.1 mg/kg) each. On comparing the above phthalate concentrations with presently acceptable tolerable daily intake values (TDI), we are talking about only a small average intake [di(2-ethylhexyl) phthalate and diethyl phthalate less than 1 and 8% of the TDI] by indoor air for children. The dominant intake path was the ingestion of foodstuffs. For certain subsets of the population, notably premature infants (through migration from soft polyvinyl chloride products), children and other patients undergoing medical treatment like dialysis, exchange transfusion, an important additional intake of phthalates must taken into account. PRACTICAL IMPLICATIONS: The phthalate and musk compounds load in a sample of apartments and kindergartens were low with a typical distribution pattern in air and household dust, but without a significant correlation between air and dust concentration. The largest source of general population exposure to phthalates is dietary. For certain subsets of the general population non-dietary ingestion (medical and occupational) is important.     

Evaluation of Simple Treat 3.0 for two hydrophobic and slowly biodegradable chemicals: polycyclic musks HHCB and AHTN

In the current study, predictions by Simple Treat 3.0, a fate model for organic chemicals in sewage treatment plants (STPs), are compared with actual measurements in three STPs. Two polycyclic musks, Tonalide (AHTN) and Galaxolide (HHCB), were used for model evaluation. Results show that Simple Treat 3.0 is able to predict the removal efficiency within a factor 4. Predicted concentrations of both chemicals within the different physical compartments of STPs show a high correlation (r(2)=0.80) with experimental values. Although predicted free concentration levels were similar to previously reported experimental data, the trends along the compartments showed an inverse relationship. This bias of the model can be caused by an underestimation of BOD-removal (solids), or an overestimation of bacterial growth, evaporation, or a combination of these three factors. Results show that Simple Treat 3.0 is a valid tool for the risk assessment of slowly biodegradable chemicals, but still some adjustments of the model could be incorporated from a scientific point of view.     

Synthetic musk emissions from wastewater aeration basins

Wastewater aeration basins at publicly owned treatment works (POTWs) can be emission sources for gaseous or aerosolized sewage material. In the present study, particle and gas phase emissions of synthetic musks from covered and uncovered aeration basins were measured. Galaxolide (HHCB), tonalide (AHTN), and celestolide (ADBI) were the most abundant, ranging from 6704 to 344,306 ng m⁻³, 45-3816 ng m⁻³, and 2-148 ng m⁻³ in the gas phase with particle phase concentrations 3 orders of magnitude lower. The musk species were not significantly removed from the exhaust air by an odor control system, yielding substantial daily emission fluxes (∼200 g d⁻¹ for HHCB) into the atmosphere. However, simple dispersion modeling showed that the treatment plants are unlikely to be a major contributor to ambient air concentrations of these species. Emission of synthetic musk species during wastewater treatment is a substantial fate process; more than 14% of the influent HHCB is emitted to the atmosphere in a POTW as opposed to the <1% predicted by an octanol-water partition coefficient and fugacity-based US EPA fate model. The substantial atmospheric emission of these compounds is most likely due to active stripping that occurs in the aeration basins by bubbling air through the sludge.     

Polybrominated diphenyl ethers in sewage sludge and treated biosolids: Effect factors and mass balance

Polybrominated diphenyl ether (PBDE) flame retardants have been consistently detected in sewage sludge and treated biosolids. Two hundred and eighty-eight samples including primary sludge (PS), waste biological sludge (WBS) and treated biosolids from fifteen wastewater treatment plants (WWTPs) in Canada were analyzed to investigate the factors affecting accumulation of PBDEs in sludge and biosolids. Factors examined included environmental/sewershed conditions and operational parameters of the WWTPs. PBDE concentrations in PS, WBS and treated biosolids were 230–82,000 ng/g, 530–8800 ng/g and 420–6000 ng/g, respectively; BDE-209,-99, and -47 were the predominant congeners. Concentrations were influenced by industrial input, leachate, and temperature. Several examinations including the measurement of BDE-202 indicated minimal debromination during wastewater treatment. Estimated solids-liquid distribution coefficients were moderately correlated to hydraulic retention time, solids loading rate, mixed liquor suspended solids, solids retention time, and removal of organic solids, indicating that PBDE partitioning to solids can be optimized by WWTPs' operational conditions. Solids treatment type strongly affected PBDE levels in biosolids: 1.5 times increase after solids digestion, therefore, digestion efficiency could be a potential factor for variability of PBDEs concentration. In contrast, alkaline treatment reduced PBDE concentrations in biosolids. Overall, mass balance approaches confirmed that PBDEs were removed from the liquid stream through partitioning to solids. Variability of PBDE levels in biosolids could result in different PBDEs burdens to agricultural land, and different exposure levels to soil organisms.     

Fate and distribution of pharmaceuticals in wastewater and sewage sludge of the conventional activated sludge (CAS) and advanced membrane bioreactor (MBR) treatment

In this paper we report on the performances of full-scale conventional activated sludge (CAS) treatment and two pilot-scale membrane bioreactors (MBRs) in eliminating various pharmaceutically active compounds (PhACs) belonging to different therapeutic groups and with diverse physico-chemical properties. Both aqueous and solid phases were analysed for the presence of 31 pharmaceuticals included in the analytical method. The most ubiquitous contaminants in the sewage water were analgesics and anti-inflammatory drugs ibuprofen (14.6-31.3 μg/L) and acetaminophen (7.1-11.4 μg/L), antibiotic ofloxacin (0.89-31.7 μg/L), lipid regulators gemfibrozil (2.0-5.9 μg/L) and bezafibrate (1.9-29.8 μg/L), β-blocker atenolol (0.84-2.8 μg/L), hypoglycaemic agent glibenclamide (0.12-15.9 μg/L) and a diuretic hydrochlorothiazide (2.3-4.8 μg/L). Also, several pharmaceuticals such as ibuprofen, ketoprofen, diclofenac, ofloxacin and azithromycin were detected in sewage sludge at concentrations up to 741.1, 336.3, 380.7, 454.7 and 299.6 ng/g dry weight. Two pilot-scale MBRs exhibited enhanced elimination of several pharmaceutical residues poorly removed by the CAS treatment (e.g., mefenamic acid, indomethacin, diclofenac, propyphenazone, pravastatin, gemfibrozil), whereas in some cases more stable operation of one of the MBR reactors at prolonged SRT proved to be detrimental for the elimination of some compounds (e.g., β-blockers, ranitidine, famotidine, erythromycin). Moreover, the anti-epileptic drug carbamazepine and diuretic hydrochlorothiazide by-passed all three treatments investigated.Furthermore, sorption to sewage sludge in the MBRs as well as in the entire treatment line of a full-scale WWTP is discussed for the encountered analytes. Among the pharmaceuticals encountered in sewage sludge, sorption to sludge could be a relevant removal pathway only for several compounds (i.e., mefenamic acid, propranolol, and loratidine). Especially in the case of loratidine the experimentally determined sorption coefficients (K_ds) were in the range 2214-3321 L/kg (mean). The results obtained for the solid phase indicated that MBR wastewater treatment yielding higher biodegradation rate could reduce the load of pollutants in the sludge. Also, the overall output load in the aqueous and solid phase of the investigated WWTP was calculated, indicating that none of the residual pharmaceuticals initially detected in the sewage sludge were degraded during the anaerobic digestion. Out of the 26 pharmaceutical residues passing through the WWTP, 20 were ultimately detected in the treated sludge that is further applied on farmland.     

Investigating the distribution of polybrominated diphenyl ethers through an Australian wastewater treatment plant

The aim of this study was to quantify the amount of polybrominated diphenyl ethers (PBDEs) released into the environment (biosolids, effluent) from a conventional Australian activated sludge treatment wastewater treatment plant (WWTP). The concentration of PBDE congeners was measured at various treatment stages and included four aqueous samples (raw, primary, secondary and tertiary effluents) and three sludges (primary, secondary and lime stabilized biosolids), collected at three sampling events over the course of the experiment (29 days). Semi-permeable membrane devices (SPMDs) were also installed for the duration of the experiment, the first time that SPMDs have been used to measure PBDEs in a WWTP. Over 99% of the PBDEs entering the WWTP were removed through the treatment processes, principally by sedimentation. The main congeners detected were BDE 47, 99 and 209, which are characteristic of the two major commercial formulations viz penta-BDE and deca-BDE. All the PBDE congeners measured were highly correlated with each other, suggesting a similar origin. In this case, the PBDEs are thought to be from domestic sources since domestic wastewater is the main contribution to the in-flow (∼ 95%). The mean concentration of ΣPBDEs in chemically stabilized sewage sludge (biosolids) was 300 μg kg^− 1 dry weight. It is calculated that 2.3 ± 0.3 kg of PBDEs are disposed of each year with biosolids generated from the WWTP. If all Australian sewage sludge is contaminated to at least this concentration then at least 110 kg of PBDEs are associated with Australian sewage sludge annually. Less than 10 g are released annually into the environment via ocean outfall and field irrigation; this level of contamination is unlikely to pose risk to humans or the environment. The environmental release of treated effluent and biosolids is not considered a large source of PBDE environmental emissions compared to the quantities used annually in Australia.     

Polycyclic and nitro musks in indoor air: a primary school classroom and a women's sport center

Indoor air gas and particulate-phase samples (PM(2.5) ) were collected from a primary school classroom and a women's sport center because children are one of the sensitive population subgroups and women are frequent users of personal care products in addition to the high level of activity in this specific microenvironment. PM(2.5) was collected with a Harvard impactor, and polyurethane foam was used for the gas phase. Samples were ultrasonically extracted, concentrated, and analyzed with a GC-MS. The mean gas-phase concentrations in the classroom ranged from 0.12 ± 0.2 ng/m(3) for MK to 267 ± 56?ng/m(3) for HHCB, while it was from 0.08 ± 0.10 ng/m(3) for AHMI to 144 ± 61 ng/m(3) for HHCB in the sports center. Particulate-phase average concentrations in the sports center ranged from 0.22 ± 0.11 ng/m(3) for ATII to 1.34 ± 071 ng/m(3) for AHTN, while it ranged from 0.05 ± 0.02 ng/m(3) (musk xylene) to 2.50 ± 0.94 ng/m(3) (HHCB) in the classroom. Exposure-risk assessment showed that inhalation route is most probably far less significant than the dermal route; however, it should be noted that the exposure duration covered in this study was not the larger fraction of the day. PRACTICAL IMPLICATIONS: Synthetic musk compounds (SMCs) are found everywhere because their use in household and personal care products (laundry detergents, carpet cleaners, cleaning agents, fabric softener soaps, shampoos, cosmetics, etc.) has been increasing. These compounds are semi-volatiles that may result in direct and indirect exposures through inhalation route. Although SMCs were found to be dominant in the gas phase, exposure via inhalable particles may be important as we found several compounds in the particulate phase (PM(2.5)).     

Detection of the antimicrobials triclocarban and triclosan in agricultural soils following land application of municipal biosolids

The occurrence of the antimicrobials triclocarban (TCC) and triclosan (TCS) was investigated in agricultural soils following land application of biosolids using liquid chromatography-tandem mass spectrometry (LC-MS-MS) with negative ion multimode ionization. The method detection limits were 0.58 ng TCC/g soil, 3.08 ng TCC/g biosolids, 0.05 ng TCS/g soil and 0.11 ng TCS/g biosolids and the average recovery from all of the sample matrices was >95%. Antimicrobial concentrations in biosolids from three Michigan wastewater treatment plants (WWTPs) ranged from 4890 to 9280 ng/g, and from 90 to 7060 ng/g, for TCC and TCS respectively. Antimicrobial analysis of soil samples, collected over two years, from ten agricultural sites previously amended with biosolids, indicated TCC was present at higher concentrations (1.24-7.01 ng/g and 1.20-65.10 ng/g in 2007 and 2008) compared to TCS (0.16-1.02 ng/g and from the method detection limit, <0.05-0.28 ng/g in 2007 and 2008). Soil antimicrobial concentrations could not be correlated to any soil characteristic, or to the time of last biosolids application, which occurred in either 2003, 2004 or 2007. To our knowledge, our data represent the first report of TCC, and the first comparison of TCC and TCS concentrations, in biosolids-amended agricultural soils. Such information is important because approximately 50% of US biosolids are land applied, therefore, any downstream effects of either antimicrobial are likely to be widespread.     

Total and methyl mercury transformations and mass loadings within a wastewater treatment plant and the impact of the effluent discharge to an alkaline hypereutrophic lake

Concerns over the fate and bioaccumulation of mercury (Hg) inputs to Onondaga Lake, a hypereutrophic lake in central New York, prompted an investigation into the concentrations and fluxes of Hg discharge from the Onondaga County Metropolitan Wastewater Treatment Plant (METRO WWTP). Discharge of methyl Hg (MeHg) is of concern because it is the form of Hg that readily bioaccumulates along the aquatic food chain. This study incorporated clean protocols for sampling and Hg analysis to evaluate: seasonal patterns in the concentrations of total Hg (THg) and MeHg in the WWTP unit processes; the production of MeHg within the unit processes of the WWTP; the overall fate of THg and MeHg within the WWTP; and the relative impact of the Hg discharged from the WWTP to Onondaga Lake. Concentrations of THg (range: 80-860 ng/L) and MeHg (0.7-17 ng/L) in raw sewage were highly variable, with higher concentrations observed in the summer months. The dynamics of THg though the WWTP were correlated with total suspended solids (TSS). As a result, the majority of the THg removal (55%) occurred during primary treatment. Overall, about 92% of the THg entering the plant was removed as sludge, with volatilization likely a minor component of the overall Hg budget. The transformation of MeHg through the plant differed from THg in that MeHg was not correlated with TSS, and displayed strong seasonal differences between winter (November to April) and summer (May-October) months. During the summer months, substantial net methylation occurred in the activated sludge secondary treatment, resulting in higher MeHg concentrations in secondary effluent. Net demethylation was the dominant mechanism during tertiary treatment, resulting in removal of substantial MeHg from the secondary effluent. The overall MeHg removal efficiency through the plant was about 70% with more efficient removal during summer months. Sediment trap collections made below the epilimnion of Onondaga Lake indicated average deposition rates of 12 μg/m²-day for THg and 0.33 μg/m²-day for MeHg. These deposition rates are more than an order of magnitude higher than the thermocline area normalized external loads from METRO effluent (0.85 μg/m²-day for THg, 0.05 μg/m²-day for MeHg). Our findings indicate that the impact of the discharge from METRO is relatively small, contributing about 10-15% of Hg to the total gross Hg input to the hypolimnion of the lake.     

Ozonation: a tool for removal of pharmaceuticals,contrast media and musk fragrances from wastewater?

A pilot plant for ozonation and UV-disinfection received effluent from a German municipal sewage treatment plant (STP) to test the removal of pharmaceuticals, iodinated X-ray contrast media (ICM) and musk fragrances from municipal wastewater. In the original STP effluent, 5 antibiotics (0.34-0.63 microgl(-1)), 5 betablockers (0.18-1.7 microgl(-1)), 4 antiphlogistics (0.10-1.3 microgl(-1)), 2 lipid regulator metabolites (0.12-0.13 microgl(-1)), the antiepileptic drug carbamazepine (2.1 microgl(-1)), 4 ICM (1.1-5.2 microgl(-1)), the natural estrogen estrone (0.015 microgl(-1)) and 2 musk fragrances (0.1-0.73 microgl(-1)) were detected by LC-electrospray tandem MS and/or GC/MS/MS. ICM, derived from radiological examinations, were present with the highest concentrations (diatrizoate: 5.7 microgl(-1), iopromide: 5.2 microgl(-1)). By applying 10-15 mgl(-1) ozone (contact time: 18 min), all the pharmaceuticals investigated as well as musk fragrances (HHCB, AHTN) and estrone were no longer detected. However, ICM (diatrizoate, iopamidol, iopromide and iomeprol) were still detected in appreciable concentrations. Even with a 15 mgl(-1) ozone dose, the ionic diatrizoate only exhibited removal efficiencies of not higher than 14%, while the non-ionic ICM were removed to a degree of higher than 80%. Advanced oxidation processes (O(3)/UV-low pressure mercury arc, O(3)/H(2)O(2)), which were non-optimized for wastewater treatment, did not lead significantly to a higher removal efficiency for the ICM than ozone alone.     

Pharmaceutical and personal care products in tile drainage following land application of municipal biosolids

Land application of municipal biosolids (sewage) is a common farming practice in many parts of the world. There is potential for transport of pharmaceuticals and personal care products (PPCPs) from agricultural fields to adjacent surface waters via tile drainage systems. In this study, liquid municipal biosolids (LMB) (total solids=11,933 mg L(-1)), supplemented with selected PPCPs and the fluorescent dye tracer rhodamine WT (RWT), were applied to tile drained fields using two land application approaches. Objectives included evaluating the relative benefits of land application practices with respect to reducing PPCP loadings to tile drains, evaluating PPCP persistence in tile water, and determining whether rhodamine WT can be used to estimate PPCP mass loads in tile. The PPCPs examined included an antibacterial agent used in personal care products (triclosan), a metabolite of nicotine (cotinine), and a variety of drugs including two sulfonamide antimicrobials (sulfapyridine, sulfamethoxazole), a beta-blocker (atenolol), an anti-epileptic (carbamazepine), an antidepressant (fluoxetine), analgesic/anti-inflammatories (acetaminophen, naproxen, ibuprofen), and a lipid-regulator (gemfibrozil). Maximum observed PPCP concentrations in the spiked LMB were about 10(3) ng g(-1) dry weight. PPCPs were shown to move rapidly via soil macropores to tile drains within minutes of the land application. Maximum observed PPCP concentrations in tile effluent associated with the LMB application-induced tile flow event were approximately 10(1) to 10(3) ng L(-1). PPCP mass loads, for the application-induced tile-hydrograph event, were significantly (p<0.1) higher for surface spreading over non-tilled soil (incorporation tillage occurring 20 h post-application), relative to aerating soil immediately prior to surface spreading using an AerWay slurry deposition system. PPCP concentrations that were detected above the limit of quantitation (LOQ) in tile water during several precipitation-induced tile flow events that occurred post-application, included: triclosan (max. approximately 1.5 x 10(2) ng L(-1)), carbamazepine (max. approximately 7 x 10(1) ng L(-1)), atenolol (max approximately 4 x 10(1) ng L(-1)), and cotinine (max approximately 2 x 10(1) ng L(-1)). In spite of their presence in biosolids, the other PPCPs were not observed above LOQ concentrations during these events. PPCP concentrations were predicted from RWT concentrations over a 40 day study period. Tile mass loads as a percent of PPCP mass applied to soil ranged from 4.2%+/-SD of 9.2% to 7.1%+/-10.9% for the AerWay system and surface spreading plus incorporation treatments, respectively.     

Oxidative and photochemical processes for the removal of galaxolide and tonalide from wastewater

Synthetic musks have been reported in wastewaters at concentrations as high as tens of micrograms per litre. The two most significant polycyclic musk fragrance compounds are 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran (HHCB, trade name galaxolide^®) and 7-acetyl-1,1,3,4,4,6-hexamethyltetrahydronaphthalene (AHTN, trade name tonalide^®). We report the result of several irradiation and advanced oxidation processes carried out on samples of the effluent of a wastewater treatment plant located in Alcalá de Henares, Madrid. Wastewater samples were pre-ozonated and spiked with 500 ng/L of tonalide or galaxolide in order to obtain final concentrations in the same order as the raw effluent. The treatments assayed were ozonation with and without the addition of hydrogen peroxide (O₃, O₃/H₂O₂), ultraviolet (254 nm low pressure mercury lamp) and xenon-arc visible light irradiation alone and in combination with ozone (UV, O₃/UV, Xe, O₃/Xe) and visible light photocatalytic oxidation using a Ce-doped titanium dioxide photocatalyst performed under continuous oxygen or ozone gas bubbling (O₂/Xe/Ce-TiO₂, O₃/Xe/Ce-TiO₂). In all cases, samples taken at different contact times up to 15 min were analyzed. An analytical method based on stir bar sorptive extraction (SBSE), followed by comprehensive two-dimensional gas chromatography (SBSE-GC × GC-TOF-MS), was used for the automatic searching and evaluation of the synthetic musks and other nonpolar or semipolar contaminants in the wastewater samples. In all cases tonalide was more easily removed than galaxolide. The best results for the latter (more than 75% removal after 5 min on stream) were obtained from ozonation (O₃) and visible light photocatalytic ozonation (O₃/Xe/Ce-TiO₂). A significant removal of both pollutants (∼60% after 15 min) was also obtained during visible light photocatalysis (O₂/Xe/Ce-TiO₂). UV radiation was able to deplete tonalide (+90%) after 15 min but only reduced the concentration of galaxolide to about half of its initial concentration. The toxicity of treated samples decreased for O₃/UV and O₃/Ce-TiO₂, but increased during irradiation processes UV, Xe and Xe/Ce-TiO₂. Ozone treatments tend to decrease toxicity up to a certain dosage, from which point the presence of toxic transformation products has adverse effects on aquatic microorganisms.     

Occurrence of androgens and progestogens in wastewater treatment plants and receiving river waters: Comparison to estrogens

Research has shown that exposure to androgens and progestogens can cause undesirable biological responses in the environment. To date, however, no detailed or direct study of their presence in wastewater treatment plants has been conducted. In this study, nine androgens, nine progestogens, and five estrogens were analyzed in influent and final effluent wastewaters in seven wastewater treatment plants (WWTPs) of Beijing, China. Over a period of three weeks, the average total hormone concentrations in influent wastewaters were 3562 (Wujiacun WWTP)-5400 ng/L (Fangzhuang WWTP). Androgens contributed 96% of the total hormone concentrations in all WWTP influents, with natural androgen (androsterone: 2977 ± 739 ng/L; epiandrosterone: 640 ± 263 ng/L; and androstenedione: 270 ± 132 ng/L) being the predominant compounds. The concentrations of synthetic progestogens (megestrol acetate: 41 ± 25 ng/L; norethindrone: 6.5 ± 3.3 ng/L; and medroxyprogesterone acetate: 6.0 ± 3.2 ng/L) were comparable to natural ones (progesterone: 66 ± 36 ng/L; 17α,20β-dihydroxy-4-progegnen-3-one: 4.9 ± 1.2 ng/L; 21α-hydroxyprogesterone: 8.5 ± 3.0 ng/L; and 17α-hydroxyprogesterone: 1.5 ± 0.95 ng/L), probably due to the wide and relatively large usage of synthetic progestogens in medical therapy. In WWTP effluents, androgens were still the dominant class accounting for 60% of total hormone concentrations, followed by progestogens (24%), and estrogens (16%). Androstenedione and testosterone were the main androgens detected in all effluents. High removal efficiency (91-100%) was found for androgens and progestogens compared with estrogens (67-80%), with biodegradation the major removal route in WWTPs. Different profiles of progestogens in the receiving rivers and WWTP effluents were observed, which could be explained by the discharge of a mixture of treated and untreated wastewater into the receiving rivers.     

Steroid hormones in biosolids and poultry litter: a comparison of potential environmental inputs

Steroid hormones can act as potent endocrine disruptors when released into the environment. The main sources of these chemicals are thought to be wastewater treatment plant discharges and waste from animal feeding operations. While these compounds have frequently been found in wastewater effluents, few studies have investigated biosolids or manure, which are routinely land applied, as potential sources. This study assessed the potential environmental contribution of steroid hormones from biosolids and chicken litter. Hormone concentrations in samples of limed biosolids collected at a waste treatment plant over a four year period ranged from < 2.5 to 21.7 ng/g dry weight for estrone (E1) and < 2.5 to 470 ng/g dry weight for progesterone. Chicken litter from 12 mid-Atlantic farms had averages of 41.4 ng/g dry weight E1, 63.4 ng/g dry weight progesterone, and 19.2 ng/g dry weight E1-sulfate (E1-S). Other analytes studied were 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2), testosterone, E2-3-sulfate (E2-3-S), and E2-17-sulfate (E2-17-3).