Nonylphenol Monoethoxylate Research Articles

Simultaneous determination of the free and total forms of nonylphenol, nonylphenol monoethoxylate, and nonylphenol diethoxylate in human urine by gas chromatography-mass spectrometry.

Nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and nonylphenol diethoxylate (NP2EO) are widely used in various daily products and have been cataloged as endocrine-disrupting chemicals. Due to their high lipophilicity and low biodegradability, these compounds remain in the environment and enter the human body through the food chain. Growing concerns regarding the potential negative effects of NP, NP1EO, and NP2EO on human health have raised the need for biomonitoring to investigate human exposure to these compounds. In this study, a simultaneous analysis method using solid-phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) was established by controlling the background contamination of NP, NP1EO, and NP2EO, which are ubiquitous in laboratory environments. The proposed method showed proper linearity of over 0.999 and a recovery greater than 85.8% for all analytes. Accuracy and precision were verified in ranges of 92.97-116.30% and 0.65-9.29%, respectively. The detection limits for NP, NP1EO, and NP2EO were 0.0363μg L-1, 0.0401μg L-1, and 0.0364μg L-1, respectively, which were suitable for determining the trace analytes in human urine. Therefore, this simple and integrated analytical method was applied to measure the free and total forms of the target analytes in 25 human urine samples collected in Korea. Overall, free NP, NP1EO, and NP2EO were detected with average contents of 3.94 ± 4.14μg L-1, 4.63 ± 2.62μg L-1, and 0.293 ± 0.638μg L-1, respectively, and with total NP, NP1EO, and NP2EO contents of 6.14 ± 8.24μg L-1, 5.99 ± 2.91μg L-1, and 0.806 ± 1.10μg L-1, respectively. These data showed that these compounds are prevalent in human urine, and indicate the need for further studies.

Nonylphenol, Octylphenol, and Nonylphenol Ethoxylates Dissemination in the Canadian Freshwater Environment.

Nonylphenol, octylphenol, and nonylphenol ethoxylates are manmade compounds that are only discharged in the environment due to anthropogenic activities. The objectives of this study were to determine the current concentrations of these substances in the Canadian freshwater environment and to determine if past regulatory actions were beneficial to the environment. Freshwater samples (n = 241) were collected and analysed for 4-nonylphenols (NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), and octylphenols at 35 sites in Canada from 2014 to 2019 with individual compound concentrations ranging from 1.29 to 477.22ng/L. In addition, 18-65% of the samples were reported to be under the laboratory detection limit, depending on the compound. Sampling sites were categorised into five groups based on the dominant activities present upstream in their watersheds: mixed use sites; municipal waste water treatment plant (MWWTP)-associated sites; textile mill-associated sites; urban; and reference sites. All four compounds in the study were detected more frequently in urban and MWWTP-associated sites than at other locations. Additionally, there is a statistically significant (p < 0.05) downward temporal trend in NP concentrations in Canadian surface waters from 2014 to 2019. There were no exceedances of the Canadian Water Quality Guideline of 1000ng/L.

Anthropogenic Contaminants and Histopathological Findings in Stranded Cetaceans in the Southeastern United States, 2012–2018

Anthropogenic contaminants in the marine environment often biodegrade slowly, bioaccumulate in organisms, and can have deleterious effects on wildlife immunity, health, reproduction, and development. In this study, we evaluated tissue toxicant concentrations and pathology data from 83 odontocetes that stranded in the southeastern United States during 2012–2018. Mass spectrometry was used to analyze blubber samples for five organic toxicants (atrazine, bisphenol-A, diethyl phthalates, nonylphenol monoethoxylate [NPE], triclosan), and liver samples were analyzed for five non-essential elements (arsenic, cadmium, lead, mercury, thallium), six essential elements (cobalt, copper, manganese, iron, selenium, zinc) and one toxicant mixture class (Aroclor1268). Resultant data considerably improve upon the existing knowledge base regarding toxicant concentrations in stranded odontocetes. Toxicant and element concentrations varied based on animal demographic factors including species, sex, age, and location. Samples from bottlenose dolphins had significantly higher average concentrations of lead, manganese, mercury, selenium, thallium, and zinc, and lower average concentrations of NPE, arsenic, cadmium, cobalt, and iron than samples from pygmy sperm whales. In adult female bottlenose dolphins, average arsenic concentrations were significantly higher and iron concentrations were significantly lower than in adult males. Adult bottlenose dolphins had significantly higher average concentrations of lead, mercury, and selenium, and significantly lower average manganese concentrations compared to juveniles. Dolphins that stranded in Florida had significantly higher average concentrations of lead, mercury, and selenium, and lower concentrations of iron than dolphins that stranded in North Carolina. Histopathological data are presented for 72 animals, including microscopic evidence of Campula spp. and Sarcocystis spp. infections, and results of Morbillivirus and Brucella spp. molecular diagnostic testing. Sublethal cellular changes related to toxicant exposure in free-ranging odontocetes may lead to health declines and, in combination with other factors, may contribute to stranding.

Nonylphenol ethoxylates biodegradation increases estrogenicity of textile wastewater in biological treatment systems

The formation of estrogenic intermediates, i.e. nonylphenol diethoxylate (NP2EO), nonylphenol monoethoxylate (NP1EO), and nonylphenol (NP), following nonylphenol ethoxylates (NPEOs) biodegradation in textile wastewater raises concerns about its endocrine disruptive activity, but the estrogenicity changes of textile wastewater throughout biological treatment processes remain unknown. In the present study, the estrogenicity of textile wastewater sampled from 10 wastewater treatment plants (WWTPs) were investigated using the reporter gene-based T47D-KBluc bioassay. Results showed that the estrogenicity of the textile wastewater significantly increased after either anaerobic or aerobic treatment in all WWTPs, with an average fold change of 3.21, although traditional pollutants were effectively removed. The estradiol equivalents of the effluent (ranging from 1.50 to 4.12 ng-E2/L) were generally higher than published effect based trigger values, indicating an increased risk for the receiving waters. Removal efficiency was high (84.46%) for NPEOs, but was low for NP2EO and NP1EO in the biological treatment processes. Nevertheless, NP had increased concentrations after the treatment. Bioanalytical equivalent concentration of the textile wastewater and that of NP2EO, NP1EO, and NP showed a good linear correlation, of which NP alone contributed more than 70% to the observed estrogenicity. Extending hydraulic retention time was found effective in reducing the estrogenicity as it allows relatively complete degradation of NP, which was further confirmed by running lab-scale A/O reactors fed with NP10EO. The results may extend our knowledge regarding the estrogenicity of textile wastewater and its reduction technologies used in WWTPs.

Removal of nonylphenol and nonylphenol monoethoxylate from water and anaerobically digested sewage sludge by Ferrate(VI)

Nonylphenol (NP) and nonylphenol monoethoxylate (NP1EO) have toxic and persistent characteristics, and are incompletely degraded in conventional wastewater treatment processes. These compounds are present in sewage sludge that can be reused as fertilizers or soil conditioners. Accordingly, NP and NP1EO should be properly removed before being discharged in the environment. In this study, potassium ferrate (K2FeO4) containing hexavalent iron (Fe(VI)) was used as an environment-friendly oxidizing agent to mediate NP and NP1EO degradation. The aim of this study was to investigate the effects of pH and Fe(VI) dosage on the degradation of NP and NP1EO in water and anaerobically digested sewage sludge samples. In water samples, under conditions examined in this study, maximum removal efficiencies for NP and NP1EO were 98% and 92%, respectively. For digested sewage sludge samples, the maximum removal efficiencies of NP and NP1EO were 58% and 96%, respectively. The results demonstrated that Fe(VI) can potentially degrade NP and NP1EO in water and digested sewage sludge samples. However, organic matter as a matrix in the sludge sample would inhibit the degradation of NP and NP1EO by Fe(VI). The pH values before and after adding K2FeO4 to the samples had an obvious influence on the removal of NP and NP1EO.

Transfer of organic pollutants from sewage sludge to earthworms and barley under field conditions

We investigated dissipation, earthworm and plant accumulation of organic contaminants in soil amended with three types of sewage sludge in the presence and absence of plants. After 3 months, soil, plants and earthworms were analyzed for their content of organic contaminants. The results showed that the presence of plant roots did not affect dissipation rates, except for galaxolide. Transfer of galaxolide and triclosan to earthworms was significant, with transfer factors of 10–60 for galaxolide and 140–620 for triclosan in the presence of plants. In the absence of plants, transfer factors were 2–9 times higher. The reduced transfer to worms in the presence of plants was most likely due to roots serving as an alternative food source. Nonylphenol monoethoxylate rapidly dissipated in soil, but initial exposure resulted in uptake in worms, which was detected even 3 months after sewage sludge application. These values were higher than the soil concentration at the start of the exposure period. This indicates that a chemical's short half-life in soil is no guarantee that it poses a minimal environmental risk, as even short-term exposure may cause bioaccumulation and risks for chronic or even transgenerational effects.

Analysis of Bisphenol A, Alkylphenols, and Alkylphenol Ethoxylates in NIST SRM 2585 and Indoor House Dust by Gas Chromatography-Tandem Mass Spectrometry (GC/MS/MS).

Background: Ingestion of house dust has been demonstrated to be an important exposure pathway to several contaminants in young children. These compounds include bisphenol A (BPA), alkylphenols (APs), and alkylphenol ethoxylates (APEOs). Analysis of these compounds in house dust is challenging because of the complex composition of the sample matrix. Objective: The objective was to develop a simple and sensitive method to measure BPA, APs, and APEOs in indoor house dust. Methods: An integrated method that involved solvent extraction using sonication, sample cleanup by solid-phase extraction, derivatization by 2,2,2-trifluoro-N-methyl-N-(trimethylsilyl)acetamide, and analysis by GC coupled with tandem MS was developed for the simultaneous determination of BPA, APs, and APEOs in NIST Standard Reference Material (SRM) 2585 (Organic contaminants in house dust) and in settled house dust samples. Results: Target analytes included BPA, 4-tert-octylphenol (OP), OP monoethoxylate, OP diethoxylate, 4-n-nonylphenol (4nNP), 4nNP monoethoxylate (4nNP1EO), branched nonylphenol (NP), NP monoethoxylate, NP diethoxylate, NP triethoxylate, and NP tetraethoxylate. The method was sensitive, with method detection limits ranging from 0.05 to 5.1 μg/g, and average recoveries between 82 and 115%. All target analytes were detected in SRM 2585 and house dust except 4nNP and 4nNP1EO. Conclusions: The method is simple and fast, with high sensitivity and good reproducibility. It is applicable to the analysis of target analytes in similar matrixes, such as sediments, soil, and biosolids. Highlights: Values measured in SRM 2585 will be useful for future research in method development and method comparison.

Identification, contribution, and estrogenic activity of potential EDCs in a river receiving concentrated livestock effluent in Southern Taiwan

We assessed 22 selected endocrine-disrupting compounds (EDCs) and other emerging, potentially endocrine-active compounds with estrogenic activity from the waters of the Wuluo River, southern Taiwan. This watershed receives high amounts of livestock and untreated household wastewaters. The river is surrounded by concentrated animal feedlot operations (CAFOs). River water samples were analyzed for selected compounds by liquid chromatography-tandem mass spectrometry (LC-MS/MS), T47D-KBluc reporter gene assay, and E-screen cell proliferation in vitro bioassay. Total concentrations of ∑alkylphenolic compounds (bisphenol A, 4-nonylphenol, t-nonylphenol, octylphenol, nonylphenol mono-ethoxylate, nonylphenol di-ethoxylate) were much higher than ∑estrogens (estrone, 17 β-estradiol, estriol, 17ß-ethynylestradiol, diethylstilbestrol), ∑preservatives (methyl paraben, ethyl paraben, propyl paraben, butyl paraben), ∑UV-filters (benzophenone, methyl benzylidene camphor, benzophenone-3), ∑antimicrobials (triclocarben, triclosan, chloroxylenol), and an insect repellent (diethyltoluamide) over four seasonal sampling periods. The highest concentration was found for bisphenol A with a mean of 302 ng/L. However, its contribution to estrogenic activity was not significant due to its relatively low estrogenic potency. Lower detection rates were found for BP, EE2, TCS, and PCMX, while DES and EP were not detected. E1 and E2 levels in raw water samples were 50% higher than the predicted no-effect concentrations (PNEC) for aquatic organisms of 6 and 2 ng/L, respectively. The potency of estrogenic activity ranged from 11.7 to 190.1 ng/L E2T47D-Kbluc and 6.63 to 84.5 ng/L E2E-Screen for extracted samples. Importantly, estrone contributed 50% of the overall activity in 60% and 44% of the samples based on T47D-KBluc and MCF-7 bioassays, followed by 17 ß-estradiol, highlighting the importance of total steroid estrogen loading. This study demonstrates that the estrogenic activity of target chemicals was comparable to levels found in different countries worldwide. More intense wastewater treatment is required in areas of intensive agriculture in order to prevent adverse impacts on the ambient environment and aquatic ecosystems.

Assessment of the environmental fate of endocrine disrupting chemicals in rivers

Laboratory tests were conducted with five endocrine disruptors (bishenol A, triclosan. nonylphenol, nonylphenol monoethoxylate and nonylphenol diethoxylate) under different redox conditions (aerobic, anoxic, anaerobic and sulfate-reducing conditions) to assess abiotic and biotic degradation in a river water/sediment system. The river water sample was collected from Spercheios River while the sediment was collected from the banks of a tributary of the river at the point where the discharge point of a wastewater treatment plant is located. To describe quantitatively elimination kinetics of the target compounds, pseudo first-order kinetics were adopted. According to the results from the microcosms studies, it can be stated that the substances are eliminated from the aqueous phase with relatively high rates under aerobic conditions due to both sorption and biotransformation processes. However, when reduced oxygen conditions were established in the microcosms incubations, biotransformation decreased, indicating the almost complete cease of the EDCs microbial degradation, while substances' sorption onto sediments showed no significant differences. All compounds were found to be biodegradable under aerobic conditions, and the low to high order of the calculated dissipation rate constants was 0.064±0.004d−1 (TCS)→0.067±0.006d−1 (NP)→0.076±0.009d−1 (NP2EO)→0.081±0.007d−1 (NP1EO)→0.103±0.011d−1 (BPA). Finally, regarding the biotransformation experiments, the elimination of the compounds limited in the absence of oxygen as compared to aerobic.

Pharmaceuticals and other anthropogenic chemicals in atmospheric particulates and precipitation

Air and precipitation samples were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography mass spectrometry (GC–MS) for pharmaceuticals, personal care products, and other commercial chemicals within the St. Paul/Minneapolis metropolitan area of Minnesota, U.S. Of the 126 chemicals analyzed, 17 were detected at least once. Bisphenol A, N,N-diethyl-meta-toluamide (DEET), and cocaine were the most frequently detected; their maximum concentrations in snow were 3.80, 9.49, and 0.171ng/L and in air were 0.137, 0.370, and 0.033ng/m3, respectively. DEET and cocaine were present in samples of rain up to 14.5 and 0.806ng/L, respectively. Four antibiotics - ofloxacin, ciprofloxacin, enrofloxacin, and sulfamethoxazole - were detected at concentrations up to 10.3ng/L in precipitation, while ofloxacin was the sole antibiotic detected in air at 0.013ng/m3. The X-ray contrast agent iopamidol and the non-steroidal anti-inflammatory drug naproxen were detected in snow up to 228ng/L and 3.74ng/L, respectively, while caffeine was detected only in air at 0.069 and 0.111ng/m3. Benzothiazole was present in rain up to 70ng/L, while derivatives of benzotriazole – 4-methylbenzotriazole, 5-methylbenzotriazole, and 5-chlorobenzotriazole - were detected at concentrations up to 1.5ng/L in rain and 3.4ng/L in snow. Nonylphenol and nonylphenol monoethoxylate were detected once in air at 0.165 and 0.032ng/m3, respectively. Although the sources of these chemicals to atmosphere are not known, fugacity analysis suggests that wastewater may be a source of nonylphenol, nonylphenol monoethoxylate, DEET, and caffeine to atmosphere. The land-spreading of biosolids is known to generate PM10 that could also account for the presence of these contaminants in air. Micro-pollutant detections in air and precipitation are similar to the profile of contaminants reported previously for surface water. This proof of concept study suggests that atmospheric transport of these chemicals may partially explain the ubiquity of these contaminants in the aquatic environment.

Seasonal variations in the concentration and removal of nonylphenol ethoxylates from the wastewater of a sewage treatment plant

In this study, we investigated the occurrence and fate of nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) in a full scale sewage treatment plant, which applied an Anaerobic/Oxic process. Concentrations of NP, NP1EO and NP2EO in the wastewater were measured during the period spanning a whole year. The results showed remarkable seasonal variation in the concentrations of the compounds. The NPnEO compounds were most abundant in winter, with the total concentrations of influent NP, NP1EO and NP2EO ranging from 3900 to 7000ng/L, 4000 to 4800ng/L and 5200 to 7200ng/L, respectively. Regarding the total removal efficiencies of the three types of short-chain NPnEO compounds, different trends were exhibited according to different seasons. The average removal efficiency of NP for the different seasons ranked as follows: winter>summer>autumn>spring; NP2EO concentrations decreased as follows: summer>autumn>winter>spring, while NP1EO concentrations reduced according to: spring>summer>autumn>winter. We also investigated the contribution ratio of individual treatment units in the A/O process, with the findings suggesting that the anaerobic treatment unit plays an important role in the elimination of short-chain NPnEOs from the wastewater.

Biotransformation of Nonylphenol Diethoxylate in anaerobic digesters: Accumulation of metabolites and their effects on digester performance

Nonylphenol(poly)ethoxylates (NPnEOs) have caused great concern over the last few decades due to their lipophilic, hydrophobic, and toxic properties. NPnEOs can be degraded to a certain extent in wastewater treatment plants; however since they accumulate in sludge, understanding their influence on digester performance and their fate become important, especially in regards to land application of biosolids. In this respect, the biotransformation of nonylphenol diethoxylate (NP2EO), an accumulative metabolite of NPnEOs, into degradation products was monitored in NP2EO-amended lab-scale semi-continuous anaerobic digesters. Determination and quantification of the degradation products, nonylphenol monoethoxylate (NP1EO), nonylphenol (NP) and nonylphenoxy acetic acid (NP1EC), was performed by gas chromatography-mass spectrometry (GC/MS). Results revealed that 90% of NP2EO was eliminated from the system within approximately 52 days following the spike. As biodegradation of NP2EO progressed, both NP1EO and NP accumulated in the sludge samples. NP1EC was not detected in any of the digesters. Methane production, solids reduction and COD removal were not affected by the spike of NP2EO or by the presence of biodegradation products (NP1EO and NP) in the digester system. The persistence and accumulation of NP and NP1EO verifies concerns about the potential danger for land application of biosolids.

Removal of Endocrine Disrupting Chemicals in HSF and VF pilot-scale constructed wetlands

During the last decade, several emerging chemicals, also referred as Endocrine Disrupting Chemicals (EDCs), have raised the interest of the scientific community, because of possible adverse effects on the environment and the living organisms. Although several treatment technologies have been applied for their removal, operation and maintenance costs are prohibitive. Therefore, this study aims to study the treatment of EDCs with an alternative and environmentally friendly technology: constructed wetlands (CWs). For this purpose, 6 pilot-scale CW units of two types, horizontal subsurface flow (HSF) and vertical flow (VF), were used for the treatment of municipal wastewater originating from a university campus, targeting the removal of five EDCs: Bisphenol A (BPA), Nonylphenol (NP), Nonylphenol monoethoxylate (NP1EO), Nonylphenol diethoxylate (NP2EO) and Triclosan (TCS). Results showed that the median removal performance in HSF-R was 49.6%, 51.4% and 48.4%, in HSF-C was 50.0%, 99.0% and 66.0%, and in HSF-Z was 55.4%, 98.9% and 80.3% for BPA, NP1EO and NP2EO, respectively. NP was not removed but its concentration was increased by 48.0%, 43.7% and 51.9% in the HSF-R, HSF-C and HSF-Z, respectively. TCS was not detected in influent wastewater. In the VF-CWs, the median removal efficiencies were: 45.6%, −12.5%, 41.5% and 72.2% in VF-R, 60.0%, 96.2%, 99.0% and 99.8% in VF-C, and 59.0%, 95.6%, 98.7% and 99.8% in VF-Z for BPA, NP, NP1EO, NP2EO, respectively. The study indicates that the main removal pathways of the target EDCs is their biodegradation under aerobic or/and anaerobic conditions and adsorption onto the organic matter retained in the substrate.

Sorption behaviour of nonylphenol and nonylphenol monoethoxylate in soils

Sorption behaviour of two alkylphenolic compounds (APCs), nonylphenol (NP) and nonylphenol monoethoxylate (NP1EO), was studied in five soils with contrasting characteristics. Sorption isotherms were obtained by equilibrating the soil samples with 0.01molL−1 CaCl2 solutions containing different initial concentrations of NP or NP1EO. Linear fitting was generally appropriate for describing the sorption behaviour of NP and NP1EO in the soils, with the exception of two cases, for which the Freundlich model was more suitable for describing the sorption pattern of NP1EO. Solid–liquid distribution coefficients derived from sorption isotherms (Kd) varied from 24 to 1059mLg−1 for NP and from 51 to 740mLg−1 for NP1EO. For most soils, sorption Kd values were higher for NP than for NP1EO due to the higher hydrophobicity of NP. Sorption reversibility of NP and NP1EO was also tested from desorption isotherms. Desorption solid–liquid distribution coefficients (Kd,des), obtained from linear fitting, were between 130 and 1467mLg−1 for NP and between 24 and 1285mLg−1 for NP1EO. Kd,des values were higher than Kd values, which demonstrated that target compounds were irreversibly sorbed into soils, with the exception of the high desorption yield (45%) of NP1EO in the soil with the lowest content of organic matter. The fraction of soil organic carbon (FOC) was a key parameter that influenced the sorption of NP and NP1EO in soils, with logKOC values of 4.0 and 3.8, respectively.

Investigation of nonylphenol and nonylphenol ethoxylates in sewage sludge samples from a metropolitan wastewater treatment plant in Turkey

Nonylphenol ethoxylates (NPEOs) have drawn significant attention within the last decade for both scientific and legislative reasons. In Turkey, the Regulation Regarding the Use of Domestic and Urban Sludges on Land states a limit value for the sum of nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) as NPE (NPE=NP+NP1EO+NP2EO). Unfortunately a standard method for the determination of these chemicals has not been yet set by the authorities and no data exists about the concentrations of NP and NPEOs in sewage sludge in Turkey. The aim of this study is to propose simple and easily applicable extraction and measurement techniques for 4-n-nonylphenol (4-n-NP), NP, NP1EO and NP2EO in sewage sludge samples and investigate the year round concentrations in a Metropolitan Wastewater Treatment Plant (WWTP) in Turkey.Different extraction techniques and GC/MS methods for sewage sludge were tested. The best extraction method for these compounds was found to be ultrasonication (5min) using acetone as the solvent with acceptable recovery of analytes suggested by USEPA and other studies. The optimized extraction method showed good repeatability with relative standard deviations (RSDs) less than 6%. The recovery of analytes were within acceptable limits suggested by USEPA and other studies. The limits of detection (LODs) were 6µgkg−1 for NP and NP1EO, 12µgkg−1 for NP2EO and 0.03µgkg−1 for 4-n-NP. The developed method was applied to sewage sludge samples obtained from the Central WWTP in Ankara, Turkey. The sum NPE (NP+NP1EO+NP2EO) was found to be in between 5.5µgkg−1 and 19.5µgkg−1, values which are in compliance with Turkish and European regulations.

Fate and degradation kinetics of nonylphenol compounds in aerobic batch digesters

Nonylphenol (NP) compounds are toxic and persistent chemicals that are not fully degraded either in natural or engineered systems. Current knowledge indicates that these compounds concentrate in sewage sludge. Therefore, investigating the degradation patterns and types of metabolites formed during sludge treatment are important for land application of sewage sludge. Unfortunately, the information on the fate of nonylphenol compounds in sludge treatment is very limited. This study aims to investigate the biodegradation patterns of nonylphenol diethoxylate (NP2EO) in aerobic batch digesters. For this purpose, two NP2EO spiked and two control laboratory aerobic batch digesters were operated. The spiked digester contained 3 mg/L NP2EO in the whole reactor content. The compounds of interest (parent compound and expected metabolites) were extracted with sonication and analyzed by gas chromatography-mass spectrometry (GC–MS) as a function of time. Results showed that, following the day of spike, NP2EO degraded rapidly. The metabolites observed were nonylphenol monoethoxylate (NP1EO), NP and dominantly, nonylphenoxy acetic acid (NP1EC). The mass balance over the reactors indicated that the total mass spiked was highly accounted for by the products analyzed. The time dependent analysis indicated that the parent compound degradation and daughter product formation followed first order kinetics. The digester performance parameters analyzed (VS and COD reduction) indicated that the spike of NP2EO did not affect the digester performance.

Fate of selected emerging micropollutants during mesophilic, thermophilic and temperature co-phased anaerobic digestion of sewage sludge.

The removal of endocrine disrupting compounds (EDCs) and non-steroidal anti-inflammatory drugs (NSAIDs) was studied in three lab-scale anaerobic digestion (AD) systems; a single-stage mesophilic, a single-stage thermophilic and a two-stage thermophilic/mesophilic. All micropollutants underwent microbial degradation. High removal efficiency (>80%) was calculated for diclofenac, ibuprofen, naproxen and ketoprofen; whereas triclosan, bisphenol A and the sum of nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate were moderately removed (40-80%). NSAIDs removal was not affected by the type of AD system used; whereas slightly higher EDCs removal was observed in two-stage system. In this system, most microcontaminants were removed in thermophilic digester. Biotransformation of NP1EO and NP was affected by the temperature applied to bioreactors. Under mesophilic conditions, higher removal of NP1EO and accumulation of NP was noticed; whereas the opposite was observed under thermophilic conditions. For most analytes, higher specific removal rates were calculated under thermophilic conditions and 20 days SRT.

Alkylphenol Polyethoxylate Derivatives in Groundwater and Blood Samples Collected from Pig Herds in Taiwan

ABSTRACTAlkylphenol polyethoxylate (APEO) derivatives, such as nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), nonylphenol (NP) and octylphenol (OP), have been detected in the surface water, sediment, food and groundwater of numerous countries. Because groundwater is the main source of water for pig herds, the aim of this study was to measure the concentrations of APEO derivatives in groundwater and blood samples that were collected from pig herds raised near the Wuluo River in Southern Taiwan. The mean concentrations of NP, OP, NP1EO and NP2EO in the groundwater supply for 10 pig herds were 0.04 µg/l, 0.26 ± 0.23 µg/l, 0.74 ± 0.69 µg/l and 0.17 ± 0.22 µg/l, respectively. NP was detected in all blood samples collected from 5 of the 10 pig herds. The highest concentrations detected in the blood samples collected from six-week-old piglets and sows were 12.00 µg/l and 56.94 µg/l, respectively. Blood samples from 4 of the 5 herds showed OP contamination. The highest OP concentrations detected in 6-week-old piglets and sows were 275.58 µg/l and 566.32 µg/l, respectively. These results indicate that APEO derivatives accumulated in the groundwater supply and the bloodstreams of the pigs.

H2O2/UV-C and Photo-Fenton treatment of a nonylphenol polyethoxylate in synthetic freshwater: Follow-up of degradation products, acute toxicity and genotoxicity

H2O2/UV-C and Photo-Fenton treatment of a nonylphenol polyethoxylate surfactant was investigated in synthetic freshwater. H2O2/UV-C treatment outperformed Photo-Fenton treatment in terms of mother pollutant abatement kinetics as well as overall organic carbon removal efficiencies. Short polyethoxy-chain nonylphenol polyethoxylates, polyethylene glycols, formic acid, acetic acid and formaldehyde were identified as the common degradation products of the nonionic surfactant. Monocarboxylated polyethylene glycols and oxalic acid were detected during H2O2/UV-C oxidation, whereas a degradation product resulting from the hydroxyl radical attack of the tertiary alkyl chain and the aromatic ring was detected during Photo-Fenton treatment. Based on the liquid chromatography–mass spectrometry results, it was suggested that the polyethoxy chain of the surfactant was more susceptible to degradation with the H2O2/UV-C treatment process, while the alkyl chain and aromatic ring were more prone to Photo-Fenton oxidation. Acute toxicity analysis employing the photobacteria Vibrio fischeri indicated that the inhibitory effect of the surfactant increased from 10% to 30% and 19% during the early stages of H2O2/UV-C and Photo-Fenton treatment, respectively. At the end of the treatment period, the inhibitory effect of the surfactant dropped back to less than 10%. According to the umu-genotoxicity test conducted with Salmonella typhimurium TA1535/pSK1002 strain, the genotoxic effect followed an increasing trend during the course of H2O2/UV-C treatment. A positive correlation was evident between the intensity of the nonylphenol monoethoxylate product ion and the genotoxic effect observed during H2O2/UV-C treatment. The genotoxic effect of Photo-Fenton-treated degradation products appeared to be relatively low as compared with those of H2O2/UV-C treatment.

Matrix Effects on Water Analysis for Alkylphenols Using Solid Phase Extraction Gas Chromatography-Mass Spectrometry

Gas chromatography with mass spectrometry is frequently used for the quantification of many classes of substances, including alkylphenols. Alkylphenol polyethoxylates are nonionic surfactants used in a wide variety of industrial and consumer applications. Alkylphenol polyethoxylates can degrade to alkylphenols, which are endocrine disruptors. In analytical validation procedures, the most common parameters studied are the detection and quantification limits, linearity, and recovery; however, the matrix effects are sometimes neglected. Although some investigators have evaluated matrix effects, there is no consensus on how to evaluate them during method validation. In this study, the matrix effects of alkylphenol polyethoxylates (nonylphenol monoethoxylate, nonylphenol diethoxylate, octylphenol monoethoxylate, octylphenol diethoxylate) and alkylphenols (nonylphenol and octylphenol) were studied using solid phase extraction and gas chromatography-mass spectrometry analysis. For alkylphenol polyethoxylates, the matrix effects ranged from 16 to 4692%, whereas for alkylphenols (nonylphenol and octylphenol), the effects were insignificant. Therefore, constructing an analytical curve in the matrix for alkylphenol polyethoxylates is essential.