Fate In Wastewater Treatment Plants Research Articles

Occurrence, removal, and fate of benzothiazoles (BTHs) and benzotriazoles (BTRs) in two wastewater treatment plants in New York State, USA

Benzothiazoles (BTHs) and benzotriazoles (BTRs) are widely used in various consumer products. However, their occurrence and fate in wastewater treatment plants (WWTPs) in the United States remain poorly understood. In this study, wastewater and sludge samples were collected from two WWTPs from the Albany area of New York State (WWTPA and WWTPB) and the concentrations of three BTH derivatives (BTH, 2-OH-BTH, and 2-Me-S-BTH) and five BTR derivatives (1-OH-BTR, XTR, 4-OH-BTR, TTR, and BTR) were determined. The geometric mean (GM) concentrations of Σ(BTHs) and Σ(BTRs) in influent were in the range of 7550–8690 and 4590–6240 ng/L, whereas those in effluent were 6650–7150 and 4620–6800 ng/L, respectively. In the influent of two WWTPs, BTH, BTR, and TTR were identified as the major chemicals at respective GM concentrations of 8440, 4200, and 1280 ng/L in WWTPA, and 7300, 1180, and 2090 ng/L in WWTPB. The removal efficiencies of BTHs and BTRs following activated sludge treatment were < 80 %, and Σ(BTRs) showed a negative removal in both WWTPs. The respective mass loadings of Σ(BTHs) and Σ(BTRs) were 7240 and 5200 mg/d/1000 individuals in WWTPA, and 3530 and 2140 mg/d/1000 individuals in WWTPB. The environmental emissions of Σ(BTHs) and Σ(BTRs) from WWTP discharges were estimated at 3110–6030 and 2160–5700 mg/d/1000 individuals, respectively. Overall, BTHs and BTRs are not efficiently removed in WWTP processes. This study provides baseline information regarding the loading, fate, and discharge of BTHs and BTRs from WWTPs in the USA.

Assessing Contributions of Synthetic Musk Compounds from Wastewater Treatment Plants to Atmospheric and Aquatic Environments.

The high environmental concentrations, persistence, and toxicity of synthetic musk compounds (SMCs) necessitate a better grasp of their fate in wastewater treatment plants (WWTPs). To investigate the importance of WWTPs as pathways of SMCs to the environment, air and wastewater samples were collected at four WWTPs in Ontario, Canada. Polycyclic musks (PCMs) were present at higher concentrations than nitro musks (NMs) and macrocyclic musks (MCMs). Three PCMs [galaxolide (HHCB), tonalide (AHTN), and iso-E super (OTNE)] were the most abundant compounds (0.30-680 ng/m3 in air, 0.40-15 μg/L in influent, and 0.007-6.0 μg/L in effluent). Analyses of multiyear data suggest that risk management measures put in place have been effective in reducing the release of many SMCs into the environment. The highest removal efficiency, up to almost 100% of some SMCs, was observed for the plant with the longest solid retention time. A fugacity-based model was established to simulate the transport and fate of SMCs in the WWTP, and good agreement was obtained between the measured and modeled values. These findings indicate that the levels of certain SMCs discharged into the atmospheric and aquatic environments were substantial, potentially resulting in exposure to both humans and wildlife.

Prevalence of microplastics and fate in wastewater treatment plants: a review

Prevalence of microplastics and fate in wastewater treatment plants: a review

Pharmaceutical active compounds in sewage sludge: Degradation improvement and conversion into an organic amendment by bioaugmentation-composting processes

Around 143,000 chemicals find their fate in wastewater treatment plants in the European Union. Low efficiency on their removal at lab-based studies and even poorer performance at large scale experiments have been reported. Here, a coupled biological technology (bioaugmentation and composting) is proposed and proved for pharmaceutical active compounds degradation and toxicity reduction. The optimization was conducted through in situ inoculation of Penicillium oxalicum XD 3.1 and an enriched consortium (obtained from non-digested sewage sludge), into pilot scale piles of sewage sludge under real conditions. This bioaugmentation-composting system allowed a better performance of micropollutants degradation (21 % from the total pharmaceuticals detected at the beginning of the experiment) than a traditional composting process. Particularly, inoculation with P. oxalicum allowed the degradation of some recalcitrant compounds like carbamazepine, cotinine and methadone, and also produced better stabilization features in the mature compost (significant passivation of copper and zinc, higher macronutrients value, adequate physicochemical conditions for soil direct application and less toxic effect on germination) compared to the control and the enriched culture. These findings provide a feasible, alternative strategy to obtain a safer mature compost and a better removal of micropollutants performance at large scale.

Adsorption–desorption behavior of malachite green by potassium permanganate pre-oxidation polyvinyl chloride microplastics

Microplastics (MPs) and the typical hydrophilic organic pollutant Malachite green (MG) are frequently detected in sewage treatment plants. Potassium permanganate (KMnO4) pre-oxidation is an economical and effective technology in wastewater treatment. It is important to study the surface physicochemical characteristics of MPs and understand their fate in wastewater treatment plants after pre-oxidation. In this study, Polyvinyl chloride (PVC) MPs were treated by single and composite KMnO4 pre-oxidation with different pH values. After the pre-oxidation treatment, the appearance of OMn spectra and surface nanoparticles indicated the oxides (MnO2) were produced on the MPs surface. Moreover, the adhesion of MnO2 is helpful to improve the hydrophilicity and adsorption capacity of MG. The adsorption capacity of pristine PVC for MG was 2.6 mg/g. But the adsorption capacity increased to 7.0 mg/g for single oxidation and 140.7 mg/g for composite oxidation, respectively. The desorption experiment results indicate the pre-oxidation process could reduce the release efficiency of MG from the PVC MPs due to the better binding of surface MnO2 nanoparticles to MG. However, the total desorption capacity is still high. which illustrates that there is a high potential risk of MG which can transfer from the surface of the PVC MPs to the gastrointestinal fluids.

Polybrominated diphenyl ethers (PBDEs) in Indian wastewater treatment plant: Occurrence, mass flow and removal.

Polybrominated diphenyl ethers (PBDEs) are categorized as a group of brominated flame retardants that cause hazardous health impacts but are still being used consistently worldwide. The studies on their occurrence and fate in wastewater treatment plants are scarce, and considering the Indian scenario, no study has been reported till date in this context. Therefore, in the present study, PBDE congeners of primary concern were investigated first time to assess the existence, dissemination and fate of PBDEs in the municipal wastewater treatment plant (MWTP) located in Nagpur city, Maharashtra, India. BDE 209 and 47 were detected as the predominant PBDE contaminants in all the analysed samples. The concentration of PBDEs was primarily found in the particulate phase of wastewater. According to mass loading analysis, 1297mg/day concentration of PBDEs is disposed of at landfill sites in the form of sludge, while 77.46mg/day is released via final effluent. The present investigation is the first of its kind of study conducted to evaluate the PBDE contamination in Indian MWTP, which reveals the presence of high PBDE concentration in Indian municipal sewage. The findings of the current study exhibit the need for appropriate action toward the sound surveillance of PBDEs in the Indian context.

Molecular insight into the variation of dissolved organic phosphorus in a wastewater treatment plant

To date, eutrophication becomes a great concern of vulnerable aquatic systems. Dissolved organic phosphorus (DOP) discharged from wastewater treatment plant (WWTP) holds a large source of phosphorus in receiving water. However, due to the complexity of DOP, their variation and fate in WWTP remain unknown at the molecular level, and are always overlooked. Here, the variation of DOP in a WWTP was uncovered via Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). Results show that 95% of DOP in the influent could be removed by the secondary biological treatment processes. The removed DOP species were mainly lipids with the molecular characteristics of low oxygen content, low unsaturation and low aromaticity. Meanwhile, during biological treatments, some new DOP species, especially lignin/carboxylic rich alicyclic molecules (CRAM) that possessed high oxygen content, high unsaturation and high aromaticity, were produced and released into the secondary effluent. In the subsequent tertiary treatment, coagulation by aluminum salt tended to remove high molecular weight and high oxygen content DOP species in the secondary effluent, which was complementary to the biological treatment. However, the sand filter usually retained microorganisms, which would result in the generation of new DOP species in this process. During the final ultraviolet disinfection process, DOP was effectively mineralized to phosphate, especially the species with high molecular weight and highly unsaturated aromatic DOP species (e.g., lignin/CRAM and tannin), which had higher UV absorbance. The revealed variation of DOP in WWTP is beneficial to optimize the treatment processes to enhance the removal of DOP.

SARS-CoV-2 from faeces to wastewater treatment: What do we know? A review

SARS-CoV-2, the virus that causes COVID-19, has been found in the faeces of infected patients in numerous studies. Stool may remain positive for SARS-CoV-2, even when the respiratory tract becomes negative, and the interaction with the gastrointestinal tract poses a series of questions about wastewater and its treatments. This review aims to understand the viral load of SARS-CoV-2 in faeces and sewage and its fate in wastewater treatment plants (WWTPs).The viral load in the faeces of persons testing positive for SARS-CoV-2 was estimated at between 5·103 to 107.6 copies/mL, depending on the infection course. In the sewerage, faeces undergo dilution and viral load decreases considerably in the wastewater entering a WWTP with a range from 2 copies/100 mL to 3·103 copies/mL, depending on the level of the epidemic. Monitoring of SARS-CoV-2 in sewage, although no evidence of COVID-19 transmission has been found via this route, could be advantageously exploited as an early warning of outbreaks. Preliminary studies on WBE seem promising; but high uncertainty of viral loads in wastewater and faeces remains, and further research is needed.The detection of SARS-CoV-2 in sewage, based on RNA sequences and RT-PCR, requires a shared approach on sample pre-treatment and on-site collection to ensure comparable results. The finding of viral RNA in stools does not imply that the virus is viable and infectious. Viability of CoVs such as SARS-CoV-2 decreases in wastewater - due to temperature, pH, solids, micropollutants - but high inactivation in WWTPs can be obtained only by using disinfection (free chlorine, UVC light). A reduction in the quantity of disinfectants can be obtained by implementing Membrane-Bioreactors with ultrafiltration to separate SARS-CoV-2 virions with a size of 60–140 nm. In sludge treatment, thermophilic digestion is effective, based on the general consensus that CoVs are highly sensitive to increased temperatures.

Vomiting symptom of acute gastroenteritis estimated from epidemiological data can help predict river contamination by human pathogenic enteric viruses

Contamination of fresh water bodies by human enteric viruses from wastewater discharge is a well-established phenomenon. Here we propose a model of viral contamination of rivers based on acute gastroenteritis epidemiology and assess how well it can simulate in situ experimental monitoring. Noroviruses, rotaviruses, enteroviruses, adenoviruses and hepatitis A viruses were quantified by molecular methods after water concentration. Water flows were obtained from the Hydro databank and wastewater treatment plant (WWTP) data. Acute gastroenteritis cases based on medical prescriptions were recorded by the French public health agency. We estimated the total number of daily viral acute gastroenteritis cases and modeled virus shedding and fate in WWTPs and rivers. Simulated virus concentrations were compared to the weighted sum of measured concentrations. Seasonal variations in viral acute gastroenteritis were predicted from vomiting occurrence. All viruses except hepatitis A virus were widely detected in wastewaters and river, in concentrations reaching 10+6 genome copies·L−1 for adenoviruses in the Artière River. We were able to predict virus load in raw wastewater and in the Artière River. Estimated weighting coefficients showed the high impact of noroviruses GII. This model can thus serve to compare water treatment, discharge and reuse scenarios.

Experimental assessment and validation of quantification methods for cellulose content in municipal wastewater and sludge.

Cellulose, mostly in the form of toilet paper, forms a major component of the particulates in raw municipal wastewater, which could lead to significant consequences due to the potential accumulation of cellulosic fibers and slow biodegradability. Despite the sparse reports on cellulose content and degradation in wastewater and sludge, an accurate and validated method for its quantification in such matrices does not exist. In this paper, four different methods were compared including dilute acid hydrolysis, concentrated acid hydrolysis, enzymatic hydrolysis, and the Schweitzer reagent method. The Schweitzer reagent method, applied to municipal wastewater and sludge, was found to be a very robust and reliable quantification method in light of its reproducibility, accuracy, and ideal (100%) recovery. The determination of cellulose content is critical to understand its fate in wastewater treatment plants as well as improve sludge management and enhance resource recovery.

Steroid hormonal bioactivities, culprit natural and synthetic hormones and other emerging contaminants in waste water measured using bioassays and UPLC-tQ-MS

Emission of compounds with biological activities from waste water treatment plant (WWTP) effluents into surface waters is a topic of concern for ecology and drinking water quality. We investigated the occurrence of hormone-like activities in waste water sample extracts from four Dutch WWTPs and pursued to identify compounds responsible for them. To this aim, in vitro reporter gene bioassays for androgenic, anti-androgenic, estrogenic, glucocorticoid and progestogenic activity and a UPLC-tQ-MS target analysis method for 25 steroid hormones used in high volumes in pharmacy were applied. Principal component analysis of the data was performed to further characterize the detected activities and compounds. All five types of activities tested were observed in the WWTP samples. Androgenic and estrogenic activities were almost completely removed during WW treatment, anti-androgenic activity was only found in treated WW. Glucocorticoid and progestogenic activities persisted throughout the treatment. The androgenic activity in both influent could predominantly be attributed to the presence of androstenedione and testosterone. Anti-androgenic activity was explained by the presence of cyproterone acetate. The glucocorticoid activity in influent was fully explained by prednicarbate, triamcinolone acetonide, dexamethasone and amcinonide. In effluent however, detected hormones could only explain 10–32% of the activity, indicating the presence of unknown glucocorticoids or their metabolites in effluent. Progesterone and levonorgestrel could explain the observed progestogenic activity. The principle component analysis confirmed the way in which hormones fit in the spectrum of other emerging contaminants concerning occurrence and fate in WWTPs.

Dynamic modelling of solids in a full-scale activated sludge plant preceded by CEPT as a preliminary step for micropollutant removal modelling.

The presence of micropollutants in the environment has triggered research on quantifying and predicting their fate in wastewater treatment plants (WWTPs). Since the removal of micropollutants is highly related to conventional pollutant removal and affected by hydraulics, aeration, biomass composition and solids concentration, the fate of these conventional pollutants and characteristics must be well predicted before tackling models to predict the fate of micropollutants. In light of this, the current paper presents the dynamic modelling of conventional pollutants undergoing activated sludge treatment using a limited set of additional daily composite data besides the routine data collected at a WWTP over oneyear. Results showed that as a basis for modelling, the removal of micropollutants, the Bürger-Diehl settler model was found to capture the actual effluent total suspended solids (TSS) concentrations more efficiently than the Takács model by explicitly modelling the overflow boundary. Results also demonstrated that particular attention must be given to characterizing incoming TSS to obtain a representative solids balance in the presence of a chemically enhanced primary treatment, which is key to predict the fate of micropollutants.

Approaching the binding between Cu(II) and aerobic granules by a modified titration and µ-XRF

Interactions between metals and activated sludge can substantially affect the fate and transport of heavy metals in wastewater treatment plants. Therefore, it is important to develop a simple, fast and efficient method to elucidate the interaction. In this study, a modified titration method with a dynamic mode was developed to investigate the binding of Cu(II), a typical heavy metal, onto aerobic granules. The titration results indicated that pH and ionic strength both had a positive effect on the biosorption capacity of the granular sludge. The µ-XRF results demonstrated that the distribution of metals on the granular surface was heterogeneous, and Cu showed strong correlations and had the same “hot spots” positions with other metal ions (e.g., Ca, Mg, Fe etc.). Ion exchange and complexing were the main mechanisms for the biosorption of Cu(II) by aerobic granules. These results would be beneficial for better understanding of Cu(II) migration and its fate in wastewater treatment plants.

A review of the fate of micropollutants in wastewater treatment plants

Municipal wastewaters are contaminated by a wide range of chemicals, from surfactants to heavy metals, including pharmaceutical residues, personal care products, various household chemicals, and biocides/pesticides. Their release into the environment, where they may generate adverse effects on aquatic organisms, depends on their fate in wastewater treatment plants (WWTPs). The sources, the typical concentrations and the fate of more than 160 micropollutants of various classes in conventional WWTPs, were investigated in order to estimate surface water contamination, risks for aquatic organisms, and to propose means to reduce their release into the environment. Relatively hydrophobic pollutants such as heavy metals, persistent organic pollutants (POPs), brominated flame retardants, and several personal care products (PCPs), as well as easily biodegradable pollutants such as surfactants, plastic additives, hormones, several PCPs, some pharmaceuticals, and household chemicals, are usually well removed (&gt;70%) in WWTPs, either by sorption onto sewage sludge or by biodegradation. Good removal efficiencies, however, do not mean that the effluent concentrations will not potentially affect aquatic life, as some of these compounds are toxic at very low concentrations. More hydrophilic and poorly‐to‐moderately biodegradable pollutants such as several pharmaceuticals, pesticides, and household chemicals (corrosion inhibitors, sweeteners, chelating agents, phosphorus flame retardants) are only poorly removed during treatments. To decrease their discharge into surface waters, source control combined to advanced treatments such as ozonation and adsorption onto activated carbon are necessary.This article is categorized under: Engineering Water &gt; Sustainable Engineering of Water Engineering Water &gt; Water, Health, and Sanitation Science of Water &gt; Water Quality

Simultaneous detection of endocrine disrupting chemicals including conjugates in municipal wastewater and sludge with enhanced sample pretreatment and UPLC-MS/MS.

The co-existence of free and conjugated estrogens and the interference from complex matrices often lead to largely variable detected concentrations and sometimes even negative removal efficiencies of typical endocrine disrupting chemicals (EDCs) in wastewater treatment plants (WWTPs). In this study, a highly selective and sensitive method was developed for simultaneous extraction, elution, and detection of 12 EDCs (i.e., 4 free estrogens, 6 conjugated estrogens, and 2 phenolic compounds) in municipal wastewater and sludge. Sample pretreatment and ultra-performance liquid chromatography-tandem mass spectrometry detection were optimized to improve the detection selectivity and sensitivity. The results indicate that the additional purification process was highly effective in reducing the matrix interference, and the limits of quantification reached as low as 0.04-2.2 ng L(-1) in wastewater and 0.05-4.9 ng g(-1) in sludge for all target EDCs. The developed method was successfully applied to explore the behavior of target EDCs in a local WWTP. The conjugates occupied a considerable portion (4.3-76.9% in molar ratio) of each related estrogen in the influent. Most of the target EDCs could not be completely removed in WWTPs, thus posing a potential threat to aquatic ecosystems.

Occurrence of eight household micropollutants in urban wastewater and their fate in a wastewater treatment plant. Statistical evaluation

The occurrence in urban wastewater of eight micropollutants (erythromycin, ibuprofen, 4-nonylphenol (4-NP), ofloxacin, sucralose, triclosan, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)) originating from household activities and their fate in a biological wastewater treatment plant (WWTP) were investigated. Their concentrations were assessed in the liquid and solid phases (sewage particulate matter and wasted activated sludge (WAS)) by liquid chromatography–tandem mass spectrometry.The analysis of sewage from two different urban catchments connected to the WWTP showed a specific use of ofloxacin in the mixed catchment due to the presence of a hospital, and higher concentrations of sucralose in the residential area.The WWTP process removed over 90% of ibuprofen and triclosan from wastewater, while only 25% of ofloxacin was eliminated. Erythromycin, sucralose and PFOA were not removed from wastewater, the influent and effluent concentrations remaining at about 0.7μg/L, 3μg/L and 10ng/L respectively. The behavior of PFOS and 4-nonylphenol was singular, as concentrations were higher at the WWTP outlet than at its inlet. This was probably related to the degradation of some of their precursors (such as alkylphenol ethoxylates and polyfluorinated compounds resulting in 4-NP and PFOS, respectively) during biological treatment.4-NP, ofloxacin, triclosan and perfluorinated compounds were found adsorbed on WAS (from 5ng/kg for PFOA to 1.0mg/kg for triclosan).The statistical methods (principal component analysis and multiple linear regressions) were applied to examine relationships among the concentrations of micropollutants and macropollutants (COD, ammonium, turbidity) entering and leaving the WWTP. A strong relationship with ammonium indicated that some micropollutants enter wastewater via human urine. A statistical analysis of WWTP operation gave a model for estimating micropollutant output from the WWTP based on a measurement of macropollution parameters.

Occurrence and removal of benzotriazole ultraviolet stabilizers in a wastewater treatment plant in China.

Benzotriazole ultraviolet stabilizers (BZT-UVs) have previously been found in sludge from wastewater treatment plants (WWTPs), which might be potential sources of BZT-UVs to the surrounding environment. In this work, the occurrence and fate of seven emerging 2-hydroxyphenyl substituted BZT-UVs were investigated in a Chinese WWTP. This group of hydrophobic BZT-UVs possess log Kow values ranging from 4.31 to 7.67 which could be associated with their fate in WWTPs. Field samples including 24 h flow composites of influent, effluent and grab sludge samples from different treatment processes were collected and analyzed. Concentrations of BZT-UVs dissolved in aqueous-phases were in the range of 4.88±1.35 (UV-234) to 34.5±12.4 ng L(-1) (UV-P) in the primary influent, while only UV-P and UV-328 were detected in the final effluent at concentrations of 10.5±6.59 and 2.74±1.73 ng L(-1), respectively. Considering the amount of target BZT-UVs adsorbed to total suspended solids (TSS), the daily mass flux in the primary influent of the WWTP ranged from 22.3 g day(-1) (UV-P, 7.99%) to 74.0 g day(-1) (UV-234, 26.5%). Total removal efficiency of the integrated treatment process ranged from 89.7% for UV-P to 99.7% for UV-234 suggesting nearly complete removal. Organic solid sedimentation in primary and secondary clarifiers was the dominant elimination route for BZT-UV analogues, which constituted 96.3% of the total removal efficiency. Advanced treatment (using ultraviolet disinfection) in this plant might further contribute to the high removal efficiencies (ranging from 19.6% to 77.3%).

A review of the detection, fate and effects of engineered nanomaterials in wastewater treatment plants

Engineered nanomaterials (ENMs) are increasingly found in a wide range of products and processes, and consequently increasing loads are expected to reach wastewater treatment plants (WWTPs). To better assess the potential risk of ENMs to the environment via input through WWTP effluents, this review considers ENM detection methods, fate in WWTPs and potential effects on biota exposed to wastewater associated ENMs. Characterising ENMs in complex matrices presents many challenges, especially at low concentrations. Combining separation methods with techniques to assess particle size and chemical composition appears to be the most suitable approach for wastewater. In a range of studies, the majority of ENMs are removed from the aqueous phase by flocculation and sedimentation and remain in the sludge. However, ENM surface coating and the presence of organic matter and surfactants can alter removal. ENMs may affect biota via discharge of treated effluent to the aquatic environment or by application of sewage sludge to soil, although observed effects in laboratory studies only occurred at concentrations several orders of magnitude higher than the expected environmental levels. More realistic experimental designs with improved quantification of ENM properties under the selected test conditions are required to better understand the fate and effect of ENMs associated with WWTPs.

Fossil organic carbon in wastewater and its fate in treatment plants

This study reports the presence of fossil organic carbon in wastewater and its fate in wastewater treatment plants. The findings pinpoint the inaccuracy of current greenhouse gas accounting guidelines which defines all organic carbon in wastewater to be of biogenic origin. Stable and radiocarbon isotopes (13C and 14C) were measured throughout the process train in four municipal wastewater treatment plants equipped with secondary activated sludge treatment. Isotopic mass balance analyses indicate that 4–14% of influent total organic carbon (TOC) is of fossil origin with concentrations between 6 and 35 mg/L; 88–98% of this is removed from the wastewater. The TOC mass balance analysis suggests that 39–65% of the fossil organic carbon from the influent is incorporated into the activated sludge through adsorption or from cell assimilation while 29–50% is likely transformed to carbon dioxide (CO2) during secondary treatment. The fossil organic carbon fraction in the sludge undergoes further biodegradation during anaerobic digestion with a 12% decrease in mass. 1.4–6.3% of the influent TOC consists of both biogenic and fossil carbon is estimated to be emitted as fossil CO2 from activated sludge treatment alone. The results suggest that current greenhouse gas accounting guidelines, which assume that all CO2 emission from wastewater is biogenic may lead to underestimation of emissions.

Occurrence and removal efficiencies of benzotriazoles and benzothiazoles in a wastewater treatment plant in Greece

Despite the widespread use of benzotriazoles and benzothiazoles and the occurrence of these compounds in wastewater treatment plants (WWTPs), no earlier study has comprehensively examined their fate in WWTPs. In this study, an integrated liquid chromatography–tandem mass spectrometry (LC–ESI(+)MS/MS) method was developed and validated for simultaneous determination of four benzotriazoles and four benzothiazoles in dissolved and particulate phases of wastewater (raw and treated), and in dewatered sewage sludge. The target benzotriazoles (BTRs) were 1H-benzotriazole, 1-hydroxy-benzotriazole, tolyltriazole, and xylyltriazole (or 5,6-dimethyl-1H-benzotriazole), and the target benzothiazoles (BTHs) were benzothiazole, 2-hydroxy-benzothiazole, 2-methylthio-benzothiazole, and 2-amino-benzothiazole. The limits of detection ranged from 0.08 (2-methylthio-benzothiazole) to 17ng/L (benzothiazole) for dissolved phase samples, and from 0.04 (2-methylthio-benzothiazole) to 13ng/g dry weight (dw) (benzothiazole) for particular matter and sludge samples. The method was applied in the analysis of wastewater and sludge samples from the WWTP in Athens, Greece. All target chemicals were detected in wastewater samples, and in some cases the concentrations were significant, on the order of a few μg/L. In sludge samples, benzothiazole and tolyltriazole were present at the highest concentrations (174 and 116ng/g dw, respectively). For benzotriazole and tolyltriazole, the removal efficiency was below 68%, and for benzothiazoles, the removal efficiency was greater than 64% in the activated sludge treatment process. Both BTRs and BTHs showed low solid–liquid distribution coefficients.