Contamination profiles and mass loadings of macrolide antibiotics and illicit drugs from a small urban wastewater treatment plant

Global occurrence, distribution, and ecological risk assessment of psychopharmaceuticals and illicit drugs in surface water environment: A meta-analysis

Psychopharmaceuticals and illicit drugs (PIDs) in aquatic environments can negatively impact ecosystem and human health. However, data on the sources, distribution, drivers, and risks of PIDs in global surface waters are limited. We compiled a dataset of 331 records spanning 23 PIDs in surface waters and sediments across 100 countries by conducting a systematic review and meta-analysis of 108 studies published between 2005 and 2022. Most PIDs were sewage-derived, as wastewater treatment rarely achieved complete removal. The highest total PID levels were in Ethiopia, Australia, and Armenia, with many highly contaminated samples from low- and middle-income countries with minimal prior monitoring. Socioeconomic factors (population, GDP) and environmental variables (water stress) influenced the distribution of PIDs. 3,4-Methylenedioxy amphetamine hydrochloride (MDA), Δ9-tetrahydrocannabinol (THC), and 11- Δ9‑hydroxy-tetrahydrocannabinol (THCOH) posed the greatest ecological risks, especially in Oceania and North America. PIDs in surface waters present risks to aquatic organisms. Our findings elucidate the current status and future directions of PID research in surface waters and provide a scientific foundation for evaluating ecological risks and informing pollution control policies.

Occurrence and distribution of emerging contaminants in wastewater treatment plants: A globally review over the past two decades

Emerging contaminants are pervasive in aquatic environments globally, encompassing pharmaceuticals, personal care products, steroid hormones, phenols, biocides, disinfectants and various other compounds. Concentrations of these contaminants are detected ranging from ng/L to μg/L. Even at trace levels, these contaminants can pose significant risks to ecosystems and human health. This article systematically summarises and categorizes data on the concentrations of 54 common emerging contaminants found in the influent and effluent of wastewater treatment plants across various geographical regions: North America, Europe, Oceania, Africa, and Asia. It reviews the occurrence and distribution of these contaminants, providing spatial and causal analyses based on data from these regions. Notably, the maximum concentrations of the pollutants observed vary significantly across different regions. The data from Africa, in particular, show more frequent detection of pharmaceutical maxima in wastewater treatment plants.

Evaluation of different functionalization methodologies for improving the removal of three target antibiotics from wastewater by a brewery waste activated carbon

This work aims to increase the efficiency of an activated carbon produced from brewery waste (AC) in the removal of three target antibiotics (sulfamethoxazole (SMX), trimethoprim (TMP), and ciprofloxacin (CIP)) by surface incorporation of oxygen, nitrogen or sulfur groups. AC was produced using spent brewery grains (the most abundant waste from the brewing industry) as raw material, K2CO3 as activating agent and microwave energy for pyrolysis. Then, seven different functionalized AC were prepared, characterized for their physicochemical properties, and tested for adsorption (%) of SMX, TMP and CIP from three different matrices (ultrapure water (pH ~5-6), buffered ultrapure water (pH 8), and effluent from a municipal wastewater treatment plant (WWTP effluent (pH 8)), under batch operation. Based on the obtained results, an oxygen functionalized AC was selected for further characterization and studies on the adsorption of the target antibiotics from the WWTP effluent. Kinetic results fitted the pseudo-second order model and the equilibrium isotherms were adequately described by the Langmuir model, reaching maximum adsorption capacities (qm) of 124 ± 1 μmol g-1, 315 ± 2 μmol g-1 and 201 ± 5 μmol g-1 for SMX, TMP and CIP, respectively. The selected functionalization increased qm by up to 58 % in comparison with the non-functionalized AC. The oxygen modified AC produced from a biomass waste remarkably improved its performance for an efficient application in the removal of antibiotics from wastewater.

Wastewater analysis for new psychoactive substances and cocaine and cannabis in a Northern Ireland Prison

The global drug market has been significantly impacted by the emergence of new psychoactive substances, leading to challenges in creating effective legislative controls and their use within recreational drug consumption. This research explores the prevalence of new psychoactive substances and non-medicinal and medicinal compounds within a prison facility in Northern Ireland. Wastewater samples collected from seven different manholes within the prison were analysed for 37 target compounds including the two most found illicit substances: benzoylecgonine (primary metabolite of cocaine) and cannabis. Using solid phase extraction with Oasis HLB and liquid-chromatography-time-of-flight-mass spectrometry across a gradient of 9 min, our analysis revealed that benzoylecgonine was the sole compound consistently present in all collected samples. Following this finding, our target compound selection was broadened to encompass medicinal compounds and employing qualitative analysis we re-evaluated the samples and discovered the presence of buprenorphine, benzodiazepines, methadone, morphine, and codeine. Finally, the study explored the application of enzymatic beta-glucuronidase hydrolysis to the samples. This final phase yielded significant findings, indicating the presence of codeine and nordiazepam at higher peak intensities, thereby shedding light on the potential implications of this enzymatic process.

A non-steroidal drug "diclofenac" is a substrate for electrochemical degradation process using graphite anode

In the electrochemical degradation process, the elimination of organic pollutants could be enhanced using supporting electrolyte and applied voltage. After degradation of the target organic compound, some by-products are formed. Chlorinated by-products are the main products formed in the presence of sodium chloride. In the present study, an electrochemical oxidation process has been applied to diclofenac (DCF) using graphite as an anode and sodium chloride (NaCl) as a supporting electrolyte. Monitoring the removal of the by-products and elucidating them were provided using HPLC and LC-TOF/MS, respectively. A high removal% of 94% DCF was observed under the conditions: 0.5 g NaCl, 5 V, and 80 min of electrolysis, while the removal% of chemical oxygen demand (COD) was 88% under the same conditions, but 360 min of electrolysis was required. The pseudo-first-order rate constant values were quite varied based on the selected experimental conditions; the rate constants were between 0.0062 and 0.054 min^-1, between 0.0024 and 0.0326 min^-1 under the influence of applied voltage and sodium chloride, respectively. The maximum values of energy consumption were 0.93 and 0.55 Wh/mg using 0.1 g NaCl and 7 V, respectively. Some chlorinated by-products, C₁₃H₁₈Cl₂NO₅, C₁₁H₁₀Cl₃NO₄, and C₁₃H₁₃Cl₅NO₅, were selected and elucidated using LC-TOF/MS.

Antibiotic Utilization during COVID-19: Are We Over-Prescribing?

The aims of this study were to analyze the utilization of antibiotics before (2018, 2019) and during the COVID-19 pandemic (2020) and the practice of prescribing antibiotics in outpatient settings for COVID-19 patients during the 2020-2022 period. The Anatomical Therapeutic Chemical Classification/Defined Daily Dose methodology was used for the analysis of outpatient antibiotic utilization in the Republic of Srpska. The data was expressed in DDD/1000 inhabitants/day. The rate of antibiotics prescribed to COVID-19 outpatients was analyzed using medical record data from 16,565 patients registered with B34.2, U07.1, and U07.2 World Health Organization International Classification of Diseases 10th revision codes. During 2020, outpatient antibiotic utilization increased by 53.80% compared to 2019. At least one antibiotic was prescribed for 91.04%, 83.05%, and 73.52% of COVID-19 outpatients during 2020, 2021, and the first half of 2022, respectively. On a monthly basis, at least one antibiotic was prescribed for more than 55% of COVID-19 outpatients. The three most commonly prescribed antibiotics were azithromycin, amoxicillin/clavulanic acid, and doxycycline. The trend of repurposing antibiotics for COVID-19 and other diseases treatment might be a double-edged sword. The long-term effect of this practice might be an increase in antimicrobial resistance and a loss of antibiotic effectiveness.

Erythromycin Scavenging from Aqueous Solutions by Zeolitic Materials Derived from Fly Ash

Erythromycin (EA) is an antibiotic whose concentration in water and wastewater has been reported to be above the standard levels. Since the methods used so far to remove EA from aquatic environments have not been effective, the development of effective methods for EA removal is necessary. In the present study, fly ash (FA)-based zeolite materials, which have not been investigated as EA sorbents before, were used. The possibilities of managing waste FA and using its transformation products for EA sorption were presented. The efficiency of EA removal from experimental solutions and real wastewater was evaluated. In addition, the sorbents' mineral composition, chemical composition, and physicochemical properties and the effects of adsorbent mass, contact time, initial EA concentration, and pH on EA removal were analyzed. The EA was removed within the first 2 min of the reaction with an efficiency of 99% from experimental solutions and 94% from real wastewater. The maximum adsorption capacities were 314.7 mg g^-1 for the fly ash-based synthetic zeolite (NaP1_FA) and 363.0 mg g^-1 for the carbon-zeolite composite (NaP1_C). A fivefold regeneration of the NaP1_FA and NaP1_C showed no significant loss of adsorption efficiency. These findings indicate that zeolitic materials effectively remove EA and can be further investigated for removing other pharmaceuticals from water and wastewater.

Wastewater pandemic preparedness: Toward an end-to-end pathogen monitoring program

Molecular analysis of public wastewater has great potential as a harbinger for community health and health threats. Long-used to monitor the presence of enteric viruses, in particular polio, recent successes of wastewater as a reliable lead indicator for trends in SARS-CoV-2 levels and hospital admissions has generated optimism and emerging evidence that similar science can be applied to other pathogens of pandemic potential (PPPs), especially respiratory viruses and their variants of concern (VOC). However, there are substantial challenges associated with implementation of this ideal, namely that multiple and distinct fields of inquiry must be bridged and coordinated. These include engineering, molecular sciences, temporal-geospatial analytics, epidemiology and medical, and governmental and public health messaging, all of which present their own caveats. Here, we outline a framework for an integrated, state-wide, end-to-end human pathogen monitoring program using wastewater to track viral PPPs.

Occurrence and distribution of azithromycin in wastewater treatment plants, seawater, and sediments of the northern part of the Persian Gulf around Bushehr port: A comparison with Pre-COVID 19 pandemic

One of the environmental effects of COVID 19 is the contamination of ecosystems with antibiotics due to their high consumption to treat this disease. Many years ago, the distribution of antibiotics including azithromycin (Azi) in wastewater treatment plants in Bushehr city, seawater, and sediment of the Persian Gulf has been investigated. As Azi has been prescribed to COVID 19 patients, contamination of the environment with this drug can also be assumed. Thus, we decided to examine this hypothesis by repeating our previous study during COVID 19 period. We collected wastewater samples from influent, effluent, and different units of three wastewater treatment plants (WWTPs) including one municipal WWTP (Plant A) and two hospital-WWTPs (Plant B and C). Seawater and adjusted sediments were gathered from 8 stations located in the Persian Gulf in two seasons to evaluate the special and temporal variation. The results showed a huge growth of Azi pollution in all studied matrixes. The mean Azi values in the influent of Plant A, B, and C were 145 ng/L, 110 ng/L, and 896 ng/L, which represented an 9, 6, and 48-time increase compared with those obtained in 2017 (before COVID 19). The Azi removal efficiency had a different behavior compared to before COVID 19. The mean concentration of Azi in seawater and sediment samples was 9 ng/L and 6 ng/g, which was 3 and 4-fold higher than the previous study. Opposed to our former study, the Azi amount in the aqueous phase was less subjected to temporal seasonal variations. Our observations indicated the wide distribution of Azi in the environment and a future threat of intense growth of antibiotic resistance in ecosystems.

Water reuse for aquaculture: Comparative removal efficacy and aquatic hazard reduction of pharmaceuticals by a pond treatment system during a one year study

Aquaculture is increasing at the global scale, and beneficial reuse of wastewater is becoming crucial in some regions. Here we selected a unique tertiary treatment system for study over a one-year period. This experimental ecosystem-based approach to effluent management included a treated wastewater pond (TWP), which receives 100% effluent from a wastewater treatment plant, and an aquaculture pond (AP) that receives treated water from the TWP for fish production. We examined the fate of a wide range of pharmaceutically active compounds (PhACs) in this TWP-AP system and a control pond fed by river water using traditional grab sampling and passive samplers. We then employed probabilistic approaches to examine exposure hazards. Telmisartan, carbamazepine, diclofenac and venlafaxine, exceeded ecotoxicological predicted no effect concentrations in influent wastewater to the TWP, but these water quality hazards were consistently reduced following treatment in the TWP-AP system. In addition, both grab and passive sampling approaches resulted in similar occurrence patterns of studied compounds, which highlights the potential of POCIS use for water monitoring. Based on the approach taken here, the TWP-AP system appears useful as a tertiary treatment step to reduce PhACs and decrease ecotoxicological and antibiotic resistance water quality hazards prior to beneficial reuse in aquaculture.

Degradation of high concentrations of azithromycin when present in a high organic content wastewater by using a continuously fed laboratory-scale UASB bioreactor

As the presence of emergent contaminants in wastewater, such as antibiotics, has become a threat for public health, the evaluation of strategies to treat them has been gaining importance. A critical example of this situation can be found in wastewaters coming from the pharmaceutical industry, where high concentrations of antibiotics are sometimes accompanied by high organic contents. Even the agroindustry can be affected by a similar problem when cattle infections are treated with antibiotics and part of the antibiotic-contaminated milk has to be wasted. With these situations in mind, in the present study we evaluated a progressive acclimation strategy for a granular sludge in a UASB reactor treating a high organic-content synthetic wastewater contaminated with azithromycin. In parallel, we tested a previously reported low-cost method for azithromycin determination by spectrophotometry, obtaining results comparable with liquid chromatography coupled to mass spectrometry. Although azithromycin has been reported as recalcitrant and resistant to biological degradation, the antibiotic was removed with efficiencies over 50% for wastewater with 10 mg L^-1 of azithromycin and a COD of more than 4000 mgO₂ L^-1. Furthermore, efficiencies over 40% were achieved for wastewater with higher azithromycin concentrations (80 mg L^-1) and a COD of 20,000 mgO₂ L^-1. A careful acclimation strategy permitted the partial removal of azithromycin from wastewater when treating concentrations comparable and higher than what would be expected for domestic and hospital wastewaters, even when its chemical oxygen demand is considerably higher than the average maximum of around 1000 mgO₂ L^-1.

First surveillance of SARS-CoV-2 and organic tracers in community wastewater during post lockdown in Chennai, South India: Methods, occurrence and concurrence

Surveillance of SARS-CoV-2 and organic tracers (OTs) were conducted in the community wastewater of Chennai city and the suburbs, South India, during partial and post lockdown phases (August-September 2020) as a response to the coronavirus disease 2019 (COVID-19) pandemic. Wastewater samples were collected from four sewage treatment plants (STPs), five sewage pumping stations (SPSs) and at different time intervals from a suburban hospital wastewater (HWW). Four different methods of wastewater concentrations viz., composite (COM), supernatant (SUP), sediment (SED), and syringe filtration (SYR) were subjected to quantitative real time-polymerase chain reaction (qRT-PCR). Unlike HWW, STP inlet, sludge and SPS samples were found with higher loading of SARS-CoV-2 by SED followed by SUP method. Given the higher levels of dissolved and suspended solids in STPs and SPSs over HWW, we suspect that this enveloped virus might exhibit the tendency of higher partitioning in solid phase. Cycle threshold (C_t) values were < 30 in 50% of the HWW samples indicating higher viral load from the COVID-19 infected patients. In the STP outlets, a strict decline of biochemical oxygen demand, >95% removal of caffeine, and absence of viral copies reflect the efficiency of the treatment plants in Chennai city. Among the detected OTs, a combination of maximum dynamic range and high concurrence percentage was observed for caffeine and N1 gene of SARS-CoV-2. Hence, we suggest that caffeine can be used as an indicator for the removal of SARS-CoV-2 by STPs. Our predicted estimated number of cases are in line with the available clinical data from the catchments. Densely distributed population of the Koyambedu catchment could be partly responsible for the high proportion of estimated infected individuals during the study period.

Preparation of DNA aptamer and development of lateral flow aptasensor combining recombinase polymerase amplification for detection of erythromycin

Erythromycin has polluted our aquatic environment for decades, leading to the risk of bacterial resistance and harmful effects on human beings, wildlife and ecosystem. There is an urgent demand of developing a portable tool capable of detecting erythromycin on site. In this study, ten aptamer candidates against erythromycin were prepared through Capture-SELEX (systematic evolution of ligands by exponential enrichment) process in 20 rounds. Aptamer candidate Ery_06 with the highest enrichment was chosen for further study, whose affinity was characterized by gold nanoparticles colorimetric assay, quartz crystal microbalance with dissipation and agarose chasing diffusion assay. It was determined by SYBR Green I fluorimetric assay that the characterized aptamer binds to erythromycin with high affinity (Kd: 20 ± 9 nM). Its specificity was also characterized by distinguishing erythromycin from different antibiotics tested. A novel lateral flow aptasensor was constructed by using the newly identified aptamer combined with recombinase polymerase amplification (RPA) and lateral flow strip (LFS). Aptamer acted as a sensing element anchoring on the surface of solid phase could be eluted by erythromycin. RPA functioned to amplify and convert the signal to be visible on LFS. The lateral flow was completed in 15 min, achieving a detection limit of 3 pM. The application feasibility of the aptasensor was proved by the detection of tap water samples spiked with erythromycin.

Current trends and advances in analytical techniques for the characterization and quantification of biologically recalcitrant organic species in sludge and wastewater: A review

The study of organic matter in wastewater is a major regulatory and environmental issue and requires new developments to identify non-biodegradable refractory compounds, produced mainly by thermal treatments. Recent advances linking physicochemical properties to spectroscopic analyzes (UV, Fluorescence, IR) have shown that the refractory property is favored by several physicochemical parameters: weight, hydrophobicity, aromaticity and chemical functions. Currently, the most effective developments for the quantification of refractory compounds are obtained with hyphenated methods, based on steric separation of the macromolecular species by steric exclusion chromatography (SEC)/PDA/Fluorescence systems. Hyphenated techniques using High Resolution Mass Spectrometry (HRMS), ultra-high-resolution mass spectrometry with Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and NMR have been developed to analyze macromolecules in wastewater with minor sample preparation procedures. A particular class has been identified, the melanoidins, generated by Maillard reactions between sugars, amino acids, peptides and proteins present in wastewater and sludge, but low molecular weight compounds formed as intermediates, such as ketones, aldehydes, pyrazines, pyridines or furans, are also recalcitrant and are complex to identify in the complex matrices. The lack of available standards for the study of these compounds requires the use of specific techniques and data processing. Advances in chemometrics are obtained in the development of molecular or physicochemical indices resulting from the data generated by the analytical detectors, such as aromaticity calculated by SUVA₂₅₄ and determined by UV, fluorescence, molar mass, H/C ratio or structural studies (measuring the amount of unsaturated carbon) given by hyphenated techniques with SEC. It is clear that nitrogen compounds are widely involved in refractoriness. New trends in nitrogen containing compounds characterization follow two axes: through SEC/PDA/Fluorescence and HRMS/NMR techniques with or without separation. Other techniques widely used in food or marine science are also being imported to this study, as it can be seen in the use of "omics" methods, high-performance thin layer chromatography (HPTLC) and chromatography at the critical condition, rounding out the important developments around SEC. While improving the performance of stationary phases is one of the challenges, it results in a fundamental understanding of the retention mechanisms that today provide us with more information on the structures identified. The main objective of this review is to present the spectroscopic and physicochemical techniques used to qualify and characterize refractoriness with a specific focus on chemometric approaches.

Paper-based nanosensors to evaluate community-wide illicit drug use for wastewater-based epidemiology

Wastewater-based epidemiology (WBE) is a powerful technique for monitoring illicit drugs of abuse in the community. Here, we report upon a surface-enhanced Raman spectroscopy (SERS) sensor for the sensitive and selective detection of methamphetamine based upon the assembly of noble metal core-shell nanoparticles on a bespoke glassy nanofibrous electrospun paper matrix. The hierarchical structure of the fibrous paper, modified with the synthesized Au@Ag core-shells (Au@Ag) gave strong SERS signalling, enabling us to evaluate the community-wide prevalence of methamphetamine in wastewater treatment plants within Beijing. We show that, when normalized for the daily flow of the wastewater treatment plants and for population density, higher mass loads of drugs are generally found in sewage influent from urban areas, implying greater local methamphetamine usage than that in less populated areas. The user-friendly and disposable paper sensors demonstrate the applicability of rapid on-site illicit drug detection, illustrating the application to wastewater-based epidemiology, which has the potential to inform government agencies regarding societal interventions.

Understanding the photophysics of stercobilin-Zn(II) and urobilin-Zn(II) complexes towards faecal pigment analysis

A detailed photophysical study of two faecal pigments (FPs), Urobilin (UB) and Stercobilin (SB), and their zinc complexes [FP-Zn(II)] was carried out. The enhancement of UB and SB fluorescence resulting from the formation of their Zn(II) complexes was attributed to the complexation-induced rigidity of the chromophoric units, and the corresponding decrease of nonradiative decay rate constants of the excited singlet states (k_nr). The effect of various physicochemical environments was also studied in detail in order to understand the fluorescence behaviour of the Zn(II) complexes. FP-Zn(II) complexes have a lower solubility in water that results in the formation of molecular aggregates. The aggregation-induced loss of fluorescence of FP-Zn(II) complexes could be overcome by using the appropriate mixture of ethanol and water (70:30). Molecular orbital calculations on the FP-Zn(II) complexes provided a good idea of the geometry of the complexes and helped rationalise the enhancement of fluorescence after complexation. This study could pave the way towards developing a convenient non-extraction aqueous phase analytical procedure for detection of FPs using Zn(II) complexation method.

Occurrence and fate of antibiotics, antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) in municipal wastewater treatment plant: An overview

The occurrence and fate of antibiotics and antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) in Municipal Wastewater Treatment Plants (WWTPs) worldwide were reviewed. The prevalence of antibiotics in WWTPs among different periods (1999-2009 and 2010-2019) and geographical areas (Europe, America, Asia and Africa) was summarized, analyzed and evaluated. The classes of macrolides (clarithromycin, erythromycin/erythromycin-H₂O, azithromycin, roxithromycin), sulfonamides (sulfamethoxazole), trimethoprim, quinolones (ofloxacin, ciprofloxacin, norfloxacin) and tetracyclines (tetracycline) were the antibiotics most frequently detected, while bla (bla_CTXM, bla_TEM), sul (sul1, sul2), tet (tetO, tetQ, tetW) and ermB genes were the ARGs commonly reported in WWTPs. There was a positive correlation between antibiotics and ARGs commonly detected in WWTPs, except for β-lactam antibiotics and bla genes. The genes bla were found frequently, despite β-lactam antibiotics were seldom detected owing to the hydrolysis. Most of antibiotics had lower levels in the period 2010-2019 in Asian countries than that in period 1999-2009 in North American and European countries. In the effluent of secondary treatment, the concentration of trimethoprim was the highest (138 ng/L in median) and the concentration of other antibiotics remained at lower than 80 ng/L, while the relative abundance of ARGs ranged 2.9-4.6 logs (copies/mL, in median). Future researches on the development of effective antibiotic removal technologies, such as advanced oxidation processes, are suggested to focus on antibiotics frequently detected and their corresponding ARGs in WWTPs.

A review of the toxicity in fish exposed to antibiotics

Antibiotics are widely used in the treatment of human and veterinary diseases and are being used worldwide in the agriculture industry to promote livestock growth. However, a variety of antibiotics that are found in aquatic environments are toxic to aquatic organisms. Antibiotics are not completely removed by wastewater treatment plants and are therefore released into aquatic environments, which raises concern about the destruction of the ecosystem owing to their non-target effects. Since antibiotics are designed to be persistent and work steadily in the body, their chronic toxicity effects have been studied in aquatic microorganisms. However, research on the toxicity of antibiotics in fish at the top of the aquatic food chain is relatively poor. This paper summarizes the current understanding of the reported toxicity studies with antibiotics in fish, including zebrafish, to date. Four antibiotic types; quinolones, sulfonamides, tetracyclines, and macrolides, which are thought to be genetically toxic to fish have been reported to bioaccumulate in fish tissues, as well as in aquatic environments such as rivers and surface water. The adverse effects of these antibiotics are known to cause damage to developmental, cardiovascular, and metabolic systems, as well as in altering anti-oxidant and immune responses, in fish. Therefore, there are serious concerns about the toxicity of antibiotics in fish and further research and strategies are needed to prevent them in different regions of the world.

Antibiotic and herbicide concentrations in household greywater reuse systems and pond water used for food crop irrigation: West Bank, Palestinian Territories

Greywater is increasingly treated and reused for agricultural irrigation in off-grid communities in the Middle East and other water scarce regions of the world. However, there is a dearth of data regarding levels of antibiotics and herbicides in off-grid greywater treatment systems. To address this knowledge gap, we evaluated levels of these contaminants in two types of greywater treatment systems on four farms in the West Bank, Palestinian Territories. Samples of household greywater (influent, n = 23), treated greywater effluent intended for agricultural irrigation (n = 23) and pumped groundwater held in irrigation water ponds (n = 12) were collected from October 2017 to June 2018. Samples were analyzed using high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) for the following antibiotics and herbicides: alachlor, ampicillin, atrazine, azithromycin, ciprofloxacin, erythromycin, linezolid, oxacillin, oxolinic acid, penicillin G, pipemidic acid, sulfamethoxazole, triclocarban, tetracycline, triflualin, and vancomycin. All tested antibiotics and herbicides were detected in greywater influent samples at concentrations ranging from 1.3 to 1592.9 ng/L and 3.1-22.4 ng/L, respectively. When comparing influent to effluent concentrations, removal was observed for azithromycin, alachlor, linezolid, oxacillin, penicillin G, pipemidic acid, sulfamethoxazole, triclocarban, and vancomycin. Removal was not observed for atrazine, ciprofloxacin, erythromycin, oxolinic acid, tetracycline, and trifluralin. Pond water also contained the majority of tested contaminants, but at generally lower concentrations. To our knowledge, this is the first description of an extensive array of antibiotics and herbicides detected in household greywater from off-grid treatment systems.

Variations in Illicit Compound Discharged from Treated Wastewater

The detection and monitoring of illicit drug concentrations in environmental waters is of increasing interest. This study aimed to determine if illicit and regulated compounds, their potential pre-cursors, and metabolites varied in amount discharged into the environment from treated wastewater at different facilities. Water samples were taken from discharge points of four different tertiary wastewater treatment plants discharging directly into the Hawkesbury-Nepean River (Australia) on two different occasions and analysed to determine the concentrations of compounds including: ephedrine, pseudoephedrine, amphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, methamphetamine, cocaine, and benzoylecgonine. Here, we show that detectable levels of illicit drug and metabolites are being emitted on a consistent basis after having persisted through the wastewater treatment process. The concentrations of methamphetamine are in excess of previously reported surface water concentrations. The estimated total load of compounds being discharged on a daily basis is greater than similar sized catchment areas. The results presented here are of concern from both an ecological and human health perspective.

Degradation of typical macrolide antibiotic roxithromycin by hydroxyl radical: kinetics, products, and toxicity assessment

The degradation of roxithromycin (ROX) by hydroxyl radical (·OH) generated by UV/H₂O₂ was systematically investigated in terms of degradation kinetics, effects of water chemistry parameters, oxidation products, as well as toxicity evaluation. The degradation of ROX by UV/H₂O₂ with varying light irradiation intensity, initial ROX concentration, and H₂O₂ concentration in pure water and wastewater all followed pseudo-first-order kinetics. The second-order rate constant for reaction between ROX and ·OH is 5.68 ± 0.34 × 10⁹/M/s. The degradation rate of ROX increased with the pH; for instance, the apparent degradation rates were 0.0162 and 0.0309/min for pH 4 and pH 9, respectively. The presence of natural organic matter (NOM) at its concentrations up to 10 mg C/L did not significantly affect the removal of ROX. NO₃^- and NO₂^- anions inhibited the degradation of ROX due to the consumption of ·OH in reactions with these ions. Fe³⁺, Cu²⁺, and Mg²⁺ cations inhibited the degradation of ROX, probably because of the formation of ROX-metal chelates. A total of ten degradation products were tentatively identified by HPLC/LTQ-Orbitrap XL MS, which mainly derived from the attack on the oxygen linking the lactone ring and the cladinose moiety, tertiary amine and oxime side chain moiety by ·OH. The toxicity evaluation revealed that UV/H₂O₂ treatment of ROX induced the toxicity to bioluminescent bacteria increased.

Performance of secondary wastewater treatment methods for the removal of contaminants of emerging concern implicated in crop uptake and antibiotic resistance spread: A review

Contaminants of emerging concern (CEC) discharged in effluents of wastewater treatment plants (WWTPs), not specifically designed for their removal, pose serious hazards to human health and ecosystems. Their impact is of particular relevance to wastewater disposal and re-use in agricultural settings due to CEC uptake and accumulation in food crops and consequent diffusion into the food-chain. This is the reason why the chemical CEC discussed in this review have been selected considering, besides recalcitrance, frequency of detection and entity of potential hazards, their relevance for crop uptake. Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been included as microbial CEC because of the potential of secondary wastewater treatment to offer conditions favourable to the survival and proliferation of ARB, and dissemination of ARGs. Given the adverse effects of chemical and microbial CEC, their removal is being considered as an additional design criterion, which highlights the necessity of upgrading conventional WWTPs with more effective technologies. In this review, the performance of currently applied biological treatment methods for secondary treatment is analysed. To this end, technological solutions including conventional activated sludge (CAS), membrane bioreactors (MBRs), moving bed biofilm reactors (MBBRs), and nature-based solutions such as constructed wetlands (CWs) are compared for the achievable removal efficiencies of the selected CEC and their potential of acting as reservoirs of ARB&ARGs. With the aim of giving a picture of real systems, this review focuses on data from full-scale and pilot-scale plants treating real urban wastewater. To achieve an integrated assessment, technologies are compared considering also other relevant evaluation parameters such as investment and management costs, complexity of layout and management, present scale of application and need of a post-treatment. Comparison results allow the definition of design and operation strategies for the implementation of CEC removal in WWTPs, when agricultural reuse of effluents is planned.

Fate of selected drugs in the wastewater treatment plants (WWTPs) for domestic sewage

The wide diffusion of Emerging Organic Micropollutants (EOMs) in the environment is receiving increasing attention due to their potential toxicological effects on living organisms. So far, the Wastewater Treatment Plants (WWTPs) have not been designed with the purpose to remove these contaminants; therefore, they can represent the major source of release into the environment both through the effluent and the wasted sludge. The fate of EOMs in the WWTPs is still not completely known; further investigations are therefore needed to assess if it is possible to exploit the existing treatment units to reduce EOM concentrations or which processes must be implemented to this purpose. Among the wide class of EOMs, the present study focused on the following drugs of abuse: amphetamine (AM), methamphetamine (MET), 11-nor-Δ9-THC-9carboxy (THC-COOH) and benzoylecgonine (BEG). Presence and removal efficiency of these drugs in the activated sludge tank of a WWTP for domestic sewage was investigated through analyses at both full-scale and laboratory scale. Determinations conducted in the full-scale WWTP highlighted that, among the searched drugs, AM was found to be the most abundant in the influent and effluent of the biological oxidation tank, while 11-nor-Δ9-THC-9carboxy was present at the lowest concentration. Some removal took place in the units prior to the oxidation tank, although the main reduction was observed to occur in the biological oxidation reactor. All the drugs showed a wide variability of the measured concentrations during the week and the day. Taking into account results from both full-scale observations and batch tests, removals in the biological reactor were found within the following ranges: 33-84% for AM, 33-97% for MET, 33-57% for BEG and 29-83% for THC-COOH. These removals were due to a combination of adsorption and biodegradation mainly, while volatilization did not play a significant role. Other processes, e.g. hydrolysis, were likely to occur.

Estimation of the consumption of illicit drugs during special events in two communities in Western Kentucky, USA using sewage epidemiology

Sewage epidemiology is a cost-effective, comprehensive, and non-invasive technique capable of determining semi-real-time community usage of drugs utilizing the concentration of drug residues in wastewater, wastewater inflow, and the population size served by a wastewater treatment plant. In this study, semi-real-time consumption rates of ten illicit drugs were determined using sewage epidemiology during special events including Independence Day, the 2017 solar eclipse, and the first week of an academic semester in the Midwestern United States. The average per-capita consumption rate of amphetamine, methamphetamine, cocaine, and THC were significantly different between two similar-sized communities during Independence Day observation week (p<0.046) and a typical week (p<0.001). Compared to a typical day, the consumption rate of amphetamine, methamphetamine, cocaine, morphine, and methadone was significantly higher on Independence Day (p<0.021) and during solar eclipse observation (p=0.020). The estimated percentage of the population that consumed cocaine in a community is similar to the conventionally estimated consumption of cocaine; however, the combined estimated population that consumed amphetamine and methamphetamine based on sewage epidemiology was ~2 to 4 fold higher than the conventional estimates. This study is the first to compare community use of drugs during special events in the USA using sewage epidemiology.

Contamination profiles, mass loadings, and sewage epidemiology of neuropsychiatric and illicit drugs in wastewater and river waters from a community in the Midwestern United States

In this study, residues of the neuropsychiatric and illicit drugs including stimulants, opioids, hallucinogens, antischizophrenics, sedatives, and antidepressants were determined in influent and effluent samples from a small wastewater treatment plant, a receiving creek, and river waters in the Four Rivers region of the Midwestern United States. Nineteen neuropsychiatric drugs, eight illicit drugs, and three metabolites of illicit drugs were detected and quantitated in the water samples using HPLC-MS/MS. Residual concentrations of the drugs varied from below the detection limit to sub-μg/L levels. The source of residual cocaine and benzoylecgonine in wastewater is primarily from human consumption of cocaine rather than direct disposal. Wastewater based epidemiology is utilized to estimate the community usage of drugs based on the concentration of drug residues in wastewater, wastewater inflow, and the population served by the centralized wastewater treatment plant. The per-capita consumption rate of methamphetamine (1740 mg/d/1000 people) and amphetamine (970 mg/d/1000 people) found in this study were the highest reported per-capita consumption rates in the USA. Antidepressant venlafaxine found to have the highest environmental emission from the WWTP (333 ± 160 mg/d/1000 people) followed by citalopram (132 ± 60.2 mg/d/1000 people), methamphetamine (111 ± 43.6 mg/d/1000 people), and hydrocodone (108 ± 90.1 mg/d/1000 people). Bee Creek, an immediate receiving water body, is found to be a source of several neuropsychiatric and illicit drugs including methamphetamine, methadone, alprazolam, oxazepam, temazepam, carbamazepine, venlafaxine, citalopram, sertraline, oxycodone, and hydrocodone (p < 0.036) in the Clarks River.

Occurrence of illicit drugs in water and wastewater and their removal during wastewater treatment

This review critically evaluates the types and concentrations of key illicit drugs (cocaine, amphetamines, cannabinoids, opioids and their metabolites) found in wastewater, surface water and drinking water sources worldwide and what is known on the effectiveness of wastewater treatment in removing such compounds. It is also important to amass information on the trends in specific drug use as well as the sources of such compounds that enter the environment and we review current international knowledge on this. There are regional differences in the types and quantities of illicit drug consumption and this is reflected in the quantities detected in water. Generally, the levels of illicit drugs in wastewater effluents are lower than in raw influent, indicating that the majority of compounds can be at least partially removed by conventional treatment processes such as activated sludge or trickling filters. However, the literature also indicates that it is too simplistic to assume non-detection equates to drug removal and/or mitigation of associated risks, as there is evidence that some compounds may avoid detection via inadequate sampling and/or analysis protocols, or through conversion to transformation products. Partitioning of drugs from the water to the solids fraction (sludge/biosolids) may also simply shift the potential risk burden to a different environmental compartment and the review found no information on drug stability and persistence in biosolids. Generally speaking, activated sludge-type processes appear to offer better removal efficacy across a range of substances, but the lack of detail in many studies makes it difficult to comment on the most effective process configurations and operations. There is also a paucity of information on the removal effectiveness of alternative treatment processes. Research is also required on natural removal processes in both water and sediments that may over time facilitate further removal of these compounds in receiving environments.

The removal of illicit drugs and morphine in two waste water treatment plants (WWTPs) under tropical conditions

The consumption of drugs of abuse has been recently investigated in Martinique using the back-calculation approach, also called the "sewage epidemiology" method. Results demonstrated a very high consumption considering the international data. Wastewater treatment plants (WWTPs) are located just behind the Martinique island shoreline, and effluents could impact the vulnerable corals and marine seagrass ecosystem. The present article aims to determine a WWTP's efficiency by comparing the influent and effluent of two WWTPs, with different residence times and biological treatments, located either outdoors or indoors. In parallel, a degradation study is conducted using spiked wastewater exposed to tropical and ambient temperatures. Results demonstrate the consistent efficiency of the two processes, especially for the outdoor WWTP which uses the activated sludge process. The positive effect of the tropical temperature is showed by the increase of cocaine degradation at 31 °C. Thus, low illicit drug residue concentrations in effluent would indicate that wastewater treatment is efficient and even enhanced under tropical context. This fact should be confirmed with others molecules. Furthermore, our results highlight the need for subsequent studies of sludge contamination because of their local recycling as compost.

Influence of Select Antibiotics on Vibrio fischeri and Desmodesmus subspicatus at μg L-1 Concentrations

The presence of pharmaceuticals in the aquatic environment is a contemporary reality and it is necessary to understand more about the effects of this presence on organisms. The purpose of this work was to assess the ecotoxicity of antibiotics metronidazole, nitrofurantoin, trimethoprim, and sulphamethoxazole (single and mixture) in Vibrio fischeri and Desmodesmus subspicatus at μg L^-1 concentrations. The evaluation of the toxic effect of the antibiotics on V. fischeri and D. subspicatus was based on fluorescence and bioluminescence tests, respectively, using nominal concentrations. When tested individually, the four antibiotics gave rise to a toxic effect on the evaluated organisms. Sulphamethoxazole caused a higher toxic effect on V. fischeri and D. subspicatus from 7.81 to 500 μg L^-1. Trimethoprim and sulphamethoxazole showed hormesis for the concentrations, which ranged from 7.81 to 62.5 μg L^-1. The mixture of antibiotics induced a toxic effect on the V. fischeri and D. subspicatus organisms (from 0.03 to 1 μg L^-1 concentrations) than when the antibiotics were evaluated individually. These results were significant since water quality problems are widespread all over the word, and emerging pollutants such as antibiotics have been detected in the aquatic environment in very low concentrations.

A new method for macrolide antibiotics determination in wastewater from three different wastewater treatment plants

An effective and practical method for the determination of macrolide antibiotics azithromycin, clarithromycin, erythromycin and roxithromycin in wastewater samples has been developed. The analytical method combines solid phase extraction followed by a chromatographic separation by hydrophilic interaction liquid chromatography (HILIC) coupled with an ion trap mass spectrometer utilizing the electrospray ionization technique. Detection of positively charged ions was performed in full scan mode from 500 to 900 m/z. The method detection limits and method quantification limits obtained were in the range of 2.03-7.59 ng L-1 and 6.08-23.84 ng L-1, respectively. Recoveries of solid phase extraction were obtained using SupelTM-Select HLB cartridges ranging from 85.76 % to 92.54 %. All target antibiotics were detected in 100 % of the collected raw influent samples with concentrations varying from 15 ng L-1 to 1849 ng L-1. Azithromycin, clarithromycin and erythromycin were also detected in 100 % of the treated water samples and roxithromycin was present in 96 % of the samples. The highest determined concentration in the treated water samples was 1404 ng L-1 of azithromycin. Based on the determined macrolide concentrations, removal efficiencies of individual wastewater treatment plants were calculated to range from 13 % to 100 %.

Antibiotic Concentrations Decrease during Wastewater Treatment but Persist at Low Levels in Reclaimed Water

Reclaimed water has emerged as a potential irrigation solution to freshwater shortages. However, limited data exist on the persistence of antibiotics in reclaimed water used for irrigation. Therefore, we examined the fate of nine commonly-used antibiotics (ampicillin, azithromycin, ciprofloxacin, linezolid, oxacillin, oxolinic acid, penicillin G, pipemidic acid, and tetracycline) in differentially treated wastewater and reclaimed water from two U.S. regions. We collected 72 samples from two Mid-Atlantic and two Midwest treatment plants, as well as one Mid-Atlantic spray irrigation site. Antibiotic concentrations were measured using liquid-chromatography- tandem mass spectrometry. Data were analyzed using Mann-Whitney-Wilcoxon tests and Kruskal Wallis tests. Overall, antibiotic concentrations in effluent samples were lower than that of influent samples. Mid-Atlantic plants had similar influent but lower effluent antibiotic concentrations compared to Midwest plants. Azithromycin was detected at the highest concentrations (of all antibiotics) in influent and effluent samples from both regions. For most antibiotics, transport from the treatment plant to the irrigation site resulted in no changes in antibiotic concentrations, and UV treatment at the irrigation site had no effect on antibiotic concentrations in reclaimed water. Our findings show that low-level antibiotic concentrations persist in reclaimed water used for irrigation; however, the public health implications are unclear at this time.

Occurrence and elimination of antibiotics in three sewage treatment plants with different treatment technologies in Urumqi and Shihezi, Xinjiang

Fourteen antibiotics, including five quinolones (QNs), five sulfonamides (SAs), and four tetracyclines (TCs), were selected to investigate their occurrence and elimination in three sewage treatment plants (STPs) by employing different treatment technologies in Urumqi (two STPs) and Shihezi (one STP), China. The STP in Shihezi was chosen as representative to investigate the distribution of antibiotics in a sludge-sewage system. Results showed that the concentrations of most detected antibiotics ranged from tens to hundreds of nanograms per liter in influent samples and under 100 ng L^-1 in effluent samples. QNs and TCs were dominant species with concentrations of 2.33 mg kg^-1 to 3.34 mg kg^-1 and 0.36 mg kg^-1 to 0.47 mg kg^-1 in sludge samples, respectively. The elimination rates of target antibiotics by various STPs ranged from 17% to 100%. The STP with anaerobic/anoxic/aerobic and membrane bio-reactor technology removed antibiotics more efficiently than those with anaerobic/anoxic/oxic and oxidation ditch technology. The elimination capacities of treatment units from the three STPs were also investigated. SAs were mainly degraded in biological treatment units; conversely, QNs and TCs were significantly eliminated in sedimentary treatment units. Ozonation effectively removed remaining antibiotics but not UV and chlorination disinfection in this study.

Drugs of abuse and their metabolites in the urban rivers of Beijing, China: Occurrence, distribution, and potential environmental risk

The occurrence and distribution of five drugs of abuse and their metabolites, namely, methamphetamine (METH), amphetamine (AMP), ketamine (KET), ephedrine (EPH), and hydroxylimine (HY), were investigated in the surface water in urban rivers in Beijing, China. A total of 117 surface water samples were collected from the seven rivers in the Beijing urban areas during four different seasons. Laboratory analyses revealed that EPH and METH were the most predominant drugs, with detection frequency ranging from 94% to 100% and from 65% to 100%, respectively. High levels of METH and KET were observed in the center part of the urban areas, which was likely associated with the drug abuse and the entertainment activities. Seasonal variation of the drug occurrence showed that the highest concentration of drugs of abuse was found during winter, which was likely due to the high consumption, low temperature, and low water flows during the cold weather. By contrast, the concentration and detection frequency of AMP and HY were relatively low. Risk assessment by the risk quotient method indicated that the five drugs of abuse and their metabolites were not likely to exert biological effects on the aquatic ecosystems at current levels in the surface water. However, the potential adverse effect of drugs of abuse and their metabolites on ecosystem functioning and human health should not be neglected.

Occurrence of new psychoactive substances in wastewater of major Chinese cities

New psychoactive substances have become increasingly popular across the globe in recent years, which may cause certain public health issues. In this work, sewage-based epidemiology was applied to examine the use of two synthetic cathinones, mephedrone and methylenedioxypyrovalerone (MDPV), and three piperazines, benzylpiperazine (BZP), trifluoromethylphenylpiperazine (TFMPP), and 1-(3-Chlorophenyl)piperazine (mCPP), across China. Influent wastewater samples were collected from 36 sewage treatment plants (STPs) in 18 major cities that cover all the geographic regions of the country. Effluent samples were also collected from selected STPs to determine removal rates. Mephedrone, TFMPP, and mCPP were below detection limits in all the wastewater samples collected, indicating negligible use of these substances in China. MDPV was detected in wastewater at 13 STPs. However, its loads were <1mg/1000inh/d at most of these STPs, indicating low use of this substance. BZP was detected at all the STPs examined, with loads typically falling within the range of 3-10mg/1000inh/d. No clear geographic pattern in BZP occurrence in wastewater was identified. Since BZP in wastewater may also come from its legal sources, whether widespread occurrence of BZP means widespread abuse is yet to be confirmed. Apparent removal of MDPV by wastewater treatment was low (<25%), whereas removal of BZP was nearly complete (typically>95%).

Linking drugs of abuse in wastewater to contamination of surface and drinking water

The concentrations of 17 drugs of abuse, including cocaine, several amphetamines, opioid drugs, and 2 metabolites--benzoylecgonine, a metabolite of cocaine, and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrolidine, a metabolite of methadone--were investigated in an urban watershed that is heavily impacted by discharges of municipal wastewater. The artificial sweetener sucralose was also monitored as a persistent tracer of contamination from municipal wastewater. Monitoring was conducted in a municipal wastewater treatment plant (WWTP) and at sites upstream and downstream of the WWTP discharge, as well as in a drinking water treatment plant (DWTP) located 19 km downstream of the WWTP discharge that withdraws raw water from the river. Drug concentrations were monitored with polar organic chemical integrative samplers deployed for 2 wk in the river and in the WWTP and DWTP. Several of the investigated compounds exhibited a decrease in concentration with distance downstream from the wastewater discharge into the river, but there was little attenuation of sucralose, cocaine, benzoylecgonine, morphine, acetylmorphine, acetylcodeine, and oxycodone. Heroin and methadone were not detected at any sample locations. Amphetamine, methamphetamine, 3,4-methylenedioxy-methamphetamine, and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrolidine were not detected in the samples collected at the drinking water intake. Many of the drugs of abuse were not removed effectively in the DWTP, including cocaine, benzoylecgonine, methylenedioxyamphetamine, ephedrine, and several prescription opioids, most probably because the DWTP was operating at or above its rated treatment capacity. These data indicate that there can be transport of drugs of abuse from wastewater sources into drinking water in urban watersheds.

The urgent need for risk assessment on the antibiotic resistance spread via sewage sludge land application

Sewage sludge is an ever-increasing by-product of the wastewater treatment process frequently used as a soil fertiliser. To control its quality and prevent any possible hazardous impact of fertilisation, some mandatory limits of heavy metal content have been established by the European Commission (Sewage Sludge Directive). However, since the implementation of the limits, new emerging contaminants have been reported worldwide. Regardless of the wastewater treatment process, sewage sludge contains antibiotics, antibiotic-resistant bacteria and antibiotic resistance genes, which can be released into the environment through its land application. Such a practice may even boost the dissemination and further development of antibiotic resistance phenomenon - already a global problem challenging modern medicine. Due to the growing pharmaceutical pollution in the environment, the time is ripe to assess the risk for the human and environmental health of sewage sludge land application in the context of antibiotic resistance spread. In this review we present the current knowledge in the field and we emphasise the necessity for more studies.

Fast-Target Analysis and Hourly Variation of 60 Pharmaceuticals in Wastewater Using UPLC-High Resolution Mass Spectrometry

A fast and sensitive monitoring method for trace pharmaceuticals in the environment is vital because many of these compounds are ubiquitous, persistent, and biologically active with recognized endocrine-disruption and pharmacological functions. A rapid and reliable ultra high-performance liquid chromatography combined with tandem mass spectrometry was developed in the present study to simultaneously identify, confirm, and quantify 60 target pharmaceuticals in wastewater samples. The method uses a sub-2 µm particle column for separating target compounds, which were subsequently quantified with the mass spectrometer. Using this high-throughput analysis method, a single injection could provide results within 5 min for the pharmaceuticals. All of the target compounds were analyzed by the multiple-reaction monitoring with 15-ms fast polarity switching. Both intraday and interday precision analyses indicate excellent coefficient of variability. To evaluate the performance of the method, a standard solution (100 and 1000 ng L(-1)) was spiked into complex wastewater samples. The tailing factor and peak width were also monitored and adjusted for optimizing peaks from the ultra high-performance liquid chromatograph. Of the target pharmaceuticals in wastewater of a sewage-treatment plant analyzed on an hourly basis, only 17 compounds were detected, and others were lower than the method detection limits. Acetaminophen, cimetidine, and iopromide were all detected at >1 μg L(-1), and their concentration profiles were similar to that of a nonsteroidal anti-inflammatory drug detected in wastewater. Other noticeable pharmaceuticals were sulfamethoxazole and trimethoprim. Sources of pharmaceuticals in wastewater are briefly discussed.

Representative input load of antibiotics to WWTPs: Predictive accuracy and determination of a required sampling quantity

Predicting the input loads of antibiotics to wastewater treatment plants (WWTP) using certain input data (e.g. prescriptions) is a reasonable method if no analytical data is available. Besides the spatiotemporal uncertainties of the projection itself, only a few studies exist to confirm the suitability of required excretion data from literature. Prescription data with a comparatively high resolution and a sampling campaign covering 15 months were used to answer the question of applicability of the prediction approach. As a result, macrolides, sulfamethoxazole and trimethoprim were almost fully recovered close to 100% of the expected input loads. Nearly all substances of the beta-lactam family exhibit high elimination rates during the wastewater transport in the sewer system with a low recovery rate at the WWTP. The measured input loads of cefuroxime, ciprofloxacin and levofloxacin fluctuated greatly through the year which was not obvious from relatively constant prescribed amounts. The latter substances are an example that available data are not per se sufficient to monitor the actual release into the environment. Furthermore, the extensive data pool of this study was used to calculate the necessary number of samples to determine a representative annual mean load to the WWTP. For antibiotics with low seasonality and low input scattering a minimum of about 10 samples is required. In the case of antibiotics exhibiting fluctuating input loads 30 to 40 evenly distributed samples are necessary for a representative input determination. As a high level estimate, a minimum number of 20-40 samples per year is proposed to reasonably estimate a representative annual input load of antibiotics and other micropollutants.

Photocatalytic degradation of methamphetamine by UV/TiO2 - kinetics, intermediates, and products

Methamphetamine (MAT) is a prescription drug and often a substance of abuse. It is found in WWTP influents and effluents as well as surface waters in many regions, elevating concerns about their potential impact. MAT is not effectively removed by conventional processes of domestic wastewater treatment plants (WWTPs). To contemplate advanced treatment, this study evaluates the feasibility of eliminating MAT by UV-illuminated TiO2, a potential retrofit to existing UV disinfection units. The degradation kinetics and mechanism of MAT by TiO2 under low-wattage UV illumination (9 W with maximum output at 365 nm) were investigated. Experimental parameters were varied including the TiO2 loading, MAT concentration, and pH. During treatment, MAT and its intermediates were tracked by HPLC-MS/MS, along with TOC and IC measurements to determine the mineralization extent. In contact with 0.1 g/L of TiO2 under illumination at pH 7, an entire spike amount of 100 μg/L of MAT was removed from deionized water after 3 min and 76 μg/L of MAT was removed from the secondary wastewater effluent after 30 min. The degradation of MAT followed an apparent first-order kinetics. Near complete mineralization of MAT from 10 mg/L was achieved in 180 min with 0.1 g/L of TiO2 at pH 5, by which the organic nitrogen was converted to NH4(+) and NO3(-). Based on identified intermediates, two degradation pathways were deduced that involved cleavage of the side chain as well as hydroxylation of the MAT compound. The photocatalytic UV/TiO2 process shows promise in arresting the release of MAT and its intermediate derivatives into the water environment.

Storage effect on the analysis of pharmaceuticals and personal care products in wastewater

In this study, the stability of 124 target analytes in influent and effluent wastewater samples during short-term (4°C) and long-term (-18°C) storage was assessed. The most common storage scenario was considered, in which samples were frozen immediately after sampling without any pre-treatment. During short-term storage more analytes remained stable (concentration during storage was in the range of 60-120% of the initial concentration) at 4°C than at -18°C. During long-term storage (-18°C), three types of behavior were observed: constant concentrations throughout the experimental period, decreasing concentrations with time, and loss of the compound from the sample after freezing. Differences between effluent and influent samples were observed for 50 out of 124 tested PPCPs. The amount of stable analytes decreased with time during long-term storage. 72% and 56% of the target compounds in the effluent and influent wastewater, respectively, remained stable during 60days of storage. The number of stable compounds decreased to 57 (46%) and 46 (37%) in the effluent and influent, respectively, over 120days. 15 Pharmaceuticals were lost after freezing/thawing cycle. The results stress the importance of storage factors during analysis of pharmaceuticals in wastewater. The stability of target compounds in the samples under the planned storage conditions should be checked before starting the experiment to obtain reliable data.

Drugs of abuse and benzodiazepines in the Madrid Region (Central Spain): seasonal variation in river waters, occurrence in tap water and potential environmental and human risk

This work analyzes the seasonal variation (winter and summer) of ten drugs of abuse, six metabolites and three benzodiazepines in surface waters from the Jarama and Manzanares Rivers in the Madrid Region, the most densely populated area in Spain. The occurrence of these compounds in tap water in this region is also investigated and a preliminary human health risk characterization performed for those substances found in tap water. Finally, a screening level risk assessment that combines the measured environmental concentrations (MECs) with dose-response data to estimate Hazard Quotients (HQs) for the compounds studied is also presented. The results of this study show the presence of fourteen out of the nineteen compounds analyzed in winter and twelve of them in summer. The most ubiquitous compounds, with a frequency of detection of 100% in both seasons, were the cocaine metabolite benzoylecgonine (BE), the amphetamine-type stimulant (ATS) ephedrine (EPH), the opioid methadone (METH), the METH metabolite 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and the three benzodiazepines investigated, namely alprazolam (ALP), diazepam (DIA) and lorazepam (LOR). The highest concentrations observed corresponded to EPH (1020ngL(-1) in winter and 250ngL(-1) in summer). The only compounds not detected in both seasons were heroin (HER) and its metabolite 6-acetylmorphine (6ACM), lysergic acid diethylamide (LSD) and its metabolite 2-oxo-3-hydroxy-LSD (O-H-LSD), and Δ(9)-tetrahydrocannabinol (THC). In terms of overall concentration, all sampling points presented higher concentrations in winter than in summer. Statistical analyses performed to gather evidence concerning occasional seasonal differences in the concentrations of individual substances between summer and winter showed statistically significantly higher concentrations (p<0.05) of BE, EPH and the opioid morphine (MOR) in winter than in summer. Two out of the nineteen compounds studied, namely cocaine (CO) and EPH, were detected in tap water from one sampling point at concentrations of 1.61 and 0.29ngL(-1), respectively. The preliminary human health risk characterization showed that no toxic effects could be expected at the detected concentration level in tap water. The screening level risk assessment showed that MOR, EDDP and the THC metabolite 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THC-COOH) were present in at least one of the sampling sites in a concentration leading to a Hazard Quotient (HQ) value between 1.0 and 10.0, thus indicating some possible adverse effects. The cumulative HQ or Toxic units (TUs) calculated for each of the groups studied showed that opioids and cannabinoids were present at concentrations high enough to potentially generate some adverse effects on at least one sampling point.

Estimation of amphetamine and methamphetamine uses in Beijing through sewage-based analysis

Sewage epidemiology has been proven as an effective approach to estimate the use of illicit drugs by a population. In this study, sewage analysis was applied to examine the patterns of amphetamine (AMP) and methamphetamine (METH) uses in the urban area of Beijing. Influent and effluent samples were collected from all the thirteen sewage treatment plants (STPs) in the urban area during two sampling campaigns. METH concentrations in influents were found to range from several tens to several hundred ng·L(-1), whereas AMP concentrations ranged from several to several tens ng·L(-1). The concentration ratios between AMP and METH in influents at most STPs were close to the rate of AMP excretion following METH ingestion, indicating that AMP in sewage in Beijing was predominately from the metabolism of METH. Much higher METH loads were observed in the center part of the urban area in Beijing, indicating a strong correlation between METH use and economic level and entertainment activities. Seasonal variation in METH loads was significant, with greater use in summer than in winter. Significant difference in METH loads between weekdays and weekend days were observed in winter but not in summer. No clear trend in diurnal variation of METH use was observed. Nearly complete removal of METH occurred at the STPS in Beijing. Apparent removal rates of AMP were lower than those of METH, likely due to degradation of METH into AMP during the wastewater treatment processes. In summary, this study represents the first application of sewage epidemiology to the entire urban population of a metropolitan in mainland China and provided an overview of METH and AMP uses in the city.

Impact of approach used to determine removal levels of drugs of abuse during wastewater treatment

In this study the levels of 19 drugs of abuse were estimated throughout a wastewater treatment plant using polar organic chemical integrative samplers (POCIS), 24h composite samples and grab samples. Overall removal efficiencies and removals in between each treatment unit were calculated using load data for each sampling technique as well as removals that take into account the hydraulic residence time distribution of the treatment plant (time-shifted mass balancing approach). Amphetamine-type stimulants, cocaine and its major metabolite, benzoylecgonine and opioid levels determined with 24h composite samples were generally comparable to those obtained with POCIS and grab samples. Negative mass balances resulting from the estimation of overall removal efficiencies by POCIS, day-to-day mass balancing of 24h composite and grab sample data did not occur when the hydraulic retention time (HRT) distributions of the plant were taken into account for calculation. Among the compounds investigated, cocaine exhibited the highest overall removal (90%) while codeine had the lowest with 13%, respectively. Sampling between the treatment units revealed that highest removal occurs during biological treatment as compared to primary or secondary clarification. Methylenedioxyamphetamine (MDA), fentanyl, dihydrocodeine and heroin were not detected in wastewater at any of the sampling locations at the treatment plant regardless of the sampling technique. The study demonstrates the benefits of applying the time-shifted mass balancing approach to the calculation of removals of drugs of abuse during wastewater treatment.