Occurrence and environmental implications of pharmaceuticals in Chinese municipal sewage sludge

Combining Nontargeted Analysis with Computer-Based Hazard Comparison Approaches to Support Prioritization of Unregulated Organic Contaminants in Biosolids

Biosolids are a byproduct of wastewater treatment that can be beneficially applied to agricultural land as a fertilizer. While U.S. regulations limit metals and pathogens in biosolids intended for land applications, no organic contaminants are currently regulated. Novel techniques can aid in detection, evaluation, and prioritization of biosolid-associated organic contaminants (BOCs). For example, nontargeted analysis (NTA) can detect a broad range of chemicals, producing data sets representing thousands of measured analytes that can be combined with computational toxicological tools to support human and ecological hazard assessment and prioritization. We combined NTA with a computer-based tool from the U.S. EPA, the Cheminformatics Hazard Comparison Module (HCM), to identify and prioritize BOCs present in U.S. and Canadian biosolids (n = 16). Four-hundred fifty-one features were detected in at least 80% of samples, with identities of 92 compounds confirmed or assigned probable structures. These compounds were primarily categorized as endogenous compounds, pharmaceuticals, industrial chemicals, and fragrances. Examples of top prioritized compounds were p-cresol and chlorophene, based on human health end points, and fludioxonil and triclocarban, based on ecological health end points. Combining NTA results with hazard comparison data allowed us to prioritize compounds to be included in future studies of the environmental fate and transport of BOCs.

The resistance of hydrogenotrophic methanogenic microorganisms to ofloxacin in sludge anaerobic digestion process

Ofloxacin (OFL) is a commonly used antibiotic that can enter wastewater treatment plants and be adsorbed by the sludge, resulting in a high OFL concentration in sludge and affecting the subsequent sludge anaerobic digestion process. However, the micro mechanisms involved in this process have not been thoroughly studied. Therefore, this study focuses on the effect of OFL on the sludge anaerobic digestion of sludge to provide such support. The experimental results showed that the maximal methane yield decreased from 277.7 to 164.7 mL/g VSS with the OFL concentration increased from 0 to 300 mg/L. Additionally, OFL hindered the intermediate biochemical processes of hydrolysis, acidogenesis, acetogenesis, and acetoclastic methanogenesis. However, it promoted hydrogenotrophic methanogenesis process, using H2 as substrate, with the concentration of 300 mg/L OFL was 5.54 fold methane production of that in the control. Further investigation revealed that the negative effect of OFL was likely due to the induction of reactive oxygen species, which led to a decrease in cell activity and interference with the activity of key enzymes. Microbiological analysis revealed that OFL reduced the relative abundance of hydrolysis and acidogenesis bacteria, and Methanosaeta archaea, while increasing the relative abundance of hydrogenotrophic methanogenesis microorganism from 36.54% to 51.48% as the OFL concentration increase from 0 to 300 mg/L.

Quantitative Non-targeted Screening to Profile Micropollutants in Sewage Sludge Used for Agricultural Field Amendments

A considerable number of micropollutants from human activities enter the wastewater network for removal. However, at the wastewater treatment plant (WWTP), some proportion of these compounds is retained in the sewage sludge (biosolids), and due to its high content of nutrients, sludge is widely applied as an agricultural fertilizer and becomes a means for the micropollutants to be introduced to the environment. Accordingly, a holistic semiquantitative nontarget screening was performed on sewage sludges from five different WWTPs using nanoflow liquid chromatography coupled to high-resolution Orbitrap mass spectrometry. Sixty-one inorganic elements were measured using inductively coupled plasma mass spectrometry. Across all sludges, the nontarget analysis workflow annotated >21,000 features with chemical structures, and after strict prioritization and filtering, 120 organic micropollutants with diverse chemical structures and applications such as pharmaceuticals, pesticides, flame retardants, and industrial and natural compounds were identified. None of the tested sludges were free from organic micropollutants. Pharmaceuticals contributed the largest share followed by pesticides and natural products. The predicted concentration of identified contaminants ranged between 0.2 and 10,881 ng/g dry matter. Through quantitative nontarget analysis, this study comprehensively demonstrated the occurrence of cocktails of micropollutants in sewage sludges.

Isavuconazole Induces Neurodevelopment Defects and Motor Behaviour Impairment in Zebrafish Larvae

Isavuconazole is a broad-spectrum antifungal drug used for the treatment of serious infections caused by invasive aspergillosis and mucormycosis in adults. With the continuous use of this drug, its safety and environmental impact have received increasing attention. However, information on the adverse effects of the drug is very limited. Fish is a particularly important model for assessing environmental risks. In this study, the aquatic vertebrate zebrafish was used as a model to study the toxic effects and mechanisms of isavuconazole. We exposed zebrafish embryos to 0.25, 0.5, and 1 mg/L of isavuconazole 6 h after fertilization. The results showed that at 72 hpf, isavuconazole exposure reduced heart rate, body length, and survival of zebrafish embryos compared to controls. Secondly, when isavuconazole reached a certain dose level (0.25 mg/L), it caused morphological changes in the Tg(elavl3:eGFP) transgenic fish line, with the head shrunk, the body bent, the fluorescence intensity becoming weaker, the abnormal motor behaviour, etc. At the same time, exposure of zebrafish embryos to isavuconazole downregulated acetylcholinesterase (AchE) and adenosine triphosphate (ATPase) activities but upregulated oxidative stress, thereby disrupting neural development and gene expression of neurotransmitter pathways. In addition, astaxanthin partially rescued the neurodevelopmental defects of zebrafish embryos by downregulating oxidative stress. Thus, our study suggests that isavuconazole exposure may induce neurodevelopment defects and behavioural disturbances in larval zebrafish.

Metagenomic insights into the toxicity of carbamazepine to functional microorganisms in sludge anaerobic digestion

Contaminants of emerging concern (CECs) contained in sludge, such as carbamazepine, may be toxic to microorganisms and affect the biogenesis of methane during anaerobic digestion. In this study, different scales of anaerobic digesters were constructed to investigate the inhibitory effect of carbamazepine. Results showed that carbamazepine reduced methane production by 11.3 % and 62.1 % at concentrations of 0.4 and 2 mg/g TS, respectively. Carbamazepine hindered the dissolution of organic matter and the degradation of protein. Carbamazepine inhibited some fermentative bacteria, especially uncultured Aminicenantales, whose abundance decreased by 9.5-93.4 % under carbamazepine stress. It is worth noting that most prior studies investigated the effects of CECs only based on well-known microorganisms, ignoring the metabolisms of uncultured microorganisms. Genome-predicted metabolic potential suggested that 54 uncultured metagenome-assembled genomes (MAGs) associated with acidogenesis or acetogenesis. Therein, uncultured Aminicenantales related MAGs were proved to be acetogenic fermenters, their significant reduction may be an important reason for the decrease of methane production under carbamazepine stress. The toxicity of carbamazepine to microorganisms was mainly related to the overproduction of reactive oxygen species. This study elucidates the inhibition mechanism of carbamazepine and emphasizes the indispensable role of uncultured microorganisms in anaerobic digestion.

Effect of dissolved ozone flotation thickening process on coliform bacteria and antibiotics simultaneous abatement: A pilot-scale study

This study focused on the removal of the total coliforms, fecal coliforms and four target antibiotics in the dissolved ozone flotation (DOF) thickening sludge process. Additionally, the thickened effluent chromaticity and its effect on thickened sludge hydrolysis process were investigated. Ozonation in the DOF process could inactivate coliforms by oxidizing cellular components and destroying genetic material, as well as altering the chemical structure of antibiotics, leading to the degradation of antibiotics. At an O3 dosage of 16 mg/g TS, the concentration of total coliforms and fecal coliforms decreased by 2.2 log and 2.4 log, corresponding to an overall removal rate of 99.4 % and 99.7 %, respectively. The total degradation rate of four target antibiotics (tetracycline (TC), oxytetracycline (OTC), norfloxacin (NOR), ofloxacin (OFL)) were 66.5 %, 68.8 %, 53.3 % and 57.5 %, respectively. The chromaticity removal rate of the thickened effluent reached 95 %. Analysis of fluorescence spectra indicated alterations in the fluorescence properties of dissolved organic matter, resulting in a decrease in fluorescence intensity by ozonation. The thickened sludge had higher hydrolysis rates, resulting in a greater production of volatile fatty acids (VFAs). This was mainly attributed to the increased amount of soluble protein and carbohydrate in the substrate after DOF treatment, which was more conducive for the rapid conversion of hydrolysis into VFAs during the initial stage. These results provided new ideas for upgrading and transforming the thickening process of wastewater treatment plants (WWTPs).

Environmental remediation of the norfloxacin in water by adsorption: Advances, current status and prospects

Antibiotics are considered as the new generation water pollutants as these disturb endocrine systems if water contaminated with antibiotics is consumed. Among many antibiotics norfloxacin is present in various natural water bodies globally. This antibiotic is considered an emerging pollutant due to its low degradation in aquatic animals. Besides, it has many side effects on human vital organs. Therefore, the present article discusses the recent advances in the removal of norfloxacin by adsorption. This article describes the presence of norfloxacin in natural water, consumption, toxicity, various adsorbents for norfloxacin removal, optimization factors for norfloxacin removal, kinetics, thermodynamics, modeling, adsorption mechanism and regeneration of the adsorbents. Adsorption takes place in a monolayer following the Langmuir model. The Pseudo-second order model represents the kinetic data. The adsorption capacity ranged from 0.924 to 1282 mg g-1. In this sense, the parameters such as the NFX concentration added to the adsorbent textural properties exerted a great influence. Besides, the fixed bed-based removal at a large scale is also included. In addition to this, the simulation studies were also discussed to describe the adsorption mechanism. Finally, the research challenges and future perspectives have also been highlighted. This article will be highly useful for academicians, researchers, industry persons, and government authorities for designing future advanced experiments.

Occurrence, distribution, and risk assessment of quinolone antibiotics in municipal sewage sludges throughout China

A nationwide study of the occurrence, distribution, potential drivers, and ecological risks of 24 quinolone antibiotics (QNs) in 74 Chinese sludge samples from 48 wastewater treatment plants (WWTPs) was conducted. In domestic sludge, the ∑QNs concentrations were <LOD to 21,925.10 ug/kg (mean: 4808.67 ug/kg), and ofloxacin had the highest concentration (<LOD-11,138.52 ug/kg), and detection frequency (98.48%). Of four generations QNs, the levels showed the following order: 2nd-generation QNs > 3rd-generation QNs > 4th-generation QNs > 1st-generation QNs. Meanwhile, abundant veterinary and human/veterinary quinolones (<LOD-2606.96 and <LOD-12,643.47 ug/kg, respectively) were detected in municipal sludge. Interestingly, the relatively low levels of veterinary quinolones (<LOD-299.21 ug/kg) were also found in industrial sludge (the relevant WWTPs receiving ≤ 10% domestic wastewater, without other direct entry of antibiotics). The correlation analysis demonstrated QNs contamination was negatively influenced by the air temperature of sampling days. The positive correlation between moxifloxacin contents and regional economy possibly suggested local regions with relatively high economic levels face a more difficult situation of QNs antibacterial activity. Environmental risk assessment indicated ofloxacin, ciprofloxacin, and moxifloxacin posed high ecological risks to the domestic sludge. This work delineates a valuable nationwide QNs contamination profile to support their safe use and control in China.

Risk control of antibiotics, antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) during sewage sludge treatment and disposal: A review

Sewage sludge is an important reservoir of antibiotics, antibiotic resistance genes (ARGs), and antibiotic resistant bacteria (ARB) in wastewater treatment plants (WWTPs), and the reclamation of sewage sludge potentially threats human health and environmental safety. Sludge treatment and disposal are expected to control these risks, and this review summarizes the fate and controlling efficiency of antibiotics, ARGs, and ARB in sludge involved in different processes, i.e., disintegration, anaerobic digestion, aerobic composting, drying, pyrolysis, constructed wetland, and land application. Additionally, the analysis and characterization methods of antibiotics, ARGs, and ARB in complicate sludge are reviewed, and the quantitative risk assessment approaches involved in land application are comprehensively discussed. This review benefits process optimization of sludge treatment and disposal, with regard to environmental risks control of antibiotics, ARGs, and ARB in sludge. Furthermore, current research limitations and gaps, e.g., the antibiotic resistance risk assessment in sludge-amended soil, are proposed to advance the future studies.

Simultaneous determination of fourteen pharmaceuticals in sewage sludge using online solid-phase extraction-liquid chromatography-tandem mass spectrometry combined with accelerated solvent extraction

An online solid-phase extraction (SPE) liquid chromatography tandem mass spectrometry method (HPLC-MS/MS) combined with accelerated solvent extraction (ASE) was developed for simultaneous determination of 14 pharmaceuticals in sludge. In the online SPE procedures, ultrapure water with no additives was used as the loading solvent. In addition, low molecular weight targets such as atenolol were difficult to retain on SPE column after acetone was added to the washing solvent. The response signal of analytes can be greatly improved by adding 0.2% formic acid to the mobile phase. Under the optimized conditions, the recoveries of all the analytes ranged between 75.1 and 112%. Moreover, the limit of detections ranged from 1.8 to 7.9 ug/kg. The precision of analytical data was determined with relative standard deviation (RSD) ≤ 4.87%. This method was successfully applied to determine the concentration of pharmaceuticals in sludge.

Wet oxidation and catalytic wet oxidation of pharmaceutical sludge

In this work, wet oxidation and catalytic wet oxidation of pharmaceutical sludge using homogeneous and heterogeneous catalysts were investigated. The results indicate that wet oxidation is a promising method for the highly efficient degradation of pharmaceutical sludge. Under optimal conditions, the highest removal efficiencies of volatile suspended solids (VSS) 86.8% and chemical oxygen demand (COD) 62.5% were achieved at 260 °C for 60 min with an initial oxygen pressure of 1.0 MPa. NaOH exhibited excellent acceleration performance on the VSS removal. The highest VSS removal efficiency of 95.2% was obtained at 260 °C for 60 min with an initial oxygen pressure of 1.0 MPa and 10 g·L^-1 of NaOH. By using a Cu-Ce/γ-Al₂O₃ catalyst, the highest removal rates of VSS 87.3% and COD 72.6% were achieved at 260 °C for 60 min with an initial oxygen pressure of 1.0 MPa and 10 g·L^-1 of catalyst. The wet oxidation reaction can be maintained itself owing to the exothermic heat. The produced low-molecular-weight carboxylic acids have potential commercial utilization as organic carbon sources in the biological wastewater treatment processes. The inorganic residues can be utilized for the building materials production. These results implied that the catalytic wet oxidation is a promising method for the volume reduction and resource utilization of pharmaceutical sludge.

Determination of pharmaceuticals and metabolites in sludge and hydrochar after hydrothermal carbonization using sonication-QuEChERS extraction method and UHPLC LTQ/Orbitrap MS

Pharmaceuticals (PhACs) are an important group of emerging contaminants that are released continuously in the environment from wastewater treatments plants (WWTPs). They can produce biological effects even though at very low concentrations. Conventional WWTPs are not able to remove or degrade completely emerging pollutants resulting in the presence of PhACs in sewage sludge after wastewater treatment. PhACs are found in sludge at low ppb-ppt levels, and their analysis and detection is a difficult task due to the complexity of sewage sludge matrices. Hydrothermal carbonization is currently being proposed as a suitable conversion technology for sewage sludge management to recover valuable products and to be used for soil amendment. In this work, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methodology with a dispersive solid-phase extraction (d-SPE) clean-up followed by ultra-high-performance liquid chromatography coupled with high-resolution linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ/Orbitrap MS), operated in positive ionization mode, was adopted to investigate 33 multiclass pharmaceuticals in sewage sludge and in hydrochar produced after hydrothermal carbonization. The analytical method was first optimized studying various extraction parameters and finally validated in terms of linearity, recovery, intra and inter-day precisions, expanded uncertainty (%U)/Horrat ratio at three spiking levels, matrix-effects (ME), process efficiency (PE), and limits of detection and quantification. The developed methodology fulfilled all analytical requirements and was finally applied to sludge samples from the WWTP of Ioannina city where a group of antibiotics was detected at concentrations up to 15 ng g^-1 and psychiatric drugs such as amisulpride, clozapine, and citalopram were detected at higher concentration levels up to 205, 87.4 and 63.2 ng g^-1, respectively. The method was also applied to hydrothermally treated sludge sample under different reaction conditions. Most of the antibiotic compounds were not detected, and several psychiatric drugs such as mirtazapine, bupropion, valsartan, diazepam, and caffeine were found at concentrations below the LOQ.

Pharmaceutical Sorption to Lab Materials May Overestimate Rates of Removal in Lab-Scale Bioreactors

Environmental contamination from pharmaceuticals has received increased attention from researchers in the past 20 years. As such, numerous lab-scale studies have sought to characterize the effects of these contaminants on various targets, as well as determine improved removal methods. Many studies have used lab-scale bioreactors to investigate pharmaceutical effects on wastewater bacteria, as wastewater treatment plants often act as reservoirs for pharmaceuticals. However, few-if any-of these studies report the specific lab materials used during testing, such as tubing or pipette tip type. In this study, the pharmaceuticals erythromycin, diclofenac, and gemfibrozil were exposed to different micropipette tips, syringe filters, and tubing types, and losses over time were evaluated. Losses to tubing and syringe filters were particularly significant and neared 100%, depending on the pharmaceutical compound and length of exposure time. Results discussed herein indicate that pharmaceutical sorption to various lab supplies results in decreases to both dosed and quantified pharmaceutical concentrations. Studies that fail to consider this source of loss may therefore draw inaccurate conclusions about pharmaceutical effects or removal efficiencies.

PPCPs and heavy metals from hydrothermal sewage sludge-derived biochar: migration in wheat and physiological response

Once the sludge was directly used in the farmland, it will have a negative impact on human health through the food chain because sludge contains pollutants. Sewage sludge pyrolysis into biochar is an effective way to realize sludge harmless and resourceful utilization. This research used hydrothermal carbonization method to convert sludge into sludge biochar (SLBC) to reduce the types and contents of pharmaceuticals and personal care products (PPCPs) and available heavy metals. Furthermore, migration of the residual caffeine (Caf), acetaminophen (Ace), and heavy metals (Cr, Pb, Cu, Zn) released from the SLBC in the wheat was assessed. The results showed that the levels of Caf, Ace, Pb, Cu, and Zn accumulated in the shoots were lower than the limit regulated by Drug and Food Additive Use Standard in China (Caf: 150 mg/kg; Ace: 2.5 ~ 5 mg/kg; Pb: 0.3 mg/kg; Cu: 10 mg/kg; Zn: 20 mg/kg). The migration of Cr from roots to shoots was also significantly controlled by SBLC. SBLC delayed the germination time of wheat seeds with increasing in hydrothermal temperature, the germination rate and root length showed a decreasing trend. Evans blue and O₂^- fluorescence staining of root tips also confirmed this conclusion. When the wheat was exposed to the low temperature and dose of SLBC, the chlorophyll contents and growth of wheat can be significantly increased; the oxidative damage of cell plasma membrane and net photosynthetic rate were reduced. However, 0.8 g/L of SLBC made plants suffer abiotic stress and caused oxidative damage to plants, and decreased membrane system stability. The study provides some parameters for sludge to realize resource utilization in the agricultural system.

From Sewage Sludge to the Soil-Transfer of Pharmaceuticals: A Review

Sewage sludge, produced in the process of wastewater treatment and managed for agriculture, poses the risk of disseminating all the pollutants contained in it. It is tested for heavy metals or parasites, but the concentration of pharmaceuticals in the sludge is not controlled. The presence of these micropollutants in sludge is proven and there is no doubt about their negative impact on the environment. The fate of these micropollutants in the soil is a new and important issue that needs to be known to finally assess the safety of the agricultural use of sewage sludge. The article will discuss issues related to the presence of pharmaceuticals in sewage sludge and their physicochemical properties. The changes that pharmaceuticals undergo have a significant impact on living organisms. This is important for the implementation of a circular economy, which fits perfectly into the agricultural use of stabilized sewage sludge. Research should be undertaken that clearly shows that there is no risk from pharmaceuticals or vice versa: they contribute to the strict definition of maximum allowable concentrations in sludge, which will become an additional criterion in the legislation on municipal sewage sludge.

Pharmaceutical residues in digested sewage sludge: Occurrence, seasonal variation and risk assessment for soil

The occurrences, temporal variations and ecotoxicological risks of 38 selected pharmaceuticals from 7 therapeutic classes (i.e. antibiotics, analgesics, anti-inflammatories, beta-blockers, lipid regulators, anticancer agents, and psychiatric drugs) have been observed in the anaerobically treated sludge of the urban wastewater treatment plant (WWTP) in Konya, Turkey. Sampling was carried out to assess the seasonal variations in one year. The total daily wastewater flow rate of the WWTP was approximately 200,000 m³/day, and 140 tons/day of treated sludge were produced. The total concentrations of all pharmaceutical compounds ranged from 280 to 4898 μg/kg of dry matter (dm). The dominant therapeutic class was analgesics and anti-inflammatories (49%), which was followed by antibiotics (31%). Clarithromycin and azithromycin were the most abundant compounds, with concentrations of 1496 μg/kg dm. The total daily pharmaceutical load in the treated sludge was as high as 1.002 kg/day in the winter season, while the annual pharmaceutical mass load that was discharged into the environment was estimated to be approximately 71.6 kg. The use of treated sludge as fertilizer in agricultural lands causes continuous contamination of the terrestrial environment by pharmaceuticals. Five antibiotics (i.e., azithromycin, clarithromycin, erythromycin, sulfamethoxazole, and doxycycline), one analgesic (acetylsalicylic acid) and one beta-blocker (atenolol) in the digested sludge pose acute and short chronic high risks to environment. The highest short chronic risk in the digested sludge-amended soils was determined for azithromycin (RQ: 54.9). To reduce the potential environmental impact of pharmaceuticals, digested sludge should be monitored in terms of the pharmaceutical contents before being applied to soil.

Assessment of the occurrence of 455 pharmaceutical compounds in sludge according to their physical and chemical properties: A review

Sludge agronomical reuse is of major interest due to the beneficial contribution of nutrients. However, it implies the introduction of unregulated pharmaceuticals into amended-soils and creates a controversial issue about sludge management. To limit their dissemination, it is essential to identify the compounds of interest and understand their attenuation mechanisms through the sludge processes. This paper summarizes the knowledge on 455 investigated pharmaceuticals among 32 therapeutical categories in amendable sludge matrices. It contributes to enlarging the list of commonly quantified compounds to 305 residues including 84 additional compounds compared to previous reviews. It highlights that sorption appears as the main mechanism controlling the occurrence of pharmaceuticals in sludge matrices and shows the considerable residual levels of pharmaceuticals reaching several mg/kg in dry weight. Antibiotics, stimulants, and antidepressants show the highest concentrations up to 232 mg/kg, while diuretics, anti-anxieties or anticoagulants present the lowest concentrations reaching up to 686 µg/kg. Collected data show the increase in investigated compounds as antifungals or antihistamines, and underline emerging categories like antidiabetics, antivirals, or antiarrhythmics. The in-depth analysis of the substantial database guides onto the pharmaceuticals that are the most likely to occur in these amendable matrices to assist future research.

Revealing the intrinsic drawbacks of waste activated sludge for efficient anaerobic digestion and the potential mitigation strategies

Anaerobic digestion (AD) is an effective approach for waste activated sludge (WAS) disposal with substantial recovery of valuable substrates. Previous studies have extensively explored the correlations of common operational parameters with AD efficiency, but the impacts of intrinsic characteristics of WAS on the AD processes are generally underestimated. This study focused on disclosing the association of intrinsic drawbacks in WAS with AD performance, and found that the cemented WAS structure, low fraction of biomass and various high levels of inhibitory pollutants (e.g., organic pollutants and heavy metals), as the integral parts of WAS all greatly restricted the AD performance. The main potential strategies and underlying mechanisms to mitigate the restrictions for efficient WAS digestion, including the practical pretreatment methods, bioaugmentation and aided substances addition, were critically analyzed. Also, future directions for the improvement of WAS digestion were proposed from the perspectives of technical, management and economic aspects.

Prioritization of antibiotic contaminants in China based on decennial national screening data and their persistence, bioaccumulation and toxicity

The potential adverse impacts of antibiotic contamination on environmental quality are generating increasing concern. Given that an alarming amount and variety of antibiotics have been used in China, a list of priority antibiotics is urgently needed to develop regulatory frameworks to control antibiotic use and monitor environmental pollution. This study established a new method of ranking priority antibiotics based on their prevalence (Pv), occurrence (O), persistence, and bioaccumulation, and toxicity (PBT) in the environment. The Pv and O criteria were weighted and quantified using the decennial national screening datasets (>15,000 concentration values for 105 candidate antibiotics in eight environmental compartments), and quantitative structure-activity relationships were used to estimate PBT values. A total of 26 high priority antibiotics were identified using the PvOPBT method, including 8 quinolones, 5 sulfonamides, 5 macrolides, 4 tetracyclines, 3 from other classes, and 1 unclassified antibiotic. For individual antibiotic classes, the β-lactams and aminoglycosides were ranked from no priority to low priority, whereas the macrolides and tetracyclines were ranked from medium to high priority. Although the PvOPBT ranking scores for the aqueous and solid phases demonstrated an apparent difference for some candidate antibiotics, eighteen antibiotics were ranked as high priority in both aqueous phases and solid phases and are suggested as the top priorities worthy of immediate attention. These top priority antibiotics are primarily utilized in animal husbandry within China. Therefore, urgent action is needed to limit the use of these top priority antibiotics in the animal industry.

A new insight into the ARG association with antibiotics and non-antibiotic agents-antibiotic resistance and toxicity

Although concerns have been raised about co-selection for antibiotic resistance and various antibiotics and non-antibiotic agents, the data on their association in urban sludge is still limited. In addition, antibiotic contamination can result in not only the toxicity but also the antibiotic resistance. In this study, the first large-scale identification of antibiotics and non-antibiotic agents concern for co-selection of resistance against antibiotics was conducted in urban sludge. Co-occurrence analysis showed that antibiotic resistance genes (ARGs) had no significant correlation with the corresponding antibiotics. Therefore, the results of co-occurrence analysis based on antibiotic concentration and ARG abundance were always ambiguous and difficult to interpret. However, antibiotic resistance was positively correlated with highly toxic compounds such as diclofenac, enrofloxacin and nicotine, suggesting that environmental contaminants might influence antibiotic resistance while exerting toxicity through mechanisms such as changes in microbial community and enzyme activity. The close correlation between class 1 integrase gene (intI1) and diclofenac/enrofloxacin indicated that the co-selection scenario between environmental contaminants and ARGs was likely mediated via intI1. In total, the derived co-occurrence patterns improve our understanding of the co-selection between ARGs, antibiotics and non-antibiotic agents, and also reaffirm the importance of potential role of non-antibiotic agents in the global spread of antibiotic resistance.

Characterization of organic compounds and drugs in sewage sludge aiming for agricultural recycling

The application of sewage sludge in soils can bring benefits to agricultural productivity, however, the risks arising from this application must be measured and carefully evaluated. Persistent organics compounds and drugs can be present in the sewage sludge and if applied to the soil, they can cause severe risks to the soil biota and contamination of groundwater. This work determined 174 persistent organic compounds and drugs in sludge samples from a wastewater treatment plant using chromatographic methods. The drugs ciprofloxacin, enrofloxacin and diclofenac were quantified, and values varied according to sampling period. For persistent organic compounds, cresols were the most abundant compounds in sewage sludge. With the analyses made of both the elutriate and the filtrate, it was possible to verify the potential for soil retention or leaching that each compound can present with the application of sewage sludge in the agriculture.

Kinetic removal of acetaminophen and phenacetin during LED-UV365 photolysis of persulfate system: Reactive oxygen species generation

Acetaminophen (ACT) and phenacetin (PNT) removal during light-emitting diode (LED)-UV photolysis of persulfate (PS) was evaluated with a typical wavelength of 365 nm. Decay of PNT and ACT in pH ranges of 5.5-8.5 followed pseudo-first order kinetics. Maximum pseudo-first order rate constants (k_obs) of ACT and PNT decomposition of 1.8 × 10^-1 and 1.2 × 10^-1 min^-1, respectively, were obtained at pH 8.5. Hydroxyl radicals (·OH), sulfate radicals (SO₄·^-), superoxide radicals (O₂^-·), and singlet oxygen (¹O₂) were determined in-situ electron paramagnetic resonance (EPR) and alcohol scavenging tests. The average contributions of ·OH and SO₄·^- were 23.5% and 53.0% for PNT removal, and 15.9% and 53.0% for ACT removal at pH ranges of 5.5-8.5. In samples subjected to chlorination after LED-UV₃₆₅/PS pre-oxidation, a relatively small total concentration of five halogenated disinfection by-products (DBPs) was obtained of 90.9 μg L^-1 (pH 5.5) and 126.7 μg L^-1 (pH 7.0), which is 58.5% and 30.2% lower than that in system without LED-UV₃₆₅/PS pre-oxidation. Meanwhile, a higher maximum value of total DBP concentration was obtained at pH 8.5 (445.6 μg L^-1) following LED-UV₃₆₅/PS pre-oxidation. The results of economy evaluation showed that UV₃₆₅ was more cost-effective in application for organic contaminant removal compared with UV₂₅₄.

A preliminary study on the ecotoxic potency of wastewater treatment plant sludge combining passive sampling and bioassays

Sewage sludge is an inevitable byproduct produced in wastewater treatment. Reusing nutrient-rich sludge will diminish the amount of waste ending in soil dumping areas and will promote circular economy. However, during sewage treatment process, several potentially harmful organic chemicals are retained in sludge, but proving the safety of processed sludge will promote its more extensive use in agriculture and landscaping. Environmental risk assessment of sludge requires new methods of characterizing its suitability for various circular economy applications. Bioavailable and bioaccessible fractions are key variables indicating leaching, transport, and bioaccumulation capacity. Also, sludge treatments have a significant effect on chemical status and resulting environmental risks. In this study, the concentrations of polyaromatic hydrocarbons (PAHs), triclosan (TCS), triclocarban (TCC), methyl triclosan (mTCS), and selected active pharmaceutical ingredients (APIs) were determined in different sludge treatments and fractions. Passive samplers were used to characterize the bioavailable and bioaccessible fractions, and the sampler extracts along the sludge and filtrate samples were utilized in the bioassays. The TCS and PAH concentrations did not decrease as the sludge was digested, but the contents diminished after composting. Also, mTCS concentration decreased after composting. The API concentrations were lower in digested sludge than in secondary sludge. Digested sludge was toxic for Aliivibrio fischeri, but after composting, toxicity was not observed. However, for Daphnia magna, passive sampler extracts of all sludge treatments were either acutely (immobility) or chronically (reproduction) toxic. Secondary and digested sludge sampler extracts were cytotoxic, and secondary sludge extract was also genotoxic. The measured chemical concentration levels did not explain the toxicity of the samples based on the reported toxicity thresholds. Bioassays and sampler extracts detecting bioavailable and bioaccessible contaminants in sludge are complementing tools for chemical analyses. Harmonization of these methodswill help establish scientifically sound regulative thresholds for the use of sludge in circular economy applications.

A multi-residue analytical method for extraction and analysis of pharmaceuticals and other selected emerging contaminants in sewage sludge

Sewage sludge is a by-product of wastewater treatment processes, and may be employed in agriculture as a fertilizer or in forestry for land reclamation. It is an important source of nutrients but its reuse can arouse concern on account of the wide range of contaminants that are retained and may persist during treatments. Information on the emerging contaminants (ECs) in sewage sludge in Italy is limited. The present study developed and applied a reliable analytical method for the analysis of 44 ECs in sewage sludge. ECs were extracted by accelerated solvent extraction followed by a clean-up step on solid-phase cartridges. High performance liquid chromatography coupled to mass spectrometry was used for analysis. The ECs, selected on the basis of their use and documented presence in the environment, were 42 pharmaceuticals belonging to 12 therapeutic categories and 2 perfluorinated substances. The method performance was good, with recoveries higher than 70%, good repeatability (<20%) and sensitivity in the low ng g^-1 range, allowing measurement of the analytes selected. The method was applied for analysis of sludge from 12 wastewater treatment plants in Italy. The most abundant compounds were antibiotics, anti-inflammatories and antihypertensives and ranged up to 5 μg g^-1 (ciprofloxacin). Seasonal differences were found for some antibiotics and anti-inflammatory drugs as well as some differences - in terms of concentration - with other European countries. This is the first Italian study to investigate the presence of a large number of ECs in sewage sludge and the results may be useful to drive future regulatory actions.

Occurrence, fate, and persistence of emerging micropollutants in sewage sludge treatment

Sludge generated at sewage treatment plants is of environmental concern due to the voluminous production and the presence of a high concentration of emerging contaminants (ECs). This review discusses the fate of ECs in sewage sludge treatment with an emphasis on fundamental mechanisms driving the degradation of compounds based on chemical properties of the contaminant and process operating conditions. The removal of ECs in sewage sludge through various treatment processes of sludge stabilization, such as anaerobic digestion (AD), composting, and pre-treatment methods (thermal, sonication, and oxidation) followed by AD, are discussed. Several transformation mechanisms and remediation strategies for the removal of ECs in sludge are summarized. The study concludes that pH, sludge type, and the types of functional groups are the key factors affecting the sorption of ECs to sludge. During conventional waste stabilization processes such as composting, the degradation of ECs depends on the type of feedstock (TOC, N, P, C/N, C/P) and the initial concentration of the contaminant. In AD, the degree of degradation depends on the hydrophilicity of the compound. The estrogenicity of the sludge may sometimes increase due to the conversion to estrogenic compounds. The pre-treatment techniques can increase the partitioning of ECs in the soluble fraction resulting in enhanced biodegradation up to 10-60%. However, the formation of by-products and loss of OH· to scavenging under high organic content during advanced oxidation processes can make the process uneconomical and require further research.

Simultaneous quantification of five pharmaceuticals and personal care products in biosolids and their fate in thermo-alkaline treatment

The presence of pharmaceuticals and personal care products (PPCPs) in biosolids applied to farmland is of concern due to their potential accumulation in the environment and the subsequent effects on humans. Thermo-alkaline hydrolysis (TAH) is a method used for greater stabilization of biosolids after anaerobic digestion. In this work, the effect of TAH on five selected PPCPs including fluoroquinolone antibiotics, ciprofloxacin (CIP), and ofloxacin (OFLX), and three commonly used antimicrobial agents, miconazole (MIC), triclosan (TCS) and triclocarban (TCC) was evaluated. At the onset, extraction and analytical methods were optimized for maximum simultaneous recovery and LC-MS quantification of the target PPCPs from both water and biosolids for improved accuracy. The compounds were detected in the range of 54 ± 3 to 6166 ± 532 ng/g in raw biosoilds collected from a local WWTP. Next, batch control adsorption experiments of the selected PPCPs were conducted in various sludges, which indicated about 89%-98% sorption of the PPCPs onto solid phase due to their high octanol-water coefficients. Subsequently, thermo-alkaline (pH 9.5, 75 °C, 45 min) hydrolysis (TAH) was conducted to determine the extent of degradation of these compounds in deionized (DI) water and biosolids due to treatment. The degradation of these compounds due to TAH ranged from 42% to 99% and 37%-41% in pure water and biosolids, respectively, potentially lowering their risk in the environment due to land application. A list of compounds for which the optimized analytical method potentially can be used for detection and quantification in environmental samples is provided in the supporting document.

Multiple roles of Ca2+ in the interaction of ciprofloxacin with activated sludge: Spectroscopic investigations of extracellular polymeric substances

Calcium ion is an important cation influencing the binding of recalcitrant organic contaminants with activated sludge during wastewater treatment process, but there is still unknown about its role in amphoteric fluoroquinolones binding. Binding experiments show that Ca²⁺ markedly inhibited binding of ciprofloxacin (CIP) onto sludge, causing 7-203 times of CIP release. Multi-spectroscopic examinations indicate that tryptophan-like and tyrosine-like proteins in extracellular polymeric substances (EPS) were dominant components for CIP binding by static quenching and forming CIP-proteins complexes. Addition of Ca²⁺ into EPS and CIP binding systems induced increase of association constants (from 0.024-0.064 to 0.027-0.084 L/μmol) and binding constants (from 0.002-0.039 to 0.012-0.107) and decrease of binding sites number (from 0.893-2.007 to 0.721-1.386). Functional groups of EPS and secondary structure of proteins were remarkably changed upon reactions with CIP and Ca²⁺. Calcium ion interacted with EPS and CIP binding system in two distinct ways: Ca²⁺ shielded CO in amide I in EPS for CIP binding, whereas strengthened binding between CIP and functional groups including CO in carboxyl groups in extra-microcolony polymers and OH in extra-cellular polymers by forming ternary complexes. Cation competition for CO in amide I is responsible for Ca²⁺ induced CIP release from the sludge. Results suggest the highly potential release of CIP from high saline wastewater and cation-conditioned sludge which needs further monitoring and evaluation.

Effects of biostimulation by sugarcane bagasse and coffee grounds on sewage sludges, focusing agricultural use: Microbial characterization, respirometric assessment and toxicity reduction

Sewage sludge (SS) exhibits a relevant agronomic potential due to the high content of organic matter and nutrients. However, the presence of several toxic substances can prevent its agricultural application. This study evaluated if the incorporation of stimulating agents (coffee grounds and sugarcane bagasse) could contribute to an effective increase of the SS biodegradability in order to decrease its toxicity. The samples were prepared mixing aerobic or anaerobic sludge with soil, soil and bagasse, and soil and coffee grounds. Respirometric tests showed that stimulating agents enhanced the CO₂ production. However, in terms of biodegradation efficiency, more satisfactory results were verified for the anaerobic SS, especially when mixed with coffee grounds. The biodegradation also favored the SS sanitization, eliminating the Enterobacteria. For baseline toxicity (Microtox with Aliivibrio fischeri) and phytotoxicity (Lactuca sativa), all the initial samples showed higher effects. Nevertheless, after the biodegradation, this toxicity was significantly decreased and the best results were obtained for the mixtures containing only soil and sludge. For the AREc32 assay (NRF₂ mediated oxidative stress response), although a very weak response was observed, this effect was attenuated for the aerobic SS or completely eliminated for the anaerobic SS after the biodegradation. Thus, even though the use of biostimulation agents during the biodegradation led to an enhancement of microbial respiration, their incorporation to the samples do not seem to interfere in the decrease of the toxic potential of the studied SSs. However, the SS biodegradation in aerobiosis was crucial for toxicity reduction and to accelerate its maturity.

Occurrence, sources and risk assessment of fluoroquinolones in dumpsite soil and sewage sludge from Chennai, India

Soil and sludge are major reservoirs of organic compounds such as fluoroquinolones (FQs) which are broad-spectrum antibacterial agents. Hence, we monitored three major FQs, namely, ciprofloxacin (CIP), norfloxacin (NOR), and ofloxacin (OFL), in surface soil from two major dumpsites and dry and wet sludge from sewage treatment plants in Chennai city. The mean concentration of FQs in soil and sludge samples were 20 μg/g and 26 μg/g, respectively. Nearly 50% of the total FQs in dumpsite soil was contributed by CIP followed by NOR (32%) and OFL (13%). Similarly, CIP was the major contributor in sludge samples followed by NOR and OFL. The concentration of FQs was two folds higher in wet sludge than dry sludge most likely indicating that water solubility of these compounds might play an important role for elevated level of FQs in wet sludge. Solid waste from pharmaceutical industries, households, and sludge from wastewater treatment plants were expected to be the major source of FQs in dumpsite soil. Predicted risk assessment using soil to water migration concentrations via surface run off indicated high risk to aquatic organisms. However, risk quotient (RQ) was found less to earthworm in most of the soil samples. The findings from this study might help in future policies on disposal of household antibiotics in the solid waste stream.

Adsorption characteristics and mechanism of norfloxacin in water by γ-Fe2O3@BC

Using waste pomelo peel as raw material, pomelo peel-based biochar (BC) was prepared by pyrolysis at 400 °C, and the pomelo peel-based biochar was prepared by loading γ-Fe₂O₃ onto the surface of the pomelo peel-based biochar by unlimited oxygen chemical precipitation. The results showed that the pomelo peel biochar loaded with γ-Fe₂O₃ had higher specific surface area and larger pore volume. The load of γ-Fe₂O₃ gives γ-Fe₂O₃@BC excellent magnetic separation ability, and its magnetic saturation intensity is as high as 30.60 emu/g. BC and γ-Fe₂O₃@BC were applied to remove norfloxacin (NOR) from a water body. It was found that the adsorption of NOR by both of them followed the pseudo-second-order kinetic model. The adsorption isotherm mainly conforms to the Sips model, and the adsorption process of NOR is a spontaneous endothermic reaction. The pH and ionic strength have a great influence on the adsorption of NOR by BC and γ-Fe₂O₃@BC, and they play a role mainly by influencing the morphology of NOR in water. The adsorption mechanism showed that cation exchange and hydrogen bonding were the main forces for BC to adsorb NOR. Moreover, the γ-Fe₂O₃ particles enhanced the hydrophobicity of the pomelo peel-based biochar, making the hydrophobicity become the main force for the adsorption of NOR by the γ-Fe₂O₃@BC. The adsorption-desorption experiment showed that after four cycles of recycling, the adsorption capacity of γ-Fe₂O₃@BC for NOR was still up to 61.43% of the initial adsorption capacity, and it had a good recycling property.

Effects of tetracycline residuals on humification, microbial profile and antibiotic resistance genes during vermicomposting of dewatered sludge

Vermicomposting is a green technology used in the recycling of sewage sludge using the joint action of earthworms and microorganisms. Although tetracycline is present in abundance in sewage sludge, little attention has been given to its influence on vermicomposts. This study investigated the effects of different tetracycline concentrations (0, 100, 500 and 1000 mg/kg) on the decomposition of organic matter, microbial community and antibiotic resistance genes (ARGs) during vermicomposting of spiked sludge. The results showed that 100 mg/kg tetracycline could stimulate earthworms' growth, accompanied by the highest humification and decomposition rates of organic matter in the sludge. The abundance of active microbial cells and diversity decreased with the increase in tetracycline concentrations. The member of Bacteroidetes dominated in the tetracycline spiked treatments, especially in the higher concentration treatments. Compared to its counterparts, the addition of tetracycline significantly increased the abundances of ARGs (tetC, tetM, tetX, tetG and tetW) and Class 1 integron (int-1) by 4.7-186.9 folds and 4.25 folds, respectively. The genera of Bacillus and Mycobacterium were the possible bacterial pathogen hosts of ARGs enriched in tetracycline added group. This study suggests that higher concentration of tetracycline residual can modify microbial communities and increase the dissemination risk of ARGs for final sludge vermicompost.

Occurrence and distribution of pharmaceutical compounds in the Danshuei River Estuary and the Northern Taiwan Strait

Ten pharmaceutically active compounds (PhACs) were determined in northern Taiwan estuarine waters and Taiwan Strait (TS) seawater. The ecological risk of these PhACs was assessed using risk quotient (RQ), which is the ratio of the measured maximum concentration to the predicted no-effect concentration. Six PhACs were detected within the estuarine waters. Caffeine concentration (130-718 ng l^-1) was the highest among the analyzed PhACs. The distribution of PhACs in the Danshuei River Estuary generally exhibited addition behavior, except that caffeine showed conservative behavior. Carbamazepine, gemfibrozil, caffeine, and ketoprofen were detected in TS seawaters. Their concentrations follow the sequence: gemfibrozil > ketoprofen > caffeine > carbamazepine. The caffeine concentrations in TS seawaters were 2-3 orders of magnitude lower than those in Danshuei estuarine waters. With few exceptions for caffeine, erythromycin, and sulfadiazine posing low risk in some estuarine waters, most of the RQ values were <0.01, suggesting no adverse effects on aquatic organisms.

Removal and dissipation pathway of typical fluoroquinolones in sewage sludge during aerobic composting

To observe the effect of aeration strategies on the dissipation of fluoroquinolones (FQs) during aerobic composting and explore their dissipation pathways, 60-L composting and 0.5-L incubation experiments were carried out in this study. Three aeration strategies (windrow, static aeration, feedback aeration) were applied to remove two typical FQs (Norfloxacin (NOR) and Ofloxacin (OFL)) during the 60-L composting of sewage sludge with 5 mg kg^-1 of FQs added. Then, three 0.5 L-sample groups were taken during the three phases of the 60-L composting matrixes without FQs under static aeration, and were inoculated separately at 35 °C, 55 °C and 40 °C after being added with 5 mg kg^-1 of FQs. In each group, incubation was carried out for three treatments (sterilization + no aeration, sterilization + aeration, and no sterilization + aeration). The FQs in the sewage sludge were mainly removed in the mesophilic and thermophilic phases in all the aeration strategies. The removal efficiencies were high for the whole process: 89.6-95.4% for NOR and 87.2-95.4% for OFL. The order of removal efficiency of FQs was static aeration > feedback aeration > windrow. The combination of composting phases facilitated to the rapid dissipation of FQs, which reduced the half-life to about 1/6 to 1/5 of the values in each phase. In the mesophilic and thermophilic compost, biodegradation was the main pathway for the dissipation of FQs followed by irreversible adsorption. Irreversible adsorption and biodegradation provided similar removal efficiencies for the curing compost. The volatilization of FQs was non-negligible in all phases.

Nationwide reconnaissance of five parabens, triclosan, triclocarban and its transformation products in sewage sludge from China

China's rapid growth of both population size and sanitation infrastructure have created a heightened need for responsible management of sewage sludge. We applied liquid chromatography in conjunction with isotope dilution tandem mass spectrometry to measure multiple endocrine disrupting antimicrobials and their transformation products in 100 sewage sludge samples collected across 21 Chinese provinces/districts. Occurrences (detection frequencies) and concentrations (ng/g dry weight) were as follows: triclosan (99%; <4-4870), triclocarban (95%; <3-43,300), 2'-hydroxy-triclocarban (94%; <1-2340), 3'-hydroxy-triclocarban (91%; <1-1250), 3,3',4,4'-tetrachlorocarbanilide (100%; 22-580), dichlorocarbanilide (94%; <2-23,890), monocarbanilide (92%; <2-120), carbanilide (90%; <3-1,340), and five parabens: methyl- (98%; <2-630), ethyl- (96%; <2-170), propyl- (99%; <2-27), butyl- (89%; <2-11) and benzyl-paraben (7%; <2-12). The transformation products of triclocarban were measured for the first time in Chinese wastewater system, and ratios of transformation products to parental triclocarban indicate ongoing triclocarban dechlorination during wastewater treatment. Contaminant profiles and concentrations differed by region, treatment capacity, and wastewater type. Extrapolation of collected data yielded an estimate for the total mass of 13 analytes sequestered in Chinese sewage sludge of 68 t/y with an upper bound of 400 t/y. This China-wide survey established baseline levels of selected antimicrobials in sludges whose current disposal is performed with little regulatory oversight and enforcement.

Effects of antibiotic residuals in dewatered sludge on the behavior of ammonia oxidizers during vermicomposting maturation process

Antibiotics existed in dewatered sludge may affect the organic decomposition and nitrification efficiency of vermicomposting process, and thus lowering the agricultural value of sludge vermicompost. However, few studies have focused on the effects of antibiotics during vermicomposting process of sludge, notably for the maturated phage. Hence, this study aimed to investigate the effects of antibiotics on the nitrification rate and the features of ammonia oxidizing archaea (AOA) and bacteria (AOB) during vermicomposting maturated phage of sludge. The treatments including the additions of tetracycline and ofloxacin with high and low concentrations were compared with the control without adding antibiotics. The results showed the antibiotics enhanced the nitrification rate of 15.8%-42% in vermicomposting maturated phage compared with the counterpart, with a better stimulating effect in the low concentration of tetracycline. The population of amoA genes increased in antibiotic treatments with low concentrations but decreased in these with high concentrations. In addition, high through-put sequencing results revealed that the tetracycline had a stronger influence on the α and β diversities of AOA and AOB, relative to the ofloxacin. In contrast to the AOB, the AOA played a more important role in ammonia oxidization, in the presence of antibiotics. This study suggests that the antibiotics of dewatered sludge can strongly affect the ammonia oxidization process through modifying the numbers and community structures of AOA and AOB during vermicomposting and these effects are associated with the types and concentrations of antibiotics.

Amendment of municipal sewage sludge with lime and mussel shell: Effects on fate of organic matter and pharmaceutically active compounds

The deterioration in its strength from long-term degradation of organic matter and release of pharmaceutically active compounds (PhACs) have caused adverse environmental effects in municipal sewage sludge (MSS) landfill. Lime and a mixture of lime and mussel shell were employed as potential stabilization agents for MSS in this work. Their efficacy was assessed by investigating the effects on transformation of organic matter, as well as the occurrence and fate of four PhACs (fluoxetine, gemfibrozil, triclosan and carbamazepine) over 42 days. The addition of the selected agents: (i) prevented the microbial degradation of organic matter; (ii) modified the predominant functional groups of amide groups (amide I and II) and polysaccharides to deprotonated carboxylic groups and destruction of amide groups; and (iii) shifted the abundance of organic constituents from microbial by-products to humic acid-like organics with conformational changes. The measurement method provided reliable and precise results for determining PhAC concentrations in MSS with and without amendment, although matrix effects and process effects were found to affect measurement sensitivity. Available fractions of the PhACs increased in MSS with lime addition, but decreased in the presence of the mixture of lime and mussel shell due to the strong adsorption effects of the shells. The mixture of lime and mussel shell would be recommended for stabilizing MSS prior to being landfilled. However, longer term and larger scale investigation may be needed to better evaluate the applicability of lime and mussel shell for reducing the hazards and facilitating the management of MSS.

Effects of individual and combined zinc oxide nanoparticle, norfloxacin, and sulfamethazine contamination on sludge anaerobic digestion

This work investigated the individual and combined effects of zinc oxide, norfloxacin, and sulfamethazine on sludge anaerobic digestion-associated methane production, protein and carbohydrate metabolism, and microbial diversity. Norfloxacin and sulfamethazine (500 mg/kg) did not inhibit methane production, but inhibited its production rate. Zinc oxide nanoparticles with antibiotics inhibited hydrolysis, fermentation, and methanogenesis over varying digestion periods. Complex pollution had a greater impact on methane production than zinc oxide alone, with acute, synergistic toxicity to methanogenesis over short periods. Complex pollution also had varying effects on bacterial and archaeal communities during digestion. These results aid understanding of the toxicity of emerging contaminants in sludge digestion, with the potential to improve pollution removal and reduce associated risks.

Green pharmacy - a narrative review

Introduction

Active pharmaceutical ingredients are present in various sections of the environment, because of both the human and veterinary use of medicinal products. Ways of minimizing the risk of environmental contamination should be observed during all pharmaceutical activities (research, manufacturing, prescribing, dispensing and disposal of medicinal products).

Methods

For the present study we searched specific literature on this subject, using the main international databases (Thomson Reuters – Web of Science, SCOPUS and Science Direct).

Results

This narrative review focuses on the main aspects concerning environmental contamination with medicinal products. Consequently, the present study is structured on four different topics: environmental research on medicinal products, minimizing environmental contamination, waste disposal management and towards a greener community pharmacy.

Conclusion

Waste management activities are important for reducing the presence of active pharmaceutical ingredients in the environment. Pharmacists should inform patients on proper pharmaceutical waste disposal and organize collection programs for unused and expired medicines, in order to develop a greener pharmacy for the future.

A pressurized liquid extraction approach followed by standard addition method and UPLC-MS/MS for a fast multiclass determination of antibiotics in a complex matrix

In this work a fast analytical method for the determination of macrolides, tetracyclines and fluoroquinolones in a compost originating from a mixture of sewage sludge, palm waste and grass was developed by ultra-high performance liquid chromatography coupled to mass spectrometry (U-HPLC/MS). Antibiotics were extracted from compost by using the accelerated solvent extraction (ASE). The chromatographic separation was carried out on a T3 Cortecs C18 column using a mobile phase gradient mixture of water acidified with 1% of formic acid and acetonitrile. Recoveries of 24-30%, 53-93%, 33-57%, 69-135% and 100-171% were obtained for roxithromycin (ROX), chlortetracycline (CTC), oxytetracycline (OTC), enrofloxacin (ENR) and ciprofloxacin (CIP), respectively. As the most part of antibiotics showed significant matrix effect (ME), the method was validated using the standard addition method (SAM) to correct the observed ME. Instrumental variation, of LC/MS system, showed that 93.75% of the relative standard deviation (RSD %) are below 15%, although the organic load of extracts. This analytical method was applied to assess the fate of antibiotics during composting. Two composting experiments were conducted separately after spiking sludge at 2 different concentrations levels. The resulting elimination rates were of 52-76, 69-100, 100 and 24-50% for ROX, CTC, OTC and CIP, respectively. These results suggest that composting process contributes to the removal of residuals concentrations of macrolides and tetracyclines while the fluoroquinolones persist in the final compost product.

Highly efficient degradation of pharmaceutical sludge by catalytic wet oxidation using CuO-CeO2/γ-Al2O3 as a catalyst

Pharmaceutical sludge is considered as a hazardous material with high treatment and disposal costs. In the present study, the catalytic wet oxidation (CWO) of pharmaceutical sludge by CuO-CeO₂/γ-Al₂O₃ as the catalyst was investigated. The catalyst was prepared by traditional wet impregnation. The catalyst was characterized using X-ray Powder Diffraction (XRD) and Scanning Electron Microscopy (SEM). CWO was performed in an experimental batch reactor. Several parameters that could affect the catalytic degradation efficiency, including catalyst dose, temperature, time, oxygen pressure and pH, were investigated. Under optimum conditions, the highest removal rate of volatile suspended solids (VSS) was 87.3% and was achieved at 260°C for 60 min with an oxygen pressure of 1.0 MPa and 10 g/L of catalyst. At the same time, the chemical oxygen demand (COD) removal rate reached as high as 72.6%. This work implies that catalytic wet oxidation is a promising method for the highly efficient degradation of pharmaceutical sludge.

Mobility of pharmaceutical and personal care products in lime amended wastewater biosolids

Lime amendment of biosolids can produce large quantities of hydroxyl ions and increase biosolids pH. The mobility of some pharmaceutical and personal care products (PPCPs) is closely correlated with the pH of biosolids. In this study the mobility of six PPCPs: erythromycin, fluoxetine, carbamazepine, naproxen, gemfibrozil and triclosan, was measured in unamended and lime-amended biosolids over 63days. Biosolids were equilibrated either a at pH range of 5.5-11.5 or cured over a time period up to 63days. The mobility was calculated as the proportion of PPCPs associated with the soluble phase after a given equilibrium time or a curing period. In unamended biosolids the mobility of erythromycin, fluoxetine, gemfibrozil and triclosan decreased, the mobility of naproxen increased and the mobility of carbamazepine was almost unchanged over 63days of curing. Compared to unamended biosolids, lime addition increased the mobility of erythromycin and naproxen by 21.7% and 33.8% respectively, but suppressed the mobility of carbamazepine, fluoxetine, gemfibrozil and triclosan by up to 100% after 63days. The pH influence on hydrophobicity and speciation of PPCPs correlated well with the mobility of erythromycin and fluoxetine, but only partially correlated with the mobility of the other 4 compounds over the pH of 5.5-11.5. Attenuated total reflectance Fourier transformed infrared (ATR-FTIR) and emission-excitation matrices (EEMs) provided spectroscopic evidences showing that the increases in amide and carboxylic groups, the decrease in polysaccharides, and the increases in humic substances in dissolved organic matter (DOM) may be responsible for the changes in the PPCPs' mobility. The effects of lime amendment lasted for approximately a month. The results of this work suggest that lime amendment prevents some PPCPs from being dissolved in biosolids soluble phases, but may not "lock" all PPCPs into biosolids.

Variation of antibiotics in sludge pretreatment and anaerobic digestion processes: Degradation and solid-liquid distribution

Degradation and solid-liquid distribution of antibiotics in three sludge pretreatments (ultrasonic, alkaline and thermal hydrolysis pretreatment) and subsequent anaerobic digestion processes were investigated. The contamination of fluoroquinolones (FQs) was most serious in the raw sludge, while sulfonamides (SAs) were negligible. Obvious solubilization of antibiotics was observed after sludge pretreatments. The intracellular antibiotics were released after thermal hydrolysis pretreatment, meanwhile tetracyclines (TCs) were thermally decomposed. Compared to TCs and macrolides (MLs), FQs were hardly degraded in anaerobic digestion with removal efficiencies lower than 42.02%, and the residual FQs were mostly adsorbed on the digested sludge. The limiting step for FQs reduction was the biodegradation, rather than desorption of adsorbed antibiotics. Addition of pretreatments had no obvious effect on the degradation and distribution of antibiotics in the anaerobic digested sludge, except that the thermal hydrolysis enhanced the migration of antibiotics to the liquid phase.

Targeted eco-pharmacovigilance for ketoprofen in the environment: Need, strategy and challenge

Implementing "targeted" eco-pharmacovigilance(EPV) which focuses on individual or specific pharmaceuticals on a prioritised basis is a feasible, economical and customized approach to reduce the environmental concentrations and risks of pharmaceuticals. Non-steroidal anti-inflammatory drugs(NSAIDs) remaining in environment are a kind of priority hazard substances, due to a notable case that diclofenac residues caused the loss of more than 99% of vultures across the Indian sub-continent. Ketoprofen, as another widely used NSAID with comparable or even higher global consumption than diclofenac, in the environment has been shown to present a potential risk to non-target terrestrial and aquatic species. Based on the review of 85 articles reporting the analyses of ketoprofen residues in environment since 2010, we found that this NSAID frequently present in various environmental compartments around the world. Therefore, it is urgent to implement EPV targeting ketoprofen pollution. Here, we provide some recommendations for implementing the targeted EPV for ketoprofen, including: Closely monitoring ketoprofen in the natural environment; Reducing the residues of ketoprofen through source control; Encouraging urine source separation and treatment; Limiting the application of veterinary ketoprofen; Designing and constituting a framework system of targeted EPV. But some challenges, such as ambiguity in the accountability of the main bodies responsible for continued monitoring of ketoprofen residues, the lack of optimized urine source separation scenarios and procedure, the need for detailed design and application schemes of the framework system of targeted EPV, etc. should be addressed.

Implementing ecopharmacovigilance (EPV) from a pharmacy perspective: A focus on non-steroidal anti-inflammatory drugs

Environmental experts have made great efforts to control pharmaceutical pollution. However, the control of emerged environmental problems caused by medicines should draw more attention of pharmacy and pharmacovigilance researchers. Ecopharmacovigilance (EPV) as a kind of pharmacovigilance for the environment is recognized worldwide as crucial to minimize the environmental risk of pharmaceutical pollutants. But continuing to treat the pollution of pharmaceuticals as a group of substances instead of targeting individual pharmaceuticals on a prioritized basis will lead to a significant waste of resources. Considering vulture population decline caused by non-steroidal anti-inflammatory drugs (NSAIDs) residues, we presented a global-scale analysis of 139 reports of NSAIDs occurrence across 29 countries, in order to provide a specific context for implementing EPV. We found a heavy regional bias toward research in Europe, Asia and America. The top 5 most frequently studied NSAIDs included ibuprofen, diclofenac, naproxen, acetaminophen and ketoprofen. The profile of NSAIDs was dominated by acetaminophen in wastewater influents and effluents. Ibuprofen was the most abundant NSAID in surface water. Only 9 NSAIDs were reported in groundwater samples. And majority of NSAIDs were detected in solid matrices at below 1μg/g except for ketoprofen, diclofenac and ibuprofen. From a pharmacy perspective, we get some implication and propose some management practice options for EPV implementation. These include: Further popularizing and applying the concept of EPV, together with developing relevant regulatory guidance, is necessary; More attention should be paid to how to implement EPV for the pollution control of older established drugs; Triggering "a dynamic watch-list mechanism" in conjunction with "source control"; Implementing targeted sewage treatment technologies and strengthening multidisciplinary collaboration; Pharmaceutical levels in aquatic organisms as biological indicators for monitoring pharmaceutical pollution within the water environment; Upgrading drinking water treatment plants with the aim of removing pharmaceutical residues; Paying more attention to EPV for pharmaceuticals in solid matrices.

Photolysis of pharmaceuticals and personal care products in the marine environment under simulated sunlight conditions: irradiation and identification

The photochemical fate of 16 pharmaceuticals and personal care products (PPCPs) found in the environment has been studied under controlled laboratory conditions applying a sunlight simulator. Aqueous samples containing PPCPs at environmentally relevant concentrations were extracted by solid-phase extraction (SPE) after irradiation. The exposed extracts were subsequently analysed by liquid chromatography combined with triple quadrupole mass spectrometry (HPLC-MS/MS) for studying the kinetics of photolytic transformations. Almost all exposed PPCPs appeared to react with a half-life time (τ _1/2) of less than 30 min. For ranitidine, sulfamethoxazole, diclofenac, warfarin, sulfamethoxazole and ciprofloxacin, τ_1/2 was found to be even less than 5 min. The structures of major photolysis products were determined using quadrupole-time-of-flight mass spectrometry (QToF) and spectroscopic data reported in the literature. For diclofenac, the transformation products carbazol-1-yl-acidic acid and 8-chloro-9H-carbazol-1-yl-acetic acid were identified based on the mass/charge ratio of protonated ions and their fragmentation pattern in negative electrospray ionization (ESI^--QTOF). Irradiation of carbamazepine resulted in three known products: acridine, carbamazepine-10,11-epoxide, and 10,11-dihydro-10,11-dihydroxy-carbamazepine, whereas acetaminophen was photolytically transformed to 1-(2-amino-5 hydroxyphenyl) ethenone. These photochemical products were subsequently identified in seawater or fish samples collected at sites exposed to wastewater effluents on the Saudi Arabian coast of the Red Sea.

Review of Antimicrobial Resistance in the Environment and Its Relevance to Environmental Regulators

The environment is increasingly being recognized for the role it might play in the global spread of clinically relevant antibiotic resistance. Environmental regulators monitor and control many of the pathways responsible for the release of resistance-driving chemicals into the environment (e.g., antimicrobials, metals, and biocides). Hence, environmental regulators should be contributing significantly to the development of global and national antimicrobial resistance (AMR) action plans. It is argued that the lack of environment-facing mitigation actions included in existing AMR action plans is likely a function of our poor fundamental understanding of many of the key issues. Here, we aim to present the problem with AMR in the environment through the lens of an environmental regulator, using the Environment Agency (England’s regulator) as an example from which parallels can be drawn globally. The issues that are pertinent to environmental regulators are drawn out to answer: What are the drivers and pathways of AMR? How do these relate to the normal work, powers and duties of environmental regulators? What are the knowledge gaps that hinder the delivery of environmental protection from AMR? We offer several thought experiments for how different mitigation strategies might proceed. We conclude that: (1) AMR Action Plans do not tackle all the potentially relevant pathways and drivers of AMR in the environment; and (2) AMR Action Plans are deficient partly because the science to inform policy is lacking and this needs to be addressed.