Identification of indicator PPCPs in landfill leachates and livestock wastewaters using multi-residue analysis of 70 PPCPs: Analytical method development and application in Yangtze River Delta, China

Peroxysulfur species-mediated enhanced oxidation of micropollutants by ferrate(VI): Peroxymonosulfate versus peroxydisulfate

Many studies have shown that Peroxymonosulfate (PMS) works synergistically with ferrate (Fe(VI)) to remove refractory organic compounds in a few minutes. However, little has been reported on the combined effects of peroxydisulfate (PDS) and Fe(VI). Since PDS is stable and cost effective, it is of practical significance to study the reaction mechanism and conditions of the PDS/Fe(VI) system. The results of the study indicate that the intermediate Fe(II) is formed during the decomposition of Fe(VI), which is then rapidly oxidized. Due to the asymmetry of the PMS molecular structure, PMS can rapidly trap Fe(II) (kPMS/Fe(II)= 3 × 104 M-1∙s-1), whereas PDS cannot (kPDS/Fe(II)= 26 M-1∙s-1). Hydroxylamine hydrochloride (HA) can reduce Fe(VI) and Fe(III) to Fe(II) to excite PDS to produce SO4•-. Acetate helps to detect Fe(II), but does not help PDS to trap Fe(II). Active species such as SO4•-, •OH, 1O2, and Fe(IV), Fe(V) are present in both systems, but in different amounts. In the PMS/Fe(Ⅵ) system, all these active species react with ibuprofen (IBP) and degrade IBP within several minutes. The effects of the initial pH, PMS or Fe(VI) dosage, and different amounts of IBP on the removal rate of IBP were investigated. According to the intermediates detected by the GC-MS, the degradation process of IBP includes hydroxylation, demethylation and single bond breakage. The degradation pathways of IBP were proposed. The degradation of IBP in tap water and Songhua River was also investigated. In actual water treatment, the dosage needs to be increased to achieve the same results. This study provides a basis and theoretical support for the application of PMS/Fe(Ⅵ) and PDS/Fe(VI) system in water treatment.

Microplastics as carriers of antibiotic resistance genes and pathogens in municipal solid waste (MSW) landfill leachate and soil: a review

Landfill leachate contains antibiotic resistance genes (ARGs) and microplastics (MPs), making it an important reservoir. However, little research has been conducted on how ARGs are enriched on MPs and how the presence of MPs affects pathogens and ARGs in leachates and soil. MPs possess the capacity to establish unique bacterial populations and assimilate contaminants from their immediate surroundings, generating a potential environment conducive to the growth of disease-causing microorganisms and antibiotic resistance genes (ARGs), thereby exerting selection pressure. Through a comprehensive analysis of scientific literature, we have carried out a practical assessment of this topic. The gathering of pollutants and the formation of dense bacterial communities on microplastics create advantageous circumstances for an increased frequency of ARG transfer and evolution. Additional investigations are necessary to acquire a more profound comprehension of how pathogens and ARGs are enriched, transported, and transferred on microplastics. This research is essential for evaluating the health risks associated with human exposure to these pollutants.

Graphical Abstract

Assessment of environmental forensic indicator for anthropogenic groundwater contamination via target/suspect/nontarget analysis using HRMS techniques

This study compared target/suspect/nontarget analysis via liquid chromatography-high-resolution mass spectrometry (LC-HRMS) with traditional environmental forensic methods, specifically nitrate and its stable N isotope, in assessing groundwater pollution from livestock manure and agriculture. Using an in-house database of 1471 target and suspects, 35 contaminants (pesticides, veterinary drugs, surfactants) were identified, some uniquely linked to specific pollution sources, such as sulfamethazine and 4-formylaminoantipyrine in manure-affected areas. Pesticides were widespread, typically showing higher intensity in agricultural zones. On the other hand, the results of stable N isotope analysis (δ15N-NO3: 4.8 to 16.4‰) indicated the influence of human activities such as fertilizers, sewage, and manure in all sampling sites, including the control site far from the pollution sources and cannot differentiate the specific sources. The study underscores LC-HRMS's efficacy in different pollution sources, surpassing the limitations of stable N isotope analysis, and provides valuable insights for polluted groundwater source tracking strategies.

Environmental health hazards of untreated livestock wastewater: potential risks and future perspectives

Due to technological and economic limitations, waste products such as sewage and manure generated in livestock farming lack comprehensive scientific and centralized treatment. This leads to the exposure of various contaminants in livestock wastewater, posing potential risks to both the ecological environment and human health. This review evaluates the environmental and physical health risks posed by common pollutants in livestock wastewater and outlines future treatment methods to mitigate these risks. Residual wastes in livestock wastewater, including pathogenic bacteria and parasites surviving after epidemics or diseases on various farms, along with antibiotics, organic wastes, and heavy metals from farming activities, contribute to environmental damage and pose risks to human health. As the livestock industry's development increasingly impacts society's future negatively, addressing the issue of residual wastes in livestock wastewater discharge becomes imperative. Ongoing advancements in wastewater treatment systems are consistently updating and refining practices to effectively minimize waste exposure at the discharge source, mitigating risks to environmental ecology and human health. This review not only summarizes the "potential risks of livestock wastewater" but also explores "the prospects for the development of wastewater treatment technologies" based on current reports. It offers valuable insights to support the long-term and healthy development of the livestock industry and contribute to the sustainable development of the ecological environment.

Environmental pitfalls and associated human health risks and ecological impacts from landfill leachate contaminants: Current evidence, recommended interventions and future directions

The improper management of solid waste, particularly the dumping of untreated municipal solid waste, poses a growing global challenge in both developed and developing nations. The generation of leachate is one of the significant issues that arise from this practice, and it can have harmful impacts on both the environment and public health. This paper presents an overview of the primary waste types that generate landfill leachate and their characteristics. This includes examining the distribution of waste types in landfills globally and how they have changed over time, which can provide valuable insights into potential pollutants in a given area and their trends. With a lack of specific regulations and growing concerns regarding environmental and health impacts, the paper also focuses on emerging contaminants. Furthermore, the environmental and ecological impacts of leachate, along with associated health risks, are analyzed. The potential applications of landfill leachate, suggested interventions and future directions are also discussed in the manuscript. Finally, this work addresses future research directions in landfill leachate studies, with attention, for the first time to the potentialities that artificial intelligence can offer for landfill leachate management, studies, and applications.

An integrated framework to develop an efficient valid green (EVG) HPLC method for the assessment of antimicrobial pollutants with potential threats to human health in aquatic systems

The persistence of antimicrobial drugs in aquatic environments has raised critical concerns about their possible impact on drinkable water quality and human health. The Nile River is experiencing water pollution owing to increasing discharges of highly contaminated home and industrial effluents and inadequate water management systems. Investigations of the presence of three antimicrobial agents, ciprofloxacin (CIP), sulfamethoxazole (SMZ), and albendazole (ALB), in the Egyptian aquatic system are recommended using a chromatographic method because of their reported existence in the African aquatic environment. In this study, an integrated framework, Efficient Valid Green (EVG), for analytical techniques is proposed and displayed via its radar chart. The EVG framework is achieved through three main pillars: efficiency, validation, and greenness. The proposed EVG-HPLC method was developed and optimized using the AQbD methodology via a face-centered composite (FCC) design by identifying the proper critical method parameters (CMPs) that influence critical quality attributes (CQAs). The method was fully validated according to ICH guidelines, including a factorial robustness study within concentration ranges of 1-100 μg mL-1, 2-100 μg mL-1, and 10-100 μg mL-1 for CIP, SMZ, and ALB, respectively. The proposed method was evaluated in terms of greenness using AGREE (score 0.55) and ComplexGAPI metrics. The optimized chromatographic conditions included a C18 column and a mobile phase of water : acetonitrile : methanol in a ratio of 60 : 19 : 21, v/v/v, respectively, with an aqueous solution of pH 3.5 adjusted with phosphoric acid at a flow rate of 1.57 mL min-1 at 285 nm. The raw water samples collected from Nile River freshwater at different locations were treated using Oasis® PRiME HLB cartridges with satisfactory recoveries for the three analytes (>90%), and the three drugs were detected using the proposed EVG-HPLC method.

Anthelmintics in the environment: Their occurrence, fate, and toxicity to non-target organisms

Anthelmintics are drugs used for the treatment and prevention of diseases caused by parasitic worms (helminths). While the importance of anthelmintics in human as well as in veterinary medicine is evident, they represent emerging contaminants of the environment. Human anthelmintics are mainly used in tropical and sub-tropical regions, while veterinary anthelmintics have become frequently-occurring environmental pollutants worldwide due to intensive agri- and aquaculture production. In the environment, anthelmintics are distributed in water and soil in relation to their structure and physicochemical properties. Consequently, they enter various organisms directly (e.g. plants, soil invertebrates, water animals) or indirectly through food-chain. Several anthelmintics elicit toxic effects in non-target species. Although new information has been made available, anthelmintics in ecosystems should be more thoroughly investigated to obtain complex knowledge on their impact in various environments. This review summarizes available information about the occurrence, behavior, and toxic effect of anthelmintics in environment. Several reasons why anthelmintics are dangerous contaminants are highlighted along with options to reduce contamination. Negative effects are also outlined.

Physical and chemical characterization and pollution index applied in the assessment of the polluting potential of leachate from urban landfills

During the operation of the landfills, leachate should be managed with caution to avoid possible negative environmental impacts. Considering this, the present study aims to evaluate the relationship between different variables in the leachate composition and elucidate the transformation processes through which this effluent passes during the landfill's period of operation. The study was conducted with eight sanitary landfills from the state of Minas Gerais, in southeastern Brazil, and used descriptive statistical analysis, principal component analysis (PCA), correlation analysis, and calculation of the leachate pollution index (LPI). The biochemical oxygen demand (BOD5)/chemical oxygen demand (COD) ratio was between 0.20 and 0.60. We also observed a significant correlation of 0.45 between Cl- and N-NH4+, which reflects the biological degradation processes that contribute to the presence of both variables. The PCA showed that inorganic variables and organic matter dominated the first component, with coefficients above 0.65, indicating the importance of those variables in determining the general data variability. The LPI values were between 15.26 and 25.97, with BOD5, COD, and N-NH4+ having sub-indexes above 35, being the main variables that increase the pollution potential of the leachate. On the other hand, trace metals present sub-indexes below 7 due to precipitation caused by increased pH and the characteristics of the waste discarded in landfills. The study provides essential information regarding the landfill leachate characteristics and its variation over time, which can contribute to the definition of treatment technologies for this affluent in different scenarios.

Ecological risks induced by consumption and emission of Pharmaceutical and personal care products in Qinghai-Tibet Plateau: Insights from the polar regions

As the third pole of the world and Asia's water tower, the Tibetan Plateau experiences daily release of pharmaceutical and personal care products (PPCPs) due to increasing human activity. This study aimed to explore the potential relationship between the concentration and composition of PPCPs and human activity, by assessing the occurrence of PPCPs in areas of typical human activity on the Qinghai-Tibet Plateau and evaluating their ecological risk. The results indicate that 28 out of 30 substances were detected in concentrations ranging from less than 1 ng/L to hundreds of ng/L, with the average concentration of most PPCPs in the Tibet Autonomous Region being higher than that in Qinghai Province. Among the detected substances, CAF, NOR, CTC, CIP, TCN, OTC, AZN, and DOX accounted for over 90% of the total concentration. The emission sources of PPCPs were identified by analyzing the correlation coefficients of soil and water samples, with excess PPCPs used by livestock breeding discharged directly into soil and then into surface water through leaching or runoff. By comparing the concentration and composition of PPCPs with those in other regions, this study found that CIP, ENR, LOM, NOR, CTC, DOX, OTC, and TCN were the most commonly used PPCPs in the Qinghai-Tibet Plateau. To assess the ecological risk of PPCPs, organisms at different trophic levels, including algae, crustaceans, fish, and insects, were selected. The prediction of the no effect concentration of each PPCP showed that NOR, CTC, TCN, CAF, and CBZ may have deleterious effects on water biota. This study can assist in identifying the emission characteristics of PPCPs from different types and intensities of human activities, as well as their occurrence and fate during the natural decay of aquatic systems.

Multimedia fate of sulfamethoxazole (SMX) in a water-scarce city by coupling fugacity model and HYDRUS-1D model

Increased concentrations of pharmaceutical and personal care products (PPCPs) have raised concerns about their impact on the ecological system and human health. To understand the environmental impact of PPCPs, we evaluated the fate of a typical PPCP of sulfamethoxazole (SMX) in a water-scarce city of Tianjin during 2013-2020 using a coupled model based on the dynamic fugacity model and HYDRUS-1D model. The results showed that the coupled model successfully simulated the reported SMX concentrations in the main fate media of water and soils, which accounted for 46.4 % and 53.0 % with equilibrium concentrations of 135-165 ng/L and 0.4-0.5 ng/g, respectively. The cross-media transfer flux results showed that advection was the prime input path for SMX in water, while degradation was the dominant output path. Wastewater irrigation and degradation were the main transfer processes of SMX in the soil. Moreover, human activities (i.e., emission loads) and climate (i.e., temperature and precipitation) change can significantly affect the concentrations and transfer rate of SMX in the media. These findings provide basic data and methods for the risk assessment of SMX in water-scarce regions.

Impacts of garbage classification and disposal on the occurrence of pharmaceutical and personal care products in municipal solid waste leachates: A case study in Shanghai

Leachate generated during the treatment and disposal of municipal solid wastes (MSWs) can be an important source of pharmaceutical and personal care products (PPCPs) in the environment. With the implementation of garbage classification policy in China, the disposal methods of MSWs have changed, while its impacts on the occurrence of PPCPs in the generated leachate remain unknown. In this study, we investigated 49 target PPCPs in the leachates of classified MSWs, i.e. residual waste leachate (RWL) and food waste leachate (FWL), and revealed the influence of garbage classification implementation on the occurrence of PPCPs in leachates to be treated. The results showed the concentration and mass load of target PPCPs in the RWL samples (median values: 34.9 ng/L and 52.3 mg/d, respectively) were significantly higher than those in the FWL samples (median values: 19.3 ng/L and 14.5 mg/d, respectively). Macrolide (ML) antibiotics were the predominant PPCPs in the RWL samples, while in the FWL samples, quinolone (QL) antibiotics exhibited the highest concentration and mass load. The implementation of garbage classification policy led to the reduction of PPCP mass load (from 739 g/d to 262 g/d) in leachates to be treated. The findings are helpful for better designing or managing MSW treatment and disposal processes to minimize the emission of PPCPs from MSW leachates.

Occurrence, ecology risk assessment and exposure evaluation of 19 anthelmintics in dust and soil from China

In order to fill the blank of domestic research on anthelmintics in dust and soil, 159 paired dust (including indoor and outdoor dust) and soil samples were collected nationwide. All 19 kinds of the anthelmintics were detected in the samples. The total concentration of the target substances in the outdoor dust, indoor dust and soil samples ranged from 1.83 to 1.30 × 10³ ng/g, from 2.99 to 6.00 × 10³ ng/g and from 0.23 to 8.03 × 10² ng/g, respectively. The total concentration of the 19 anthelmintics in northern China were significantly higher than those in southern China in the outdoor dust and soil samples. No significant correlation was found in the total concentration of anthelmintics between the indoor and outdoor dust because of strong human activities interference, however, a significant correlation existed between the outdoor dust and soil samples and between the indoor dust and soil samples. High ecological risk was found at 35% and 28% of all the sampling sites to non-target organisms in the soil respectively for IVE and ABA, and merits further study. The daily anthelmintics intakes were evaluated via ingestion and dermal contact of soil and dust samples for both children and adults. Ingestion was the predominant way for anthelmintics exposure, and the anthelmintics in soil and dust did not pose a health threat to human health at present.

Insight into pharmaceutical and personal care products removal using constructed wetlands: A comprehensive review

Pharmaceutical and personal care products (PPCPs) were regarded as emerging environmental pollutants due to their ubiquitous appearance and high environmental risks. The wastewater treatment plants (WWTPs) became the hub of PPCPs receiving major sources of PPCPs used by humans. Increasing concern has been focused on promoting cost-effective ways to eliminate PPCPs within WWTPs for blocking their route into the environment through effluent discharging. Among all advanced technologies, constructed wetlands (CWs) with a combination of plants, substrates, and microbes attracted attention due to their cost-effectiveness and easier maintenance during long-term operation. This study offers baseline data for risk control and future treatment by discussing the extent and dispersion of PPCPs in surface waters over the past ten years and identifying the mechanisms of PPCPs removal in CWs based on the up-to-present research, with a special focus on the contribution of sediments, vegetation, and the interactions of microorganisms. The significant role of wetland plants in the removal of PPCPs was detailed discussed in identifying the contribution of direct uptake, adsorption, phytovolatilization, and biodegradation. Meanwhile, the correlation between the physical-chemical characteristics of PPCPs, the configuration operation of wetlands, as well as the environmental conditions with PPCP removal were also further estimated. Finally, the critical issues and knowledge gaps before the real application were addressed followed by promoted future works, which are expected to provide a comprehensive foundation for study on PPCPs elimination utilizing CWs and drive to achieve large-scale applications to treat PPCPs-contaminated surface waters.

Estimating the Mass of Pharmaceuticals Harbored in Municipal Solid Waste Landfills by Analyzing Refuse Samples at Various Ages and Depths

Pharmaceuticals have been detected at high concentrations in municipal solid waste (MSW) landfill leachates, which are recognized as an underestimated source of pharmaceutical residues in the environment. However, limited efforts have been made to characterize pharmaceuticals in MSW landfill refuse, which is also of significant concern given the potential long-term environmental impact. Herein, we excavated landfill refuse from six cells with landfill ages of 7-27 years in the largest MSW landfill in Shanghai (in each cell, landfill refuse was collected from different depths of 2-8 m) and analyzed samples for the presence of 55 pharmaceuticals, including antibiotics and non-antibiotics. The results reveal the presence of 42 pharmaceuticals in landfill refuse, with median concentrations ranging from 0.30 to 116 μg/kg. Antibiotic and non-antibiotic pharmaceuticals exhibited diverse concentration trends with age, related to changes in policy intervention and consumption over time. Different concentration variations of individual pharmaceuticals were observed in refuse samples excavated at different depths and positively correlated to their sorption ability. The mass of pharmaceuticals in the investigated landfill was estimated from the obtained concentrations to be 80-220 tons with 95% probability, based on Monte Carlo analysis. To the best of our knowledge, this study provides the first estimate of pharmaceutical mass in an MSW landfill. The results will be helpful for understanding the potential long-term environmental impact of pharmaceuticals in landfills.

Pharmaceutical active compounds in a heavily industrialized and urbanized bay, Eastern China

Bays are transition zones connecting freshwater ecosystems and marine ecosystems, and they are strongly influenced by intensive human activities. Pharmaceuticals are of concern in bay aquatic environments because of their potential threat to marine food web. We studied the occurrence, spatial distribution, and ecological risks of 34 pharmaceutical active compounds (PhACs) in Xiangshan Bay, a heavily industrialized and urbanized area in Zhejiang Province, Eastern China. PhACs were ubiquitously detected in the coastal waters of the study area. A total of twenty-nine compounds were detected in at least one sample. Carbamazepine, lincomycin, diltiazem, propranolol, venlafaxine, anhydro erythromycin, and ofloxacin had the highest detection rate (≥ 93%). These compounds were detected with maximum concentrations of 31, 127, 0.52, 1.96, 2.98, 75, and 98 ng/L, respectively. Human pollution activities included marine aquacultural discharge and effluents from the local sewage treatment plants. These activities were the most influential sources in this study area based on principal component analysis. Lincomycin was an indicator of veterinary pollution of coastal aquatic environment, and the concentrations of lincomycin were positively related to the total phosphorus in this area (r = 0.28, p < 0.05). Typical PhACs such as venlafaxine, ofloxacin, norfloxacin, roxithromycin, and clarithromycin were significantly and positively correlated with nitrate and total nitrogen (r > 0.26, p < 0.05) based on Pearson's correlation analysis. Carbamazepine was negatively correlated with salinity (r <  - 0.30, p < 0.01). Land use pattern was also correlated with the occurrence and distribution of PhACs in the Xiangshan Bay. Some PhACs, i.e., ofloxacin, ciprofloxacin, carbamazepine, and amitriptyline posed medium to high ecological risks to this coastal environment. The results of this study could be helpful to understand the levels of pharmaceuticals, potential sources, and ecological risks in marine aquacultural environment.

An advanced LC-MS/MS protocol for simultaneous detection of pharmaceuticals and personal care products in the environment

RATIONALE

The development of appropriate analytical screening techniques for pharmaceuticals and personal care products (PPCPs) is the basis for studying the distribution and environmental impact of emerging contaminants (ECs). Mass spectrometry-based screening methods vary with the complexity of the target compounds. It is challenging to balance both positive and negative ion quantification with a low detection limit. To establish a set of experimental methods including extraction, chromatography-separation and mass spectrometry screening is one of the most important topics in PPCP research. This paper describes a universal and efficient qualification and quantification protocol for the simultaneous detection of 34 PPCPs in different environmental samples in a single analytical data acquisition run.

METHODS

Thirty-four representative PPCPs, which are widely distributed in the environment with high ecological toxicity and complex chemical structures, were selected as representative target ECs. The extraction of the target PPCPs was achieved using only one solid-phase extraction cartridge without the need to adjust the pH of samples. The enriched samples were detected by LC-MS/MS in both positive and negative ion modes simultaneously. The protocol was evaluated based on the accuracy, precision, detection limits and matrix effects.

RESULTS

This method achieved simultaneous detection of PPCPs in both positive and negative ion modes, with a single analytical cycle of 12 min. The observed SPE recoveries were between 40% and 115%. The instrumental detection limits (IDL) varied from 0.01 to 1 pg, and the method detection limits (MDL) were between 0.002 and 3.323 ng/l in different matrices. Most of the PPCPs were subjected to matrix suppression below 30%. The method was successfully applied for quantitative analysis of the PPCPs in different environmental samples, including river samples, wastewater treatment plant (WWTP) samples and soil samples.

CONCLUSIONS

This protocol developed a rapid and efficient detection method to simultaneous qualitative and quantitative 34 representative PPCPs in the environment. The IDL ranged from 0.01 to 1 pg and the MDL ranged from 0.002 to 3.323 ng/l in different matrices. The detection limit was one order of magnitude lower compared to previous studies. The protocol also provided a wide application range for different environmental matrices, which permitted the migration and transformation of PPCPs to be explored.

New insights into lincomycin biodegradation by Conexibacter sp. LD01: Genomics characterization, biodegradation kinetics and pathways

The aerobic, lincomycin-degrading bacterial strain Conexibacter sp. LD01, belonging to the phylum Actinobacteria, was isolated from activated sludge. Both second- and third-generation sequencing technologies were applied to uncover the genomic characterization and high-quality genome with 99.2% completeness and 2.2% contamination was obtained. The biodegradation kinetics of lincomycin fit well with the modified Gompertz model (R² > 0.97). Conexibacter sp. LD01 could subsist with lincomycin as the sole source of carbon, nitrogen, and energy. When 500 mg/L of glucose was added as a co-substrate, the biodegradation rate improved significantly, whereas the addition of 500 mg/L sodium pyruvate had a slight inhibitory effect. Ammonia nitrogen was the best nitrogen source for Conexibacter sp. LD01 when growing and degrading lincomycin. In total, 17 metabolic products consisting of nine novel products were detected, and five biodegradation pathways, including N-demethylation, breakage of the amido bond, sulfoxidation, and oxidation of the pyrrolidine ring and propylamino chain, were proposed. This study significantly expands our understanding of the functional microorganisms and mechanism involved in lincomycin biodegradation at the phylum level.

Efficient peroxymonosulfate activation by biochar-based nanohybrids for the degradation of pharmaceutical and personal care products in aquatic environments

Recently, pharmaceutical and personal care products (PPCPs) have been of wide concern due to their ecological toxicity, persistence, and ubiquity in aquatic environments. Peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) have shown great potential for eliminating PPCPs due to their superior oxidation ability and adaptability. Biochar-based nanohybrids have been employed as emerging catalysts for peroxymonosulfate (PMS) activation. Until now, few researchers have summarized PMS activation by biochar-based catalysts for PPCPs removal. In this review, the types, sources, fates, and ecological toxicities of PPCPs were first summarized. Furthermore, various preparation and modification methods of biochar-based catalysts were systematically introduced. Importantly, the application of activating PMS with biochar-based multifunctional nanocomposites for eliminating PPCPs was reviewed. The influencing factors, such as catalysts dosage, PMS dosage, solution pH, temperature, anions, natural organic matters (NOMs), and pollutants concentration were broadly discussed. Biochar-based catalysts can act as electron donors, electron acceptors, and electron shuttles to activate PMS for the removal of PPCPs through radical pathways or/and non-radical pathways. The degradation mechanisms of PPCPs are correlated with persistent free radicals (PFRs), metal species, defective sites, graphitized degree, functional groups, electronic attributes, and the hybridization modes of biochar-based catalysts. Finally, the current problems and further research directions on the industrial application of biochar-based nanocomposites were proposed. This study provides some enlightenment for the efficient removal of PPCPs with biochar-based catalysts in PMS-AOPs.

Sample pretreatment and analytical methodology for the determination of antibiotics in swine wastewater and activated sludge

An analytical method for the simultaneous extraction and determination of eight veterinary antibiotics in swine wastewater and activated sludge was developed and validated based on the instrumental determination by liquid chromatography tandem quadrupole mass spectrometry. Ultrasound-assisted extraction and solid-phase extraction were introduced into the pretreatment procedure of the two complex environmental matrices. The critical steps involved in the sample pretreatment procedure and the instrumental analysis conditions were optimized progressively. Recoveries of the optimized method were good with 75.3-118.2% in wastewater and 82.8-130.1% in sludge. The absolute deviations of methods were lower than 11.7%, presenting a high reproducibility and precision. The limits of quantification for the eight pharmaceuticals in wastewater and sludge were 5-15 ng·L^-1 and 2-6 ng·g^-1, showing high sensitivity of the methods. The developed method has been successfully applied to evaluate the actual concentration levels of tetracyclines, quinolones, and sulfonamides in actual swine wastewater (maximum detected concentration of 87.377 μg·L^-1) and activated sludge (maximum detected concentration of 51242.3 ng·g^-1).

Discharge of pharmaceuticals from a municipal solid waste transfer station: Overlooked influence on the contamination of pharmaceuticals in surface waters

During the temporal storage of municipal solid wastes (MSWs), pharmaceutically contained in MSWs may percolate into leachates and migrate into receiving waters via surface runoff. However, knowledge of their intra-event variations during the rainfall is quite limited. To fill in this gap, we collected runoff samples in a typical MSW transfer station over the full length of a rainfall event to comprehensively characterize the pharmaceutical contamination profiles. The results showed that 18 pharmaceuticals were detected in the runoff samples with high frequencies and concentrations ranging from below MQL to 18.6 μg/L. During the rainfall event, pharmaceuticals exhibited discrepant leachabilities as a result of different sorption capacities; two concentration peaks of each pharmaceutical were observed, suggesting the leaching effect by rainwater and the potential influence of human-related rinse. A further sampling campaign for one-week-long runoff samples generated by diurnal rinse water was conducted, and the results indicated comparable mass loads of pharmaceuticals in surface runoff receiving rinse water (0.37-8250 μg) to those in rainfall runoff (0.58-1754 μg), suggesting the similar discharge of pharmaceuticals from MSW transfer stations despite the weather. The estimated per capita discharge load of caffeine, one of the typical Pharmaceuticals, from MSW transfer stations was 4383 ng capita^-1 d^-1, higher than that in other emission sources, e.g. municipal wastewater effluent, indicating an overlooked influence of MSW transfer stations on its contamination in the surface waters in Shanghai.

Influence of nitrate/nitrite on the degradation and transformation of triclosan in the UV based disinfection

This study investigated the influence of nitrate/nitrite on the degradation and transformation pathway of triclosan (TCS) in UV, UV/peracetic acid (PAA) and UV/HClO processes. The results indicated that the function of nitrate/nitrite significantly depended on the UV source and wavelength, especially nitrate. Generally, the presence of nitrate decreased the direct photo-degradation of TCS in the UV based disinfection. In the LED-UV and LED-UV/HClO processes, the presence of nitrate improved the radical oxidation, and transformation pathway of TCS was varied accordingly. However, nitrate more played a role of photo-competitor in the UV/PAA process, and the reactive nitrogen species (RNS) was difficult to participant in the degradation of TCS due to low redox potential. Compared to nitrate, the presence of nitrite decreased the degradation of TCS in three different UV based disinfection processes. Under UV irradiation, nitrite primarily acted as an irradiation competitor and radical scavenger. Thus, the indirect photo-degradation of TCS was reduced. Noticeably, nitrate/nitrite were the improtant precersors of nitrogenous products in the UV base disinfection. Many new nitrogenous products were identified. But RNS preferentially reacted with the intermediates by -NO₂ addition compared to directly reacted with TCS.

Distribution and Ecological Risk Assessment of Pharmaceuticals and Personal Care Products in Sediments of North Canal, China

The pollution of water bodies by pharmaceuticals and personal care products (PPCPs) has attracted widespread concern due to their widespread use and pseudo-persistence, but their effects on sediments are less known. In this study, solid-phase extraction-high performance liquid chromatography–tandem mass spectrometry (SPE-LC/MSMS) was used to investigate the occurrence and ecological risks of five typical pharmaceuticals and personal care products (PPCPs) in thirteen key reservoirs, sluices, dams, and estuaries in the Haihe River Basin. At the same time, the PPCP exchanges of surface water, groundwater, and sediments in three typical sections were studied. Finally, the PPCP’s environmental risk is evaluated through the environmental risk quotient. The results showed that the five PPCPs were tri-methoprazine (TMP), sinolamine (SMX), ibuprofen (IBU), triclosan (TCS), and caffeine (CAF). The average concentration of these PPCPs ranged from 0 to 481.19 μg/kg, with relatively high concentrations of TCS and CAF. The relationship between PPCPs in the surface sediments was analyzed to reveal correlations between SMX and TMP, CAF and IBU, CAF and TCS. The risk quotients (RQ) method was used to evaluate the ecological risk of the five detected PPCPs. The major contributors of potential environmental risks were IBU, TCS and CAF, among which all the potential environmental risks at the TCS samples were high risk. This study supplemented the research on the ecological risk of PPCPs in sediments of important reaches of the North Canal to reveal the importance of PPCP control in the North Canal and provided a scientific basis for pollution control and risk prevention of PPCPs.

Determination of trace organic contaminants by a novel mixed-mode online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry

In this study, a novel mixed-mode online solid-phase extraction (SPE) method was developed to recover miscellaneous trace organic contaminants (TrOCs) from environmental water samples. Six kinds of sorbents, including C₁₈ substances, hypercross-linked polymers (2), cation-exchange resins, anion-exchange resins, and graphitized nonporous carbons, were packed into a single online SPE cartridge. Furthermore, a fully automated analytic method was established by coupling this mixed-mode online SPE with liquid chromatography tandem mass spectrometry (online SPE-LC-MS/MS). Sixty-nine TrOCs with diverse properties were selected to examine the performance of this mixed-mode SPE cartridge in comparison with solo-mode online SPE cartridges. The method quantification limit (MQL) and the relative recovery coefficient of TrOCs in diverse water matrices, including groundwater, surface water and sewage effluent were evaluated. The MQL of most TrOCs was lower than 10 ng L^-1. The relative recovery coefficients for most TrOCs in the groundwater (50/69) and surface water (38/69) matrix fit in the satisfactory range. Moreover, mixed-mode online SPE coupled with LC-high-resolution MS was applied for a suspect screening of TrOCs in sewage effluents. A series of highly polar TrOCs that had scarcely been reported by previous studies were identified by this practical and easily accessible method. Finally, this novel mixed-mode online SPE with LC-MS/MS method was applied to quantify the TrOCs in the environmental water samples.

Influence of Rural Development of River Tourism Resources on Physical and Mental Health and Consumption Willingness in the Context of COVID-19

This study took the Three Gorges Dam as an example and discussed the influence of river regulation decisions on the sustainable development of surrounding villages. The study used mixed research methods, snowball sampling, and convenience sampling to obtain samples. The questionnaire samples were analyzed by basic statistical tests, t-test, and structural equation modeling (SEM). The respondents’ opinions were collected through semi-structured interviews and finally the results were discussed by multivariate analysis. The findings were that even though the villages were not well developed in terms of economy, environment, and natural ecology, as long as the community security could be stable, the living could be safe and convenient, people’s daily life patterns and leisure behaviors could be maintained, and people could stabilize their minds and emotions and maintain physical and mental health in order to meet their living needs and reduce the burden. There would be time and funds to invest in leisure, tourism activities, and consumption behavior. If the above consumption patterns are continued, people will gain positive perceptions, stimulating people’s willingness to invest in property purchases or to make travel plans again.

Quantitatively identifying the emission sources of pharmaceutically active compounds (PhACs) in the surface water: Method development, verification and application in Huangpu River, China

Recognizing the main sources of pharmaceutically active compounds (PhACs) found in surface waters has been a challenge to the effective control of PhAC contamination from the sources. In the present study, a novel method based on Characteristic Matrix (ChaMa) model of indicator PhACs to quantitatively identify the contribution of multiple emission sources was developed, verified, and applied in Huangpu River, Shanghai. Carbamazepine (CBZ), caffeine (CF) and sulfadiazine (SDZ) were proposed as indicators. Their occurrence patterns in the corresponding emission sources and the factor analysis of their composition in the surface water samples were employed to construct the ChaMa model and develop the source apportionment method. Samples from typical emission sources were collected and analyzed as hypothetical surface water samples, to verify the method proposed. The results showed that the calculated contribution proportions of emission sources to the corresponding source samples were 45%-85%, proving the feasibility of the method. Finally, the method was applied to different sections in Huangpu River, and the results showed that livestock wastewater was the dominant emission source, accounting for 55%-73% in the upper reach of Huangpu River. Untreated municipal wastewater was dominant in the middle and lower reaches of Huangpu River, accounting for 76%-94%. This novel source apportionment method allows the quantitative identification of the contribution of multiple PhAC emission sources. It can be replicated in other regions where the occurrence of localized indicators was available, and will be helpful to control the contamination of PhACs in the water environment from the major sources.

Migration, Transformation and Removal of Macrolide Antibiotics in The Environment: A Review

Macrolide antibiotics (MAs), as a typical emerging pollutant, are widely detected in environmental media. When entering the environment, MAs can interfere with the growth, development and reproduction of organisms, which has attracted extensive attention. However, there are few reviews on the occurrence characteristics, migration and transformation law, ecotoxicity and related removal technologies of MAs in the environment. In this work, combined with the existing relevant research, the migration and transformation law and ecotoxicity characteristics of MAs in the environment are summarized, and the removal mechanism of MAs is clarified. Currently, most studies on MAs are based on laboratory simulation experiments, and there are few studies on the migration and transformation mechanism between multiphase states. In addition, the cost of MAs removal technology is not satisfactory. Therefore, the following suggestions are put forward for the future research direction. The migration and transformation process of MAs between multiphase states (such as soil-water-sediment) should be focused on. Apart from exploring the new treatment technology of MAs, the upgrading and coupling of existing MAs removal technologies to meet emission standards and reduce costs should also be concerned. This review provides some theoretical basis and data support for understanding the occurrence characteristics, ecotoxicity and removal mechanism of MAs.

Screen-Printed Voltammetric Sensors-Tools for Environmental Water Monitoring of Painkillers

The dynamic production and usage of pharmaceuticals, mainly painkillers, indicates the growing problem of environmental contamination. Therefore, the monitoring of pharmaceutical concentrations in environmental samples, mostly aquatic, is necessary. This article focuses on applying screen-printed voltammetric sensors for the voltammetric determination of painkillers residues, including non-steroidal anti-inflammatory drugs, paracetamol, and tramadol in environmental water samples. The main advantages of these electrodes are simplicity, reliability, portability, small instrumental setups comprising the three electrodes, and modest cost. Moreover, the electroconductivity, catalytic activity, and surface area can be easily improved by modifying the electrode surface with carbon nanomaterials, polymer films, or electrochemical activation.

A review on the landfill leachate treatment technologies and application prospects of three-dimensional electrode technology

With the expansion of urbanisation, the total amount of solid waste produced by urban residents has been increasing, and the problem of municipal solid waste disposal has also been aggravated. Landfill leachate treatment technologies could be divided into three categories: biological, physical and advanced oxidation treatment technology. Among them, advanced oxidation treatment technology has a good effect on the treatment of landfill leachate with little secondary pollution and has excellent application potential. Three-dimensional (3D) electrode technology, as a new type of advanced oxidation technology, could remove refractory pollutants in water and has attracted considerable attention. This article aims to (1) compare existing landfill leachate treatment technologies, (2) summarise 3D electrode technology application scenarios, (3) discuss the advantages of 3D electrode technology in landfill leachate treatment and (4) look ahead the future directions of 3D electrode technology in landfill leachate treatment. We hope that this article will be helpful to researchers who are interested in the field of landfill leachate treatment.

In vitro nematocidal activity of Punica granatum L. against gastrointestinal helminths in goats

The objective of this study was to evaluate the in vitro ovicidal activity, phytochemistry, and toxicity of a saline extract obtained from peel of Punica granatum L fruits. The ovicidal activity was evaluated by the hatching inhibition of eggs recovered from fecal samples of naturally infected goats; the phytochemical analysis was carried out using the fruit peel; and the toxicity was tested on Artemia salina, using saline extract. The results showed that the ovicidal effect of the tested extract was 99% (25 mg mL^-1), 99% (12.5 mg mL^-1), 98% (6.25 mg mL^-1), and 95% (3.12 mg mL^-1), higher than that of the control drug, thiabendazole (83%). The phytochemical analysis showed presence of phenols, anthraquinones, and condensed and hydrolysable tannins in the fruit extract. The toxicity test of the extract of P. granatum showed an LC50 of 6.19 mg mL^-1, which indicates a safe use for a concentration of 3.12 mg mL^-1, since it was the tested concentration that was below the reliable LC50. The saline extract from peels of P. granatum has ovicidal activity, important secondary metabolites, and absence of toxicity at the lowest concentration tested. However, in vivo tests in experimental models are recommended before performing experiments in ruminants.

A poly-(L-serine)/reduced graphene oxide-Nafion supported on glassy carbon (PLS/rGO-Nafion/GCE) electrode for the detection of naproxen in aqueous solutions

A new electrode was constructed via the anodic electropolymerization of poly-(L-serine) (PLS) on an rGO-Nafion-modified glassy carbon electrode (GCE) for the detection of the emerging organic contaminant naproxen (NPX). The morphology, crystal phase, and surface elements of the electrode were investigated with SEM, TEM, XRD, Raman, ATR-FTIR, zeta potential, C-H-O, and XPS analyses. Results of the surface analysis showed a porous structure resembling graphene sheets inside the Nafion/GCE architecture. Various electrochemical parameters, including scan rate, pH, and NPX concentration, were studied to evaluate the performance of the electrode. The synergistic effect of PLS and rGO-Nafion greatly facilitated the catalytic oxidation of NPX on PLS/rGO-Nafion/GCE. Electrochemical NPX oxidation was a one-electron transfer and adsorption limited process. The optimal working potential was 0.92 V vs. Ag/AgCl. The oxidation current of NPX increased with the increase in the concentration of analyte and scan rate but decreased with pH. The modified electrode exhibited excellent linearity with respect to NPX concentration in the range of 4.3 to 87 μM and limit of detection of 0.23 μM (S/N = 3). The PLS/rGO-Nafion/GCE is a fast, sensitive, reliable, and economical electrode for the detection of NPX in water.

Phycoremediation integrated approach for the removal of pharmaceuticals and personal care products from wastewater - A review

Pharmaceuticals and personal care products (PPCPs) are of emerging concerns because of their large usage, persistent nature which promised their continuous disposal into the environment, as these pollutants are stable enough to pass through wastewater treatment plants causing hazardous effects on all the organisms through bioaccumulation, biomagnification, and bioconcentration. The available technologies are not capable of eliminating all the PPCPs along with their degraded products but phycoremediation has the advantage over these technologies by biodegrading the pollutants without developing resistant genes. Even though phycoremediation has many advantages, industries have found difficulty in adapting this technology as a single-stage treatment process. To overcome these drawbacks recent research studies have focused on developing technology that integrated phycoremediation with the commonly employed treatment processes that are in operation for treating the PPCPs effectively. This review paper focuses on such research approaches that focused on integrating phycoremediation with other technologies such as activated sludge process (ASP), advanced oxidation process (AOP), Up-flow anaerobic sludge blanket reactor (UASBR), UV irradiation, and constructed wetland (CW) with the advantages and limitations of each integration processes. Furthermore, augmenting phycoremediation by co-metabolic mechanism with the addition of sodium chloride, sodium acetate, and glucose for the removal of PPCPs has been highlighted in this review paper.

Source-specific risk apportionment and critical risk source identification of antibiotic resistance in Fenhe River basin, China

A comprehensive understanding of the sources and distribution of antibiotic resistance risk is essential for controlling antibiotic pollution and resistance. Based on surface water samples collected from the Fenhe River basin in the flood season, using the positive matrix factorization (PMF) model, the risk quotient (RQ) method and the multiple attribute decision making (MADM) method, the resistance risk and source-specific resistance risk of antibiotics were analyzed in this study. The results showed that sulfonamides (SAs) were the dominant antibiotics with a mean concentration of 118.30 ng/L, whereas tetracyclines (TCs) and macrolides (MLs) had the highest detection frequencies (100%). The significant resistance risk rate of antibiotics in the entire river basin was 48%, but no high risk occurred. The significant resistance risk rate of quinolones (QNs) was the highest (100%), followed by that of MLs and TCs. Owing to human activities, the most serious resistance risk occurred in the midstream of the river basin. The resistance risk was the lowest upstream. The antibiotics were mainly contributed by six sources. Pharmaceutical wastewater was the main source, accounting for 30%, followed by livestock discharge (22%). The resistance risk from the six sources showed clear differences, but none of the sources caused a high risk of antibiotic resistance. Pharmaceutical wastewater poses the greatest risk of antibiotic resistance in the Fenhe River basin and is widely distributed. The second greatest source was livestock discharge, which was mainly concentrated in the upstream and midstream areas. The critical sources upstream, midstream, and downstream were all pharmaceutical wastewater, whereas the sequences of other sources were different because different areas were affected by different human activities. The proposed method might provide an important reference for the identification the key source of antibiotics and management of antibiotic pollution, as well as help for the management of antibiotics in Fenhe and Shanxi Province.

Occurrence and risk assessment of pharmaceuticals and personal care products (PPCPs) against COVID-19 in lakes and WWTP-river-estuary system in Wuhan, China

The consumption of pharmaceuticals and personal care products (PPCPs) for controlling and preventing the COVID-19 would have sharply increased during the pandemic. To evaluate their post-pandemic environmental impacts, five categories of drugs were detected in lakes and WWTP-river-estuary system near hospitals of Jinyintan, Huoshenshan and Leishenshan in the three regions (J, H and L) (Regions J, H and L) in Wuhan, China. The total amount of PPCPs (ranging from 2.61 to 1122 ng/L in water and 0.11 to 164 ng/g dry weight in sediments) were comparable to historical reports in Yangtze River basin, whereas the detection frequency and concentrations of ribavirin and azithromycin were higher than those of historical studies. The distribution of concerned drugs varied with space, season, media and water types: sampling sites located at WWTPs-river-estuary system around two hospitals (Regions L and J) usually had relatively high waterborne contamination levels, most of which declined in autumn; lakes had relatively low waterborne contamination levels in summer but increased in autumn. The potential risks of detected PPCPs were further evaluated using the multiple-level ecological risk assessment (MLERA): sulfamethoxazole and azithromycin were found to pose potential risks to aquatic organisms according to a semi-probabilistic approach and classified as priority pollutants based on an optimized risk assessment. In general, the COVID-19 pandemic did not cause serious pollution in lakes and WWTPs-river-estuary system in Wuhan City. However, the increased occurrence of certain drugs and their potential ecological risks need further attention. A strict source control policy and an advanced monitoring and risk warning system for emergency response and long-term risk control of PPCPs is urgent.

Application of a fast and sensitive method for the determination of contaminants of emerging concern in wastewater using a quick, easy, cheap, effective, rugged and safe-based extraction and liquid chromatography coupled to mass spectrometry

The inefficiency of wastewater treatment plants (WWTPs) to remove contaminants of emerging concern (CECs) leads to their continuous release to the environment. Consequently, CECs are present at low concentrations in the treated wastewater (TWW), producing unpredicted and unwanted effects on living organisms as they are discharged into water receiving bodies. This work presents a fast and reliable method for the determination of CECs in TWW based on the innovative application of a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for water extraction and determination by sensitive liquid chromatography coupled to quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS). The scope of the proposed QuEChERS-based method allows the monitoring of 107 CECs, including pharmaceuticals (58), antibiotics (16) and pesticides (33). The proposed method was successfully validated in urban TWW at two concentration levels (50 and 500 ng L^-1) and it is a feasible alternative to conventional and time-consuming solid-phase extraction (SPE) methodologies. 89% of the CECs presented mean recovery values in the 70-120% range with relative standard deviations (RSDs) always < 20% (intra and inter-day precision), and limits of quantification (LOQs) in the range 5-500 ng L^-1 (89% of the compounds showed a LOQ ≤ 50 ng L^-1). The applicability of the method was demonstrated by the analysis of urban TWW samples (7 sampling events). In total, 35 CECs (23 pharmaceuticals, 2 antibiotics and 10 pesticides) were detected in the monitored samples with concentrations ranging from 5 to 677 ng L^-1.

Au nanoparticle plasmon-enhanced electrochemiluminescence aptasensor based on the 1D/2D PTCA/CoP for diclofenac assay

The combination of localized surface plasmon resonance (LSPR) and electrochemiluminescence (ECL) can be an effective way to amplify the signal intensity. In this work, an ECL aptasensor with 3,4,9,10-perylenetetracarboxylic acid-decorated cobalt phosphate (denoted as PTCA/CoP) as the ECL emitter and Au nanoparticles (NPs) as plasma was proposed for diclofenac assay. The prepared PTCA/CoP with special 1D/2D structure exhibited good ability and excellent ECL performance. The diclofenac aptamer acted as a bridge to link the PTCA/CoP and Au NPs; thus, the ECL performance of PTCA/CoP was greatly improved due to the plasma effect of Au NPs. Besides, it was found that the ECL signal of the aptasensor was obviously quenched by the introduction of diclofenac, which might be due to the transformation from the LSPR process to the resonance energy transform (RET) process. Under optimal conditions, the difference of ECL intensity was negatively correlated with the concentration of diclofenac in the range 0.1 pM to 10 μM with a low detection limit of 0.072 pM at the potential of -1.8 V vs. Ag/AgCl (S/N = 3). The aptasensor was proved to be suitable for the detection of diclofenac in real samples, suggesting its great practicability.

Pharmaceutical and Personal Care Products in Different Matrices: Occurrence, Pathways, and Treatment Processes

The procedures for analyzing pharmaceuticals and personal care products (PPCPs) are typically tedious and expensive and thus, it is necessary to synthesize all available information from previously conducted research. An extensive collection of PPCP data from the published literature was compiled to determine the occurrence, pathways, and the effectiveness of current treatment technologies for the removal of PPCPs in water and wastewater. Approximately 90% of the compiled published papers originated from Asia, Europe, and the North American regions. The incomplete removal of PPCPs in different water and wastewater treatment processes was widely reported, thus resulting in the occurrence of PPCP compounds in various environmental compartments. Caffeine, carbamazepine, diclofenac, ibuprofen, triclosan, and triclocarban were among the most commonly reported compounds detected in water and solid matrices. Trace concentrations of PPCPs were also detected on plants and animal tissues, indicating the bioaccumulative properties of some PPCP compounds. A significant lack of studies regarding the presence of PPCPs in animal and plant samples was identified in the review. Furthermore, there were still knowledge gaps on the ecotoxicity, sub-lethal effects, and effective treatment processes for PPCPs. The knowledge gaps identified in this study can be used to devise a more effective research paradigm and guidelines for PPCP management.

Selective enrichment of antibiotic resistance genes and pathogens on polystyrene microplastics in landfill leachate

Landfill leachate is an important reservoir of antibiotic resistance genes (ARGs) and microplastics (MPs). However, the enrichment characteristics of ARGs on MPs and the effect of MPs' presence on ARGs in surrounding leachates are little studied. Therefore, we investigated the differences of ARGs, mobile genetic elements (MGEs), bacterial communities and pathogens on polystyrene MPs, in MPs-surrounding leachate and in control (leachate with the absence of MPs). The results revealed that ARGs were selectively enriched on MPs, which was similar in three types of leachate environments. The genes strB and bla_TEM were maximally enriched and mefA, ermB, tetM and tetQ were slightly enriched on MPs, and the degree of ARGs enrichment increased with time during the 60 days of the experiment. Furthermore, compared to the leachate, MPs were observed to have the higher abundances of MGEs and distinct bacterial communities, both of which were closely associated with ARGs on MPs. Pathogens were distinct and more abundant on MPs compared to that in leachate, and 11 pathogens were identified as potential hosts for ARGs on MPs. Additionally, the presence of MPs (500 mg/L) induced few changes in ARGs' abundances, MGEs' abundances and bacterial communities in MP-surrounding leachate within 60 days. Overall, this study suggested that MPs could selectively enrich ARGs and pathogens from the surrounding environments, which promoted the understanding of the combined pollution properties of MPs and ARGs.

Potential Environmental and Human Health Risks Caused by Antibiotic-Resistant Bacteria (ARB), Antibiotic Resistance Genes (ARGs) and Emerging Contaminants (ECs) from Municipal Solid Waste (MSW) Landfill

The disposal of municipal solid waste (MSW) directly at landfills or open dump areas, without segregation and treatment, is a significant concern due to its hazardous contents of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs), and metal resistance genes (MGEs). The released leachate from landfills greatly effects the soil physicochemical, biological, and groundwater properties associated with agricultural activity and human health. The abundance of ARB, ARGs, and MGEs have been reported worldwide, including MSW landfill sites, animal husbandry, wastewater, groundwater, soil, and aerosol. This review elucidates the occurrence and abundance of ARB, ARGs, and MRGs, which are regarded as emerging contaminants (ECs). Recently, ECs have received global attention because of their prevalence in leachate as a substantial threat to environmental and public health, including an economic burden for developing nations. The present review exclusively discusses the demands to develop a novel eco-friendly management strategy to combat these global issues. This review also gives an intrinsic discussion about the insights of different aspects of environmental and public health concerns caused due to massive leachate generation, the abundance of antibiotics resistance (AR), and the effects of released leachate on the various environmental reservoirs and human health. Furthermore, the current review throws light on the source and fate of different ECs of landfill leachate and their possible impact on the nearby environments (groundwater, surface water, and soil) affecting human health. The present review strongly suggests the demand for future research focuses on the advancement of the removal efficiency of contaminants with the improvement of relevant landfill management to reduce the potential effects of disposable waste. We propose the necessity of the identification and monitoring of potential environmental and human health risks associated with landfill leachate contaminants.

CdS nanoparticle decorated triazine-based COFs with enhanced photocatalytic activity for highly effective degradation of emerging contaminants

COF-based photocatalysts containing C3N4 units decorated with CdS were constructed and employed as the mediator of peroxydisulfate activation for removing pollutants.

MoS2-assisted Fe2+/peroxymonosulfate oxidation for the abatement of phenacetin: efficiency, mechanisms and toxicity evaluation

In this study, molybdenum disulfide (MoS₂) was chosen as a co-catalyst to enhance the removal efficiency of phenacetin (PNT) in water by a ferrous ion-activated peroxymonosulfate (Fe²⁺/PMS) process. Operating parameters, such as the initial solution pH and chemical dose on PNT degradation efficiency were investigated and optimized. Under an initial pH of 3, an Fe²⁺ dose of 25 μM, a PMS dose of 125 μM and a MoS₂ dose of 0.1 g L⁻¹, the degradation efficiency of PNT reached 94.3%, within 15 min. The presence of common water constituents including Cl⁻, HCO₃⁻, SO₄²⁻ and natural organic matter (NOM) will inhibit degradation of PNT in the MoS₂/Fe²⁺/PMS system. Radical quenching tests combined with electron paramagnetic resonance (EPR) results indicated that in addition to free radical species (˙OH, SO₄˙⁻ and O₂˙⁻), nonradical reactive species (¹O₂) were also crucial for PNT degradation. The variations in the composition and crystalline structure of the MoS₂ before and after the reaction were characterized by XPS and XRD. Further, the degradation pathways of PNT were proposed according to the combined results of LC/TOF/MS and DFT calculations, and primarily included hydroxylation of the aromatic ring, cleavage of the C–N bond of the acetyl-amino group, and cleavage of the C–O bond of the ethoxy group. Finally, toxicity assessment of PNT and its products was predicted using the ECOSAR program.

Performance, mechanisms and toxicity evaluation of PNT degradation by the MoS₂/Fe²⁺/PMS system were investigated.