Pharmaceuticals of Emerging Concern in Aquatic Systems: Chemistry, Occurrence, Effects, and Removal Methods

Simultaneous degradation of 30 pharmaceuticals by anodic oxidation: Main intermediaries and by-products

The anodic oxidation (AO) of 30 pharmaceuticals including antibiotics, hormones, antihistaminics, anti-inflammatories, antidepressants, antihypertensives, and antiulcer agents, in solutions containing different supporting electrolytes media (0.05 M Na₂SO₄, 0.05 M NaCl, and 0.05 M Na₂SO₄ + 0.05 M NaCl) at natural pH was studied. A boron-doped diamond (BDD) electrode and a stainless-steel electrode were used as anode and cathode, respectively, and three current densities of 6, 20, and 40 mA cm^-2 were applied. The results showed high mineralization rates, above 85%, in all the tested electrolytic media. 25 intermediaries produced during the electrooxidation were identified, depending on the supporting electrolyte together with the formation of carboxylic acids, NO₃^-, SO₄^2- and NH₄⁺ ions. The formation of intermediates in chloride medium produced an increase in absorbance. Finally, a real secondary effluent spiked with the 30 pharmaceuticals was treated by AO applying 6 mA cm^-2 at natural pH and without addition of supporting electrolyte, reaching c.a. 90% mineralization after 300 min, with an energy consumption of 18.95 kW h m^-3 equivalent to 2.90 USD m^-3. A degradation scheme for the mixture of emerging contaminants in both electrolytic media is proposed. Thus, the application of anodic oxidation generates a high concentration of hydroxyl radicals that favors the mineralization of the pharmaceuticals present in the spiked secondary effluent sample.

Occurrence of caffeine, fluoxetine, bezafibrate and levothyroxine in surface freshwater of São Paulo State (Brazil) and risk assessment for aquatic life protection

The prioritization of active pharmaceutical ingredients (APIs) for monitoring programmes and/or environmental risk assessment (ERA) purposes is based on several criteria, including environmental occurrence data. However, data on API occurrence in Brazilian surface freshwaters are still scarce. The Brazilian Unified Health System (SUS) provides several medicines free-of-charge, including medications that have bezafibrate, fluoxetine and levothyroxine as the API. Thus, our objective was to investigate the occurrence of bezafibrate, fluoxetine and levothyroxine in samples collected at sampling sites included in the surface freshwater monitoring program of the São Paulo State Environmental Agency (CETESB); caffeine was also included in the analysis because it is commonly used as an anthropogenic marker of aquatic environment contamination. Monitoring results showed that levothyroxine was not found in any of the analysed samples. Caffeine was ubiquitous in the analysed samples, thus indicating anthropic contamination in the studied water bodies. Caffeine and bezafibrate presented risk quotient (RQ) < 1 for all the sampling sites and periods evaluated in this study. For fluoxetine, RQs > 1 were found in all water samples in which this API was found, indicating a potential risk for freshwater pelagic biota. Thus, fluoxetine should be regulated in São Paulo State in order to protect the aquatic biota. Additional occurrence studies in other Brazilian states are still needed to evaluate if fluoxetine is a nationwide pollutant.

Enhancing Circular Dichroism Signals with Vector Beams

Circular dichroism (CD) is broadly employed for distinguishing molecular chiralities. However, its practical application is often limited by the weak magnitude of chiral signal. We propose to use azimuthally and radially polarized vector beams to probe CD spectra. By taking advantage of the strong longitudinal components of the vector beams, the transmitted light can be detected in the radial direction. The resulting CD signal is several orders of magnitude stronger than conventional CD signal with plane waves. Quantitative analysis and numerical simulations show that the enhancement factor is independent of molecular properties and can be increased by decreasing the path length of the sample cuvette and the interaction cross section between the light beam and molecular sample. The proposed novel CD spectroscopy is feasible with the current optical technology.

LC and NMR Studies for Identification and Characterization of Degradation Byproducts of Olmesartan Acid, Elucidation of Their Degradation Pathway and Ecotoxicity Assessment

The discovery of various sartans, which are among the most used antihypertensive drugs in the world, is increasingly frequent not only in wastewater but also in surface water and, in some cases, even in drinking or groundwater. In this paper, the degradation pathway of olmesartan acid, one of the most used sartans, was investigated by simulating the chlorination process normally used in a wastewater treatment plant to reduce similar emerging pollutants. The structures of nine isolated degradation byproducts (DPs), eight of which were isolated for the first time, were separated via chromatography column and HPLC methods, identified by combining nuclear magnetic resonance and mass spectrometry, and justified by a proposed mechanism of formation beginning from the parent drug. Ecotoxicity tests on olmesartan acid and its nine DPs showed that 50% of the investigated byproducts inhibited the target species Aliivibrio fischeri and Raphidocelis subcapitata, causing functional decreases of 18% and 53%, respectively.

Aquatic Insects Transfer Pharmaceuticals and Endocrine Disruptors from Aquatic to Terrestrial Ecosystems

A wide range of pharmaceuticals and endocrine disrupting compounds enter freshwaters globally. As these contaminants are transported through aquatic food webs, understanding their impacts on both aquatic and terrestrial ecosystems remains a major challenge. Here, we provide the first direct evidence of the transfer of pharmaceuticals and endocrine disruptors through the aquatic-terrestrial habitat linkage by emerging aquatic insects. We also show that the type of insect metamorphosis and feeding behavior determine the bioaccumulation patterns of these contaminants. Adult Trichoptera, an important food source for riparian predators, showed an increased body burden of pharmaceuticals and endocrine disruptors. This implies that terrestrial predators, such as spiders, birds, and bats, are exposed to mixtures of pharmaceuticals and endocrine disruptors of aquatic origin, which may impact their physiology and population dynamics. Overall, our study provides valuable insights into the bioaccumulation patterns and trophic cross-ecosystem transfer of these contaminants, from aquatic primary producers to terrestrial predators.

Silicate-Enhanced Heterogeneous Flow-Through Electro-Fenton System Using Iron Oxides under Nanoconfinement

Herein, a silicate-enhanced flow-through electro-Fenton system with a nanoconfined catalyst was rationally designed and demonstrated for the highly efficient, rapid, and selective degradation of antibiotic tetracycline. The key active component of this system is the Fe₂O₃ nanoparticle filled carbon nanotube (Fe₂O₃-in-CNT) filter. Under an electric field, this composite filter enabled in situ H₂O₂ generation, which was converted to reactive oxygen species accompanied by the redox cycling of Fe³⁺/Fe²⁺. The presence of the silicate electrolyte significantly boosted the H₂O₂ yield by preventing the O-O bond dissociation of the adsorbed OOH*. Compared with the surface coated Fe₂O₃ on the CNT (Fe₂O₃-out-CNT) filter, the Fe₂O₃-in-CNT filter demonstrated 1.65 times higher k_L value toward the degradation of the antibiotic tetracycline. Electron paramagnetic resonance and radical quenching tests synergistically verified that the dominant radical species was the ¹O₂ or HO· in the confined Fe₂O₃-in-CNT or unconfined Fe₂O₃-out-CNT system, respectively. The flow-through configuration offered improved tetracycline degradation kinetics, which was 5.1 times higher (at flow rate of 1.5 mL min^-1) than that of a conventional batch reactor. Liquid chromatography-mass spectrometry measurements and theoretical calculations suggested reduced toxicity of fragments of tetracycline formed. This study provides a novel strategy by integrating state-of-the-art material science, Fenton chemistry, and microfiltration technology for environmental remediation.

Urban Groundwater Contamination by Non-Steroidal Anti-Inflammatory Drugs

Pharmaceuticals, such as non-steroidal anti-inflammatory drugs (NSAIDs) and their metabolites, have become a major concern due to their increasing consumption and their widespread occurrence in the environment. In this paper, we investigate the occurrence of NSAIDs and their metabolites in an urban aquifer, which may serve as a potential resource for drinking water, and propose a methodology to assess the removal of these substances in the river–groundwater interface. Then, risk quotients (RQs) are computed, in order to determine the risk posed by the single NSAIDs and their mixture to human health. To this end, six NSAIDs and two metabolites were collected from an urban aquifer located in the metropolitan area of Barcelona (NE, Spain), in which the major pollution source is a contaminated river. All of the target NSAIDs were detected in groundwater samples, where the concentrations in the aquifer were higher than those found in the river water (except for ibuprofen). Diclofenac, ketoprofen, propyphenazone and salicylic acid were detected at high mean concentrations (ranging from 91.8 ng/L to 225.2 ng/L) in the aquifer. In contrast, phenazone and mefenamic acid were found at low mean concentrations (i.e., lower than 25 ng/L) in the aquifer. According to the proposed approach, the mixing of river water recharge into the aquifer seemed to some extent to promote the removal of the NSAIDs under the sub-oxic to denitrifying conditions found in the groundwater. The NSAIDs that presented higher mean removal values were 4OH diclofenac (0.8), ibuprofen (0.78), salicylic acid (0.35) and diclofenac (0.28), which are likely to be naturally attenuated under the aforementioned redox conditions. Concerning human health risk assessment, the NSAIDs detected in groundwater and their mixture do not pose any risk for all age intervals considered, as the associated RQs were all less than 0.05. Nevertheless, this value must be taken with caution, as many pharmaceuticals might occur simultaneously in the groundwater.

Biodegradation and metabolic pathway of anthraquinone dyes by Trametes hirsuta D7 immobilized in light expanded clay aggregate and cytotoxicity assessment

Biodegradation and metabolic pathways of three anthraquinone dyes, Reactive Blue 4 (RB4), Remazol Brilliant Blue - R (RBBR), and Acid Blue 129 (AB129) by Trametes hirsuta D7 fungus immobilized in light expanded clay aggregate (LECA) were investigated. Morphological characteristics observed with scanning electron microscope (SEM) showed successful immobilization of the fungus in LECA. Based on UV absorbance measurement, immobilized T. hirsuta D7 effectively degraded 90%, 95%, and 96% of RB4, RBBR and AB129, respectively. Metabolites were identified with high-resolution mass spectrometry (HRMS) and degradation pathway of the dyes by T. hirsuta D7 was proposed. Toxicity assay on human dermal fibroblast (HDF) showed that anthraquinone dyes exhibits significant toxicity of 35%, 40%, and 34% reduction of cell viability by RB4, RBBR, and AB129, respectively. Fungal treatment resulted in an abatement of the toxicity and cell viability was increased up to 94%. The data clearly showed the effectiveness of immobilized T. hirsuta D7 in LECA on detoxification of anthraquinone dyes. This study provides potential and fundamental understanding of wastewater treatment using the newly isolated fungus T. hirsuta D7.

Environmental aspects of hormones estriol, 17β-estradiol and 17α-ethinylestradiol: Electrochemical processes as next-generation technologies for their removal in water matrices

Hormones as a group of emerging contaminants have been increasingly used worldwide, which has increased their concern at the environmental level in various matrices, as they reach the water bodies through effluents due to the ineffectiveness of conventional treatments. Here we review the environmental scenario of hormones estriol (E3), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2), explicitly their origins, their characteristics, interactions, how they reach the environment, and, above all, the severe pathological and toxicological damage to animals and humans they produce. Furthermore, studies for the treatment of these endocrine disruptors (EDCs) are deepened using electrochemical processes as the remediation methods of the respective hormones. In the reported studies, these micropollutants were detected in samples of surface water, underground, soil, and sediment at concentrations that varied from ng L^-1 to μg L^-1 and are capable of causing changes in the endocrine system of various organisms. However, although there are studies on the ecotoxicological effects concerning E3, E2, and EE2 hormones, little is known about their environmental dispersion and damage in quantitative terms. Moreover, biodegradation becomes the primary mechanism of removal of steroid estrogens removal by sewage treatment plants, but it is still inefficient, which shows the importance of studying electrochemically-driven processes such as the Electrochemical Advanced Oxidation Processes (EAOP) and electrocoagulation for the removal of emerging micropollutants. Thus, this review covers information on the occurrence of these hormones in various environmental matrices, their respective treatment, and effects on exposed organisms for ecotoxicology purposes.

Ultrathin S-doped graphitic carbon nitride nanosheets for enhanced sulpiride degradation via visible-light-assisted peroxydisulfate activation: Performance and mechanism

The wide use and distribution of sulpiride (SP) has caused potential threats to the water environment and human health. In this study, ultrathin S-doped graphitic carbon nitride nanosheets (US-CN) was successfully synthesized and characterized, and its SP removal efficiency was evaluated under various conditions via the visible-light-assisted peroxydisulfate (PDS) activation method. The degradation pathways and mechanism were also discussed through quenching experiments, density functional theory (DFT) calculations, and intermediate products detection. After sulfur doping and ultrasonic treatment, graphitic carbon nitride (CN) possessed an ultra-thin and porous structure, which facilitated the electronic distribution and more photocurrent, thus resulting in the excellent stability and removal efficiency for SP via PDS activation upon visible light irradiation. The singlet oxygen (¹O₂) generated by the US-CN/PDS/VL system played a significant role in SP degradation. Based on the bonds of electron-rich atoms fracturing and the SO₂ extrusion, the SP degradation pathway was proposed. This work provides a useful information for the SP photocatalytic degradation via PDS activation.

Emerging Hybrid Nanocomposite Photocatalysts for the Degradation of Antibiotics: Insights into Their Designs and Mechanisms

The raising occurrence of antibiotics in the global water bodies has received the emerging concern due to their potential threats of generating the antibiotic-resistive and genotoxic effects into humans and aquatic species. In this direction, the solar energy assisted photocatalytic technique offers a promising solution to address such emerging concern and paves ways for the complete degradation of antibiotics with the generation of less or non-toxic by-products. Particularly, the designing of hybrid photocatalyticcomposite materials has been found to show higher antibiotics degradation efficiencies. As the hybrid photocatalysts are found as the systems with ideal characteristic properties such as superior structural, surface and interfacial properties, they offer enhanced photoabsorbance, charge-separation, -transfer, redox properties, photostability and easy recovery. In this context, this review study presents an overview on the recent developments in the designing of various hybrid photocatalytic systems and their efficiency towards the degradation of various emerging antibiotic pharmaceutical contaminants in water environments.

Effect of salinity on preconcentration of contaminants of emerging concern by nanofiltration: Application of solar photo-Fenton as a tertiary treatment

This study focused on the effect of salinity on the performance of a pilot-scale nanofiltration (NF) for preconcentration of microcontaminants (MCs) in combination with solar photo-Fenton or photo-Fenton-like treatment for their elimination from NF permeate and concentrate streams. Photo-Fenton was carried out in a solar simulator at pH of 3 and at natural pH using Ethylenediamine-N, N'-disuccinic acid (EDDS) as an iron complexing agent. Degradation efficacy was tested with MCs commonly found in urban wastewater treatment plant effluents (caffeine, imidacloprid, thiacloprid, carbamazepine and diclofenac). Hydrogen peroxide and persulfate were compared in solar processes. Increase in salinity and pressure had a negligible influence on MC permeability order and NF selectivity. Solar photo-Fenton was able to degrade MCs present in the concentrated stream, and rapidly eliminate any residual MCs that might finally be present in permeate streams. Persulfate used instead of hydrogen peroxide was shown to be inefficient for the selected MCs. Fe(III):EDDS at circumneutral pH was able to remove MCs as quickly as classical photo-Fenton at acid pH, or even faster. This effect supports use of Fe(III):EDDS at natural pH for treating NF concentrates or polishing NF permeates when NF membranes are operated under extreme conditions of salinity.

Fabric Phase Sorptive Extraction of Selected Steroid Hormone Residues in Commercial Raw Milk Followed by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Hormones in edible matrices, such as milk, are a subject of concern because of their adverse effects on the endocrine system and cell signaling and the consequent disruption of homeostasis in human consumers. Therefore, the assessment of the presence of hormones in milk as potential endocrine-disrupting compounds is warranted. However, the complexity of milk as a sample matrix and the ultra-low concentration of hormones pose significant analytical challenges. Fabric phase sorptive extraction (FPSE) has emerged as a powerful analytical technique for the extraction of emerging pollutants from complex aqueous matrices. FPSE allows for substantially simplified sample handling and short extraction and desorption times, as well as the decreased use of organic solvents. It is considered a green alternative to traditional extraction methodologies. In this work, the FPSE technique was evaluated to perform the simultaneous extraction of 15 steroid hormones from raw milk without employing any sample pretreatment steps. Clean and preconcentrated hormone solutions obtained from FPSE of raw milk were analyzed using ultra-high-performance liquid chromatography–tandem mass spectrometry to achieve low detection limits, which ranged from 0.047 to 1.242 ng·mL⁻¹. Because of the presence of many interferents in milk, such as proteins, lipids, and sugar, the effect of fat content on the extraction procedure was also thoroughly studied. Additionally, for the first time, the effect of lactose on the extraction of steroid hormones was evaluated, and the results showed that the extraction efficiencies were enhanced in lactose-free samples. Finally, the optimized methodology was applied to commercial samples of cow and goat milk, and no measurable concentrations of the studied hormones were detected in these samples.

Graphene-Based Composites as Catalysts for the Degradation of Pharmaceuticals

The incessant release of pharmaceuticals into the aquatic environment continues to be a subject of increasing concern. This is because of the growing demand for potable water sources and the potential health hazards which these pollutants pose to aquatic animals and humans. The inability of conventional water treatment systems to remove these compounds creates the need for new treatment systems in order to deal with these class of compounds. This review focuses on advanced oxidation processes that employ graphene-based composites as catalysts for the degradation of pharmaceuticals. These composites have been identified to possess enhanced catalytic activity due to increased surface area and reduced charge carrier recombination. The techniques employed in synthesizing these composites have been explored and five different advanced oxidation processes-direct degradation process, chemical oxidation process, photocatalysis, electrocatalyis processes and sonocatalytic/sono-photocatalytic processes-have been studied in terms of their enhanced catalytic activity. Finally, a comparative analysis of the processes that employ graphene-based composites was done in terms of process efficiency, reaction rate, mineralization efficiency and time required to achieve 90% degradation.

Emerging contaminants in the water bodies of the Middle East and North Africa (MENA): A critical review

Many emerging contaminants (ECs) are not currently removed by conventional water treatment methods and consequently, often reach the aquatic environment. In the absence of proper management strategies, ECs can accumulate in water bodies, which poses potential environmental and health risks. This paper critically reviews, for the first time, the reported occurrence and treatment of ECs in the Middle Eastern and North Africa (MENA) region. The paper also provides recommendations to properly manage EC risks. In the MENA region, pharmaceuticals and personal care products (PPCPs) have been detected in surface water, seawater, groundwater, and wastewater treatment plants. A focus on surface water in the published literature suggests that studies are skewed towards worldwide trends, whereas studies on ECs in seawater are of great importance in the study region. The types of PPCPs detected in the MENA region vary, but anti-inflammatories and antibiotics dominate. In comparison, microplastics have mainly been studied in surface waters and seawater with much less focus on drinking water. The majority of microplastics in the region are secondary types resulting from the degradation of larger plastic debris; polyethylene (PE) and polypropylene (PP) fibers are the most frequently detected polymers, which are indicative of local anthropogenic sources. Research progress on ECs varies between countries, having received more attention in Iran and Tunisia. Most MENA countries have now begun monitoring water bodies for ECs; however, studies are still lacking in some countries including Sudan, Djibouti, Syria, Ethiopia, and Bahrain. Based on this review, critical knowledge gaps and research needs are identified. Countries in the MENA region require further research on a broader range of EC types. Overall, water pollution due to the use and release of ECs can be tackled by improving public awareness, public campaigns, government intervention, and advanced monitoring and treatment methods.

Producing Magnetic Nanocomposites from Paper Sludge for the Adsorptive Removal of Pharmaceuticals from Water-A Fractional Factorial Design

In view of a simple after-use separation, the potentiality of producing magnetic activated carbon (MAC) by intercalation of ferromagnetic metal oxide nanoparticles in the framework of a powder activated carbon (PAC) produced from primary paper sludge was explored in this work. The synthesis conditions to produce cost effective and efficient MACs for the adsorptive removal of pharmaceuticals (amoxicillin, carbamazepine, and diclofenac) from aqueous media were evaluated. For this purpose, a fractional factorial design (FFD) was applied to assess the effect of the most significant variables (Fe³⁺ to Fe²⁺ salts ratio, PAC to iron salts ratio, temperature, and pH), on the following responses concerning the resulting MACs: Specific surface area (S_BET), saturation magnetization (M_s), and adsorption percentage of amoxicillin, carbamazepine, and diclofenac. The statistical analysis revealed that the PAC to iron salts mass ratio was the main factor affecting the considered responses. A quadratic linear regression model A = f(S_BET, M_s) was adjusted to the FFD data, allowing to differentiate four of the eighteen MACs produced. These MACs were distinguished by being easily recovered from aqueous phase using a permanent magnet (M_s of 22-27 emu g^-1), and their high S_BET (741-795 m² g^-1) were responsible for individual adsorption percentages ranging between 61% and 84% using small MAC doses (35 mg L^-1).

Theoretical study of the adsorption of analgesic environmental pollutants on pristine and nitrogen-doped graphene nanosheets

Interactions of the analgesic medications dextropropoxyphene (DPP, opioid), paracetamol (PCL, nonnarcotic), tramadol (TDL, nonnarcotic), ibuprofen (IBN, nonsteroidal anti-inflammatory drug (NSAID)), and naproxen (NPX, NSAID) with pristine graphene (GN) and nitrogen-doped GN (NGN; containing only graphitic N atoms) nanosheets were explored using density functional theory (DFT) in the gas and aqueous phases. Calculations in the aqueous phase were performed using the integral equation formalism polarized continuum model (IEFPCM). Calculated geometry-optimized structures, partial atomic charges (determined using Natural Bond Orbital analysis), highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps, work functions (determined using time-dependent DFT), and molecular electrostatic potential plots showed that the adsorption process is physical in nature (viz. physisorption), primarily due to noncovalent π-π and van der Waals interactions. In addition, calculated adsorption energies (ΔEad) were exergonic, indicating that formation of the analgesic/GN and analgesic/NGN complexes is thermodynamically favorable in the gas (ΔEad values for analgesic/GN and analgesic/NGN were in the range of -66.56 kJ mol-1 to -106.78 kJ mol-1) and aqueous phases (ΔEad values for analgesic/GN and analgesic/NGN complexes were in the range of -58.75 kJ mol-1 to -100.46 kJ mol-1). Generally, for GN and NGN, adsorption was more endergonic in the aqueous phase by as much as +10.41 kJ mol-1. Calculated solvation energies (ΔEsolvation) were exergonic for all analgesic/GN complexes (ΔEsolvation values were in the range of -56.50 kJ mol-1 to -66.17 kJ mol-1) and analgesic/NGN complexes (ΔEsolvation values were in the range of -77.26 kJ mol-1 to -87.96 kJ mol-1), with analgesic/NGN complexes exhibiting greater stability in aqueous solutions (∼20 kJ mol-1 more stable). In summary, the results of this theoretical study demonstrate that the adsorption and solvation of analgesics on GN and NGN nanosheets is thermodynamically favorable. In addition, generally, analgesic/NGN complexes exhibit higher adsorption affinities and solvation energies in the gas and aqueous phases. Therefore, GN and NGN nanosheets are potential adsorbents for extracting analgesic contaminants from aqueous environments such as aquatic ecosystems.

Rapid and efficient removal of diclofenac sodium from aqueous solution via ternary core-shell CS@PANI@LDH composite: Experimental and adsorption mechanism study

The efficient removal of Diclofenac sodium (DCF), a nonsteroidal anti-inflammatory drug, has attracted more and more attention. In this work, ternary core-shell CS@PANI@LDH composite was synthesized via the in-situ growth of Mg/Al layered double hydroxide plates onto polyaniline-wrapped carbon sphere and applied for DCF removal. Various influence factors like concentration, pH, time, temperature, and background electrolytes were systematically investigated. The maximum adsorption capacity was 618.16 mg/g. Besides, after 5 regeneration cycles, CS@PANI@LDH still retained high adsorption capacity. The adsorption mechanism was investigated by Fourier transformed infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) characterization analyses. Simultaneously, the Multiwfn program combined the Chimera program was applied to calculate and visualize the localized orbit locator (LOL) of π electrons in DCF^- molecule, which explored the π electronic structure and conjugation characteristics of DCF^- molecule. Moreover, the Independent Gradient Model (IGM) analysis based on pro-molecular density revealed the interaction sites and interaction strength between DCF and LDH. The adsorption mechanism could be explained through electrostatic interaction and hydrogen bonding between LDH and DCF, π-π interaction between DCF and PANI. It was the synergistic effects of different interactions that improved the adsorption of DCF by CS@PANI@LDH composite.

Acute effects of acetaminophen on the developmental, swimming performance and cardiovascular activities of the African catfish embryos/larvae (Clarias gariepinus)

Acetaminophen is a widely used analgesic that has been detected in many water bodies with few reports concerning its potential toxicity to fish. This study sought to assess the developmental, swimming performance and cardiovascular activities of embryo/larvae catfish (Clarias gariepinus) exposed to acetaminophen. The Organization for Economic Development (OECD) Fish Embryo Acute Toxicity Test (OECD 236) was employed. Fertilized embryo were exposed to different concentrations of acetaminophen (0, 0.5, 1, 10 µg/L) for 96 h. Hatching rates of the embryo were observed to decrease with increasing concentrations of acetaminophen. Fish embryo exposed to acetaminophen displayed varying levels of teratogenic effects at different levels of development in a dose-dependent manner. The results also showed a significant (p < 0.05) dose-dependent increase in swimming speed and movement patterns in fish larvae exposed to acetaminophen, with distance travelled in larvae exposed to the highest concentration of acetaminophen (10 µg/L) about eight (8) times the distance travelled by the control larvae, indicating that acetaminophen-induced erratic swimming behaviour in the catfish species. Cardiotoxicity was evident, with a significant reduction in heartbeat rate with increasing concentrations of acetaminophen. The results showed that exposure to acetaminophen resulted in teratogenic, neurotoxic and cardiotoxic effects in embryo/larvae of Clarias gariepinus. The findings suggest that acetaminophen which has recently been detected in many water bodies could potentially impact on survival of aquatic life, especially catfish.

Water-soluble graphitic carbon nitride for clean environmental applications

The removal of halogenated dye and sensing of pharmaceutical products in the water bodies with quick purification time is of high need due to the scarcity of drinking water. The present work reported on the preparation of graphitic carbon nitride (g-C₃N₄) for quick time water contaminant adsorption, followed by synthesizing silver nanoparticles decorated graphitic carbon nitride for pharmaceutical product sensing using in-situ SERS technique. The prepared graphitic carbon nitride is used to study the adsorption behavior of water contaminants at room temperature, in the presence of methylene blue (MB) as an adsorbate model. The water-soluble graphitic carbon nitride, even at low concentration, possesses an excellent ability to adsorb halogenated organic dye. As a result, the dyes are found to adsorb within ∼5s even without any additional physical or chemical activation. From the UV-Vis absorption investigations, it has been perceived that in the presence of graphitic carbon nitride (g-C₃N₄) the dye adsorption efficacy is observed nearly 80% with the well fitted linearly of R² = 0.9731. Effective in-situ surface-enhanced Raman scattering (SERS) studies for Ag nanoparticles decorated graphitic carbon nitride has been carried out and the obtained result shows good sensing performance of the material towards acetaminophen drug. This method opens the possibility of the Nobel metal decorated graphitic carbon nitride for real-time sensing of SERS-based drug products along with the development of high-performance sensing of the target analyte in the future.

Constructing Mesoporous Adsorption Channels and MOF-Polymer Interfaces in Electrospun Composite Fibers for Effective Removal of Emerging Organic Contaminants

Recently, metal-organic framework (MOF)-based electrospun fibers have attracted considerable attention as adsorbents for organic contaminant removal from water. To prepare these fibers, two common strategies including blending electrospinning and surface coating are employed. However, fibers obtained from the two strategies still have some disadvantages, such as adsorption site blockage and unstable loading. Here, we constructed interconnected mesopores in the electrospun zeolitic imidazolate framework-8 (ZIF-8)/polyacrylonitrile (PAN) fibers with the assistance of poly(vinylpyrrolidone) to expose more adsorption sites of ZIF-8 and make ZIF-8 more stable. Moreover, the mesopores could also enhance the diffusion of contaminant molecules and create MOF-polymer interfaces in the fiber, which improve the adsorption rate and adsorption capacity, respectively. The obtained fibers were used to adsorb antibiotic tetracycline from water. Benefiting from the mesoporous adsorption channels and the MOF-polymer interface, porous ZIF-8/PAN fibers showed faster adsorption kinetics than ZIF-8/PAN blending fibers and larger adsorption capacity than ZIF-8-coated PAN fibers and ZIF-8/PAN blending fibers. The maximum adsorption capacity of porous ZIF-8/PAN fibers was 885.24 mg/g, which is close to that of pure ZIF-8. After 10 adsorption-desorption cycles, the removal efficiency was still above 97%. In addition, porous ZIF-8/PAN fibers could act as the membrane adsorbents to dynamically separate tetracycline with a treated capacity of 9.93 × 10³ bed volumes. These results demonstrate that our prepared porous ZIF-8/PAN fibers have great potential in antibiotic drug removal.

Electrospun Functional Nanofiber Membrane for Antibiotic Removal in Water: Review

As a new kind of water pollutant, antibiotics have encouraged researchers to develop new treatment technologies. Electrospun fiber membrane shows excellent benefits in antibiotic removal in water due to its advantages of large specific surface area, high porosity, good connectivity, easy surface modification and new functions. This review introduces the four aspects of electrospinning technology, namely, initial development history, working principle, influencing factors and process types. The preparation technologies of electrospun functional fiber membranes are then summarized. Finally, recent studies about antibiotic removal by electrospun functional fiber membrane are reviewed from three aspects, namely, adsorption, photocatalysis and biodegradation. Future research demand is also recommended.

Effect of Metal Ions on Oxidation of Micropollutants by Ferrate(VI): Enhancing Role of FeIV Species

This paper investigated the oxidation of recalcitrant micropollutants [i.e., atenolol (ATL), flumequine, aspartame, and diatrizoic acid] by combining ferrate(VI) (Fe^VIO₄^2-, Fe^VI) with a series of metal ions [i.e., Fe(III), Ca(II), Al(III), Sc(III), Co(II), and Ni(II)]. An addition of Fe(III) to Fe^VI enhanced the oxidation of micropollutants compared solely to Fe^VI. The enhanced oxidation of studied micropollutants increased with increasing [Fe(III)]/[Fe^VI] to 2.0. The complete conversion of phenyl methyl sulfoxide (PMSO), as a probe agent, to phenyl methyl sulfone (PMSO₂) by the Fe^VI-Fe(III) system suggested that the highly reactive intermediate Fe^IV/Fe^V species causes the increased oxidation of all four micropollutants. A kinetic modeling of the oxidation of ATL demonstrated that the major species causing the increase in ATL removal was Fe^IV, which had an estimated rate constant as (6.3 ± 0.2) × 10⁴ M^-1 s^-1, much higher than that of Fe^VI [(5.0 ± 0.4) × 10^-1 M^-1 s^-1]. Mechanisms of the formed oxidation products of ATL by Fe^IV, which included aromatic and/or benzylic oxidation, are delineated. The presence of natural organic matter significantly inhibited the removal of four pollutants by the Fe^VI-Fe(III) system. The enhanced effect of the Fe^VI-Fe(III) system was also seen in the oxidation of the micropollutants in river water and lake water.

Starch-Mg/Al layered double hydroxide composites as an efficient solid phase extraction sorbent for non-steroidal anti-inflammatory drugs as environmental pollutants

Using a co-precipitation method, starch-Mg/Al layered double hydroxide (S-Mg/Al LDH) composites were synthesized. Their physicochemical properties were assessed by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermo-gravimetric analysis. The quantification of six non-steroidal anti-inflammatory drugs (NSAIDs) was conducted using real samples (e.g., hospital waste water, river water, sewage treatment plant water, and tablet formulations) by gas chromatography-mass spectrometry. For the development of this method, the system was optimized in terms of several key variables (e.g., pH, flow rate, and eluent type/volume). The developed method for NSAIDs exhibited good resolution, sensitivity, reproducibility, and specificity even in complex matrices with limits of detection between 4 and 20 pg/mL. Hence, S-Mg/Al LDH composites were proven to be efficient and fast solid phase extraction (SPE) sorbents for NSAIDs. In addition, each LDH-SPE cartridge showed good reusability without a noticeable change in performance (e.g., up to 30 cycles) and target recoveries between 99.5 - 82.9 %. This work should open up new opportunities for a sesnsitive and sustainable quantitative method for the determination of NSAIDs in complex samples.

Unravelling metabolism and microbial community of a phytobed co-planted with Typha angustifolia and Ipomoea aquatica for biodegradation of doxylamine from wastewater

Pharmaceutical contaminants in environment induce unexpected effects on ecological systems and human; thus, development of efficient technologies for their removal is immensely necessary. In this study, biodegradation and metabolic fate of a frequently found pharmaceutical contaminant, doxylamine by Typha angustifolia and Ipomoea aquatica was investigated. Microbial community of the plant rhizosphere has been identified to understand the important roles of the functional microbes. The plants reduced 48-80.5 % of doxylamine through hydrolysis/dehydroxylation and carbonylation/decarbonylation. A constructed phytobed co-planted with T. angustifolia and I. aquatica removed 77.3 %, 100 %, 83.67 %, and 61.13 % of chemical oxygen demand, total nitrogen, total phosphorus, and doxylamine respectively from real wastewater. High-throughput sequencing of soil and rhizosphere indicated that the phyla Proteobacteria, Bacteroidetes, Firmicutes, Planctomycetes, Actinobacteria, and Cyanobacteria dominated the microbial communities of the phytobed. Current study has demonstrated the applicability of the developed phytobeds for the treatment of doxylamine from municipal wastewater and provide a comprehensive understanding of its metabolism through plant and its rhizospheric microbial communities.

Efficient removal of pharmaceuticals from water using graphene nanoplatelets as adsorbent

Recently, pharmaceutical pollutants in water have emerged as a global concern as they give threat to human health and the environment. In this study, graphene nanoplatelets (GNPs) were used to efficiently remove antibiotics sulfamethoxazole (SMX) and analgesic acetaminophen (ACM) as pharmaceutical pollutants from water by an adsorption process. GNPs; C750, C300, M15 and M5 were characterized by high-resolution transmission electron microscopy, Raman spectroscopy, X-ray diffraction and Brunauer-Emmett-Teller. The effects of several parameters viz. solution pH, adsorbent amount, initial concentration and contact time were studied. The parameters were optimized by a batch adsorption process and the maximum removal efficiency for both pharmaceuticals was 99%. The adsorption kinetics and isotherms models were employed, and the experimental data were best analysed with pseudo-second kinetic and Langmuir isotherm with maximum adsorption capacity (Qm) of 210.08 mg g-1 for SMX and 56.21 mg g-1 for ACM. A regeneration study was applied using different eluents; 5% ethanol-deionized water 0.005 M NaOH and HCl. GNP C300 was able to remove most of both pollutants from environmental water samples. Molecular docking was used to simulate the adsorption mechanism of GNP C300 towards SMX and ACM with a free binding energy of -7.54 kcal mol-1 and -5.29 kcal mol-1, respectively, which revealed adsorption occurred spontaneously.

Development and application of a QuEChERS method with liquid chromatography-quadrupole time of flight-mass spectrometry for the determination of 50 wastewater-borne pollutants in earthworms exposed through treated wastewater

Soil-dwelling earthworms are valuable sentinels in soil pollution monitoring and, in case of wastewater reuse for agricultural irrigation, they are continuously exposed to a multitude of organic micro-pollutants. In the present work, an analytical methodology for the determination of 50 wastewater-borne pollutants in earthworms (Lumbricus terrestris) using a fast extraction and sensitive detection method was developed. In total, 17 protocols based on QuEChERS extraction methods were evaluated including the choice of extraction salt (EN vs Original) and the solvent pH as well as the cleanup type. EN with cleanup on Oasis PRiME HLB (P-16) provided the best overall performance. Compound quantification was accomplished by liquid chromatography-mass spectrometry on a QToF-MS system using the ultra-fast high-resolution multiple reaction monitoring (MRM^HR) mode. The method quantification limits ranged from 0.002 to 1.6 ng g^-1. In comparison to previously reported methods the present protocol afforded improved accuracy with recovery rates exceeding 80%. The validated method was applied to the analysis of 36 earthworm samples originating from laboratory experiments and fields that had been irrigated with treated wastewater. Among the eight analytes detected in field samples, the highest concentration levels were measured for gemfibrozil (13 ng g^-1) and caffeine (12 ng g^-1). To the best of our knowledge, this is the first report of the transfer of wastewater-borne contaminants to earthworms following irrigation under natural farming practices.

Photochemistry of dissolved organic matter extracted from coastal seawater: Excited triplet-states and contents of phenolic moieties

Coastal seawater constitutes an important ecosystem receiving inputs of organic micropollutants (OMPs) such as sulfa antibiotics from land-based sources or mariculture activities. It is necessary to investigate photodegradation of OMPs in coastal seawaters for assessing their environmental fate and risks. However, effects of coastal seawater dissolved organic matter (S-DOM) on OMPs photodegradation are largely unknown, given that chemical compositions of S-DOM are different from those of freshwater DOM. Herein, photochemical characteristics of S-DOM extracted from Dalian coastal seawaters were investigated by simulating photochemical experiment adopting sulfachloropyridazine as a case. Results show that S-DOM accelerates the photodegradation mainly through excited triplet-state DOM (³DOM*) with an apparent rate constant (4.43 × 10⁸ M^-1 s^-1) ten folds of that of freshwater DOM, which is mainly due to much lower phenol contents detected in the S-DOM (0.022 mg-Gallic acid mg-C^-1). The S-DOM impacted by mariculture can photogenerate more high-energy ³DOM* than those less impacted by mariculture, further contributing to the high ³DOM* reactivity. The study shows that to accurately predict photolytic persistence of OMPs in field water bodies, it is of significance to determine the second-order reaction rate constants between ³DOM* and target OMPs using DOM extracted from relevant water bodies.

AIE-active polyelectrolyte based photosensitizers: the effects of structure on antibiotic-resistant bacterial sensing and killing and pollutant decomposition

A facile and effective multifunctional platform with high bacterial detection sensitivity, good antibacterial activity, and excellent dye decomposition efficiency holds great promise for wastewater treatment. To explore the design rationality and mechanism of material platforms with various integrated components into a single molecule for wastewater treatment applications, herein, four kinds of polyelectrolyte photosensitizers with aggregation-induced emission (AIE) fluorescent units are synthesized and systematically studied to investigate the structure-property relationship that influences the level of conjugation and the hydrophobicity-hydrophilicity balance. By improving the strength of the conjugation, the new AIE photosensitizers DBPVEs (including DBPVE-4 and DBPVE-6) generate a reactive oxygen species (ROS), and a decomposition efficiency of around 55% is obtained for dyes when they are exposed to DBPVEs under white light irradiation, which is higher than those of DBPEs (including DBPE-4 and DBPE-6). More importantly, owing to the longer and more flexible aliphatic chains of DBPVE-6 that facilitate efficient intercalation into cell membranes, the staining ability of DBPVE-6 for methicillin-resistant S. epidermidis (MRSE) is greatly enhanced as compared to that of DBPVE-4. It should be noted that the antibacterial experiment indicates that DBPVE-6 displays potent toxicity to MRSE with 99.9% killing efficiency under white light irradiation. This work provides essential theoretical and experimental guidance on the designing of new photosensitizers for wastewater treatment.

Metal–organic frameworks for the removal of the emerging contaminant atenolol under real conditions

A defective Metal-Organic Frameworks as an improved material for the construction of a fixed-bed system working under continuous flow conditions for the removal of the emerging contaminant atenolol.

Can ocean warming alter sub-lethal effects of antiepileptic and antihistaminic pharmaceuticals in marine bivalves?

The negative effects induced in marine organisms by Climate Change related abiotic factors consequences, namely ocean warming, are well-known. However, few works studied the combined impacts of ocean warming and contaminants, as pharmaceutical drugs. Carbamazepine (CBZ) and cetirizine (CTZ) occur in the marine environment, showing negative effects in marine organisms. This study aimed to evaluate the impacts of ocean warming on the effects of CBZ and CTZ, when acting individually and combined (drug vs drug), in the edible clam Ruditapes philippinarum. For that, drugs concentration, bioconcentration factors and biochemical parameters, related with clam's metabolic capacity and oxidative stress, were evaluated after 28 days exposure to environmentally relevant scenarios of these stressors. The results showed limited impacts of the drugs (single and combined) at control and warming condition. Indeed, it appeared that warming improved the oxidative status of contaminated clams (higher reduced to oxidized glutathione ratio, lower lipid peroxidation and protein carbonylation levels), especially when both drugs were combined. This may result from clam's defence mechanisms activation and reduced metabolic capacity that, respectively, increased elimination and limited production of reactive oxygen species. At low stress levels, defence mechanisms were not activated which resulted into oxidative stress. The present findings highlighted that under higher stress levels clams may be able to activate defence strategies that were sufficient to avoid cellular damages and loss of redox homeostasis. Nevertheless, low concentrations were tested in the present study and the observed responses may greatly change under increased pollution levels or temperatures. Further research on this topic is needed since marine heat waves are increasing in frequency and intensity and pollution levels of some pharmaceuticals are also increasing in coastal systems.

Ce ion surface-modified TiO2 aerogel powders: a comprehensive study of their excellent photocatalytic efficiency in organic pollutant removal

The surface modification of TiO₂ aerogel powders by cerium ions has led to enhanced photoinduced properties.

Performance and mechanisms of sulfadiazine removal using persulfate activated by Fe3O4@CuOx hollow spheres

A Fe-Cu bimetal catalyst (FCHS) was synthesized by depositing Fe₃O₄ on the shell of CuO_x hollow spheres, which were prepared via a soft template method. Several characterization methods, including XRD, SEM-EDS&mapping, TEM, FTIR, and XPS, were used to reveal the morphology and surface properties of FCHS. The characterization results demonstrated that the double-shell hollow structure is formed with a dense coating of Fe₃O₄ nanoparticles on the surface of CuO_x hollow spheres. FCHS can exhibit excellent catalytic activity to degrade sulfadiazine (SDZ) with the oxidant of persulfate (PS). The optimal SDZ removal performance was explored by adjusting reaction parameters, including catalyst dosage, oxidant dosage, and solution pH. The SDZ removal efficiency in the FCHS + PS system could reach 95% at the optimal reaction condition ([catalyst]₀ = 0.2 g/L, [PS]₀ = 2 mM, pH = 7.0) with 5 mg/L of SDZ. Meanwhile, the degradation efficiency decreased with the coexistence of phosphate or carbonate anions. According to the results of radicals scavenging experiments and the electron paramagnetic resonance analysis, the radicals of SO₄·^-, O₂·^- and ·OH generated in the FCHS + PS system contribute to the degradation of SDZ. Moreover, the results of XPS revealed that the solid-state charge-transfer redox couple of Fe(III)/Fe(II) and Cu(I)/Cu(II) can promote the activation of PS. It means that the cooperation effect between Cu oxides and Fe oxides in the double-shell structure is beneficial to the catalytic degradation of SDZ. Furthermore, four possible pathways for SDZ degradation were proposed according to the analysis of intermediate products detected by the LCMS-IT-TOF.

Mixtures of co-occurring chemicals in freshwater systems across the continental US

Trace chemicals are common in marine and freshwater ecosystems globally. It is recognized that in the environment, individual chemicals are rarely found in isolation. Insufficient work has examined which chemicals co-occur and which methods best identify these mixtures. Using an existing data set, we found evidence that simple correlation analysis is better at identifying mixtures of commonly co-occurring trace chemicals than more commonly used PCA methods. Moreover, simple correlation analysis, unlike PCA, can be used in cases with unbalanced designs and with data points below reportable limits. Application of this approach allowed identification of 10 groups of chemicals commonly found together in freshwaters of the continental US, representing common "chemical syndromes." Better identification of co-occurring chemical combinations could aid in our understanding of biological and ecological effects of aquatic contaminants. This research provides evidence of correlation analyses as a more effective method for identifying commonly co-occurring aquatic contaminants. We also examined the patterns of these mixtures with a dataset consisting of concentrations of 406 trace chemicals from 38 sample locations across the continental US.

Charge-Enhanced Separation of Organic Pollutants in Water by Anionic Covalent Organic Frameworks

The effective removal of organic pollutants in wastewater is a key environmental challenge. In this work, an anionic covalent organic framework (named TpPa-SO₃Na) was synthesized through a green two-in-one synthesis strategy with autocatalytic imine formation. The slowly generated acetic acid as a catalyst is favorable to sustain the reversibility of the covalent organic framework (COF) formation reaction and improve the crystallinity of TpPa-SO₃Na. TpPa-SO₃Na consists of a homogeneous distribution of sulfonate groups to produce negatively charged regular channels. The strong electrostatic and hydrogen-bonding interactions between the sulfonate groups anchored in the nanochannels and the amine groups in organic pollutants improve the adsorption selectivity and capacity. These structures allow a high degree of control over adsorption processes to boost the adsorption kinetics and improve selective separation. TpPa-SO₃Na exhibits ultrafast adsorption (<1 min) of cationic antibiotics and dyes (average over 95%). Furthermore, TpPa-SO₃Na exhibits high selectivity for the uptake of dye molecules on the basis of the differences in charge and molecular size. This work explored functional designs and green manufacturing of anionic COFs for removal of hydrophilic organic pollutants.

Chitosan film as recyclable adsorbent membrane to remove/recover hazardous pharmaceutical pollutants from water: the case of the emerging pollutant Furosemide

Due to the negative effects of emerging contaminants on the environment, that can potentially induce deleterious effects in aquatic and human life, this paper focuses on the removal from the water of Furosemide, through the adsorption process. Indeed, only a few papers are available in the literature about the Furosemide adsorption and, chitosan films are thus proposed for this purpose as safe, sustainable, and recyclable adsorbent materials. In the present work, the effects on the adsorption process of several experimental parameters such as the pH values, ionic strength, amount of adsorbent/pollutant, and temperature values were investigated. The kinetics models, isotherms of adsorption, and the thermodynamic parameters were studied showing that the Furosemide physisorption occurred on the heterogeneous Chitosan surface, endothermically (ΔH° = +31.27 ± 3.40 kJ mol^-1) and spontaneously (ΔS° = +150.00 ± 10.00 J mol^-1 K^-1), following a pseudo-second-order kinetic model. The 90% of the pollutant was adsorbed in 2 h, with a maximum adsorption capacity of 3.5 mg × g^-1. Despite these relatively low adsorption capacities, experiments of desorption were performed and 100% of adsorbed Furosemide was recovered by using concentrated NaCl solutions, proposing a low-cost and green approach, with respect to the previous literature relative to the Furosemide adsorption, fundamental for the pollutant recovery and adsorbent reuse.

Miniaturized analytical methods for determination of environmental contaminants of emerging concern - A review

The determination of contaminants of emerging concern (CECs) in environmental samples has become a challenging and critical issue. The present work focuses on miniaturized analytical strategies reported in the literature for the determination of CECs. The first part of the review provides brief overview of CECs whose monitoring in environmental samples is of particular significance, namely personal care products, pharmaceuticals, endocrine disruptors, UV-filters, newly registered pesticides, illicit drugs, disinfection by-products, surfactants, high technology rare earth elements, and engineered nanomaterials. Besides, an overview of downsized sample preparation approaches reported in the literature for the determination of CECs in environmental samples is provided. Particularly, analytical methodologies involving microextraction approaches used for the enrichment of CECs are discussed. Both solid phase- and liquid phase-based microextraction techniques are highlighted devoting special attention to recently reported approaches. Special emphasis is placed on newly developed materials used for extraction purposes in microextraction techniques. In addition, recent contributions involving miniaturized analytical flow techniques for the determination of CECs are discussed. Besides, the strengths, weaknesses, opportunities and threats of point of need and portable devices have been identified and critically compared with chromatographic methods coupled to mass chromatography. Finally, challenging aspects regarding miniaturized analytical methods for determination of CECs are critically discussed.

Fabrication of an electrochemical sensor with Au nanorods-graphene oxide hybrid nanocomposites for in situ measurement of cloxacillin

In recent years, considering the increasing use of antibiotics, and their continued entry into the environment, extensive research has been conducted on the impact of antibiotics on human health, water resources, and the environment. In this study, a suitable method has been proposed for detecting and elimination the trace amounts of the antibiotic cloxacillin in aqueous. For identify trace amounts of cloxacillin in solution, a new electrochemical nanosensor based on a screen printed carbon electrode (SPCE) modified with gold nanorods/graphene oxide was proposed. This nanosensor, which was prepared by self-assembling method, was capable of measuring cloxacillin in the 5.0-775.0 nM with a detection limit of 1.6 nM. In order to reduce the amount of antibiotics in the environment, a novel carbon nanocomposite based on sol-gel method was prepared and its application as a high-capacity adsorbent for the removal of cloxacillin was studied. In the antibiotic removal experiments, the effect of pH, contact time, different mass ratios of SWCNT and amount of nanocomposite adsorbent were also optimized by response surface methodology (RSM). The prepared nanosensor and synthesized carbon nanocomposites were then characterized by commonly identical techniques involve SEM, EDAX, BET and FT-IR. The presented nanosensor was successfully used for the in situ determination of Clox in adsorptive tests with reliable recovery. As well, the AuNR/GO/SPC electrode presented well stability, repeatability and reproducibility. In addition, good performance and high adsorption capacity make developed adsorbent as a suitable case for the removal of water-soluble pharmaceutical contaminants.

Occurrence and risk assessment of steroid estrogens in environmental water samples: A five-year worldwide perspective

The ubiquitous occurrence of steroid estrogens (SEs) in the aquatic environment has raised global concern for their potential environmental impacts. This paper extensively compiled and reviewed the available occurrence data of SEs, namely estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinyl estradiol (EE2), based on 145 published articles in different regions all over the world including 51 countries and regions during January 2015-March 2020. The data regarding SEs concentrations and estimated 17β-estradiol equivalency (EEQ) values are then compared and analyzed in different environmental matrices, including natural water body, drinking and tap water, and wastewater treatment plants (WWTPs) effluent. The detection frequencies of E1, 17β-E2, and E3 between the ranges of 53%-83% in natural water and WWTPs effluent, and the concentration of SEs varied considerably in different countries and regions. The applicability for EEQ estimation via multiplying relative effect potency (REP_i) by chemical analytical data, as well as correlation between EEQ_bio and EEQ_cal was also discussed. The risk quotient (RQ) values were on the descending order of EE2 > 17β-E2 > E1 > 17α-E2 > E3 in the great majority of investigations. Furthermore, E1, 17β-E2, and EE2 exhibited high or medium risks in water environmental samples via optimized risk quotient (RQ_f) approach at the continental-scale. This overview provides the latest insights on the global occurrence and ecological impacts of SEs and may act as a supportive tool for future SEs investigation and monitoring.

Pharmaceuticals as emerging contaminants in the aquatic environment of Latin America: a review

Pharmaceutical active compounds (PhACs) are environmentally ubiquitous around the world, and the countries of Latin America (LATAM) are not the exception; however there is still little knowledge of the magnitude and conditions of their occurrence in LATAM and of the environmental consequences of their presence. The present work reviews 79 documents published from 2007 to 2019 on the occurrence, concentrations, and sources of PhACs and hormones in surface water (SW), wastewater (WW), and treated wastewater (TWW) in LATAM and on the circumstances of their release to the environment. Research efforts are reported in only ten countries and confirm the presence of 159 PhACs, mainly analgesics and anti-inflammatories, although extraordinarily high concentrations of carbamazepine (830 μg/L) and ethinylestradiol (6.8 μg/L) were found in Ecuador and Brazil, respectively. The analysis of maximum concentrations and the ecotoxicological risk assessment corroborate that (1) these values exceed the environmental concentrations found in other parts of the world, (2) the environmental risk posed by these concentrations is remarkably high, and (3) there is no statistically significant difference between the maximum concentrations found in WW and those found in TWW. The main source of PhACs in LATAM's aquatic environment is WW; hence, these countries should direct substantial efforts to develop efficient and cost-effective treatment technologies and plan and apply WW management strategies and regulations. This analysis presents the current states of occurrence, concentrations, and sources of PhACs in the aquatic environment of LATAM and outlines the magnitude of the environmental problem in that part of the world.

Detection, transformation, and toxicity of indole-derivative nonsteroidal anti-inflammatory drugs during chlorine disinfection

As important emerging contaminants, nonsteroidal anti-inflammatory drugs (NSAIDs) are the most intensively prescribed pharmaceuticals introduced to drinking water due to their incomplete removal in wastewater treatment. While concentrations of NSAIDs in drinking water are generally low, they have been attracting increasing concern as a result of their disinfection byproducts (DBPs) generated in drinking water disinfection. In this work, detection methods were set up for four representative indole-derivative NSAIDs (indomethacin, acemetacin, sulindac, and etodolac) using ultra performance liquid chromatography/electrospray ionization-triple quadruple mass spectrometry (UPLC/ESI-tqMS). ESI+ was better for detection of indomethacin and sulindac, whereas ESI- was suitable to detection of acemetacin and etodolac. With optimized MS parameters, the instrument detection and quantitation limits of the four indole derivatives were achieved to be 1.1-24.6 ng/L and 3.7-41.0 ng/L, respectively. During chlorination, indomethacin and acemetacin could undergo five major reaction types (chlorine substitution, hydrolysis, decarboxylation, C-C coupling, and C-N cleavage) to form a series of DBPs, among which 19 were proposed/identified with structures. Based on the revealed structures of DBPs, transformation pathways of indomethacin and acemetacin in chlorination were partially elucidated. Notably, individual and mixture toxicity of indomethacin and acemetacin before/after chlorination were evaluated using a well-established acute toxicity assessment and a Hep G2 cell cytotoxicity assay, respectively. Results showed that the predicted acute toxicity of a few chlorination DBPs were higher than their precursors; chlorination substantially enhanced the mixture cytotoxicity of indomethacin by over 10 times and slightly increased the mixture cytotoxicity of acemetacin.

Environmental side effects of the injudicious use of antimicrobials in the era of COVID-19

Use of antimicrobials in the treatment and prevention of COVID-19, caused by novel coronavirus SARS-CoV-2, is on the rise. The increased use of antimicrobials can have serious consequences on the environment. Antibiotics have had a reasonable role in bacterial co-infections with regards to the management of COVID-19. However, recent evidences suggest that there has been injudicious prescription of antimicrobials. Moreover, a large number of people are self-medicating with antibiotics in a misguided attempt to protect themselves from the virus. This practice is especially prevalent in developing communities. Although common soaps are effective at inactivating enveloped viruses, such as the SARS-CoV-2, use of antibacterial products bearing biocides has increased during this pandemic. Current wastewater treatment techniques are unable to offer complete elimination of antibacterial biocides. These compounds can then accumulate in different environmental compartments thus, disrupting the functioning of native microbes. These microbes are involved in the biogeochemical cycling of elements and environmental remediation. In addition, the presence of antimicrobial elements in the environment can stimulate antimicrobial resistance. Concrete actions are needed to address this issue. Development of an antimicrobial policy specific for COVID-19 is urgently needed. Investments into improving wastewater infrastructure as well as public awareness is crucial. Moreover, global monitoring programs and multidisciplinary collaborations are required to understand the environmental impact of this pandemics.