Emerging contaminants: Here today, there tomorrow!

Behavioural, Teratogenic and Genotoxic Effects of Antibacterial Compounds, Triclocarban and Triclosan, in Hydra vulgaris

Triclocarban (TCC) and triclosan (TCS) are antibacterial compounds used in household, veterinary, industrial and personal care products, which are known to be environmental pollutants and also toxic to organisms. The toxicological effects of these antibacterial chemicals on higher organisms have been studied in detail. But in lower invertebrates like hydra, it is still rare and yet to be explored. In this study, the toxicological effects of these two antibacterial compounds in Hydra vulgaris was performed to clearly understand the organismal, developmental, molecular and behavioural changes. Both TCC and TCS are toxic with respective LC50 values of 0.09 and 0.25 mg/L, whereas TCC is comparatively more toxic than TCS. The structural damage of battery cell complexes (BCCs) on the tentacles was observed and ultimately made prey capturing difficult. It was evident that TCC and TCS exposure caused developmental toxicity by affecting reproduction and regeneration in H. vulgaris at higher sublethal doses (0.045 and 0.125 mg/L, respectively). TCC and TCS also caused DNA damage resulting in apoptosis. This study further reveals that these two antibacterial compounds are teratogenic and genotoxic in the organisms.

"Groundbreaking study: Combined effect of marine heatwaves and polyethylene microplastics on Pacific oysters, Crassostrea gigas"

Microplastics (MPs) and rising marine seawater temperatures are one of the major environmental problems threatening the survival of marine organisms and biodiversity. However, interactions between such multiple stressors are virtually unexplored. This study aimed to assess the combined effect of two temperatures and polyethylene MPs on the Pacific oyster Crassostrea gigas, one of the most globalized mollusc species for aquaculture. Our work highlights the potential ecological risk posed by these two factors on marine bivalve molluscs. The experimental design was carried out following a 14-day exposure of oysters to environmental concentrations of polyethylene MPs (0.01 mg.L-1), and to two temperatures (15 °C and 22 °C). Sampling was performed on days 0, 7, and 14. The μ-FTIR analysis was applied to quantify MPs of interest and to check a potential environmental contamination. Tissue samples of digestive glands were collected from the oysters to evaluate the activity of biomarkers including superoxide dismutase, glutathione-s-transferase, malondialdehyde and laccase through protein levels. We note that the combination of MPs and high water temperature (HWT, 22 °C) had a significant impact both on the survival of animals and on stress markers, by modifying lipid peroxidation and immune responses. This original study gave the first innovative results on this topic and provides us with knowledge of the combined effects of MPs pollution and HWT (simulating marine heatwaves situation) on C. gigas. There remains a lack of information on the toxicity and the potential environmental hazard of plastics in the marine environment.

Transgenerational effects of the levonorgestrel-based birth control pill in zebrafish offspring

The consumption of hormone-derived medicines, such as levonorgestrel (LNG), is increasing worldwide, and its discharge into the environment reaches non-target organisms. In our previous study, we exposed the parental generation of zebrafish to environmentally relevant concentrations of LNG during the developmental phase. Subsequently, they had grown in a tank with clean water until adulthood. Now, we allowed this parental generation to reproduce to obtain F1 progeny unexposed to LGN, in order to analyze the transgenerational effects of parental LNG exposure on the survival and hatching of unexposed F1 embryos and the stress and behavior of F1 larvae. Here, we found decreased survival rates with higher LNG concentrations, providing a transgenerational effect. This highlights the environmental impact of exposure to LNG, causing damage at the individual and population level and affecting the next generation at the beginning of development, impacting qualities in the survival of the species.

Competitive adsorption of acetaminophen and caffeine onto activated Tingui biochar: characterization, modeling, and mechanisms

Tingui biochar (TB) activated with potassium hydroxide (TB-KOH) was synthesized in the present study. The adsorption capacity of TB-KOH was evaluated for the removal of acetaminophen and caffeine in monocomponent and bicomponent solutions. As a result, the study of the TB-KOH characterization as well as the adsorption kinetics, isotherm, thermodynamics, and a suggestion of the global adsorption mechanism are presented. TB-KOH was characterized through physical-chemical analysis to understand its surface morphology and how it contributes to the adsorption of these drugs. Furthermore, modelling using advanced statistical physical models was performed to describe how acetaminophen and caffeine molecules are adsorbed in the active sites of TB-KOH. Through the characterizations, it was observed that the activation with KOH contributed to the development of porosity and functional groups (-OH, C-O, and C = O) on the surface of TB. The monocomponent adsorption equilibrium was reached in 90 min with a maximum adsorption capacity of 424.7 and 350.8 mg g-1 for acetaminophen and caffeine, respectively. For the bicomponent solution adsorption, the maximum adsorption capacity was 199.4 and 297.5 mg g-1 for acetaminophen and caffeine, respectively. The isotherm data was best fitted to the Sips model, and the thermodynamic study indicated that acetaminophen removal was endothermic, while caffeine removal was exothermic. The mechanism of adsorption of acetaminophen and caffeine by TB-KOH was described by the involvement of hydrogen bonds and π-π interactions between the surface of TB-KOH and the molecules of the contaminants.

A Simultaneous Calibration and Detection Strategy for Electrochemical Sensing with High Accuracy in Complex Water

The electrochemical sensors loaded with nanomaterials have exhibited a great sensitivity. Nonetheless, the field detection for complex waterbodies can be affected by cross-sensitivity, environmental conditions such as temperature and pH value, as well as the relatively low reproducibility and stability of nanomaterials. In this paper, a simultaneous calibration and detection (SCD) strategy is proposed to introduce a simultaneous and precise calibration during field electrochemical detection, which is composed of a linear regression algorithm and a compact electrochemical sensor containing a series of identical sensing cells. This design can significantly mitigate cross-sensitivity in complex water and the inconsistency of sensing materials. Applied in the NO2- detection for practical waterbodies, the SCD strategy has exhibited a relative error of no more than 9.6% for the measurement compared to the results obtained by the standard Griess method and higher accuracy than the normal electrochemical method. The SCD strategy is independent of sensing materials, indicating that it can be widely applied to various detections by just switching the corresponding sensing material.

Analytical Methods for the Determination of Pharmaceuticals and Personal Care Products in Solid and Liquid Environmental Matrices: A Review

Among the various compounds regarded as emerging contaminants (ECs), pharmaceuticals and personal care products (PPCPs) are of particular concern. Their continuous release into the environment has a negative global impact on human life. This review summarizes the sources, occurrence, persistence, consequences of exposure, and toxicity of PPCPs, and evaluates the various analytical methods used in the identification and quantification of PPCPs in a variety of solid and liquid environmental matrices. The current techniques of choice for the analysis of PPCPs are state-of-the-art liquid chromatography coupled to mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS2). However, the complexity of the environmental matrices and the trace levels of micropollutants necessitate the use of advanced sample treatments before these instrumental analyses. Solid-phase extraction (SPE) with different sorbents is now the predominant method used for the extraction of PPCPs from environmental samples. This review also addresses the ongoing analytical method challenges, including sample clean-up and matrix effects, focusing on the occurrence, sample preparation, and analytical methods presently available for the determination of environmental residues of PPCPs. Continuous development of innovative analytical methods is essential for overcoming existing limitations and ensuring the consistency and diversity of analytical methods used in investigations of environmental multi-class compounds.

Spring water quality monitoring using multiple bioindicators from multiple collection sites

The aim of this study was to examine the water quality of the Extrema River spring in a Brazilian Cerrado area. Three collection sites (P1 - P3) were sampled in the dry and rainy seasons, which are close to industries from different sectors. In the physicochemical analysis, a decrease in dissolved oxygen levels (<5 mg/L) and pH (< 6) at P3 was detected. An increase in heterotrophic bacteria count was recorded at all sites (> 500 colonies/ml). In ecotoxicological analyses, P2 and P3 exhibited toxicity using Vibrio fischeri (> 20%). In evaluating toxicity, the reduction in seed germination was significant utilizing Lactuca sativa at all locations and with Allium cepa only at P2; rootlet length was decreased at P3 on L. sativa and at all sites with A. cepa. In contrast, loss of membrane integrity and mitochondrial function of meristems was adversely affected at all locations using both L. sativa and A. cepa assays. Principal components analysis (PCA) approach indicated that seasonality apparently did not markedly interfere with the obtained data, but it is important to include more collection locations to be evaluated with multiple bioindicators in the spring region. Our data indicate the urgent need for more rigorous programs to monitor the discharge of effluents into water springs.

Uptake and accumulation of emerging contaminants in processing tomato irrigated with tertiary treated wastewater effluent: a pilot-scale study

The reuse of treated wastewater for crop irrigation is vital in water-scarce semi-arid regions. However, concerns arise regarding emerging contaminants (ECs) that persist in treated wastewater and may accumulate in irrigated crops, potentially entering the food chain and the environment. This pilot-scale study conducted in southern Italy focused on tomato plants (Solanum lycopersicum L. cv Taylor F1) irrigated with treated wastewater to investigate EC uptake, accumulation, and translocation processes. The experiment spanned from June to September 2021 and involved three irrigation strategies: conventional water (FW), treated wastewater spiked with 10 target contaminants at the European average dose (TWWx1), and tertiary WWTP effluent spiked with the target contaminants at a triple dose (TWWx3). The results showed distinct behavior and distribution of ECs between the TWWx1 and TWWx3 strategies. In the TWWx3 strategy, clarithromycin, carbamazepine, metoprolol, fluconazole, and climbazole exhibited interactions with the soil-plant system, with varying degradation rates, soil accumulation rates, and plant accumulation rates. In contrast, naproxen, ketoprofen, diclofenac, sulfamethoxazole, and trimethoprim showed degradation. These findings imply that some ECs may be actively taken up by plants, potentially introducing them into the food chain and raising concerns for humans and the environment.

Removal of fipronil by advanced oxidative processes using sulfite activated by cobalt immobilized on silica

Sulfite auto-oxidation catalyzed by cobalt complexed with ammonia deposited on silica (CoNSi) was used to generate sulfate radicals. The material was characterized by ATR-FTIR, suggesting that the silica structure did not change, and SEM-EDS, indicating an uniform dispersion of cobalt across the material surface according with XRD results. BET analysis provided information on a mesoporous material (type IV isotherm) with regular morphology (H1 hysteresis). The DSC analysis showed that CoNSi is thermally stable under the studied conditions. Quantitative analysis of Fipronil (FIP) was performed by HPLC-DAD, where the applied method was selective and linear. The Box-Behnken experimental design (BBD) method was used to define the best condition for removing the analyte in water. It was found that in 60 min, 76% removal of 1.8 mg L-1 of FIP was reached by adding 0.30 g of the material and 0.30 g of the sulfite in a solution under stirring, aeration, pH 8.0, and room temperature and protected from radiation. However, analysis of cobalt leaching into the solution by FAAS showed a small amount of the metal (0.44 mg L-1) informing that the synthesis of the material must be improved.

Adsorptive removal of pharmaceutically active compounds from multicomponent system using Azadirachta indica induced zinc oxide nanoparticles: analysis of competitive and cooperative adsorption

In this research, zinc oxide (ZnO) nanoparticles synthesized using neem leaf (Azadirachta indica) extract were used as an adsorbent for removing two widely used pharmaceutical compounds acetaminophen (AMP) and sulfadiazine (SDZ). The synthesized ZnO nanoparticles were characterized using SEM-EDS, FTIR, TEM, BET, and XRD analysis. The synthesized ZnO nanoparticles were found to be in the size range of 10 nm with a surface area of 48.551 m²/g. The adsorptive performance of ZnO nanoparticles in both mono-component (MoS) and multi-component system (MuS) was investigated under various operational parameters viz. contact time, temperature, pH, concentration of pharmaceutical compound and ZnO nanoparticles dose. It was observed that the maximum adsorption capacity of ZnO nanoparticles was 7.87 mg/g and 7.77 mg/g for AMP and SDZ, respectively, under the optimum conditions of 7 pH and 2 g/L adsorbent dosage. The experimental data best-fitted with the pseudo-second-order model and Langmuir model, indicating monolayer chemisorption. Further investigation on removal of AMP and SDZ from multicomponent system was modelled using a Langmuir competitive model. The desorption study has shown 25.28% and 22.4% removal of AMP and SDZ from the surface of ZnO nanoparticles. In general, green synthesized ZnO nanoparticles can be utilized effectively as adsorbent for removal of pharmaceutically active compounds from wastewater.

Functionalization of graphene nanostructures with inorganic nanoparticles and their use for the removal of pharmaceutical pollutants in water

Emerging pollutants such as pharmaceuticals are of special concern because despite their low environmental concentration, their biological activity can be intense, and they should be prevented to reach uncontrolledly to the environment. A graphene-based hybrid material decorated with Fe3O4 and TiO2 nanoparticles (NPs) has been prepared to effectively remove emerging pollutants as nonsteroidal anti-inflammatory drugs (NSAIDs) Ibuprofen and Diclofenac present in water at low environmental concentrations by a one-step functionalization process following a novel gentle and scalable surfactant depletion approach. Following this methodology, nanoparticles are progressively deprived of their original surfactant in the presence of graphene, leading to the formation of hybrid nanostructures composed of two different types of nanoparticles well dispersed over the graphene nanosheets. Ibuprofen and Diclofenac adsorption kinetics on the composites was investigated via UV-Vis spectroscopy. The as prepared hybrid material possesses high adsorption capacity, superparamagnetic properties, photocatalytic behavior, and good water dispersibility. Thanks to incorporating TiO2 nanoparticles as in situ catalysts, the adsorption performance of composites is restored after use, which could be a promising recycling pathway for the adsorbents in wastewater treatments.

Biotransformation of 17β-Estradiol through a Denitrifying Sludge

17β-estradiol (E2) is the natural estrogen with the most significant potential for endocrine disruption in the biota of aquatic ecosystems at trace concentrations. It is, therefore, essential to study treatments for water polluted with E2 that would guarantee its complete elimination and mineralization. Denitrification is a biological process shown to have the capacity to completely biodegrade drugs, such as ampicillin. This work is aimed to evaluate the biotransformation of 17β-estradiol by employing a denitrifying sludge. The assays performed were: (I) abiotic with 3.5 mg E2-C L^-1 and (II) denitrifying with 10 mg CH₃COO^--C L^-1 as the reference, 10 mg E2-C L^-1 as the sole electron donor, and a mixture of (mg L^-1) 10 E2-C with 10 CH₃COO^--C at C N^-1 of 1.1. The E2-C and NO₃^--N consumption efficiencies were greater than 99%, and HCO₃^--C and N₂ production yields were close to 1 in all assays. The denitrifying sludge could biodegrade up to 10 mg E2-C L^-1 as the sole electron donor and when mixed with 10 mg CH₃COO^--C L^-1. No intermediate metabolites were generated from the process.

Organic Amendments: Direct Application and Residual Effects on Vegetative and Reproductive Growth of Hot Pepper

The high production potential of coffee and animals in the Gedeo zone that could produce huge amounts of coffee pulp and animal manure wastes has been polluting the environment. In this sense, this study was aimed at averting pollution and managing plant and animal wastes, focusing on the effect of coffee pulp and animal manure in the form of vermicompost, biochar, and ordinary compost on hot pepper vegetative and reproductive growth. A 15 ton per hectare of each treatment was applied in a randomized complete block design replicated three times. Vegetative and reproductive growth parameters (plant height, leaf number, number of branches, days to 50% flowering, total fresh biomass, number of fruits per plant, single fruit length, and fruit yield per hectare) were recorded, and the statistical difference was determined at 5% significance level using R-program. The result showed that there was a significant difference among treatments. Coffee pulp vermicompost prepared using Eisenia fetida earthworm had significantly ( $P<0.05$ ) higher results in plant height, leaf number, number of branches, total fresh biomass, number of fruits per plant, single fruit length, and total yield, while the minimum values were recorded in topsoil (control treatment) and animal manure compost. The direct and residual effects of vermicompost and biochar organic amendments were the potential organic fertilizers for hot pepper fast growth and to produce enormous yield, which might be due to their nature in improving soil physicochemical and biological properties as well as nutrient uptake.

Potential of Canna indica in Constructed Wetlands for Wastewater Treatment: A Review

This article reviews investigations in which Canna indica was utilized in constructed wetlands (CW) for wastewater treatment of a variety types. It is strongly urged that ornamental flowering plants be used in CWs as monoculture or mixed species to improve the appearance of CWs whilst still treating wastewater. Plants play important roles in CWs by giving the conditions for physical filtration of wastewater, a large specific surface area for microbial growth, and a source of carbohydrates for bacteria. They absorb nutrients and integrate them into plant tissues. They release oxygen into the substrate, establishing a zone in which aerobic microorganisms can thrive and chemical oxidation can occur. They also provide wildlife habitat and make wastewater treatment system more visually attractive. The selection of plant species for CW is an important aspect during the CW design process. Canna indica’s effectiveness in CWs has shown encouraging results for eliminating contaminants from wastewater. There is still a scarcity of information on the mechanisms involved in removal of specific contaminants such as pharmaceuticals, personal care products, hormones, pesticides and steroids and their potential toxicity to the plants. Therefore, this paper reviews some published information about the performance of Canna indica in wastewater treatment, as well as potential areas for future research.

Sustainable Solar Light Photodegradation of Diclofenac by Nano- and Micro-Sized SrTiO3

Currently, photocatalytic reactions under solar illumination have attracted worldwide attention due to the tremendous set of associated environmental problems. Taking sunlight into account, it is indispensable to develop highly effective photocatalysts. Strontium titanate, SrTiO3 (STO), is a cubic perovskite-type semiconductor, an inexpensive material with high thermal stability and corrosion resistance that exhibits a similar energy bandgap to TiO2 and can represent an interesting alternative in photocatalytic applications. Particle size can significantly affect both photocatalytic and photoelectrochemical properties of a photocatalyst, thus altering the photooxidation of organic pollutants in air or water. In this context, this research aims at investigating the photocatalytic features of nano- and micro-sized commercial STO powders towards the photodegradation of diclofenac (DFC), a non-steroidal, anti-inflammatory drug, widely used as analgesic, antiarthritic, and antirheumatic. Both nano- and micro-STO photocatalysts exhibited remarkable photocatalytic efficiency towards DCF, reaching photodegradation efficiency higher than 90% within one hour. Results obtained in simulated drinking water were also compared to those obtained in ultrapure water. Both STOs showed good stability during recycling tests, maintaining high performances after three cycles. Eventually, active species were identified using various scavengers by trapping holes and radicals generated during the photocatalytic degradation process.

Relevance of sorption in bio-reduction of amoxicillin taking place in forest and crop soils

The fate of antibiotics reaching soils is a matter of concern, given its potential repercussions on public health and the environment. In this work, the potential bio-reduction of the antibiotic amoxicillin (AMX), affected by sorption and desorption, is studied for 17 soils with clearly different characteristics. To carry out these studies, batch-type tests were performed, adding increasing concentrations of AMX (0, 2.5, 5, 10, 20, 30, 40, and 50 μmol L^-1) to the soils. For the highest concentration added (50 μmol L^-1), the adsorption values for forest soils ranged from 90.97 to 102.54 μmol kg^-1 (74.21-82.41% of the amounts of antibiotic added), while the range was 69.96-94.87 μmol kg^-1 (68.31-92.56%) for maize soils, and 52.72-85.40 μmol kg^-1 (50.96-82.55%) for vineyard soils. When comparing the results for all soils, the highest adsorption corresponded to those more acidic and with high organic matter and non-crystalline minerals contents. The best adjustment to adsorption models corresponded to Freundlich's. AMX desorption was generally <10%; specifically, the maximum was 6.5% in forest soils, and 16.9% in agricultural soils. These results can be considered relevant since they cover agricultural and forest soils with a wide range of pH and organic matter contents, for an antibiotic that, reaching the environment as a contaminant, can pose a potential danger to human and environmental health.

Multifunctional Membranes-A Versatile Approach for Emerging Pollutants Removal

This paper presents a comprehensive literature review surveying the most important polymer materials used for electrospinning processes and applied as membranes for the removal of emerging pollutants. Two types of processes integrate these membrane types: separation processes, where electrospun polymers act as a support for thin film composites (TFC), and adsorption as single or coupled processes (photo-catalysis, advanced oxidation, electrochemical), where a functionalization step is essential for the electrospun polymer to improve its properties. Emerging pollutants (EPs) released in the environment can be efficiently removed from water systems using electrospun membranes. The relevant results regarding removal efficiency, adsorption capacity, and the size and porosity of the membranes and fibers used for different EPs are described in detail.

Recent Developments in the Immobilization of Laccase on Carbonaceous Supports for Environmental Applications - A Critical Review

Τhe ligninolytic enzyme laccase has proved its potential for environmental applications. However, there is no documented industrial application of free laccase due to low stability, poor reusability, and high costs. Immobilization has been considered as a powerful technique to enhance laccase's industrial potential. In this technology, appropriate support selection for laccase immobilization is a crucial step since the support could broadly affect the properties of the resulting catalyst system. Through the last decades, a large variety of inorganic, organic, and composite materials have been used in laccase immobilization. Among them, carbon-based materials have been explored as a support candidate for immobilization, due to their properties such as high porosity, high surface area, the existence of functional groups, and their highly aromatic structure. Carbon-based materials have also been used in culture media as supports, sources of nutrients, and inducers, for laccase production. This study aims to review the recent trends in laccase production, immobilization techniques, and essential support properties for enzyme immobilization. More specifically, this review analyzes and presents the significant benefits of carbon-based materials for their key role in laccase production and immobilization.

Trends in microbial degradation and bioremediation of emerging contaminants

Modernization and modern ways of living demands more improved products from pharmaceuticals, cosmetics, and food processing industries. Moreover, industries like pesticides, fertilizers, dyeing, paints, detergent etc., also needs improvised products as per demand. As the new product emerges, the pollutants from these industries also constitute new type of danger to the environment and serious health risks to the living organisms. These emerging contaminants (ECs) are from different category of sources such as personal care products (PCPs), pharmaceuticals (Phcs), endocrine disrupting chemicals (EDCs), etc. These ECs can easily escape from the conventional water treatment and eventually get discharged in to the surface water and thus enters in to the ground water, soil, sediments, and also into the oceans. When these contaminants emerge we also require progress in tremendous process for preventing these hazardous chemicals by effective removal and treatment. For the past 50 years, both developed and developing countries are working on this treatment process and found that Microbial degradation and bioremediation are very useful for effective treatment to prevent their emissions. This treatment can be designed for any sort of ECs since the microbial members are so versatile to redesign their metabolic pathways when subject to exposure. However, implementing bioremediation is not alone efficient to degrade ECs and hence, combination of bioremediation, nanotechnology and physical treatment method will also provide sustainable, potent and fast degradation process. In this Book Chapter, we discuss in detail about the ECs, sources of microbial degradation process and its usefulness in the bioremediation of these ECs.

A Multidisciplinary Approach to Evaluate the Effects of Contaminants of Emerging Concern on Natural Freshwater and Brackish Water Phytoplankton Communities

Ecotoxicological assays on monospecific phytoplankton have limited application for detecting the effects of environmental pollutants on multiple species communities. With this study, we took an ecotoxicological, ecological, and biochemical approach to evaluate the effects of two contaminants of emerging concern (zinc oxide nanoparticles, ZnO NPs, and potassium dichromate, K₂Cr₂O₇) at different concentrations (K₂Cr₂O₇ 5.6-18-50 mg/L; ZnO NPs 10-100-300 mg/L) on natural freshwater and brackish water phytoplankton communities. Cell density and absorbance values decreased in freshwater and brackish water phytoplankton communities after exposure to ZnO NPs (100 mg/L and 300 mg/L only for freshwater), whereas growth rate was increased in both freshwater and brackish water phytoplankton communities after exposure to ZnO NPs 10 mg/L. Differently, there was no clear relationship between concentration and inhibition growth after exposure to K₂Cr₂O₇: the lowest cell density was recorded after exposure to 18 mg/L. Moreover, the evenness index value was lower compared to the other concentrations, indicating the growth of a few, albeit resistant species to higher K₂Cr₂O₇ concentrations. Generally, Bacillariophyceae and Dinoficee were prevalent in phytoplankton cultures after exposure to ZnO NPs and K₂Cr₂O₇. The Shannon-Wiener index was slightly higher in the negative than the positive controls, but diversity was low after all treatments in both ecotoxicological assays. The evenness index was always very close to zero, indicating the numerical predominance of one or very few species. Finally, the decrease in chlorophyll-a and pheophytin-a in both ecotoxicological assays indicated a change in photosynthetic activity. Our findings provide evidence for alterations in natural phytoplankton after exposure to emerging contaminants that can disrupt an entire ecosystem's integrity.

Removal of Pharmaceuticals from Wastewater: Analysis of the Past and Present Global Research Activities

Water pollution is a worldwide problem. Water consumption increases at a faster rate than population and this leads to a higher pollution rate. Sustainable Development Goals (SDG) include proposals aimed at ensuring the availability of clean water and its sustainable management (Goal 6), as well as the conservation and sustainable use of oceans and seas. The current trend consists in trying to reconcile economic growth with sustainability, avoiding the negative externalities for the environment generated by human activity. More specifically, the objective of this article is to present the evolution of the research regarding the removal of polluting pharmaceuticals that are discharged into wastewater. To do that, a bibliometric analysis of 2938 articles comprising the period 1979–2020 has been carried out. This analysis includes productivity indicators in the scientific field: journals, authors, research institutions and countries. In addition, keyword analysis allows the identification of four main axes of the research regarding the removal of pharmaceutical residues found in wastewater. The first group of articles is aimed at identifying the pharmaceuticals present in polluting effluents. The second and third groups of articles focus on presenting the procedures that enable the treatment of emerging contaminants, either from a biological point of view (second group) or a physicochemical point of view (third group). The fourth group refers to water quality and its possibilities to be reused. Finally, there is a growing trend of worldwide scientific publications, which justifies the importance of polluting residues management, especially those of pharmaceutical origin, in order to achieve a more sustainable society.

A Review of Caffeine Adsorption Studies onto Various Types of Adsorbents

A systematic literature review of publications from 2000 to 2020 was carried out to identify research trends on adsorbent materials for the removal of caffeine from aqueous solutions. Publications were retrieved from three databases (Scopus, Web of Science, and Google Scholar). Words "adsorption AND caffeine" were examined into titles, abstracts, and keywords. A brief bibliometric analysis was performed with emphasis on the type of publication and of most cited articles. Materials for the removal of caffeine were classified according to the type of material into three main groups: organic, inorganic, and composites, each of them subdivided into different subgroups consistent with their origin or production. Tables resume for each subgroup of adsorbents the key information: specific surface area, dose, pH, maximum adsorption capacity, and isotherm models for the removal of caffeine. The highest adsorption capacities were achieved by organic adsorbents, specifically those with granular activated carbon (1961.3 mg/g) and grape stalk activated carbon (916.7 mg/g). Phenyl-phosphate-based porous organic polymer (301 mg/g), natural sandy loam sediment (221.2 mg/g), composites of MCM-48 encapsulated graphene oxide (153.8 mg/g), and organically modified clay (143.7 mg/g) showed adsorption capacities lower than those of activated carbons. In some activated carbons, a relation between the specific surface area (SSA) and the maximum adsorption capacity (Q max) was found.

Magnetic water treatment in a wastewater treatment plant: Part I - sorption and magnetic particles

The application of magnetic sorption to treat wastewaters is nowadays seen as a potential industrial method. In this work we apply magnetite particles to remediate real wastewater samples, with several contaminants competing for the same active sorption center at the same time. We also apply our studies at three different sampling points of a Wastewater Treatment Plant. In general terms, magnetite particles have shown a very good behaviour concerning the reduction of detergents and COD, while phosphates and total nitrogen, and the majority of heavy metals are high to moderately removed. The influence of the type of wastewater (i.e., sampling point) has also shown to be important especially for high concentration of contaminants.

Comparison of Advanced Oxidation Processes for the Degradation of Maprotiline in Water—Kinetics, Degradation Products and Potential Ecotoxicity

The impact of different oxidation processes on the maprotiline degradation pathways was investigated by liquid chromatography-high resolution mass spectrometry (LC/HRMS) experiments. The in-house SPIX software was used to process HRMS data allowing to ensure the potential singular species formed. Semiconductors photocatalysts, namely Fe-ZnO, Ce-ZnO and TiO2, proved to be more efficient than heterogeneous photo-Fenton processes in the presence of hydrogen peroxide and persulfate. No significant differences were observed in the degradation pathways in the presence of photocatalysis, while the SO4− mediated process promote the formation of different transformation products (TPs). Species resulting from ring-openings were observed with higher persistence in the presence of SO4−. In-silico tests on mutagenicity, developmental/reproductive toxicity, Fathead minnow LC50, D. magna LC50, fish acute LC50 were carried out to estimate the toxicity of the identified transformation products. Low toxicant properties were estimated for TPs resulting from hydroxylation onto bridge rather than onto aromatic rings, as well as those resulting from the ring-opening.

Enhanced Removal of Contaminants of Emerging Concern through Hydraulic Adjustments in Soil Aquifer Treatment

Water reclamation through the use of soil aquifer treatment (SAT) is a sustainable water management technique with high potential for application in many regions worldwide. However, the fate of contaminants of emerging concern (CECs) during the infiltration of treated wastewater during SAT is still a matter of research. This study investigates the removal capacity of 27 CECs during SAT by means of infiltration experiments into a 6 m soil column. Additionally, the influence of the hydraulic operation of SAT systems on the removal of CECs is investigated by changing the wetting and drying cycle lengths. Sixteen out of 27 CECs are efficiently removed during SAT under various operational modes, e.g., bezafibrate, diclofenac and valsartan. For six substances (4-methylbenzotriazole, amidotrizoic acid, benzotriazole, candesartan, hydrochlorothiazide and sulfamethoxazole), removal increased with longer drying times. Removal of amidotrizoic acid and benzotriazole increased by 85% when the drying cycle was changed from 100 to 444 min. For candesartan and hydrochlorothiazide, removal improved by 35%, and for 4-methylbenzotriazole and sulfamethoxazole, by 57% and 39%, respectively. Thus, enhanced aeration of the vadose soil zone through prolonged drying times can be a suitable technique to increase the removal of CECs during SAT.

Combination of solar photo-Fenton and adsorption process for removal of the anticancer drug Flutamide and its transformation products from hospital wastewater

The anti-cancer drug Flutamide (FLUT) is widely used and is of great environmental concern. The solar photo-Fenton (SPF) process can be an effective treatment for the removal of this type of micropollutant. The use of a single addition of 5 mg L^-1 of Fe²⁺ and 50 mg L^-1 of H₂O₂ achieved 20% primary degradation and only 3.05% mineralization. By using three additions of 5 mg L^-1 Fe²⁺, with an initial H₂O₂ concentration of 150 mg L^-1, 58% primary degradation was achieved, together with 12.07% mineralization. Consequently, thirteen transformation products (TPs) were formed. The SPF process was further combined with adsorption onto avocado seed activated carbon (ASAC) as an environmentally friendly approach for the removal of remained FLUT and the TPs. Doehlert design was used to assess the behavior of 13 TPs by optimizing the contact time and the adsorbent mass load. The optimal conditions for removal of FLUT and the TPs were 14 mg of ASAC and a contact time of 40 min. Remained FLUT and the TPs were totally removed using the adsorption process. The mechanisms of adsorption of FLUT and the TPs were strongly influenced by their polarity and π-π interactions of the TPs onto ASAC.

Removal of caffeine, nicotine and amoxicillin from (waste)waters by various adsorbents. A review

The fast growth in the anthropogenic activities, that involve a wide use of pharmaceuticals, has led to the appearance of new toxic and hazardous chemical compounds, called "emerging pollutants", which could cause unpredictable consequences to the ecosystems. The current review is focused on emerging pollutants occurring in food or air and include caffeine and nicotine, as well as on pharmaceuticals, in particular amoxicillin, and the concerns caused by its wide usage for medical purposes. This review, for the first time, analyzes and discusses the potential risks and implications of caffeine, nicotine and amoxicillin as emerging environmental pollutants, a field that remains underrepresented to date. Both caffeine and nicotine belong to life style compounds, while pharmaceutical amoxicillin is one of the very popular β-lactam antibiotics used to take care of human and animal infections. The review covers the toxic effect caused by caffeine, nicotine and amoxicillin on humans and animals and describes some of the main adsorbents utilized for their removal (e.g., grape stalk, tea waste, wheat grains, bentonite, activated carbon, acid and base modified grape slurry wastes, graphene oxides, modified graphene oxides, zeolites, etc.). The isotherm and kinetic models for the analysis of caffeine, nicotine and amoxicillin adsorption by different adsorbents are presented. The impact of pH, temperature, adsorbent dosage and thermodynamic studies were deeply analyzed. The review also discusses the mechanism of adsorption for the above-mentioned emerging pollutants, which includes π-π interaction, cation-π bonding, electron-donor and electron-acceptor forces, van der Waals forces, electrostatic interactions, etc. The present review has a potential value for chemists, ecologists, toxicologists, environmental engineers, and other professionals that are involved in environmental protection.

Green synthesis of graphitic nanobiochar for the removal of emerging contaminants in aqueous media

This study reports the preparation of nanobiochar (NBC) via top-down approach of bioenergy waste-derived dendro biochar through mechanised grinding in order to assess its capacity to remove emerging contaminants, such as antibiotics, agrochemicals, and potentially toxic elements from aqueous media. Preconditioned biochar was disc milled in ethanol media, and the resulting colloidal biochar was dispersed in water to obtain the NBC fraction by centrifugation. Adsorption edge and isotherm experiments were carried out at pH 3 to 8 and NBC dosages of 0.5 g/L for oxytetracycline (OTC), glyphosate (GL), hexavalent chromium (CrVI), and cadmium (CdII). NBC was characterised by scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area, and Fourier transform infrared spectroscopy, which demonstrated the flakey and graphitic nature of the NBC particles with a surface area of 28 m²/g and the presence of different functional groups, such as OH, CO, NH, and CH₃. The best pH for OTC and Cd(II) was 9, whereas the best pH levels for GL and Cr(VI) were 7 and 4, respectively. Isotherms depicted a positive cooperative adsorption mechanism by providing the best fit to the Hills equation, with high removal capacities for four contaminants. Dendro NBC showed the best performance, demonstrated by the high partition coefficient for the removal of OTC, GL, Cr(VI), and Cd(II) over various types of adsorbents. The overall results indicated that graphitic NBC produced by mechanical grinding of dendro biochar is a promising material for the removal of OTC, GL, Cr(VI), and Cd(II) from aqueous media.

Emerging pollutants in water environment: Occurrence, monitoring, fate, and risk assessment

The occurrence of emerging pollutants (EPs) is continuously reported worldwide. Nevertheless, only few of these compounds are toxicologically evaluated due to their vast numbers. Reliable analytical methods and toxicity assessment methods are the basis of either the management or the elimination of EPs. In this paper, literature published in 2018 on EPs were reviewed with special regard to their occurrence, detection methods, fate in the environment, and ecological toxicity assessment. Particular focus was placed on practical considerations, novel processes, and new solution strategies. PRACTITIONER POINTS: Literature published in 2018 on emerging pollutants were reviewed. This review article is with special regard to the occurrence, detection methods, fate and toxicity assessment of emerging pollutants. Particular focus was placed on practical considerations, novel processes and new solution strategies.

A Review on the Synthesis and Characterization of Metal Organic Frameworks for Photocatalytic Water Purification

This review analyzes the preparation and characterization of metal organic frameworks (MOFs) and their application as photocatalysts for water purification. The study begins by highlighting the problem of water scarcity and the different solutions for purification, including photocatalysis with semiconductors, such as MOFs. It also describes the different methodologies that can be used for the synthesis of MOFs, paying attention to the purification and activation steps. The characterization of MOFs and the different approaches that can be followed to learn the photocatalytic processes are also detailed. Finally, the work reviews literature focused on the degradation of contaminants from water using MOF-based photocatalysts under light irradiation.

Assessment of Sulfate Radical-Based Advanced Oxidation Processes for Water and Wastewater Treatment: A Review

High oxidation potential as well as other advantages over other tertiary wastewater treatments have led in recent years to a focus on the development of advanced oxidation processes based on sulfate radicals (SR-AOPs). These radicals can be generated from peroxymonosulfate (PMS) and persulfate (PS) through various activation methods such as catalytic, radiation or thermal activation. This review manuscript aims to provide a state-of-the-art overview of the different methods for PS and PMS activaton, as well as the different applications of this technology in the field of water and wastewater treatment. Although its most widespread application is the elimination of micropollutants, its use for the disinfection of wastewater is gaining increasing interest. In addition, the possibility of combining this technology with ultrafiltration membranes to improve the water quality and lifespan of the membranes has also been discussed. Finally, a brief economic analysis of this technology has been undertaken and the different attempts made to implement it at full-scale have been summarized. As a result, this review tries to be useful for all those people working in that area.

A Review on the Synthesis and Characterization of Biomass-Derived Carbons for Adsorption of Emerging Contaminants from Water

This review analyzes the preparation and characterization of biomass-derived carbons and their application as adsorbents of emerging contaminants from water. The study begins by identifying the different types of emerging contaminants more often found in water streams, including a brief reference to the available technologies for their removal. It also describes the biomass sources that could be used for the synthesis of biochars and activated carbons (AC). The characterization of the adsorbents and the different approaches that can be followed to learn about the adsorption processes are also detailed. Finally, the work reviews literature studies focused on the adsorption of emerging contaminants on biochars and activated carbons synthesized from biomass precursors.