Multi-residue determination of micropollutants in Phragmites australis from constructed wetlands using microwave assisted extraction and ultra-high-performance liquid chromatography tandem mass spectrometry

The environmental sources of benzophenones: Distribution, pretreatment, analysis and removal techniques

Benzophenones (BPs) have wide practical applications in real human life due to its presence in personal care products, UV-filters, drugs, food packaging bags, etc. It enters the wastewater by daily routine activities such as showering, impacting the whole aquatic system, then posing a threat to human health. Due to this fact, the monitoring and removal of BPs in the environment is quite important. In the past decade, various novel analytical and removal techniques have been developed for the determination of BPs in environmental samples including wastewater, municipal landfill leachate, sewage sludge, and aquatic plants. This review provides a critical summary and comparison of the available cutting-edge pretreatment, determination and removal techniques of BPs in environment. It also focuses on novel materials and techniques in keeping with the concept of "green chemistry", and describes on challenges associated with the analysis of BPs, removal technologies, suggesting future development strategies.

Translating wastewater reuse for irrigation from OECD Guidelines: Tramadol sorption and desorption in soil-water matrices

Treated and untreated wastewater is often used for agricultural irrigation and, despite the many benefits of this practice, it poses the risk of biologically active chemical pollutants (such as pharmaceuticals, like tramadol) entering the environment. The partitioning of tramadol between soil/water at environmentally relevant concentrations is important to understand its environmental toxicity. Kinetics and isotherm sorption studies based on the Organisation for Economic Cooperation and Development (OECD) 106 Guideline were undertaken, ensuring comparability to previous studies. Studies were undertaken in three soils of different characteristics using aqueous concentrations of tramadol from 500 ng L^-1 (environmentally relevant) to 100 μg L^-1 (comparable to previous studies). Two of the soils presented a significantly (p < 0.05) higher sorption at a lower initial tramadol concentration (5000 ng L^-1), compared to 20,000 ng L^-1. Hysteresis was observed in all studied soils, indicating the accumulation of tramadol. Higher sorption to soils correlated with higher clay content, with soil/water partitioning coefficients (K_d) of 5.5 ± 13.3, 2.5 ± 3.8 and 0.9 ± 3.0 L kg¹ for soils with clay contents of 41.9%, 24.5% and 7.4%, respectively. Cation exchange was proposed as the main sorption mechanism for tramadol to soils when the pH was below tramadol's pK_a values (9.41 and 13.08). A comparative kinetics study between tramadol in soil/calcium chloride buffer and soil/wastewater effluent demonstrated significantly higher (p < 0.05) tramadol sorption to soil from wastewater effluent. This has the environmental implication that clay soils will be able to retain tramadol from irrigation water, despite the organic content of the irrigation water. Therefore, our studies show that tramadol soil sorption is likely to be higher in agricultural environments reusing wastewater than that predicted from experiments using the OECD 106 Guideline calcium chloride buffer.

Uptake, Occurrence, and Effects of Nonsteroidal Anti-Inflammatory Drugs and Analgesics in Plants and Edible Crops

The plant uptake of pharmaceuticals that include nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics from contaminated environment has benefits and drawbacks. These pharmaceuticals enter plants mostly through irrigation with contaminated water and application of sewage sludge as soil fertilizer. Aquatic plants withdraw these pharmaceuticals from water through their roots. Numerous studies have observed the translocation of these pharmaceuticals from the roots into the aerial tissues. Furthermore, the occurrence of the metabolites of NSAIDs in plants has been observed. This article provides an in-depth critical review of the plant uptake of NSAIDs and analgesics, their translocation, and toxic effects on plant species. In addition, the occurrence of metabolites of NSAIDs in plants and the application of constructed wetlands using plants for remediation are reviewed. Factors that affect the plant uptake and translocation of these pharmaceuticals are examined. Gaps and future research are provided to guide forthcoming investigations on important aspects that worth explorations.

Linking plant-root exudate changes to micropollutant exposure in aquatic plants (Lemna minor and Salvinia natans). A prospective metabolomic study

Recent findings indicate that plant-root exudates can stimulate plant-associated microorganisms to enhance the biodegradation of contaminants in constructed wetlands. To understand this process, we studied the root-exudation changes of two aquatic plants (Lemna minor and Salvinia natans) upon micropollutants exposure (10, 100 and 1000 μg/L mixes containing naproxen, diclofenac, carbamazepine, and benzotriazole). After a 2-day exposure, plant exudates were collected, extracted and non-target analysis was performed with a gas chromatography-high resolution Orbitrap mass-spectrometer. Plants didn't show morphological or growth differences between the control and spiked reactors, but exudation changes were observed in both plants at all concentration levels. Partial least squares discriminant analysis showed that, for Lemna minor, the increase of micropollutants exposure was linked to the reduction of sugar and fatty acid exudation. This may trigger changes in the microbial community living on complex carbon forms. Instead, in Salvinia natans, micropollutants exposure was linked to the release of long-chain compounds such as cuticular waxes and sesquiterpenoids, which might be related to stress signaling. These results demonstrate that plant micropollutant-exposure at environmentally relevant concentration levels triggers changes in root exudates. This may help to design new strategies to enhance micropollutants degradation in nature based solutions such as in constructed wetlands.

Sample preparation and instrumental methods for illicit drugs in environmental and biological samples: A review

Detection of illicit drugs in the environmental samples has been challenged as the consumption increases globally. Current review examines the recent developments and applications of sample preparation techniques for illicit drugs in solid, liquid, and gas samples. For solid samples, traditional sample preparation methods such as liquid-phase extraction, solid-phase extraction, and the ones with external energy including microwave-assisted, ultrasonic-assisted, and pressurized liquid extraction were commonly used. The sample preparation methods mainly applied for liquid samples were microextraction techniques including solid-phase microextraction, microextraction by packed sorbent, dispersive solid-phase extraction, dispersive liquid-liquid microextraction, hollow fiber-based liquid-phase microextraction, and so on. Capillary microextraction of volatiles and airborne particulate sampling were primarily utilized to extract illicit drugs from gas samples. Besides, the paper introduced recently developed instrumental techniques applied to detect illicit drugs. Liquid chromatograph mass spectrometry and gas chromatograph mass spectrometry were the most widely used methods for illicit drugs samples. In addition, the development of ambient mass spectrometry techniques, such as desorption electrospray ionization mass spectrometry and paper spray mass spectrometry, created potential for rapid in-situ analysis.

Preparation of menthol-based hydrophobic deep eutectic solvents for the extraction of triphenylmethane dyes: quantitative properties and extraction mechanism

A series of natural, environmentally friendly and low-cost menthol-based hydrophobic deep eutectic solvents (DES) were synthesized to extract triphenylmethane (TPM) dyes.

Occurrence and removal of pharmaceutical and personal care products using subsurface horizontal flow constructed wetlands

A significant number of emerging pollutants resulting from point source and diffuse pollution are present in the aquatic environment. These are chemicals that are not commonly monitored, but have the potential to cause adverse effects on human and ecological health. One form of emerging pollutants, pharmaceutical and personal care products (PPCPs), are becoming a serious problem in the discharge of domestic wastewater. Therefore, the aim of this study was to determine their occurrence in wastewater and surface waters, and to evaluate the efficiency of subsurface horizontal flow constructed wetlands (planted in polyculture and unplanted), in removing two pharmaceuticals: carbamazepine (Cbz) and sildenafil (Sil); and a personal care product: methylparaben (Mp), present in domestic wastewater. The mixed PPCPs were added to wetlands, at nominal concentrations of 200 μg / L for each compound. The working flow of the reactors was 15 mL / min and the hydraulic retention time was three days. The physicochemical parameters evaluated were: organic load, dissolved oxygen, temperature, conductivity, redox potential, dissolved solids, pH and PPCPs concentration. The presence of the three compounds became evident in all sampled sites, with concentrations of up to 10.66 μg / L, 7.24 μg / L and 2.64 μg / L for Cbz, Mp and Sil, respectively. In planted wetlands, removal efficiencies of up to 97% were achieved for Sil, while in the unplanted these were 30% lower. Removal efficiencies greater than 97% were achieved for Mp, however, for Cbz they were less than 10%, evaluated in both treatments. The average removal efficiency for organic load was 95%. It was determined that constructed wetlands can efficiently remove simple molecular structure compounds such as Mp, and complex structures such as Sil. However, Cbz remained as a recalcitrant contaminant.

Optimization and application of hollow fiber liquid-phase microextraction and microwave-assisted extraction for the analysis of non-steroidal anti-inflammatory drugs in aqueous and plant samples

Human consumption of non-steroidal anti-inflammatory drugs (NSAIDs) is increasing, which poses a great risk of pollution by these pharmaceuticals on the aquatic environment. Therefore, this study reports the optimization of microwave-assisted extraction using water as a green solvent and hollow fiber liquid-phase microextraction (HF-LPME) methods followed by high-performance liquid chromatography-high resolution mass spectrometry analysis of NSAIDs in wastewater and aquatic plant, Eichhornia crassipes. The optimized MAE resulted in efficient transfer of selected NSAIDs from plant samples into the aqueous phase yielding the recoveries ranging from 91 to115%. A multivariate approach based on half fractional factorial and central composite design was used during the optimization of HF-LPME. Under the optimized conditions, the maximum enrichment factors for naproxen, fenoprofen, diclofenac, and ibuprofen were 49, 126, 93 and 156, respectively. The overall analytical method recoveries ranged from 86 to 116% while the limits of quantitation for wastewater and plant samples ranged from 0.09 to 0.59 μg L^-1 and from 0.11 to 0.59 μg kg^-1, respectively. The precision of the proposed analytical method which was measured in terms of RSD values did not exceed 5%. Naproxen was the most abundant compound in both wastewater and the Eichhornia crassipes plant samples with concentrations of up to 3.30 μg L^-1 and 10.97 μg kg^-1, respectively. The detection of NSAIDs in Eichhornia crassipes means this plant has the ability to bioaccumulate pharmaceutical load in surface water.

The Importance of Biological and Ecological Properties of Phragmites Australis (Cav.) Trin. Ex Steud., in Phytoremendiation of Aquatic Ecosystems—The Review

Phragmites australis (common reed) is one of the most extensively distributed species of emergent plant worldwide. The adaptive features of this plant show its competitive character. Owing to high intraspecific diversity of common reed, as well as its phenotypic plasticity, the plant shows a broad ecological amplitude. Moreover, the plant exhibits a high capacity for acclimatization to environmental conditions which are considered adverse. This plant has been used for many years in phytoremediation to purify various types of wastewater. Phragmites australis has a high ability to accumulate various nutrients, heavy metals, and micropollutants, and in this respect, it is superior to other aquatic plants. This review examines the existing literature on the biological and ecological properties of common reed, the use of common reed in wastewater treatment for removing pollutants and tolerance for metals, and in hydrophyte treatment systems. It seems vital to conduct further research on the physiology and biochemistry of the common reed, with the aim of increasing the plant’s efficiency for pollutants removal.

Monitoring pharmaceuticals in the aquatic environment using enzyme-linked immunosorbent assay (ELISA)-a practical overview

The presence of pharmaceuticals, which are considered as contaminants of emerging concern, in natural waters is currently recognized as a widespread problem. Monitoring these contaminants in the environment has been an important field of research since their presence can affect the ecosystems even at very low levels. Several analytical techniques have been developed to detect and quantify trace concentrations of these contaminants in the aquatic environment, namely high-performance liquid chromatography, gas chromatography, and capillary electrophoresis, usually coupled to different types of detectors, which need to be complemented with time-consuming and costly sample cleaning and pre-concentration procedures. Generally, the enzyme-linked immunosorbent assay (ELISA), as other immunoassay methodologies, is mostly used in biological samples (most frequently urine and blood). However, during the last years, the number of studies referring the use of ELISA for the analysis of pharmaceuticals in complex environmental samples has been growing. Therefore, this work aims to present an overview of the application of ELISA for screening and quantification of pharmaceuticals in the aquatic environment, namely in water samples and biological tissues. The experimental procedures together with the main advantages and limitations of the assay are addressed, as well as new incomes related with the application of molecular imprinted polymers to mimic antibodies in similar, but alternative, approaches. Graphical Abstract.

Effects of hydraulic loading rate and organic load on the performance of a pilot-scale hybrid VF-HF constructed wetland in treating secondary effluent

This study evaluated the performance of a pilot-scale hybrid constructed wetland system for secondary effluent and investigated bulk organic matter characteristics. The hybrid constructed wetland consisted of a vertical-flow (VF) bed followed by a horizontal-flow (HF) bed. We also investigated the effects of hydraulic loading rates and influent organic load on the performance of the pilot-scale VF-HF hybrid constructed wetland. The results showed a high removal efficiency for suspended solids (>95%) and organic matter as determined by total organic carbon (>98.5%) and dissolved organic carbon (>70%), but no significant change in nitrogen removal was observed. The wetland treatment efficiency for suspended solids and organic matter showed a good buffer capacity even when hydraulic loading rates increased from 750 to 1500 L m^-2 d^-1 and 500-1000 L m^-2 d^-1 during the VF and HF stages, respectively. Moreover, there was no significant change in the performance when influent organic load increased eight-fold. Fluorescence excitation-emission matrix and liquid chromatography-organic carbon detection (LC-OCD) were used to investigate the dissolved organic matter characteristics in the hybrid VF-HF constructed wetland. Fluorescence excitation-emission matrix spectroscopy showed that both protein- and humic-like substances did not significantly change in the effluent when hydraulic loading rates and organic load increased by two- and eight-fold, respectively. Biopolymers determined using LC-OCD were effectively removed via the VF and HF stage wetlands, indicating the occurrence of biodegradation. Fluorescence excitation-emission matrix spectroscopy and LC-OCD provided the fate of dissolved organic matter characteristics in the hybrid VF-HF constructed wetland.

A prescription for drug-free rivers: uptake of pharmaceuticals by a widespread streamside willow

Following human excretion and limited removal with wastewater treatment, pharmaceuticals are accumulating in rivers worldwide. These chemicals can challenge the health of fish and aquatic organisms and since rivers provide drinking water sources, there is concern for cumulative exposure to humans. In this study, we discovered that sandbar willow (Salix exigua), a predominant riparian shrub along streams throughout North America, has the capacity to quickly remove pharmaceuticals from aqueous solutions. Our study tracked [³H]- or [¹⁴C]-labeled substances including 17α-ethynylestradiol (EE2), a synthetic estrogen in oral contraceptives; the antihypertensive, diltiazem (DTZ); and the anti-anxiety drug, diazepam (DZP); and for comparison, atrazine (ATZ), a root-absorbed herbicide. In growth chambers, willow saplings removed 40-80% of the substances from solutions in 24 h. Following uptake, the EE2 and DTZ were retained within the roots, while DZP and ATZ were partly passed on to the shoots. The absorbed EE2 was unextractable and apparently bound to the root tissue, while DTZ, DZP, and ATZ remained largely soluble (extractable). The uptake and translocation of the pharmaceuticals, reflected in the transpiration stream and root concentration factors, were reasonably predicted from their physicochemical properties, including octanol-water partitioning coefficients. These findings suggest the removal of pharmaceuticals as an unrecognized ecosystem service provided by riparian vegetation and especially the inundation tolerant sandbar willow. This encourages the conservation of riparian willows that line riverbanks, to remove pharmaceuticals and other contaminants. This phytoremediation also encourages the preservation of complex, braided channels and islands, which increase the extent of stream shorelines and riparian willows.

Effects of pharmaceuticals on microbial communities and activity of soil enzymes in mesocosm-scale constructed wetlands

Cyperus alternifolius based mesocosm-scale constructed wetland was employed to remove pharmaceuticals. We investigated the microbial community composition using phosphor lipid fatty acids (PFLAs) analysis and substrate enzyme activity during long-term exposure to pharmaceuticals in mesocosm-scale constructed wetlands. The results showed that there was no visible inhibition effect of pharmaceuticals on CW substrate enzymes activities in the experimental range (0-500 μg/L). Microbial communities, as revealed by PFLAs, were enhanced by the presence of plants, while the PFLAs content was highest when the pharmaceutical concentration was 10 μg/L or 30 μg/L at CWs. Except for anaerobic bacteria and Saturated fatty acids, the maximum PLFAs levels were reached when the pharmaceuticals were 10 μg/L or 30 μg/L, while Bacteria, G (-), fungal bacteria, Aerobic bacteria and Monounsaturated fatty acids were remarkably affected by high pharmaceuticals (100-500 μg/L). However, the main microbial florae were not changed among the treatments. In this study, the removal efficiencies of the studied pharmaceuticals in Planted (30) was greatest, which could be attributed to the higher microbial biomass. These results indicate that C. alternifolius can phytoremediate pharmaceutical-contaminated waters in CWs. Individual fatty acid cannot be used to represent specific species; therefore, more approaches to species identification such as rRNA-based methods must be included in future studies to better understand the metabolic mechanisms of microorganisms involved in the removal of studied pharmaceuticals and improve the performance of CWs.

Uptake of pharmaceuticals by plants grown under hydroponic conditions and natural occurring plant species: A review

Sizeable amount of research has been conducted on the possible uptake of pharmaceuticals by plants from contaminated soil and water used for irrigation of crops. In most cases, pharmaceuticals are taken by roots and translocated into various tissues by transpiration and diffusion. Due to the plant uptake, the occurrence of pharmaceuticals in food sources such as vegetables is a public concern. Few review papers focusing on the uptake of pharmaceuticals, in particular antibiotics, and their translocation in plant tissues have been published. In the current review paper, the work conducted on the uptake of pharmaceuticals belonging to different therapeutic groups such as antibiotics, non-steroidal anti-inflammatory drugs, β-blockers and antiepileptics is reviewed. Such work includes the occurrence of pharmaceuticals in plants, translocation once taken by plants, toxicity studies as well as implications and future studies. Furthermore, the advantages and drawbacks associated with the detection and uptake of these pharmaceuticals by plants are discussed. In addition, the physico-chemical properties that could influence the plant uptake of pharmaceuticals are deliberated.

Biotic phase micropollutant distribution in horizontal sub-surface flow constructed wetlands

The distribution of micropollutants in biotic phases of horizontal sub-surface flow (HSSF) constructed wetlands was investigated. 88 diverse micropollutants (personal care products, pharmaceuticals and illicit drugs) were monitored for in full-scale HSSF steel slag and gravel beds to assess their fate and behaviour during tertiary wastewater treatment. Of the studied micropollutants 54 were found in receiving and treated wastewaters. Treatment reduced concentrations of several micropollutants by >50% (removal range -112% to 98%) and resulted in changes to the stereo-isomeric composition of chiral species. For example, stereo-selective changes were observed for 3,4-methylenedioxymethamphetamine (MDMA) and atenolol during HSSF constructed wetland treatment for the first time. Analysis of sludge present within the HSSF beds found 37 micropollutants to be present. However, concentrations for the majority of these micropollutants were not considered high enough to suggest partitioning into sludge was a contributing mechanism of removal. Nevertheless the preservative methylparaben was found at 2772mgbed^-1. Its daily removal from wastewater of 3.4mgd^-1 indicates partitioning and accumulation in sludge contributes to its removal. Other micropollutants found at high levels in sludge (relative to their overall removals) were the antidepressants sertraline and fluoxetine, and the metabolite desmethylcitalopram. Furthermore, process balances indicated uptake and metabolism by Phragmites australis (Cav.) Trin. ex Steud did not contribute significantly to micropollutant removal. However analysis of plant tissues evidenced uptake, metabolism and accumulation of recalcitrant micropollutants such as ketamine and carbamazepine. It is considered that the rate of uptake was too slow to have a notable impact on removal at the 14h hydraulic retention time. Despite evidence of other removal mechanisms at play (e.g., partitioning into sludge and plant uptake), findings indicate biodegradation is the dominant mechanism of micropollutant removal in HSSF constructed wetlands.