Occurrence of pharmaceutically active and non-steroidal estrogenic compounds in three different wastewater recycling schemes in Australia

Enhancing the performance of microalgal-bacterial systems with sodium bicarbonate: A step forward to carbon neutrality of municipal wastewater treatment

The microalgal-bacterial granular sludge (MBGS) process, enhanced with sodium bicarbonate (NaHCO3), offers a sustainable alternative for wastewater treatment aiming for carbon neutrality. This study demonstrates that NaHCO3, which can be derived from the flue gases and alkaline textile wastewater, significantly enhances pollutant removal and biomass production. Optimal addition of NaHCO3 was found to achieve an inorganic-to-organic carbon ratio of 1.0 and a total carbon-to-nitrogen ratio of 5.0. Metagenomic analysis and structural equation modeling showed that NaHCO3 addition increased dissolved oxygen concentrations and pH levels, creating a more favorable environment for key microbial communities, including Proteobacteria, Chloroflexi, and Cyanobacteria. Confocal laser scanning microscopy further confirmed enhanced interactions between Cyanobacteria and Proteobacteria/Chloroflexi, facilitating the MBGS process. These microbes harbored functional genes (gap2, GLU, and ppk) critical for removing organics, nitrogen, and phosphorus. Carbon footprint analysis revealed significant reductions in CO2 emissions by the NaHCO3-added MBGS process in representative countries (China, Australia, Canada, Germany, and Morocco), compared to the conventional activated sludge process. These findings highlight the effectiveness of NaHCO3 in optimizing MBGS process, establishing it as a key strategy in achieving carbon-neutral wastewater treatment globally.

Wastewater reuse and pharmaceutical pollution in agriculture: Uptake, transport, accumulation and metabolism of pharmaceutical pollutants within plants

The presence of pharmaceutical pollutants in water sources has become a growing concern due to its potential impacts on human health and other organisms. The physicochemical properties of pharmaceuticals based on their intended therapeutical application, which include antibiotics, hormones, analgesics, and antidepressants, is quite diverse. Their presence in wastewater, sewerage water, surface water, ground water and even in drinking water is reported by many researchers throughout the world. Human exposure to these pollutants through drinking water or consumption of aquatic and terrestrial organisms has raised concerns about potential adverse effects, such as endocrine disruption, antibiotic resistance, and developmental abnormalities. Once in the environment, they can persist, undergo transformation, or degrade, leading to a complex mixture of contaminants. Application of treated wastewater, compost, manures or biosolids in agricultural fields introduce pharmaceutical pollutants in the environment. As pharmaceuticals are diverse in nature, significant differences are observed during their uptake and accumulation in plants. While there have been extensive studies on aquatic ecosystems, the effect on agricultural land is more disparate. As of now, there are few reports available on the potential of plant uptake and transportation of pharmaceuticals within and between plant organs. This review summarizes the occurrence of pharmaceuticals in aquatic water bodies at a range of concentrations and their uptake, accumulation, and transport within plant tissues. Research gaps on pharmaceutical pollutants' specific effect on plant growth and future research scopes are highlighted. The factors affecting uptake of pharmaceuticals including hydrophobicity, ionization, physicochemical properties (pKa, logKow, pH, Henry's law constant) are discussed. Finally, metabolism of pharmaceuticals within plant cells through metabolism phase enzymes and plant responses to pharmaceuticals are reviewed.

Integrating pollutant levels and biochemical biomarkers in oysters (Crassostrea rhizophorae and Crassostrea gasar) indicates anthropic impacts on marine environments along the coast of Santa Catarina state, Brazil

This study aimed to carry out a general diagnosis of the contamination of the coastal marine environment of the Santa Catarina state (SC, Brazil) by different classes of environmental pollutants, as well as to evaluate possible adverse effects of the contaminants on biochemical biomarkers of oysters, Crassostrea gasar and Crassostrea rhizophorae. 107 chemicals were evaluated in water, sediment and oyster samples from nine sites along the coastline of SC. We also examined various biochemical biomarkers in the oysters' gills and digestive glands to assess potential effects of contaminants. In general, the northern and central regions of the littoral of SC presented higher occurrences and magnitudes of contaminants than the southern region, which is probably related to higher urbanization of center and northern areas of the littoral. The biomarker analysis in the oysters reflected these contamination patterns, with more significant alterations observed in regions with higher levels of pollutants. Our results may serve as a first baseline for future and more extensive monitoring actions and follow-up of the degree of contamination in the state, allowing for inspection actions and management of areas most affected by marine pollutants.

Selective Adsorption of Organic Micro-Pollutants by Smectite Clays Revealed from Atomistic Simulations

In this study, atomistic simulations were carried out to study the difference in the adsorption process between two similar molecules, diazepam and oxazepam, on Na+-montmorillonite. Kinetic and XRD measurements showed a contrasting adsorption mechanism of these two molecules, differing only by the presence/absence of methyl and hydroxyl groups, with a larger adsorption amount and intercalation for the oxazepam. The structural characterization of these molecules was investigated through DFT calculations and showed the vicinity of hydroxyl and carbonyl groups for only the chair conformation of oxazepam compared to the boat conformation. Classical molecular dynamics simulations of diazepam and the two forms of oxazepam on the external surface of Na+-montmorillonite highlighted the better coordination of the oxazepam-chair conformation, compared to its boat counterpart and diazepam. This has been confirmed through DFT calculations, from which a coordination energy that is greater by 10 kcal·mol-1 is observed. This strongly suggests that the experimentally observed intercalation of oxazepam occurs only in the chair form because of the strong coordination with the Na+ cation present in the Na-Mt interlayer. Classical MD simulations of the intercalated oxazepam chair molecule in the Na-Mt interlayer allowed the evaluation of the interlayer spacing d001, which was in very good agreement with the experimental XRD measurement.

Species-specific bioaccumulation and risk prioritization of psychoactive substances in cultured fish

Psychoactive substances are becoming new concern in environmental research with their increasing applications and the potential threats to fishery production as these substances could alter the behavior of fish and consequently affect the yield and quality of cultured fish. In this study, the accumulation and risk of twenty psychoactive substances were investigated in five species of cultured fish in Eastern China. The results showed that the total concentrations of these twenty psychoactive substances ranged from 0.15 to 0.92 ng mL^-1 in the plasma among the five species of cultured fish with an order of perch > crucian carp > bighead carp > grass carp > silver carp. Diazepam (DIAZ) and methamphetamine (MAMP) were identified as the most frequently detected compounds, which were found in 100% and 93% of the samples with a median concentration of 0.15 and 0.12 ng mL^-1 in the plasma, respectively. Although all of the psychoactive substances posed low or negligible risk, species-specific analysis of risk prioritization revealed that alprazolam, MAMP, temazepam and DIAZ exhibited the greatest potentials of hazard to all species of the cultured fish but with a species-dependent variation. These findings suggest that the adverse effects of psychoactive substances on fishery production, especially on different species, should be considered.

Analyzing the potential environmental impact of NIOSH list of hazardous drugs (group 2)

For the first time, several pharmaceuticals have been defined as priority substances in the new proposal of the revision of the Water Framework Directive (WFD). Consequently, environmental quality standards have been determined for several drugs. This is the case with the antiepileptic carbamazepine, which is considered as hazardous in healthcare settings by The National Institute for Occupational Safety and Health (NIOSH). This organism considers as such drugs that have shown teratogenicity, carcinogenicity, genotoxicity or other developmental, reproductive, or organ toxicity at low doses in studies with animals or humans. This study has been focused on the non-carcinogenic drugs classified in group 2, and their presence in the environment. This group contains many different therapeutic agents such as antineoplastics, psychoactive drugs, immunosuppressants and antivirals, among others. Of the 116 drugs included in the list, 26 have been found in aquatic environmental matrices. Certain drugs have received most attention (e.g., the antiepileptic carbamazepine, progesterone and the antidepressant paroxetine) while others completely lack environmental monitoring. Carbamazepine, fluconazole, paroxetine and warfarin have been found in invertebrates' tissues, whereas carbamazepine, oxazepam and paroxetine have been found in fish tissues. The main aim of the NIOSH's hazardous drug list is to inform healthcare professionals about adequate protection measures to prevent occupational exposure to these pharmaceuticals. However, this list contains useful information for other professionals and researchers such as environmental scientists. The paucity of relevant environmental data of certain hazardous pharmaceuticals might be important to help in the prioritization of compounds that may demand further research.

Removal of Non-Steroidal Anti-Inflammatory Drugs from Drinking Water Sources by GO-SWCNT Buckypapers

Pharmaceutical products such as antibiotics, analgesics, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) are new emerging pollutants, often present in wastewater, potentially able to contaminate drinking water resources. Adsorption is considered the cheapest and most effective technique for the removal of pollutants from water, and, recently, membranes obtained by wet filtration method of SWCNT aqueous solutions (SWCNT buckypapers, SWCNT BPs) have been proposed as self-standing porous adsorbents. In this paper, the ability of graphene oxide/single-walled carbon nanotube composite membranes (GO-SWCNT BPs) to remove some important NSAIDs, namely Diclofenac, Ketoprofen, and Naproxen, was investigated at different pH conditions (pH 4, 6, and 8), graphene oxide amount (0, 20, 40, 60, and 75 wt.%), and initial NSAIDs concentration (1, 10, and 50 ppm). For the same experimental conditions, the adsorption capacities were found to strongly depend on the graphene oxide content. The best results were obtained for 75 wt.% graphene oxide with an adsorption capacity of 118 ± 2 mg g^-1 for Diclofenac, 116 ± 2 mg g^-1 for Ketoprofen, and 126 ± 3 mg g^-1 for Naproxen at pH 4. Overall, the reported data suggest that GO-SWCNT BPs can represent a promising tool for a cheap and fast removal of NSAIDs from drinking water resources, with easy recovery and reusability features.

Recent advances in electrochemical sensor developments for detecting emerging pollutant in water environment

In the latest times, considerable studies have been performed closer to detecting emerging pollutant such as paracetamol in wastewater. Electrochemical sensor developments have recently started to determine in fewer concentrations effectively. The detection of paracetamol using standard protocols corresponding to electroanalytical techniques has a greater impact noticed in directing the detecting process toward biosensors. Non-enzymatic sensors are the peak of all electro analysis approaches. Functionalized materials, such as metal oxide nanoparticles, conducting polymers, and carbon-based materials for electrode surface functionalization have been used to create a fortification for distributing passive enzyme-free biosensors. Synergic effects are possible by enhancing loading capacity and mass transfer of reactants for attaining high analytical sensitivity using a variety of nanomaterials with large surface areas. The main focus of this study is to address the prevailing issues in the identification of paracetamol with the tasks in the non-enzymatic sensors field, followed by the useful methods of electro analysis studies.

Organic removal from coal-to-chemical brine by a multistage system of adsorption-regeneration and electrochemically driven UV/chlorine processes

Treatment of coal-to-gas brine (CGB) is a great challenge since it contains elevated inorganic salts and a high level of toxic and bio-accumulative organics. In this study, CGB treatment was conducted by adsorptionregeneration and electrochemically driven UV/chlorine (E-UV/Cl₂) processes. LS-109D macroporous resin was optimal adsorbent primarily due to unique pore structure, which preferably adsorbed the aromatic fluorescent components with quenching Cl∙ effect and low molecular weight acids recalcitrant to ∙OH. The E-UV/Cl₂ process outperformed the UV photolysis process and electrochemical advanced oxidation processes (EAOPs) for oxidation of organic compounds due to its full utilization of Cl^- in CGB to produce highly active oxidation agents. Thanks to the synergy between process units in organic matter removal, dissolved organic carbon (DOC) of CGB was reduced from 163.41 mg/L to 26.58 mg/L by the multistage system. Furthermore, the CGB with characteristics of high fluorescence and molecular weight (MW) distribution was converted to effluent with low fluorescence and MW distribution. The exhausted LS-109D was regenerated by ultrasound-assisted hot water elution at 363 K. After pretreated by ozonation, the eluate can be easily treated by biological process. The study suggests that the multistage system can provide an effective treatment option for removing organics from CGB.

Behavioral changes and neurochemical responses in Chinese rare minnow exposed to four psychoactive substances

With the increase use of psychoactive pharmaceuticals, these substances and their metabolites are frequently detected in aquatic environment. However, there is still a knowledge gap in the neurotoxicity of these pollutants on aquatic organisms as well as related behavioral effects. In this study, the effects of four psychoactive substances alprazolam (ALPZ), lorazepam (LORZ), codeine (COD) and morphine (MOR) were investigated on 23 neurochemicals and 5 behaviors in Chinese rare minnow (Gobiocypris rarus). The comprehensive neurotoxicity was then evaluated at three levels of neurochemical, neurotransmitter system and comprehensive index. The results indicated that ALPZ and LORZ not only increased serotonin and dopamine along with the decrease of glutamic acid, but also depressed the locomotory activity of Chinese rare minnow although without significance. Exposure to COD and MOR increased acetylcholine, dopamine and adrenaline, and significantly increased anxiety-related behaviors of Chinese rare minnow. Comprehensive evaluation showed that COD has the lowest neurotoxic effect on Chinese rare minnow. LORZ shows a stronger neurotoxicity at low concentration of exposure than the other three substances. MOR has the highest neurotoxic effect at high concentration of exposure among the four drugs. The findings revealed the comprehensive neurotoxicity of these psychoactive substances in fish and suggested ecological risks of these pollutants in aquatic environment.

Abundance, fate, and effects of pharmaceuticals and personal care products in aquatic environments

Pharmaceuticals and personal care products (PPCPs) are found in wastewater, and thus, the environment. In this study, current knowledge about the occurrence and fate of PPCPs in aquatic systems-including wastewater treatment plants (WWTPs) and natural waters around the world-is critically reviewed to inform the state of the science and highlight existing knowledge gaps. Excretion by humans is the primary route of PPCPs entry into municipal wastewater systems, but significant contributions also occur through emissions from hospitals, PPCPs manufacturers, and agriculture. Abundance of PPCPs in raw wastewater is influenced by several factors, including the population density and demography served by WWTPs, presence of hospitals and drugs manufacturers in the sewershed, disease burden of the population served, local regulations, and climatic conditions. Based on the data obtained from WWTPs, analgesics, antibiotics, and stimulants (e.g., caffeine) are the most abundant PPCPs in raw wastewater. In conventional WWTPs, most removal of PPCPs occurs during secondary treatment, and overall removal exceeds 90% for treatable PPCPs. Regardless, the total PPCP mass discharged with effluent by an average WWTP into receiving waters (7.35-20,160 g/day) is still considerable, because potential adverse effects of some PPCPs (such as ibuprofen) on aquatic organisms occur within measured concentrations found in surface waters.

A review on pharmaceuticals removal from waters by single and combined biological, membrane filtration and ultrasound systems

Contaminants of emerging concern (CEC) such as pharmaceuticals commonly found in urban and industrial wastewater are a potential threat to human health and have negative environmental impact. Most wastewater treatment plants cannot efficiently remove these compounds and therefore, many pharmaceuticals end up in aquatic ecosystems, inducing problems such as toxicity and antibiotic-resistance. This review reports the extent of pharmaceutical removal by individual processes such as bioreactors, advanced oxidation processes and membrane filtration systems, all of which are not 100% efficient and can lead to the direct discharge of pharmaceuticals into water bodies. Also, the importance of understanding biotransformation of pharmaceutical compounds during biological and ultrasound treatment, and its impact on treatment efficacy will be reviewed. Different combinations of the processes above, either as an integrated configuration or in series, will be discussed in terms of their degradation efficiency and scale-up capabilities. The trace quantities of pharmaceutical compounds in wastewater and scale-up issues of ultrasound highlight the importance of membrane filtration as a concentration and volume reduction treatment step for wastewater, which could subsequently be treated by ultrasound.

Observable removal of pharmaceutical residues by highly porous photoactive cellulose acetate@MIL-MOF film

Pharmaceutical products are used tremendously worldwide and subsequently released into wastewater even at very low concentration caused serious environmental problem due to their high activity. Therefore, the present work focuses on remarkable removal of paracetamol as one from the most used pharmaceutical intermediates, by using porous film based on cellulose acetate@metal organic framework (CA@Ti-MIL-NH₂). The film was designed to achieve extreme removal of paracetamol by action of both of adsorption and degradation. Metal organic frame work was directly synthesized and inserted within the pre-prepared porous CA film to obtain porous CA@Ti-MIL-NH₂ film. The synthesized films were applied in adsorption and photo-degradation of paracetamol separately and together. Due to the photocatalytic activity of Ti-MIL-NH_2, the photo-degradation of paracetamol in visible-light was much effective and considerably high degradation of paracetamol was observed (k₁ = 760.0 m^-1) comparing to the adsorption (k₁ = 160.0 m^-1). The overall removal of paracetamol was significantly enlarged from 82.7 mg/g for CA film to 519.1 mg/g for porous CA@Ti-MIL-NH₂ film. The used film exhibited quite good reusability and the removal of paracetamol was lowered from 96% to 85% after 5 regeneration cycles. Results of total organic carbon confirmed that paracetamol was fully degraded to CO₂ and water.

Pharmaceuticals Market, Consumption Trends and Disease Incidence Are Not Driving the Pharmaceutical Research on Water and Wastewater

Pharmaceuticals enhance our quality of life; consequently, their consumption is growing as a result of the need to treat ageing-related and chronic diseases and changes in the clinical practice. The market revenues also show an historic growth worldwide motivated by the increase on the drug demand. However, this positivism on the market is fogged because the discharge of pharmaceuticals and their metabolites into the environment, including water, also increases due to their inappropriate management, treatment and disposal; now, worldwide, this fact is recognized as an environmental concern and human health risk. Intriguingly, researchers have studied the most effective methods for pharmaceutical removal in wastewater; however, the types of pharmaceuticals investigated in most of these studies do not reflect the most produced and consumed pharmaceuticals on the market. Hence, an attempt was done to analyze the pharmaceutical market, drugs consumption trends and the pharmaceutical research interests worldwide. Notwithstanding, the intensive research work done in different pharmaceutical research fronts such as disposal and fate, environmental impacts and concerns, human health risks, removal, degradation and development of treatment technologies, found that such research is not totally aligned with the market trends and consumption patterns. There are other drivers and interests that promote the pharmaceutical research. Thus, this review is an important contribution to those that are interested not only on the pharmaceutical market and drugs consumption, but also on the links, the drivers and interests that motivate and determine the research work on certain groups of pharmaceuticals on water and wastewater.

Adsorption of Pharmaceuticals onto Smectite Clay Minerals: A Combined Experimental and Theoretical Study

The adsorption of two pharmaceuticals, carbamazepine and paracetamol, onto the expandable clay mineral saponite has been studied through the combination of kinetic experiments, X-ray diffraction, and theoretical modeling. Kinetic experiments indicate low adsorption for carbamazepine and paracetamol on expandable smectite clay. Accordingly, X-ray diffraction experiments show that neither compound enters smectite interlayer space. Molecular dynamics simulations were carried out to understand the interactions between the two pharmaceuticals and the saponite basal surface in the presence of Na+ cations. Calculations reveal that paracetamol almost does not coordinate solution cations, whereas a rather low coordination to cation is observed for carbamazepine. As a result, the adsorption onto the clay surface results mainly from van der Waals interactions for both pharmaceuticals. Carbamazepine does adsorb the surface via two configurations, one involving cation coordination, which corresponds to a rather stable adsorption compared to paracetamol. This is confirmed by structural analyses completed with desorption free energy profile.

Adding the Mureş River Basin (Transylvania, Romania) to the List of Hotspots with High Contamination with Pharmaceuticals

Background: The Mureș River Basin is a long-term heavily polluted watershed, in a situation of climate changes with decreasing water flow and related decreasing dilution capacity. Here, a mixture of emerging pollutants such as pharmaceuticals were targeted to reveal potential risks regarding the natural lotic ecosystems. Due to the continuous discharge into the environment, pharmaceuticals are gaining persistent organic pollutant characteristics and are considered emerging pollutants. Based on the hazard quotient, this research highlights the dangerous concentrations of carbamazepine, ibuprofen, furosemide, and enalapril in river water. Results: High levels of four pharmaceutical compounds (carbamazepine, ibuprofen, furosemide, and enalapril) and some of their derived metabolites (enalaprilat, carboxyibuprofen, 1-hydroxyibuprofen, and 2-hydroxyibuprofen) were reported in our study in the Mureș River Basin. Overall, pharmaceutical concentrations were found to be highest in the wastewater treatment plant (WWTP) effluent, median downstream of the WWTP, and lowest upstream of the WWTP, as was expected. For all pharmaceutical compounds tested, we recorded concentrations above the limit of quantification (LOQ) in at least one of the sites tested. Carbamazepine exhibited the highest mean values upstream, downstream, and at the WWTP. As expected, the highest concentrations for all the studied pharmaceutical compounds were detected in the WWTP effluent. All Hazard Quotient (HQ) values were below one (on a logarithmic scale in base 10), with the highest values in the WWTP and the lowest in the river upstream of the WWTP. The HQ intervals were in the same range for furosemide, carbamazepine, and ibuprofen at each of the three different sites: upstream WWTP effluent, and downstream. The interval for enalapril stands out as having the lowest HQ at all three sites. Conclusions: Based on these results, the large and complex hydrographical system Mureș River Basin was transformed from a grey area, with little information about pharmaceutical contamination, to a hotspot in terms of contamination with emerging pollutants. Pharmaceutical compound concentrations were found to be the highest in WWTP effluents. The WWTP effluent concentrations were among the highest in Europe, indicating that treatment plants are the primary source of water pollution with pharmaceuticals compounds. The detected levels were higher than the safety limit for carbamazepine and ibuprofen. The determined HQ values imply that the measured levels do pose a threat to the environment for the studied pharmaceuticals. Based on the obtained results, human communities can assess, monitor, predict, and adapt in time to these already-present regional challenges and risks for sustainable use of natural resources, including water and associated products and services.

Non-steroidal anti-inflammatory drugs in the environment: Where were we and how far we have come?

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most well-known pharmaceuticals with a broad scope of properties that are widely used in human and veterinary medicine. Because of their extensive utilization, NSAIDs are commonly identified in the environment as trace emerging contaminants. Regardless of vast experience with these drugs, NSAIDs are full of contradictions that trigger major concerns for environmental researchers. A limited understanding on NSAID's occurrence, distribution and eco-toxicological effects have led to an escalated dilemma in the last decade. Thus, a broad-spectrum study covering all aspects of occurrence, detection and removal is required to meet the fundamental levels of knowledge on the effects of NSAIDs in all exposed environmental aspects. Therefore, this paper focuses on classifying the sources and entry points of residual NSAIDs. Further, detecting and regulating their concentrations in both input streams and receiving environments, along with the removal processes of this specific class of emerging compounds, in the direction of developing a management policy is comprehensively reviewed.

Organics removal and in-situ granule activated carbon regeneration in FBR-Fenton/GAC process for reverse osmosis concentrate treatment

Fluidized bed reactor Fenton (FBR-Fenton) process was adopted for reverse osmosis concentrate (ROC) treatment with three types of carriers, including sand, zeolite and granular activated carbon (GAC). Adsorption studies demonstrated that GAC achieved the best adsorption performance (maximum COD removal of 78% in 15 h) among the three carriers, and the adsorption of ROC organic matters followed a two-stage adsorption model. Fenton oxidations were carried out in three fluidized beds after column saturation, and FBR-Fenton/GAC process achieved highest COD removal (72%) and most BOD₅/COD ratio enhancement (from 0.03 to 0.3) in ROC. Long-term operation data demonstrated good performance stability of GAC as the carrier. In addition, GAC fluidized bed obtained highest total iron removal rate via iron crystallization process. Continuous in-situ GAC regeneration with more than 90% recoveries of surface area, pore volume and adsorption capacity were observed along the ROC treatment with FBR-Fenton/GAC process. Mechanism studies revealed that better COD removal performance in FBR-Fenton/GAC process was attributed to the combining effects of homogenous Fenton reaction, GAC adsorption and GAC/H₂O₂ catalytic reaction.

Electrochemical oxidation of acetaminophen and its transformation products in surface water: effect of pH and current density

Several studies have been conducted worldwide to develop effective and affordable methods to degrade pharmaceuticals and their metabolites/intermediates/oxidation products found in surface water, wastewater and drinking water. In this work, acetaminophen and its transformation products were successfully degraded in surface water by electrochemical oxidation using stainless steel electrodes. The effect of pH and current density on the oxidation process was assessed and the oxidation kinetics and mechanisms involved were described. Additionally, the results were compared with those obtained in acetaminophen synthetic solutions. It was found that conducting the electrochemical oxidation at 16.3 mA/cm² and pH 5, good performance of the process was achieved and not only acetaminophen, but also its transformation products were totally degraded in only 7.5 min; furthermore, small number of transformation products were generated. On the other hand, degradation rates of acetaminophen and its transformation products in surface water were much faster (more than 2.5 times) and the reaction times much shorter (more than 4.0 times) than in synthetic solutions at all current densities and pH values evaluated. At pH 3 and pH 5, greater soluble chlorine formation due to the higher HCl amount used to acidify the surface water solutions could enhance the degradation rates of acetaminophen and its transformation products. However, constituents of surface water (ions and solids) could also have an important role on the oxidation process because at pH 9 (non-acidified solutions) the degradation rates were also much greater and the reaction times were much shorter in surface water than in acetaminophen synthetic solutions.

Biomarker-based assessment of the toxicity of the antifungal clotrimazol to the microcrustacean Daphnia magna

Among the vast list of xenobiotics that may promote harmful effects in aquatic ecosystems, pharmaceuticals are currently a prominent class due to their ability to persist in these environments and also due to the lack of information regarding their effects on the different components of the aquatic biota. Antifungals in particular, despite their massive use, are not extensively studied in environbmental terms. The main objective of this study was to characterize the toxicity of the antifungal clotrimazole to the aquatic organism Daphnia magna. To attain this purpose, the effects of this compound were measured, focusing on the determination of acute lethality, and quantification of biomarkers, such as neurotoxicity (soluble cholinesterases, ChEs); and oxidative stress and metabolism (such as catalase, CAT; and glutathione-S-transferases, GSTs). The toxicity assessment with biomarkers was based on animals exposed to concentrations similar to those already found in surface waters in order to increase the ecological relevance of the obtained data. The results showed that exposure to clotrimazole was able to induce significant increases in both CAT amd GSTs activities. ChE activity was not significantly altered after clotrimazol exposure. In view of the above, it is concluded that the drug studied caused adverse effects in terms of oxidative stress, at an ecological relevant levels, showing that the presence of clotrimazol in the wild is not innocuous.

Assessment of soil buffer capacity on nutrients and pharmaceuticals in nature-based solution applications

The ability of a soil to sustain infiltration rates and to attenuate pollutants is critical for the design and operation of Managed Aquifer Recharge/Soil Aquifer Treatment and phyto-treatment schemes, also referred to as "Blue Infrastructures". We investigated the buffering capacity of a sediment sample and a peat soil sample for nutrients and selected pharmaceutical compounds and its evolution under continuous infiltration of secondary treated wastewater (TWW) in column experiments. Samples were obtained from two blue infrastructures, the Sant'Alessio Induced River Bank Filtration plant and the San Niccolò large-scale phyto-treatment plant in Italy, and were mainly different in their organic carbon contents (0.9 and 48%, respectively). In the column experiments, a constant infiltration rate of about 0.5 L/d was maintained for 6 months. After 4 months of operation, diclofenac and carbamazepine were spiked into the TWW to evaluate their fate. Water quality was monitored by periodic water sampling from the column inflow, at sampling ports along the column length, and at the outflow. Hydraulic conductivity (K) was also monitored. The hydraulic conductivity of the Sant'Alessio sediment decreased by a factor of 10 during the first 10 days of infiltration and then stabilized, while for the San Niccolò K (initially lower) remained constant for 50 days until it decreased following a change of the redox condition in the column. The different redox conditions, due to the two different soils tested, influenced also the concentration and mobility of PO₄^3-, Fe, Mn, and NPOC, and the speciation of the redox sensitive elements (nitrogen and sulfur). NOPC and phosphate were enriched during the filtration through San Niccolò peat soil (from 2 to 4 times, respectively), while they were buffered by the Sant'Alessio sediment (from 0.2 to 0.4 times, respectively). Diclofenac removal (69% and below 20% for San Niccolò and Sant'Alessio, respectively) was related to sorption and degradation processes and it was lower than the removal of carbamazepine in both soils (76 and 35%). The buffer capacity differences between the two soils were higher for diclofenac (62%) than carbamazepine (35%). Nevertheless, since no apparent degradation of carbamazepine was detected in both soils, its persistence in the soil may have a larger impact in case of desorption, posing contamination risk to groundwater. The results highlight the importance of the soils or sediments to be used as medium in such nature-based solutions for their operations. They also offer an approach to, e.g., tailor man-made soil layers in infiltration basins. We strongly suggest that soil characteristics and test duration are carefully considered in designing these infrastructures, when nature-based processes are the choice for dealing with reuse of treated wastewater management issues.

Modeling emerging contaminants breakthrough in packed bed adsorption columns by UV absorbance and fluorescing components of dissolved organic matter

This study investigated, using rapid small-scale column testing, the breakthrough of dissolved organic matter (DOM) and eleven emerging organic contaminants (EOCs) during granular activated carbon (GAC) filtration of different water qualities, including wastewater, surface water and synthetic water (riverine organic matter dissolved in deionized water). Fluorescing organic matter was better adsorbed than UV absorbance at 254 nm (UV₂₅₄) and dissolved organic carbon (DOC) in all tested water. Furthermore, highest adsorption of DOM (in terms of DOC, UV₂₅₄ and fluorescence) was observed during wastewater filtration. UV absorbing DOM had fast and similar breakthrough in surface water and synthetic water, whereas fluorescence breakthrough was very rapid only in synthetic water. PARAFAC modeling showed that different fluorescing components were differently adsorbed during GAC process. Particularly, fluorescing components with maxima intensity at higher excitation wavelengths, which are corresponding to humic-like fluorescence substances, were better removed than other components in all waters. As opposed to DOM, EOCs were better adsorbed during synthetic water filtration, whereas the fastest EOCs breakthrough was observed during filtration of wastewater, which was the water that determined the highest carbon fouling. Exception was represented by long-chained perfluoroalkylated substances (i.e., PFOA, PFDA and PFOS). Indeed, adsorption of these compounds resulted independent of water quality. In this study was also investigated the applicability of UV₂₅₄ and fluorescing PARAFAC components to act as surrogates in predicting EOCs removal by GAC in different water matrices. Empirical linear correlation for the investigated EOCs were determined with UV₂₅₄ and fluorescing components in all water qualities. However, fluorescence measurements resulted more sensitive than UV₂₅₄ to predict EOC breakthrough during GAC adsorption. When the data from all water qualities was combined, good correlations between the microbial humic-like PARAFAC component and EOC removals were still observed and they resulted independent of water quality if considering only real water matrices (wastewater and surface water). On the contrary, correlations between EOC removals and UV₂₅₄ removals were independent of water quality when combining data of surface waters and synthetic water, but a different correlation model was needed to predict EOCs breakthrough in wastewater.

Degradation of Paracetamol and Its Oxidation Products in Surface Water by Electrochemical Oxidation

Paracetamol and its toxic transformation products have been found in surface water, wastewater, and drinking water. Effective methods to degrade these products must be found to reduce their detrimental effects on microorganisms in aquatic systems and minimize the concern on human health. Thus, this study looked into the electrochemical oxidation of paracetamol and its oxidation products on surface water, and results were compared with those of paracetamol synthetic solution oxidation. Degradation of paracetamol was conducted using a stainless steel electrode cell, a pH of 3, and direct current densities of 5.7 mA/cm² (6 V) and 7.6 mA/cm² (12 V). For both current densities applied, the pharmaceutical and its oxidation products observed by high-performance liquid chromatography with diode-array detection (HPLC-DAD) at 254 nm were totally degraded. Faster degradation of paracetamol was observed at a higher current density. Indeed, 95% of paracetamol was oxidized in only 15 min at the 7.6 mA/cm² current density. In comparison to the paracetamol synthetic solution's oxidation, degradation of paracetamol was faster in the surface water than the synthetic solution, at 5.7 mA/cm². Nevertheless, at 7.6 mA/cm², total degradation of paracetamol in surface water was delayed up to 40 min, versus 7.5 min in the synthetic solution. Three oxidation products, observed by HPLC-DAD at 254 nm, were fully oxidized. In comparison with the paracetamol synthetic solution, degradation of the oxidation products in surface water was faster than in synthetic solutions for both current densities. Furthermore, the 7.6 mA/cm² current density resulted in faster degradation of oxidation products. Results obtained from this work are promising for practical applications because short reaction times and low current densities are needed for degradation of paracetamol and its oxidation products. These densities can be potentially supplied by photovoltaic cells.

The effects of Bisphenol A on the seagrass Cymodocea nodosa: Leaf elongation impairment and cytoskeleton disturbance

Bisphenol A (BPA) is an emerging pollutant of environmental concern, classified as "moderately toxic" and "toxic", causing adverse effects on aquatic biota. Although information about BPA toxicity on aquatic fauna is available, the data about BPA effects on aquatic flora remain scarce, missing for marine macrophytes. The effects of environmentally relevant BPA concentrations (ranging from 0.03 to 3 μg L^-1) on juvenile leaf elongation and the cytoskeleton (microtubules, MTs and actin filaments, AFs) were studied in the seagrass Cymodocea nodosa for 1-10 days. The suitability of cytoskeleton disturbance and leaf elongation impairment as "biomarkers" for BPA stress were tested. The highest BPA concentrations (0.3, 0.5, 1 and 3 μg L^-1) affected significantly leaf elongation from the onset of the experiment, while defects of the cytoskeleton were observed even at lower concentrations. In particular, MTs were initially disrupted (i.e. "lowest observed effect concentrations", LOECs) at 0.1 μg L^-1, while AFs were damaged even at 0.03 μg L^-1. AFs appeared thus to be more sensitive to lower BPA concentrations, while there was a correlation between leaf elongation impairment and MT defects. Thus, AF damages, MT disruption and leaf elongation impairment in C. nodosa, in this particular order, appear to be sensitive "biomarkers" of BPA stress, at the above environmentally relevant BPA concentrations.

Predicted environmental concentration and fate of the top 10 most dispensed Australian prescription pharmaceuticals

A basic environmental risk assessment was carried out for the top 10 dispensed pharmaceuticals in Melbourne, Australia, in contrast to the more commonly assessed measure of the most used drugs by physical mass. This allowed for the evaluation of compounds that had not previously been the subject of risk assessment. Estimations of the possible fate and behaviour of the target pharmaceuticals in sewage treatment plants were also made. The predicted removal rates of most drugs within standard sewage treatment were expected to be low, with the exception of the statins, which had high removal rates. Each pharmaceutical was predicted to be present in Melbourne wastewater at the nanogram per litre range or lower. All compounds were predicted to be of low toxicity risk, although it was not possible to model mixture effects. Atorvastatin and Irbesartan were also found to possess the potential to possibly bioaccumulate in the aquatic food chain but not to the extent that would require regulation or labelling.

Alteration in DNA structure, molecular responses and Na+ -K+ -ATPase activities in the gill of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) in response to sub-lethal verapamil

The ecotoxicological consequences of residues from pharmaceutical drugs on aquatic biota have necessitated the development of sensitive and reliable techniques to assess the impact of these xenobiotics on aquatic organisms. This study investigated the alteration in DNA structure, molecular responses and the activities of Na⁺ -K⁺ -ATPase and antioxidant enzymes in the gill of Nile tilapia, Oreochromis niloticus, exposed to long-term effects at the concentrations (0.14, 0.28 and 0.57mgL^-1) of verapamil in static renewal system for 15, 30, 45 and 60 days. Evaluation of DNA structure, using single cell gel electrophoresis, revealed certain degree of DNA damages in the gill in a time and concentration-dependent relationship. Transcription of mRNA of superoxide dismutase (sod), catalase (cat) and heat shock protein (hsp70) genes in the gill of the fish showed the genes were up-regulated. Na⁺-K⁺-ATPase activity was inhibited in a concentration and time dependent manner. The indices of oxidative stress biomarkers (lipid peroxidation and carbonyl protein) as well as superoxide dismutase, glutathione peroxidase, glutathione-S-transferase were elevated in the treated fish in comparison to the control. Further, the level of reduced glutathione and catalase activity were inhibited at 0.28mgL^-1 after day 30. Long-term exposure to sub-lethal concentration of verapamil can cause DNA damages, molecular effects and oxidative stress in O. niloticus. The biomarkers analysed can be used as early warning signals in environmental biomonitoring and assessment of drug contamination in aquatic ecosystem.

Measurement and Modeling of Setschenow Constants for Selected Hydrophilic Compounds in NaCl and CaCl2 Simulated Carbon Storage Brines

Carbon capture, utilization, and storage (CCUS), a climate change mitigation strategy, along with unconventional oil and gas extraction, generates enormous volumes of produced water containing high salt concentrations and a litany of organic compounds. Understanding the aqueous solubility of organic compounds related to these operations is important for water treatment and reuse alternatives, as well as risk assessment purposes. The well-established Setschenow equation can be used to determine the effect of salts on aqueous solubility. However, there is a lack of reported Setschenow constants, especially for polar organic compounds. In this study, the Setschenow constants for selected hydrophilic organic compounds were experimentally determined, and linear free energy models for predicting the Setschenow constant of organic chemicals in concentrated brines were developed. Solid phase microextraction was employed to measure the salting-out behavior of six selected hydrophilic compounds up to 5 M NaCl and 2 M CaCl₂ and in Na-Ca-Cl brines. All compounds, which include phenol, p-cresol, hydroquinone, pyrrole, hexanoic acid, and 9-hydroxyfluorene, exhibited log-linear behavior up to these concentrations, meaning Setschenow constants previously measured at low salt concentrations can be extrapolated up to high salt concentrations for hydrophilic compounds. Setschenow constants measured in NaCl and CaCl₂ brines are additive for the compounds measured here; meaning Setschenow constants measured in single salt solutions can be used in multiple salt solutions. The hydrophilic compounds in this study were selected to elucidate differences in salting-out behavior based on their chemical structure. Using data from this study, as well as literature data, linear free energy relationships (LFERs) for prediction of NaCl, CaCl₂, LiCl, and NaBr Setschenow constants were developed and validated. Two LFERs were improved. One LFER uses the Abraham solvation parameters, which include the index of refraction of the organic compound, organic compound's polarizability, hydrogen bonding acidity and basicity of the organic compound, and the molar volume of the compound. The other uses an octanol-water partitioning coefficient to predict NaCl Setschenow constants. Improved models from this study now include organic compounds that are structurally and chemically more diverse than the previous models. The CaCl₂, LiCl, and NaBr single parameter LFERs use concepts from the Hofmeister series to predict new, respective Setschenow constants from NaCl Setschenow constants. The Setschenow constants determined here, as well as the LFERs developed, can be incorporated into CCUS reactive transport models to predict aqueous solubility and partitioning coefficients of organic compounds. This work also has implications for beneficial reuse of water from CCUS; this can aide in determining treatment technologies for produced waters.

Neurotoxic effects, molecular responses and oxidative stress biomarkers in Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) exposed to verapamil

Pharmaceutical drugs and their metabolites are detected in aquatic ecosystems and have been reported to cause ecotoxicological consequences to resident aquatic organisms. The study investigated the effects of acute and long-term exposure to verapamil on activities of acetylcholinesterase and antioxidant enzymes as well as mRNA expression of stress-related genes in brain and muscle tissues of Nile tilapia, Oreochromis niloticus. The 96h LC₅₀ of verapamil to O. niloticus was 2.29mgL^-1. Exposure to sub-lethal concentrations of verapamil (0.14, 0.29 and 0.57mgL^-1) for period of 15, 30, 45 and 60days, led to inhibition of acetylcholinesterase activities in the brain and muscle of the fish. The activities of the oxidative enzymes such as the catalase, superoxide dismutase and glutathione peroxidase were also inhibited in both the tissues while there was an increase in the activities of glutathione-S-transferase and reduced glutathione in the muscle after 15 days at 0.29mgL^-1. Lipid peroxidation and carbonyl protein showed elevated level, indicating a positive correlation with both time and concentration. The activities of energy-related biomarker (Na⁺-K⁺-ATPase) in both the tissues were significantly inhibited (p<0.05) compared with the control. Transcription of catalase (cat), superoxide dismutase (sod) and heat shock proteins 70 (hsp70) were up-regulated in both the tissues after the study period. Prolonged exposure to sub-lethal verapamil can result in oxidative stress, up-regulation of stress-related genes and neurotoxicity in O. niloticus.

A review of the occurrence of pharmaceuticals and personal care products in Indian water bodies

Little information exists on the occurrence and the ultimate fate of pharmaceuticals in the water bodies in India despite being one of the world leaders in pharmaceutical production and consumption. This paper has reviewed 19 published reports of pharmaceutical occurrence in the aquatic environment in India [conventional activated sludge wastewater treatment plants (WTPs), hospital WTPs, rivers, and groundwater]. Carbamazepine (antipsychoactive), atenolol (antihypertensive), triclocarban and triclosan (antimicrobials), trimethoprim and sulfamethoxazole (antibacterials), ibuprofen and acetaminophen (analgesics), and caffeine (stimulant) are the most commonly detected at higher concentrations in Indian WTPs that treat predominantly the domestic sewage. The concentration of ciprofloxacin, sulfamethoxazole, amoxicillin, norfloxacin, and ofloxacin in Indian WTPs were up to 40 times higher than that in other countries in Europe, Australia, Asia, and North America. A very few studies in Indian rivers reported the presence of ciprofloxacin, enoxacin, ketoprofen, erythromycin, naproxen, ibuprofen, diclofenac and enrofloxacin. Similar compounds were reported in rivers in China, indicating a similar usage pattern in both of these developing countries. In a study reported from an open well in southern India, the groundwater showed the presence of cetirizine, ciprofloxacin, enoxacin, citalopram and terbinafine, which was close to a WTP receiving effluents from pharmaceutical production.

BPA and NP removal from municipal wastewater by tropical horizontal subsurface constructed wetlands

It has been recognized that numerous synthetic compounds like Bisphenol A (BPA) and nonylphenols (NP) are present in effluents from wastewater treatment plants (WWTP) at levels of parts per billion (μg L(-1)) or even parts per trillion (ng L(-1)) with a high potential to cause endocrine disruption in the aquatic environment. Constructed wetlands (CW) are a cost-effective wastewater treatment alternative with promising performance to treat these afore mentioned compounds. This research was aimed to evaluate the efficacy of CW treatment of WWTP effluent for mitigating the effects endocrine disrupting compounds (EDCs). This research goal was accomplished by (1) quantifying the removal of BPA and NP in CWs; (2) isolating CW fungal strains and testing for laccase production; and (3) performing endocrine disruption (reproduction) bioassays using the fruit fly Drosophila melanogaster. Three pilot scale horizontal subsurface flow constructed wetlands (HSSF-CW) were operated for eight weeks: one planted with Phragmites australis; one planted with Heliconia psitacorum; and one unplanted. The Heliconia CW showed a removal efficiency of 73.3(± 19%) and 62.8(± 20.1%) for BPA and NP, respectively; while the Phragmites CW demonstrated a similar removal for BPA (70.2 ± 27%) and lower removal efficiency for NP 52.1(± 37.1%).The unplanted CW achieved 62.2 (± 33%) removal for BPA and 25.3(± 37%) removal for NP. Four of the eleven fungal strains isolated from the Heliconia-CW showed the capacity to produce laccase. Even though complete removal of EDCs was not achieved by the CWs, the bioassay confirmed a significant improvement (p < 0.05) in fly viability for all CWs, with Heliconia sp. being the most effective at mitigating adverse effects on first and second generational reproduction. This study showed that a CW planted with a native Heliconia sp. CW demonstrated a higher removal of endocrine disrupting compounds and better mitigation of reproductive disruption in the bioassay.

Occurrence of pharmaceuticals in municipal wastewater, in the recipient water, and sedimented particles of northern Lake Päijänne

The presence of five different pharmaceuticals, consisting of four anti-inflammatory and one antiepileptic drug, was determined in influent and effluent of a municipal wastewater treatment plant (WWTP) near the city of Jyväskylä, Finland, and in the receiving water, northern Lake Päijänne. In addition, samples of sedimented particles were collected among water samples from five locations near the discharge point of the treated wastewater. The solid phase extracts (SPEs) of water samples were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in the multiple reaction monitoring mode. The studied pharmaceuticals were detected from influent, effluent, and lake water but also in the sedimented particles. The concentrations of carbamazepine, diclofenac, ibuprofen, ketoprofen, and naproxen in Lake Päijänne ranged from 1 to 21 ng L(-1), 4 to 209 ng L(-1), 5 to 836 ng L(-1), 9 to 952 ng L(-1), and 2 to 129 ng L(-1), respectively. The concentrations of ketoprofen in sedimented particles ranged from 79 to 135 μg g(-1) while only trace amounts of other selected pharmaceuticals were detected. The results indicate that the concentrations of pharmaceuticals are affected by the biological and chemical reactions occurring in the wastewater treatment processes but also by the UV light in the photic layer of Lake Päijänne. It can be concluded that considerable amount of selected pharmaceuticals are present in the influent and effluent of municipal WWTP but also in the water phase and sedimented particles of northern Lake Päijänne.

Short-term exposure to L-type calcium channel blocker, verapamil, alters the expression pattern of calcium-binding proteins in the brain of goldfish, Carassius auratus

The influx of calcium ions (Ca(2+)) is responsible for various physiological events including neurotransmitter release and synaptic modulation. The L-type voltage dependent calcium channels (L-type VDCCs) transport Ca(2+) across the membrane. Calcium-binding proteins (CaBPs) bind free cytosolic Ca(2+) and prevent excitotoxicity caused by sudden increase in cytoplasmic Ca(2+). The present study was aimed to understand the regulation of expression of neuronal CaBPs, namely, calretinin (CR) and parvalbumin (PV) following blockade of L-type VDCCs in the CNS of Carassius auratus. Verapamil (VRP), a potent L-type VDCC blocker, selectively blocks Ca(2+) entry at the plasma membrane level. VRP present in the aquatic environment at a very low residual concentration has shown ecotoxicological effects on aquatic animals. Following acute exposure for 96h, median lethal concentration (LC50) for VRP was found to be 1.22mg/L for goldfish. At various doses of VRP, the behavioral alterations were observed in the form of respiratory difficulty and loss of body balance confirming the cardiovascular toxicity caused by VRP at higher doses. In addition to affecting the cardiovascular system, VRP also showed effects on the nervous system in the form of altered expression of PV. When compared with controls, the pattern of CR expression did not show any variations, while PV expression showed significant alterations in few neuronal populations such as the pretectal nucleus, inferior lobes, and the rostral corpus cerebellum. Our result suggests possible regulatory effect of calcium channel blockers on the expression of PV.

Effects of pharmaceuticals present in aquatic environment on Phase I metabolism in fish

The fate of pharmaceuticals in aquatic environments is an issue of concern. Current evidence indicates that the risks to fish greatly depend on the nature and concentrations of the pharmaceuticals and might be species-specific. Assessment of risks associated with the presence of pharmaceuticals in water is hindered by an incomplete understanding of the metabolism of these pharmaceuticals in aquatic species. In mammals and fish, pharmaceuticals are primarily metabolized by cytochrome P450 enzymes (CYP450). Thus, CYP450 activity is a crucial factor determining the detoxification abilities of organisms. Massive numbers of toxicological studies have investigated the interactions of human pharmaceuticals with detoxification systems in various fish species. In this paper, we review the effects of pharmaceuticals found in aquatic environments on fish hepatic CYP450. Moreover, we discuss the roles of nuclear receptors in cellular regulation and the effects of various groups of chemicals on fish, presented in the recent literature.

Peroxone mineralization of chemical oxygen demand for direct potable water reuse: Kinetics and process control

Mineralization of organics in secondary effluent by the peroxone process was studied at a direct potable water reuse research treatment system serving an occupied four-bedroom, four bath university residence hall apartment. Organic concentrations were measured as chemical oxygen demand (COD) and kinetic runs were monitored at varying O3/H2O2 dosages and ratios. COD degradation could be accurately described as the parallel pseudo-1st order decay of rapidly and slowly-oxidizable fractions, and effluent COD was reduced to below the detection limit (<0.7 mg/L). At dosages ≥4.6 mg L(-1) h(-1), an O3/H2O2 mass ratio of 3.4-3.8, and initial COD <20 mg/L, a simple first order decay was indicated for both single-passed treated wastewater and recycled mineral water, and a relationship is proposed and demonstrated to estimate the pseudo-first order rate constant for design purposes. At this O3/H2O2 mass ratio, ORP and dissolved ozone were found to be useful process control indicators for monitoring COD mineralization in secondary effluent. Moreover, an average second order rate constant for OH oxidation of secondary effluent organics (measured as MCOD) was found to be 1.24 × 10(7) ± 0.64 × 10(7) M(-1) S(-1). The electric energy demand of the peroxone process is estimated at 1.73-2.49 kW h electric energy for removal of one log COD in 1 m(3) secondary effluent, comparable to the energy required for desalination of medium strength seawater. Advantages/disadvantages of the two processes for municipal wastewater reuse are discussed.

Application of metabolite profiling tools and time-of-flight mass spectrometry in the identification of transformation products of iopromide and iopamidol during advanced oxidation

The efficiency of wastewater treatment systems in removing pharmaceuticals is often assessed on the basis of the decrease in the concentration of the parent compound. However, what is perceived as "removal" during treatment may not necessarily mean mineralization of the pharmaceutical compound but simply conversion into different transformation products (TPs). Using liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (LC-QToF-MS), we demonstrated conversion of iopromide in wastewater to at least 14 TPs after an advanced oxidation process (AOP) using UV (fluence = 1500 mJ/cm(2)) and H2O2 (10 mg/L). Due to the complexity of the wastewater matrix, the initial experiments were performed using a high concentration (10 mg/L) of iopromide in order to facilitate the identification of TPs. Despite the high concentration of iopromide used, cursory inspection of UV and mass spectra only revealed four TPs in the chromatograms of the post-AOP samples. However, the use of METLIN database and statistics-based profiling tools commonly used in metabolomics proved effective in discriminating between background signals and TPs derived from iopromide. High-resolution mass data allowed one to predict molecular formulas of putative TPs with errors below 5 ppm relative to the observed m/z. Tandem mass spectrometry (MS/MS) data and isotope pattern comparisons provided necessary information that allowed one to elucidate the structure of iopromide TPs. The presence of the proposed iopromide TPs was determined in unspiked wastewater from a municipal wastewater treatment plant, but no iopromide and TPs were detected. Using analogous structural modifications and oxidation that results from the AOP treatment of iopromide, the potential TPs of iopamidol (a structurally similar compound to iopromide) were predicted. The same mass fragmentation pattern observed in iopromide TPs was applied to the predicted iopamidol TPs. LC-QToF-MS revealed the presence of two iopamidol TPs in unspiked AOP-treated wastewater.

Characterization and biotoxicity assessment of dissolved organic matter in RO concentrate from a municipal wastewater reclamation reverse osmosis system

Reverse osmosis (RO) concentrate from municipal wastewater reclamation reverse osmosis (mWRRO) system containing organic compounds may associate with toxic risk, and its discharge might pose an environmental risk. To identify a basis for the selection of feasible technology in treating RO concentrates, the characteristics and biotoxicity of different fractions of dissolved organic matter (DOM) in RO concentrates from an mWRRO system were investigated. The results indicated that the hydrophilic neutrals (HIN), hydrophobic acids (HOA) and hydrophobic bases (HOB) accounted for 96% of the dissolved organic carbon (DOC) of the total DOM in the RO concentrate. According to the SEC chromatograph detected at 254 nm wavelength of UV, the DOM with molecular weight (MW) 1-3 kDa accounted for the majority of the basic and neutral fractions. The fluorescence spectra of the excitation emission matrix (EEM) indicated that most aromatic proteins, humic/fulvic acid-like and soluble microbial by-product-like substances existed in the fractions HOA and hydrophobic neutrals (HON). The genotoxicity and anti-estrogenic activity of the RO concentrate were 1795.6 ± 57.2 μg 4-NQOL(-1) and 2.19 ± 0.05 mg TAM L(-1), respectively. The HIN, HOA, and HOB contributed to the genotoxicity of the RO concentrate, and the HIN was with the highest genotoxic level of 1007.9 ± 94.8 μg 4-NQOL(-1). The HOA, HON, and HIN lead to the total anti-estrogenic activity of the RO concentrate, and HOA occupied approximately 60% of the total, which was 1.3 ± 0.17 mg TAM L(-1).

Emerging contaminants of public health significance as water quality indicator compounds in the urban water cycle

The contamination of the urban water cycle (UWC) with a wide array of emerging organic compounds (EOCs) increases with urbanization and population density. To produce drinking water from the UWC requires close examination of their sources, occurrence, pathways, and health effects and the efficacy of wastewater treatment and natural attenuation processes that may occur in surface water bodies and groundwater. This paper researches in details the structure of the UWC and investigates the routes by which the water cycle is increasingly contaminated with compounds generated from various anthropogenic activities. Along with a thorough survey of chemicals representing compound classes such as hormones, antibiotics, surfactants, endocrine disruptors, human and veterinary pharmaceuticals, X-ray contrast media, pesticides and metabolites, disinfection-by-products, algal toxins and taste-and-odor compounds, this paper provides a comprehensive and holistic review of the occurrence, fate, transport and potential health impact of the emerging organic contaminants of the UWC. This study also illustrates the widespread distribution of the emerging organic contaminants in the different aortas of the ecosystem and focuses on future research needs.

Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor

A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications.