Unveiling combined ecotoxicity: Interactions and impacts of engineered nanoparticles and PPCPs

Emerging contaminants such as engineered nanoparticles (ENPs), pharmaceuticals and personal care products (PPCPs) are of great concern because of their wide distribution and incomplete removal in conventional wastewater and soil treatment processes. The production and usage of ENPs and PPCPs inevitably result in their coexistence in different environmental media, thus posing various risks to organisms in aquatic and terrestrial ecosystems. However, the existing literature on the physicochemical interactions between ENPs and PPCPs and their effects on organisms is rather limited. Therefore, this paper summarized the ecotoxicity of combined ENPs and PPCPs by discussing: (1) the interactions between ENPs and PPCPs, including processes such as aggregation, adsorption, transformation, and desorption, considering the influence of environmental factors like pH, ionic strength, dissolved organic matter, and temperature; (2) the effects of these interactions on bioaccumulation, bioavailability and biotoxicity in organisms at different trophic levels; (3) the impacted of ENPs and PPCPs on cellular-level biological process. This review elucidated the potential ecological hazards associated with the interaction of ENPs and PPCPs, and serves as a foundation for future investigations into the ecotoxicity and mode of action of ENPs, PPCPs, and their co-occurring metabolites.

Occurrence and distribution of PPCPs in water from two largest urban lakes of China: First perspective from DGT in-situ measurement

Pharmaceutical and personal care products (PPCPs) are an important group of emerging contaminants that may threaten organisms at trace concentrations. However, research on the occurrence of PPCPs in urban lakes in China is still scarce. In this study, 15 PPCPs in the Tangxun Lake and the Donghu Lake were collected using the diffusive gradients in thin-films (DGT) technique and analyzed by high performance liquid chromatography tandem-mass spectrometry (HPLC-MS/MS). Thirteen of the 15 targeted PPCPs were detected in the Tangxun Lake, and all PPCPs were detected in the Donghu Lake, with total concentrations ranging from 160 to 730 ng/L (average: 401 ng/L) and 187 to 1933 ng/L (average: 653 ng/L), respectively. Bisphenol A (BPA) was the dominant PPCP, followed by disinfectants in both lakes. The total concentrations of PPCPs in the Donghu Lake were higher than those in the Tangxun Lake. The spatial distribution characteristics of PPCPs in the two lakes were different, with higher total concentrations in the eastern part than in the western part of the Tangxun Lake spatially and higher in the north-western part than in the south-eastern part of the Donghu Lake. The results of the risk assessment showed that BPA and estrone posed high risks to the aquatic environment (RQ ≥ 1), while triclosan and estriol presented a medium risk (0.1 ≤ RQ < 1) in some sites. This study was the first attempt to apply DGT for providing vital data on the evaluation of the ecological risk of PPCPs in the two largest lakes in China, and attention should be paid to the long-term ecological effects caused by the occurrence of PPCPs in lakes.

Prevalence of pharmaceuticals and personal care products, microplastics and co-infecting microbes in the post-COVID-19 era and its implications on antimicrobial resistance and potential endocrine disruptive effects

The COVID-19 (coronavirus disease 2019) pandemic's steady condition coupled with predominance of emerging contaminants in the environment and its synergistic implications in recent times has stoked interest in combating medical emergencies in this dynamic environment. In this context, high concentrations of pharmaceutical and personal care products (PPCPs), microplastics (MPs), antimicrobial resistance (AMR), and soaring coinfecting microbes, tied with potential endocrine disruptive (ED) are critical environmental concerns that requires a detailed documentation and analysis. During the pandemic, the identification, enumeration, and assessment of potential hazards of PPCPs and MPs and (used as anti-COVID-19 agents/applications) in aquatic habitats have been attempted globally. Albeit receding threats in the magnitude of COVID-19 infections, both these pollutants have still posed serious consequences to aquatic ecosystems and the very health and hygiene of the population in the vicinity. The surge in the contaminants post-COVID also renders them to be potent vectors to harbor and amplify AMR. Pertinently, the present work attempts to critically review such instances to understand the underlying mechanism, interactions swaying the current health of our environment during this post-COVID-19 era. During this juncture, although prevention of diseases, patient care, and self-hygiene have taken precedence, nevertheless antimicrobial stewardship (AMS) efforts have been overlooked. Unnecessary usage of PPCPs and plastics during the pandemic has resulted in increased emerging contaminants (i.e., active pharmaceutical ingredients and MPs) in various environmental matrices. It was also noticed that among COVID-19 patients, while the bacterial co-infection prevalence was 0.2-51%, the fungi, viral, protozoan and helminth were 0.3-49, 1-22, 2-15, 0.4-15% respectively, rendering them resistant to residual PPCPs. There are inevitable chances of ED effects from PPCPs and MPs applied previously, that could pose far-reaching health concerns. Furthermore, clinical and other experimental evidence for many newer compounds is very scarce and demands further research. Pro-active measures targeting effective waste management, evolved environmental policies aiding strict regulatory measures, and scientific research would be crucial in minimizing the impact and creating better preparedness towards such events among the masses fostering sustainability.

Pharmaceutical and personal care products (PPCPs) degradation and microbial characteristics of low-temperature operation combined with constructed wetlands

Emerging contaminants (ECs), which are present in water bodies, could cause global environmental and human health problems. These contaminants originate from various sources such as hospitals, clinics, households, and industries. Additionally, they can also indirectly enter the water supply through runoff from agriculture and leachate from landfills. ECs, specifically Pharmaceutical and personal care products (PPCPs), are causing widespread concern due to their contribution to persistent water pollution. Traditional approaches often involve expensive chemicals and energy or result in the creation of by-products. This study developed a practical and environmentally-friendly method for removing PPCPs, which involved combining and integrating various techniques. To implement this method, it was necessary to establish and used a field simulator based on the real-life scenario. Based on the data analysis, the average removal rates of COD, TP, TN, and NH4+-N were 57%, 59%, 63%, and 73%, respectively. the removal rate of PPCPs by CCWs was found to be 82.7% after comparing samples that were not treated by constructed wetlands and those that were treated. Combined constructed wetlands (CCWs) were found to effectively remove PPCPs from water. This is due to the combined action of plant absorption, absorption, and biodegradation by microorganisms living in the wetlands. Interestingly, the wetland plant reed had been shown to play an important role in removing these pollutants. Microbial degradation was the most important pathway for PPCPs removal in CCWs. Carbamazepine was selected as a typical PPCP for analysis. In addition, the microbial community structure of the composite filler was also investigated. High-throughput sequencing confirmed that the dominant bacteria had good adaptability to PPCPs. This technique not only reduced the potential environmental impact but also served as a foundation for further research on the use of constructed wetlands for the treatment of PPCPs contaminated water bodies and its large-scale implementation.

Predicting the removal efficiency of pharmaceutical and personal care products using heated metal oxides as adsorbents based on their physicochemical characteristics

Pharmaceutical and personal care products (PPCPs) are emerging pollutants that are commonly found in the environment and exist predominantly in nondegradable forms. Several attempts have been made to remove PPCPs via conventional wastewater treatment processes; however, these processes have limitations, such as high costs and insufficient removal efficiencies. Adsorption is a promising alternative for removing PPCPs because it is inexpensive, highly reusable, and easy to operate. Therefore, this study aims to determine the contributing characteristics that can be used to predict the adsorption behaviour of PPCPs based on their physicochemical properties, with heated metal oxide adsorbents (HMOAs). HAOP (heated aluminium oxide particles) and HIOP (heated iron oxide particles) with particle sizes below 38 μm were used. Results from the Brunauer-Emmett-Teller (BET) analysis show that HIOP has higher surface area and smaller pore size (113.7 ± 26.3 m2/g and 5.4 ± 1.8 nm) than HAOP (14.5 ± 0.6 m2/g and 18.6 ± 3.1 nm), which suggest that HIOP would show superior adsorption rates compared to HAOP. The adsorption mechanism is identified based on three major physicochemical properties of PPCPs: molecular weight (M.W.), octanol-water partition coefficient (log Kow), and acid dissociation constant (pKa). The results suggest that the most dominant factor that contributes to the adsorption of PPCPs on to HMOAs is the M.W., where the larger the molecular size, the better the adsorption efficiency. The tests conducted with varying log Kow values revealed that the hydrophilicity of the adsorbent influences the adsorption performance. It was found that HIOP exhibits better removal efficiencies with hydrophilic PPCPs (up to 83%) than with hydrophobic PPCPs (48%), while HAOP exhibits better removal efficiencies with hydrophobic PPCPs (86%) than with hydrophilic PPCPs, with less than 10% removal. Unlike the M.W. and pKa values, the log Kow does not exhibit any visible trend. Therefore, the adsorption behaviour can be predicted with the M.W. and pKa values of the PPCPs, when HAOP and HIOP are used as adsorbents.

Emerging environmental health risks associated with the land application of biosolids: a scoping review

BACKGROUND

Over 40% of the six million dry metric tons of sewage sludge, often referred to as biosolids, produced annually in the United States is land applied. Biosolids serve as a sink for emerging pollutants which can be toxic and persist in the environment, yet their fate after land application and their impacts on human health have not been well studied. These gaps in our understanding are exacerbated by the absence of systematic monitoring programs and defined standards for human health protection.

METHODS

The purpose of this paper is to call critical attention to the knowledge gaps that currently exist regarding emerging pollutants in biosolids and to underscore the need for evidence-based testing standards and regulatory frameworks for human health protection when biosolids are land applied. A scoping review methodology was used to identify research conducted within the last decade, current regulatory standards, and government publications regarding emerging pollutants in land applied biosolids.

RESULTS

Current research indicates that persistent organic compounds, or emerging pollutants, found in pharmaceuticals and personal care products, microplastics, and per- and polyfluoroalkyl substances (PFAS) have the potential to contaminate ground and surface water, and the uptake of these substances from soil amended by the land application of biosolids can result in contamination of food sources. Advanced technologies to remove these contaminants from wastewater treatment plant influent, effluent, and biosolids destined for land application along with tools to detect and quantify emerging pollutants are critical for human health protection.

CONCLUSIONS

To address these current risks, there needs to be a significant investment in ongoing research and infrastructure support for advancements in wastewater treatment; expanded manufacture and use of sustainable products; increased public communication of the risks associated with overuse of pharmaceuticals and plastics; and development and implementation of regulations that are protective of health and the environment.

Bifunctional catalytic degradation of diclofenac over Cu-Pd co-modified sponge iron-based trimetal: Parameter optimization

Currently, the pharmaceutical and personal care products (PPCPs) have posed great challenge to advanced oxidation techniques (AOTs). In this study, we decorated sponge iron (s-Fe⁰) with Cu and Pd (s-Fe⁰-Cu-Pd) and further optimized the synthesis parameters with a response surface method (RSM) to rapidly degrade diclofenac sodium (DCF). Under the RSM-optimized conditions of Fe: Cu: Pd = 100: 4.23: 0.10, initial solution pH of 5.13, and input dosage of 38.8 g/L, 99% removal of DCF could be obtained after 60 min of reaction. Moreover, the morphological structure of trimetal was characterized with high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS). Electron spin resonance (ESR) signals have also been applied to capture reactive hydrogen atoms (H*), superoxygen anions, hydroxyl radicals, and single state oxygen (¹O₂). Furthermore, the variations of DCF and its selective degradation products over a series of s-Fe⁰-based bi(tri)metals have been compared. Additionally, the degradation mechanism of DCF has also been explored. To our best knowledge, this is the first report revealing the selective dechlorination of DCF with low toxicity over Pd-Cu co-doped s-Fe⁰ trimetal.

Screening of pharmaceutical and personal care products (PPCPs) along wastewater treatment system equipped with root zone treatment: A potential model for domestic waste leachate management

We present the use of root zone treatment (RZT) based system for the removal of pharmaceutical and personal care products (PPCPs) from domestic wastewater. The occurrence of more than a dozen PPCPs were detected in an academic institution wastewater treatment plant (WWTP) at three specific locations, i.e., influent, root treatment zone, and effluents. The comparisons of observed compounds detected at various stages of WWTP suggest that the presence of PPCPs, like homatropine, cytisine, carbenoxolone, 4,2',4',6'-tetrahydroxychalcone, norpromazine, norethynodrel, fexofenadine, indinavir, dextroamphetamine, 3-hydroxymorphinan, phytosphingosine, octadecanedioic acid, meradimate, 1-hexadecanoyl-sn-glycerol, and 1-hexadecylamine, are unusual than the usual reported PPCPs in the WWTPs. In general, carbamazepine, ibuprofen, acetaminophen, trimethoprim, sulfamethoxazole, caffeine, triclocarban, and triclosan are often reported in wastewater systems. The normalized abundances of PPCPs range between 0.037-0.012, 0.108-0.009, and 0.208-0.005 in main influent, root zone effluent, and main effluents, respectively, of the WWTP. In addition, the removal rates of PPCPs were observed from -200.75% to ∼100% at RZT phase in the plant. Interestingly, we observed several PPCPs at later stages of treatment which were not detected in the influent of the WWTP. This is probably owing to the presence of conjugated metabolites of various PPCPs present in the influent, which subsequently got deconjugated to reform the parent compounds during the biological wastewater treatment. In addition, we suspect the potential release of earlier absorbed PPCPs in the system, which were absent on that particular day of sampling but have been part of earlier influents. In essence, RZT-based WWTP was found to be effective in removing the PPCPs and other organic contaminants in the study but results in stress the need for further comprehensive research on RZT system to conclude the exact removal efficacy and fate of PPCPs during treatment in the system. As a current research gap, the study also recommended RZT to be appraised for PPCPs in-situ remediation from landfill leachates, an underestimated source of PPCPs intrusion in the environment.

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

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

Global groundwater vulnerability for Pharmaceutical and Personal care products (PPCPs): The scenario of second decade of 21st century

The global production of PPCPs have increased by multiple folds promoting excessive exposure of its metabolites to humans via different aquatic systems. The higher residence time of toxic precursors of these metabolites pose direct human health risk. Among the different aquatic systems, the contamination of groundwater by PPCPs is the most concerning threat. This threat is especially critical considering the lesser oxidizing potential of the groundwater as compared to freshwater/river water. A major challenge also arises due to excessive dependency of the world's population on groundwater, which is exponentially increasing with time. This makes the identification and characterization of spatial contamination hotspots highly probabilistic as compared to other freshwater systems. The situation is more vulnerable in developing countries where there is a reported inadequacy of wastewater treatment facilities, thereby forcing the groundwater to behave as the only available sequestrating sink for all these contaminants. With increased consumption of antibiotics and other pharmaceuticals compounds, these wastes have proven capability in terms of enhancing the resistance among the biotic community of the soil systems, which ultimately can become catastrophic and carcinogenic in near future. Recent studies are supporting the aforementioned concern where compounds like diclofenac (analgesic) have attained a concentration of 1.3 mgL^-1 in the aquifer systems of Delhi, India. The situation is far worse for developed nations where prolonged and indiscriminate usage of antidepressants and antibiotics have life threating consequences. It has been confirmed that certain compounds like ofloxacin (antibiotics) and bis-(2-ethylhexyl)phthalate are present in some of the most sensitive wells/springs of the United States and Mexico. The current trend of the situation has been demonstrated by integrating a comparative approach of the published literatures in last three years. This review provides first-hand information report for formulating a directive policy framework for tackling PPCPs issues in the groundwater system.

Occurrence and distribution of Pharmaceuticals and Personal Care Products (PPCPs) in wastewater related riverbank groundwater

Pharmaceutical and personal care products (PPCPs) are among the most frequently reported groups of emerging contaminants in groundwater worldwide. PPCPs in rivers may infiltrate into groundwater through hydraulic exchange and potentially threaten drinking water safety and human health. In the present study, the occurrence and distribution of nine PPCPs in riverbank groundwater and adjacent rivers (distance up to 113 m) were investigated at four sites with different lithological features and permeabilities of aquifers in a city in North China. Seven of nine PPCPs were detectable in groundwater, ranging from <LOQ (limit of quantification) to 128 ng/L. N,N-diethyl-meta-toluamide (DEET), carbamazepine, and caffeine had the highest detection frequencies (>90%). The concentrations and major compounds in river water varied with the sampling location and water system distribution, resulting in distinct compositions of PPCPs in the groundwater at each site along with different lithology and hydrological conditions. The spatial distribution of PPCPs in riverbank groundwater was affected by the hydraulic connection between the groundwater and river and the lithology of aquifers. Direct hydraulic connection of a fine sand aquifer to the adjacent river caused a decrease in PPCPs with increasing distance. The results also suggested that sandy gravel aquifers had a lower capacity to attenuate PPCPs compared to that of fine sand. Significant correlations between PPCP concentrations and thirteen physicochemical factors of groundwater were discovered, including nitrate, potassium, and manganese. Overall, this study provides important evidence on the role of lithology and hydrological conditions on the composition, distribution, and influential physicochemical factors of PPCPs in riverbank groundwater.

Occurrence, transformation, bioaccumulation, risk and analysis of pharmaceutical and personal care products from wastewater: a review

Almost all aspects of society from food security to disease control and prevention have benefited from pharmaceutical and personal care products, yet these products are a major source of contamination that ends up in wastewater and ecosystems. This issue has been sharply accentuated during the coronavirus disease pandemic 2019 (COVID-19) due to the higher use of disinfectants and other products. Here we review pharmaceutical and personal care products with focus on their occurrence in the environment, detection, risk, and removal.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10311-022-01498-7.

Use of biochar to produce reclaimed water for irrigation use

Emerging contaminants, especially, pharmaceutical and personal care products (PPCPs) are not removed well during conventional wastewater treatment and hence pose water quality risk to the environment and potentially to public health. Long-term use of reclaimed wastewater for irrigation can lead to accumulation of trace contaminants in the soil, ground water and their subsequent uptake by plants and potentially can enter human food chain. This paper uses biochar as an adsorbent to remove emerging contaminants from treated wastewater by performing fixed bed experiments. Ten emerging contaminants namely, carbamazepine (CBZ), caffeine, diethyltoluamide (DEET), diphenhydramine (DPH), meprobamate (MPB), primidone (PMD), sulfamethoxazole (SMX), fluoxetine (FXT), perfluorooctanoic acid (PFOA) and trimethoprim (TMP) were monitored during lab scale experiments. Results from the continuous flow runs showed that the breakthrough curve for compounds caffeine, CBZ, DEET and PFOA follow second order Thomas model with adsorption capacities of 396 μg g^-1, 392 μg g^-1, 1160 μg g^-1 and 32 μg g^-1 biochar, respectively. Whereas compounds such as DPH, TMP and FXT were completely removed throughout the column runs by biochar. Results for rest of the compounds were interfered by leaching of these compounds from biochar. It was observed that commercially available GAC performed much better than biochar for all the compounds considered. Even at 1% of obtained capacity, biochar amendment to soils where reclaimed water is used for irrigation can reduce the uptake of these compounds by plants.

Occurrences of microorganic pollutants in the Kumho River by a comprehensive target analysis using LC-Q/TOF-MS with sequential window acquisition of all theoretical fragment ion spectra (SWATH)

In this study, simultaneous identification and semi-quantification of hundreds of micropollutant compounds, including pharmaceutical and personal care products (PPCPs) and pesticides were performed in river and effluent samples from the Kumho River Basin using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) with sequential window acquisition of all theoretical fragment ion spectra (SWATH). In total, 85 compounds (29 pesticides and 56 PPCPs) were identified. The highest proportions of PPCP residues were detected in the downstream area of the Kumho River, close to the central city. On the other hand, the highest proportions of pesticide residues were observed upstream, near agricultural land and golf courses. Additionally, the highly exposable chemicals were prioritized using a scoring and ranking system based on their concentration and detection frequency. Thus, 20 compounds (7 pesticides and 13 PPCPs) with scores of 200 or higher were defined as highly exposable compounds in Kumho River basin.

Do high levels of PPCPs in landfill leachates influence the water environment in the vicinity of landfills? A case study of the largest landfill in China

Landfill leachates are identified as a significant source of pharmaceutical and personal care products (PPCPs), which might pose a threat to groundwater and surface water nearby the landfill. However, knowledge of PPCP contamination in the surrounding water environment of landfills is very limited. Here we investigated eighteen PPCPs in water environment near the largest landfill in China, focusing on their occurrences and spatial distribution, as well as the environmental risks. The results showed the concentration of target PPCPs was below the limit of quantification (<LOQ) to 53.6 ng/L in the adjacent groundwater samples, decreasing with the distance of sampling sites from landfill. The composition pattern of PPCPs in the groundwater was similar to that in raw landfill leachate. These observations indicated a considerable impact of raw landfill leachates on PPCP contamination in the nearby groundwater. In surface water samples, the occurrence of PPCPs was not consistent with that in raw or treated landfill leachates, but similar to that in the same watershed far away from landfill. Spatially, no obvious difference in the PPCPs concentrations was observed, indicating negligible contribution of landfill on PPCPs in surrounding surface water. The findings allowed the first insights into the impacts of well-constructed and managed landfills on PPCP contamination in the surrounding water environment.

Use of microalgae based technology for the removal of antibiotics from wastewater: A review

The antibiotic resistance induced by the release of antibiotics to the environment has urged research towards developing effective technologies for antibiotic removal from wastewater. Traditional technologies such as activated sludge processes are not effective for antibiotic removal. Recently, microalgae-based technology has been explored as a potential alternative for the treatment of wastewater containing antibiotics by adsorption, accumulation, biodegradation, photodegradation, and hydrolysis. In this review, the toxicities of antibiotics on microalgae, the mechanisms of antibiotic removal by microalgae, and the integration of microalgae with other technologies such as ultraviolet irradiation (photocatalysis), advanced oxidation, and complementary microorganism degradation for antibiotic removal were discussed. The limitations of current microalgae-based technology and future research needs were also discussed.

Using in situ modification to enhance organic fouling resistance and rejection of pharmaceutical and personal care products in a thin-film composite nanofiltration membrane

A commercially available nanofiltration membrane, NF90, was modified using an in situ concentration polarization-enhanced radical graft polymerization method to improve the organic fouling resistance as well as the removal of pharmaceutical and personal care products (PPCPs), including ibuprofen (IBU), carbamazepine, sulfadiazine, sulfamethoxazole, sulfamethazine, and triclosan (TRI). 3-Sulfopropyl methacrylate potassium salt (SPM) and 2-hydroxyethyl methacrylate (HEMA) were used in various dosages for surface modification, and the extent of membrane modifications was quantified based on the degree of grafting. The modified NF90 exhibited a 15-40% lower flux during humic acid (HA) fouling and 25% greater NaCl rejection compared with the virgin membrane. PPCP rejection in the modified NF90 membranes before and after HA fouling was 20-45% and 5-20% greater, respectively, compared with that of the virgin membrane. Both SPM and HEMA increased the hydrophilicity of NF90 by decreasing contact angles. Scanning electron microscopy revealed lower amounts of foulants on the modified NF90 than on the virgin membrane. The main fouling mechanism for virgin NF90 was gel layer formation and those for modified NF90 were complete and intermediate blocking. Therefore, the modification of NF90 was effective for controlling organic fouling and strongly rejecting PPCPs.

A single pulse of diffuse contaminants alters the size distribution of natural phytoplankton communities

The presence of a multitude of bioactive organic pollutants collectively classified as pharmaceuticals and personal care products (PPCPs) in freshwaters is of concern, considering that ecological assessments of their potential impacts on natural systems are still scarce. In this field experiment we tested whether a single pulse exposure to a mixture of 12 pharmaceuticals and personal care products, which are commonly found in European inland waters, can influence the size distributions of natural lake phytoplankton communities. Size is one of the most influential determinants of community structure and functioning, particularly in planktonic communities and food webs. Using an in-situ microcosm approach, phytoplankton communities in two lakes with different nutrient levels (mesotrophic and eutrophic) were exposed to a concentration gradient of the PPCPs mixture at five levels. We tested whether sub-lethal PPCPs doses affect the scaling of organisms' abundances with their size, and the slope of these size spectra, which describe changes in the abundances of small relative to large phytoplankton. Our results showed that a large proportion (approximately 80%) of the dataset followed a power-law distribution, thus suggesting evidence of scale invariance of abundances, as expected in steady state ecosystems. PPCPs were however found to induce significant changes in the size spectra and community structure of natural phytoplankton assemblages. The two highest treatment levels of PPCPs were associated with decreased abundance of the most dominant size class (nano-phytoplankton: 2-5 μm), leading to a flattening of the size spectra slope. These results suggest that a pulse exposure to PPCPs induce changes that potentially lead to unsteady ecosystem states and cascading effects in the aquatic food webs, by favoring larger non-edible algae at the expense of small edible species. We propose higher susceptibility due to higher surface to volume ratio in small species as the likely cause of these structural changes.

Occurrence and distribution of pharmaceutical and personal care products, artificial sweeteners, and pesticides in groundwater from an agricultural area in Korea

This study investigated the occurrence and distribution of 33 pharmaceutical and personal care products (PPCPs), five artificial sweeteners (ASs), and six pesticides in groundwater in rural agricultural and rural non-agricultural area in South Korea. A total of 31 target compounds (15 antibiotics, four anthelmintics, seven other PPCPs, four ASs, and one pesticide) were detected in agricultural groundwater at concentrations from not detected (ND) to 49.3 ng/L for PPCPs, ND to 1340 ng/L for ASs, and ND to 116 ng/L for pesticides. Four target compounds (two PPCPs and two ASs) were detected in rural non-agricultural groundwater in the range of 0.085-5.74 ng/L for PPCPs and 5.64-1330 ng/L for ASs. Among the target compounds, ASs, especially acesulfame (detection frequency 69% in rural agricultural areas and 100% in the rural non-agricultural area) were predominantly detected in both agricultural (mean: 32.9 ng/L) and non-agricultural (mean: 536 ng/L) groundwater, but different occurrence patterns were observed according to the sources of contamination. Known markers of sewage leakage were detected in both agricultural and non-agricultural groundwater samples (e.g., acesulfame (69% and 100%), caffeine (88% and 100%), and crotamiton (62% and 100%)), while compounds related to agricultural activities were only observed in agricultural groundwater (e.g., sulfathiazole (38%), sulfamethoxazole (31%), oxfendazole (69%), and carbofuran (42%)).

Improving the organic and biological fouling resistance and removal of pharmaceutical and personal care products through nanofiltration by using in situ radical graft polymerization

In this study, an insitu radical graft polarization technique using monomers of 3-sulfopropyl methacrylate potassium salt (SPM) and 2-hydroxyethyl methacrylate (HEMA) was applied to a commercial nanofiltration membrane (NF90) to improve its removal of six commonly detected pharmaceutical and personal care products (PPCPs) and mitigate organic and biological fouling by humic acid (HA) and sodium alginate (SA). Compared with the virgin membrane, the modified NF90 membrane exhibited considerably improved fouling resistance and an increased reversible fouling percentage, especially for SA+HA composite fouling Moreover, the PPCP removal of the modified NF90 membrane was higher than that of the virgin membrane after SA and SA+HA fouling, respectively. Triclosan and carbamazepine, which are poorly rejected, could be effectively removed by modified membrane after SA or SA+HA fouling. Both monomers modified the membrane surface by increasing the hydrophilicity and decreasing the contact angle. The degree of grafting was quantified using attenuated total reflection Fourier-transform infrared spectroscopy. The mitigation in the fouling was evident from the low quantity of deposit formed on the modified membrane, as observed using scanning electron microscopy. A considerable amount of highly hydrophobic triclosan was adsorbed on the SA-fouled virgin membrane and penetrated through it. By contrast, the adsorption of triclosan was substantially lower in the SPM-modified membrane. After membrane modification, the fouling mechanism changed from solely intermediate blocking to both intermediate blocking and complete blocking after membrane modification. Thus, the in situ radical graft polymerization method effectively reduces organic and biological fouling and provides high PPCP removal, which is beneficial for fouling control and produces permeate of satisfactory quality for application in the field of membrane technology.

Micropollutants removal and health risk reduction in a water reclamation and ecological reuse system

As reclaimed water use is increasing, its safety attracts growing attention, particularly with respect to the health risks associated with the wide range of micropollutants found in the reclaimed water. In this study, sophisticated analysis was conducted for water samples from a water reclamation and ecological reuse system where domestic wastewater was treated using an anaerobic-anoxic-oxic unit followed by a membrane bioreactor (A²O-MBR), and the reclaimed water was used for replenishing a landscape lake. A total of 58 organic micropollutants were detected in the system, consisting of 13 polycyclic aromatic hydrocarbons (PAHs), 16 phenols, 3 pesticides, and 26 pharmaceuticals and personal care products (PPCPs). After treatment by the A²O-MBR process, effective removal of pesticides and phenols was achieved, while when the reclaimed water entered the landscape lake, PPCPs were further removed. From the physicochemical properties of micropollutants, it could be inferred that phenols and dichlorphos (the only pesticide with considerable concentration in the influent) would have been mainly removed by biodegradation and/or volatilization in the biological treatment process. Additionally, it is probable that sludge adsorption also contributed to the removal of dichlorphos. For the predominant PPCP removal in the landscape lake, various actions, such as adsorption, biodegradation, photolysis, and ecologically mediated processes (via aquatic plants and animals), would have played significant roles. However, according to their logK_oc, logK_ow and logD (pH = 8) values, it could be concluded that adsorption by suspended solids might be an important action. Although carcinogenic and non-carcinogenic risks associated with all the detected micropollutants were at negligible levels, the hazard quotients (HQs) of PPCPs accounted for 92.03%-97.23% of the HQ_Total. With the significant removal of PPCPs through the ecological processes in the landscape lake, the safety of reclaimed water use could be improved. Therefore, the introduction of ecological unit into the water reclamation and reuse system could be an effective measure for health risk reduction posed by micropollutants.

Impacts of irrigation water sources and geochemical conditions on vertical distribution of pharmaceutical and personal care products (PPCPs) in the vadose zone soils

Groundwater pollution by emerging contaminants, such as pharmaceutical and personal care products (PPCPs), has caused increasing concerns around the world. The vadose zone is an active zone where lithosphere, hydrosphere and biosphere interact. It is an important medium for PPCPs removal and entry into groundwater from irrigation using wastewater or polluted surface water. In the present study, the occurrence and distribution of eleven PPCPs in areas with a vadose zone (up to 16 m) was investigated from wastewater irrigated farmland, groundwater irrigated farmland and a seasonal river course in Beijing (China). Nine out of eleven PPCPs were detectable, and carbamazepine and caffeine had the highest detection frequencies, above 50%. The PPCPs were detectable deep in 16 m below ground level (bgl), and their concentrations ranged from <LOD (limit of detection) to 12.5 μg/kg. Compared to the vadose zone soils irrigated with groundwater, wastewater-irrigated vadose zone soils had significantly higher PPCPs detection frequencies and contamination levels, suggesting the important roles of irrigation water sources on PPCPs accumulation and transport in the vadose zone. Additionally, PPCPs vertical distribution presented a bell-shape pattern in the vadose zone soils with wastewater irrigation, peaking at 3-6 m bgl. Redundancy analysis (RDA) indicated a significant correlation between PPCPs concentrations in the vadose zone soils and geochemical variables, including available potassium and silt content. This study provides important evidence on the influential factors of PPCPs accumulation and migration in the vadose zone soils resulted from wastewater irrigation. The incomplete removal of PPCPs poses certain risks in subsurface environment, potentially challenging groundwater quality and drinking water safety.

Algae-mediated removal of selected pharmaceutical and personal care products (PPCPs) from Lake Mead water

The persistence and fate of pharmaceutical and personal care products (PPCPs) in the Lake Mead ecosystem are particularly important considering the potential ecological risks and human health impacts. This study evaluated the removal of five common PPCPs (i.e., trimethoprim, sulfamethoxazole, carbamazepine, ciprofloxacin, and triclosan) from Lake Mead water mediated by the green alga Nannochloris sp. The results from the incubation studies showed that trimethoprim and carbamazepine were highly resistant to uptake in the algal cultural medium and were measured at approximately 90%-100% of the applied dose after 14days of incubation. Sulfamethoxazole was found relatively persistent, with >60% of the applied dose remaining in the water after 14days, and its removal was mainly caused by algae-mediated photolysis. However, ciprofloxacin and triclosan dissipated significantly and nearly 100% of the compounds were removed from the water after 7days of incubation under 24h of light. Ciprofloxacin and triclosan were highly susceptible to light, and their estimated half-lives were 12.7hours for ciprofloxacin and 31.2hours for triclosan. Algae-mediated sorption contributed to 11% of the removal of trimethoprim and sulfamethoxazole, 13% of the removal of carbamazepine, and 27% of the removal of triclosan from the lake water. This research showed that 1) trimethoprim, sulfamethoxazole, and carbamazepine are quite persistent in aquatic environments and may potentially affect human health via drinking water intake; 2) photolysis is the dominant pathway to remove ciprofloxacin from aquatic ecosystems, which indicates that ciprofloxacin may have lower ecological risks compared with other PPCPs; and 3) triclosan can undergo photolysis as well as algae-mediated uptake and it may potentially affect the food web because of its high toxicity to aquatic species.

Application of nanoscale zero valent iron and iron powder during sludge anaerobic digestion: Impact on methane yield and pharmaceutical and personal care products degradation

Lab scale and single stage high solid anaerobic digestion of sewage sludge spiked with freshly synthesized nanoscale zero valent iron (nZVI) and commercial iron powder (IP) under mesophilic condition (37±1°C) was performed. The effects of both additives on methane yield, and pharmaceutical and personal care product (PPCP) removal were investigated. Results showed that methane yield was increased by 25.2% and 40.8% in the presence of nZVI (0.1%) and IP (1.6%), respectively. Removal efficiencies of chemical oxygen demand were 54.4% and 66.2% in the presence of nZVI and IP, respectively, which were higher compared to the control group (44.6%). In addition, most PPCPs could be partly or completely removed during the anaerobic digestion process. The application of nZVI and IP showed positive impact on the removal of chlorinated PPCPs (p<0.05), but did not show significant impact on other PPCPs (p>0.05). Our finding suggests that the application of nZVI and IP in anaerobic digestion could be a promising way to enhance methane yield but had less improvement on PPCP degradation.

Removal of trimethoprim, sulfamethoxazole, and triclosan by the green alga Nannochloris sp

Trimethoprim (TMP), sulfamethoxazole (SMX), and triclosan (TCS) are widely used and continuously released into aquatic environments. Freshwater algae can be responsible for the uptake and transfer of the contaminants because they are a major food source for most aquatic organisms. This research applied incubation studies to evaluate the removal efficiency of TMP, SMX, and TCS by the green alga Nannochloris sp. The results showed that the hydrophilic antibiotics TMP and SMX remained in the algal culture at 100% and 68%, respectively, after 14days of incubation, and therefore were not significantly removed from the medium. However, the lipophilic antimicrobial TCS was significantly removed from the medium. Immediately after incubation began, 74% of TCS dissipated and 100% of TCS was removed after 7days of incubation. Additionally, over 42% of TCS was found associated with the algal cells throughout the incubation. The results demonstrate that the presence of Nannochloris sp. eliminated TCS in the aquatic system, but could not significantly remove the antibiotics TMP and SMX. The removal mechanisms of SMX and TCS were found to be different in the algal culture. Algae-promoted photolysis was the primary process for removing SMX and algae-mediated uptake played a major role in removing TCS.

Effect of soil properties, heavy metals and emerging contaminants in the soil nematodes diversity

Among soil organisms, nematodes are seen as the most promising candidates for bioindications of soil health. We hypothesized that the soil nematode community structure would differ in three land use areas (agricultural, forest and industrial soils), be modulated by soil parameters (N, P, K, pH, SOM, CaCO3, granulometric fraction, etc.), and strongly affected by high levels of heavy metals (Cd, Pb, Zn, Cr, Ni, Cu, and Hg) and emerging contaminants (pharmaceuticals and personal care products, PPCPs). Although these pollutants did not significantly affect the total number of free-living nematodes, diversity and structure community indices vastly altered. Our data showed that whereas nematodes with r-strategy were tolerant, genera with k-strategy were negatively affected by the selected pollutants. These effects diminished in soils with high levels of heavy metals given their adaptation to the historical pollution in this area, but not to emerging pollutants like PPCPs.

Beyond the conventional life cycle inventory in wastewater treatment plants

The conventional approach for the environmental assessment of wastewater treatment plants (WWTPs) is typically based on the removal efficiency of organic load and nutrients as well as the quantification of energy and chemicals consumption. Current wastewater treatment research entails the monitoring of direct emissions of greenhouse gases (GHG) and emerging pollutants such as pharmaceutical and personal care products (PPCPs), which have been rarely considered in the environmental assessment of a wastewater treatment facility by life cycle assessment (LCA) methodology. As a result of that, the real environmental impacts of a WWTP may be underestimated. In this study, two WWTPs located in different climatic regions (Atlantic and Mediterranean) of Spain were evaluated in extensive sampling campaigns that included not only conventional water quality parameters but also direct GHG emissions and PPCPs in water and sludge lines. Regarding the GHG monitoring campaign, on-site measurements of methane (CH4) and nitrous oxide (N2O) were performed and emission factors were calculated for both WWTPs. GHG direct emissions accounted for 62% of the total global warming potential (GWP), much more relevant than indirect CO2 emissions associated with electricity use. Regarding PPCPs, 19 compounds were measured in the main streams: influent, effluent and sludge, to perform the evaluation of the toxicity impact categories. Although the presence of heavy metals in the effluent and the sludge as well as the toxicity linked to the electricity production may shade the toxicity impacts linked to PPCPs in some impact categories, the latter showed a notable influence on freshwater ecotoxicity potential (FETP). For this impact category, the removal of PPCPs within the wastewater treatment was remarkably important and arose as an environmental benefit in comparison with the non-treatment scenario.

Kinetics and pathways of ibuprofen degradation by the UV/chlorine advanced oxidation process

The UV/chlorine advanced oxidation process (AOP), which forms reactive species such as hydroxyl radicals (HO) and reactive chlorine species (RCS) such as chlorine atoms (Cl) and Cl2(-), is being considered as an alternative to the UV/H2O2 AOP for the degradation of emerging contaminants. This study investigated the kinetics and pathways of the degradation of a recalcitrant pharmaceutical and personal care product (PPCP)-ibuprofen (IBP)-by the UV/chlorine AOP. The degradation of IBP followed the pseudo first-order kinetics. The first-order rate constant was 3.3 times higher in the UV/chlorine AOP than in the UV/H2O2 AOP for a given chemical molar dosage at pH 6. The first-order rate constant decreased from 3.1 × 10(-3) s(-1) to 5.5 × 10(-4) s(-1) with increasing pH from 6 to 9. Both HO and RCS contributed to the degradation, and the contribution of RCS increased from 22% to 30% with increasing pH from 6 to 9. The degradation was initiated by HO-induced hydroxylation and Cl-induced chlorine substitution, and sustained through decarboxylation, demethylation, chlorination and ring cleavage to form more stable products. Significant amounts of chlorinated intermediates/byproducts were formed from the UV/chlorine AOP, and four chlorinated products were newly identified. The yield of total organic chlorine (TOCl) was 31.6 μM after 90% degradation of 50 μM IBP under the experimental conditions. The known disinfection by-products (DBPs) comprised 17.4% of the TOCl. The effects of water matrix in filtered drinking water on the degradation were not significant, demonstrating the practicality of the UV/chlorine AOP for the control of some refractory PPCPs. However, the toxicity of the chlorinated products should be further assessed.