Low Environmental Concentrations Research Articles

Mercury in Selected Abiotic and Biotic Elements in Two Lakes in Poland: Implications for Environmental Protection and Food Safety

Mercury, which tends to bioaccumulate and biomagnify in aquatic food webs, poses a potential health risk to wildlife and to consumers of predatory fish in particular. Its concentration in biota can be high even at low environmental concentrations. Therefore, the aim of this study was to determine mercury in both abiotic (water and sediment) and biotic elements (common reed (Phragmites australis) and fish: pike (Esox lucius), bream (Abramis brama) and roach (Rutilus rutilus)) in the context of assessing the pollution of two lakes in Poland and the safety of fish consumers. The possibility of Hg biomagnification in fish was also considered. Mercury was determined by means of cold vapor atomic absorption spectrometry (CVAAS). The concentrations of Hg in water and bottom sediments of Lake Ińsko were lower than in Lake Wisola. In the bottom sediments of both lakes, a positive correlation was found between the Hg content and organic matter. The concentration of mercury in the organs of common reed did not exceed 0.017 mg/kg dry weight (dw), and its distribution can be presented as follows: root > leaves > stems > rhizomes. In fish organs from both lakes, the average mercury content did not exceed 0.086 mg/kg of wet weight (ww) and in most cases it was the highest in pike. Higher values were only observed in the muscles and skin of roach. This indicates a lack of biomagnification in the relationships between planktivorous-predatory and benthivores-predatory fish. Based on the maximum levels of mercury in fish and the calculated parameters, i.e., estimated daily intake (EDI), target hazard quotient (THQ) and tolerable weekly intake (TWI), the muscles of the examined fish were found to be safe for consumption. The average dietary exposure to total mercury (THg) and methylmercury (MeHg) was below 0.3% of the TWI.

Metabolomics-based analysis in Daphnia magna after exposure to low environmental concentrations of polystyrene nanoparticles

Particles used in the study: 53 nm PS-NH2 and 62 nm PS-COOH. Significant metabolic responses at: 3.2 μg L−1 PS NPs.

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

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

Assessment by a multi-technique approach of PtNPs' transformations in waters under relevant environmental concentrations and conditions

Once released to the environment, platinum nanoparticles (PtNPs) can undergo different transformations and are affected by several environmental conditions. An only analytical technique cannot provide all the information required to understand those complex processes, so new analytical developments are demanded. In the present work, the potential of asymmetric flow field flow fractionation hyphenated to inductively coupled plasma mass spectrometry (AF4-ICP-MS) for these studies, has been investigated, and classical dynamic and electrophoretic light scattering (DLS & ELS) have been used as complementary techniques. The role of ionic strength, ionic water composition, and natural organic matter (NOM) in the behaviour of PtNPs of different sizes (5 and 50 nm) has been specifically studied. Dynamic and electrophoretic light scattering have been used to track changes in the hydrodynamic diameters (dh) and polydispersity index (PdI) for 50 nm PtNPs (5 nm cannot be studied by DLS) and Z-potential values (for all sizes) to monitor aggregation. AF4-ICP-MS has been also employed to have a solid insight of aggregation at low environmental concentrations for different sizes of PtNPs simultaneously. The information gathered with those techniques was useful to observe changes as the ionic strength increases, which induces aggregation. Also, it was observed that this aggregation process was attenuated in the presence of organic matter. This approach, based on complementary analytical techniques, is needed for a comprehensive study of such complex interactions of NPs in the environment. AF4-ICP-MS is still under-exploited but shows a great potential for this purpose, especially low size NPs and concentrations.

Assessing the potential for nevirapine removal and its ecotoxicological effects on Coelastrella tenuitheca and Tetradesmus obliquus in aqueous environment

Remediation of the antiretroviral (ARV) drug, nevirapine (NVP) has attracted considerable scientific attention in recent years due to its frequent detection and persistence in aquatic environments and potential hazards to living organisms. Algae-based technologies have been emerging as an environmentally friendly option for the removal of pharmaceutical compounds, but their ARV drug removal potential has not been fully explored yet. This study aimed to explore the ecotoxicity and removal potential of NVP by two microalgal species, Coelastrella tenuitheca and Tetradesmus obliquus. Lower environmental concentrations (up to 200 ng L−1) of NVP enhanced the microalgal growth, and the highest dry cell weight of 941.27 mg L−1 was obtained in T. obliquus at 50 ng L−1 NVP concentration. Both microalgae showed varying removal efficiencies (19.53–74.56%) when exposed to NVP concentration levels of up to 4000 ng L−1. At the late log phase (day 8), T. obliquus removed the highest percentage of NVP (74.56%), while C. tenuitheca removed 48% at an initial NVP concentration of 50 ng L−1. Photosynthetic efficiency (Fv/Fm and rETR) of the two microalgal species, however, was not affected by environmental concentrations of NVP (up to 4000 ng L−1) at the mid log phase of growth. SEM analysis demonstrated that both algal species produced distinct ridges on their cell surfaces after NVP uptake. In the ecotoxicity study, the calculated IC50 values of NVP (0–100 mg L−1) after 96 h of exposure were 23.45 mg L−1 (C. tenuitheca) and 18.20 mg L−1 (T. obliquus). The findings of the present study may contribute to a better understanding of the environmental hazards associated with NVP and the efficacy of microalgae in removing this pharmaceutical from aquatic environments.

The use and detection of quantum dots as nanotracers in environmental fate studies of engineered nanoparticles

Investigations of the behavior and effects of engineered nanoparticles (ENPs) on human health and the environment need detailed knowledge of their fate and transport in environmental compartments. Such studies are highly challenging due to low environmental concentrations, varying size distribution of the particles and the interference with the natural background. A strategy to overcome these limits is to use mimics of ENPs with unique detectable properties that match the properties of the ENPs as nanotracers. A special class of ENPs that can be tracked are quantum dots (QDs). QDs are composed of different metals, metalloids, or more recently also carbon (e.g., graphene), that result in unique optical properties. This allows the tracking of such particles by fluorescence microscopic and photometric techniques. Many types of QDs consist of heavy elements, allowing to track and visualize these particles also by electron microscopy and to quantitate the particles indirectly based on these elements. QDs can also be surface modified in various ways which enable them to be used as a label or as traceable mimics for ENPs. This review reflects a broad range of methods to synthesize and modify QDs based on metals, metalloids, and graphene for studying the environmental fate of nanoparticles and discusses and compares analytical methods that can be used for tracking and quantifying QDs. In addition, we review applications of QDs as ENP mimics in environmental studies of surface waters, soils, microorganisms, and plants with respect to the applied analytical techniques.

Long-Term Exposure to Polystyrene Nanoplastics Impairs the Liver Health of Medaka

Nanoplastic (NP) has become a global environmental concern due to its potentially wide distribution and unknown impacts on organisms. Many laboratory studies have reported the short-term toxicity of NPs but their long-term effects are unclear. Here, the chronic hepatoxic effects of NPs (diameter 100 nm; 0, 10, and 104 items/L) in medaka (Oryzias latipes) were evaluated after three-month exposure by investigating the alterations in enzymatic biomarkers (digestion, oxidative status, and immunity) and histopathology in the liver. The trypsin and chymotrypsin activities of digestive enzymes were induced at a low concentration of NPs (10 items/L) but inhibited at high concentration (104 items/L); only the amylase activity was significantly decreased in all NP-treated medaka. Oxidative stress was also induced by NP exposure, which was indicated by the responsive superoxide dismutase and catalase. Lysozyme was significantly reduced after exposure to a high concentration of NPs, while alkaline phosphatase was significantly induced at a low concentration. Exposure to NPs also caused liver damage (e.g., congestion and dilated sinusoids). Taken together, our findings show that chronic exposure to NPs at low particle concentrations can impair the liver health of medaka by affecting liver enzymatic functions and causing histological damage. This implies potentially long-term threats of NPs to aquatic organisms, which call for more long-term aquatic toxicological studies on various species using low environmental concentrations.

Insights into the kinetic regulation of Zn bioaccumulation at trace levels: Lighting up Saccharomycescerevisiae

Zn displays a double-edged effect by acting both as a micronutrient and a toxic metal, and quantitative analysis of its kinetic flux under low environmental concentrations is critical to understand its intracellular regulation. In the present study, we employed a Zn sensitive model eukaryote, the yeast Saccharomyces cerevisiae, which responded to intracellular Zn levels by increasing its autofluorescence, to quantify Zn influx, transportation between labile and storage pools, and efflux under different Zn exposure levels (<1 μM). We demonstrated that the yeast regulated Zn uptake from the extracellular source by a gradually decreased accumulation following an initial high accumulation rate. The subsequent reduced accumulation rate resulted in a steady-state Zn accumulation at 0.061 and 0.073 μg Zn/μg P as the threshold values for the control yeast and Zn-depleted yeast, respectively, independently of the extracellular Zn concentration. Compared with the control yeast, the Zn-depleted yeast possessed a higher accumulation rate, but the difference of bioaccumulation was maintained at approximately 0.01 μg Zn/μg P under different concentrations of extracellular Zn. In contrast, transportation between labile Zn and storage Zn pools or Zn efflux to the extracellular environment was not obvious after Zn exposure, indicating that the Zn dose was below a basal requirement. Such stabilized Zn accumulation was only induced by controlling the Zn influx at the bio-interface. With the novel monitoring of the kinetic changes of autofluorescence, our study demonstrated a remarkably tight Zn regulation system in yeast, providing enlightenment for Zn homeostasis in eukaryotes under low Zn exposure in aqueous environments.

In vivo environmental metabolomic profiling via a novel microextraction fiber unravels sublethal effects of environmental norfloxacin in gut bacteria

Emerging contaminants (ECs), especially antibiotics, have significantly polluted the environment and threaten the living circumstance of organisms. Environmental metabolomic has emerged to investigate the sublethal effects of ECs. However, lacking noninvasive and real-time sample pretreatment techniques restricts its development in environmental toxicology. Hence, in this study, a real-time and in vivo untargeted analytical technique towards microbial endogenous metabolites was developed via a novel composite solid-phase microextraction (SPME) fiber of ZIF-67 and polystyrene to realize the high-coverage capture of living gut microbial metabolites. To reveal the exposure risks of typical antibiotic − norfloxacin (NFX) to gut bacteria, four representative bacteria were exposed to NFX at environmentally relevant levels. Using the proposed SPME fiber, 70 metabolites were identified to obtain an apparent metabolic separation feature between control and NFX-treated (10 ng/mL) microbial groups, which revealed that the low environmental relevant concentration of NFX would affect normal metabolism of gut bacteria. Additionally, NFX exhibited species-specific toxic effects on microbial growth, especially Escherichia coli displaying a distinct dose-dependent trend. Antioxidative enzymatic activities results demonstrated that beneficial bacteria maintained the state of oxidative stress while symbiotic bacteria suffered from oxidative stress injury under NFX contamination, further corroborating its impact on human intestinal health. This study highlights the suitability of in vivo SPME in the field of metabolite extraction and simultaneously possesses a brilliant application foreground in the environmental metabolomics.

Aquatic Pollution and Risks to Biodiversity: The Example of Cocaine Effects on the Ovaries of Anguilla anguilla.

Simple SummaryThe increasing consumption of illicit drugs by man has determined the presence of these drugs in waters, both fresh and marine, in almost all the world. Many studies have shown the dangerousness of these substances to aquatic organisms, so the goal of this study was to investigate the effects of cocaine, one of the most used drugs, on the ovaries of the Anguilla anguilla eel, a critically endangered edible fish, to understand if this drug could also compromise fish reproduction. Our results show that cocaine may impair reproduction in eels through changes in oocyte morphology, expressions of enzymes crucial for oogenesis, and alteration in the serum levels of cortisol and gonadotropins, which regulate the development and maturation of eel gonads. Though this study was conducted on eels, other species may also suffer similar effects from cocaine exposure; our results, therefore, show that illicit drug use is a serious problem not only for humans but also for the environment.Pollution is one of the main causes of the loss of biodiversity, currently one of the most important environmental problems. Important sources of aquatic pollution are illicit drugs, whose presence in waters is closely related to human consumption; their psychoactive properties and biological activity suggest potential adverse effects on non-target organisms, such as aquatic biota. In this study, we evaluated the effect of an environmentally relevant concentration of cocaine (20 ng L−1), an illicit drug widely found in surface waters, on the ovaries of Anguilla anguilla, a species critically endangered and able to accumulate cocaine in its tissues following chronic exposure. The following parameters were evaluated: (1) the morphology of the ovaries; (2) the presence and distribution of enzymes involved in oogenesis; (3) serum cortisol, FSH, and LH levels. The eels exposed to cocaine showed a smaller follicular area and a higher percentage of connective tissue than controls (p < 0.05), as well as many previtellogenic oocytes compared with controls having numerous fully vitellogenic and early vitellogenic oocytes. In addition, the presence and location of 3β-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase, and P450 aromatase differed in the two groups. Finally, cocaine exposure decreased FSH and LH levels, while it increased cortisol levels. These findings show that even a low environmental concentration of cocaine affects the ovarian morphology and activity of A. anguilla, suggesting a potential impact on reproduction in this species.

Potential impact factors on the enhancement of antibiotic resistance in a lake environment.

There is considerable concern regarding antibiotic resistance in the water environment due to antibiotic residues from anthropogenic origins. The low antibiotic concentration in the water environment may promote the selection of antibiotic resistance. However, it is unclear how environmental factors affect resistance selection. We investigated the proliferation of quinolone-susceptible faecal bacteria (E. coli) exposed to low norfloxacin concentration (ng/L) at variable temperatures, exposure times, and carbon concentrations, simulating the conditions of the water environment. The induction of antibiotic resistance in thirteen E. coli isolates was more likely to occur at 37 °C. However, resistance also occurred at temperatures as low as 25 °C, provided a longer exposure time of 5 days. These results suggest that antibiotic resistance is more likely to be induced in regions where temperatures may reach 25-37 °C, such as tropical regions.

Tri-probe fluorescent sensor array for a wide concentration range and high precision identification of aqueous organic amines

Aqueous organic amines are threatening to organisms and ecosystem balance. Although many techniques have been used for detection, the simultaneous identification of both its type and concentration is still challenging due to its structural similarity and low environmental concentration. Sensor array is a powerful sensing technology to identify analytes via unique fingerprint patterns. However, the information from general sensor array based on the weak interaction limited its discernibility ability to similar substances. Here, we propose to design molecules with various sensing units based on strong interactions and hence rich spectral change, then construct a tri-probe sensor array for efficient fluorescent differentiation of aqueous organic amine. Different fluorescence responses to different concentrations and types of organic amines were produced by this array. Varied interaction between the probes and the amines was proved by NMR spectra analysis. The combination of probes can produce rich and complementary fluorescence changes. These unique fluorescence response patterns can be well identified and processed using hierarchical analysis (HCA) and linear discriminant analysis (LDA), enabling the 99.35% accurate differentiation of 5 concentration orders (1 μM ~ 10 mM) of 6 kinds of amines. Blind detections for samples of diethylamine, diisopropylamine in tap water and propylamine, hexylamine, trimethylamine, triethylamine in other five domestic wastewater all can be classified and distinguished successfully. The influence of temperature, pH and mental ions are also considered. This sensing method, with the feature of facile preparation, fast response, and excellent discrimination accuracy, can provide a potential option for fast quality test of water.

Carbon limitation in response to nutrient loading in an eelgrass mesocosm: influence of water residence time.

Altered primary productivity associated with eutrophication impacts not only ecosystem structure but also the biogeochemical cycling of oxygen and carbon. We conducted laboratory experiments to empirically determine how residence time (1, 3, 10 d) influences eutrophication responses in a simplified Pacific Northwest Zostera marina-green macroalgal community. We expected long-residence time (RT) systems to exhibit eutrophication impairments. Instead, we observed an accumulation of nutrients at all RTs and a shift in the dissolved inorganic carbon speciation away from CO2 (aq) with unexpected consequences for eel grass plant condition, including shoot mortality. Most metrics responded more strongly to temperature treatments than to RT treatments. No dramatic shifts in the relative abundance of Z. marina and green macro algae were detected. Z. marina shoot density proliferated in cool temperatures (12°C) with a modest decline at 20°C. Eelgrass loss was associated with high total scale pH (pHT) and CO2 (aq) concentrations of <10 μmol kg-1 CO2 (aq), but not with high nutrients. Z. marina δ13C values support the hypo thesis that carbon availability was greater at short RT. Further, very low leaf sugar concentrations are consistent with extreme photosynthetic CO2 (aq) limitation. We suggest that the effects of extremely low environ mental car bon concentrations (CO2 (aq)) and increased respiration at warm temperatures (20°C) and other physiological processes can lead to internal carbon limitation and shoot mortality. Eutrophication responses to nutrient loading are more nuanced than just light limitation of eelgrass and require additional research on the interaction of the biogeochemical environment and plant physiology to better understand estuarine ecosystem disruption.

Aquatic toxicity and aquatic ecological risk assessment of wastewater-derived halogenated phenolic disinfection byproducts

Increasing number of wastewater-derived aliphatic and phenolic disinfection byproducts (DBPs) were discharged into aquatic environment with the discharge of disinfected wastewater. However, the currently available aquatic toxicity data and the aquatic ecological risk information of them are limited, especially for wastewater-derived phenolic DBPs. In this study, we investigated the acute toxicity of 7 phenolic DBPs that selected from the typical five groups of phenolic DBPs (2,4,6-trihalo-phenols, 2,6-dihalo-4-nitrophenols, 3,5-dihalo-4-hydroxybenzaldehydes, 3,5-dihalo-4-hydroxybenzoic acids and halo-salicylic acids) and 4 aliphatic DBPs to Gobiocypris rarus and also assessed their potential aquatic ecological risk. Experimental results indicated that the half lethal concentration (LC50) values of 2,4,6-trihalo-phenols and 2,6-dihalo-4-nitrophenols ranged from 1 to 10 mg/L; While that of 3,5-dihalo-4-hydroxybenzaldehydes was between 10 and 100 mg/L, and 3,5-dihalo-4-hydroxybenzoic acids and halo-salicylic acids was >100 mg/L. The toxicity mode of action (MOA) identification results from three methods suggested that no clear and consistent MOA were obtained for those 11 DBPs currently. The species-specific aquatic toxicity analysis results highlighted that no aquatic species would be considered as the most sensitive species for all 11 DBPs. However, crustacean and fish were more sensitive than that of algae for most of tested compounds. Lastly, the aquatic ecological risk assessment results of those 11 DBPs revealed that all 7 phenolic and 2 aliphatic DBPs (2-bromoacetamide and bromodichloromethane) had low aquatic ecological risk, while dichloroacetic acid and dibromoacetonitrile had high aquatic ecological risk. The low environmental concentration was the main reason why high toxic phenolic DBPs (2,4,6-trihalo-phenols and 2,6-dihalo-4-nitrophenols) exhibited low ecological risk. Their ecological risk may increase with the increases of corresponding environmental concentration. Thus, more efforts should be made to determine other potential harmful effects of those high toxic phenolic DBPs and to minimize their potential ecological risk by taking appropriate measures.

Norethisterone exposure alters the transcriptome of Marine Medaka (Oryzias melastigma) larvae

ABSTRACT Norethisterone (NET) is one of the earliest synthetic progestins. Its widespread and long-term use means that NET is often detected on the surface and in groundwater samples, which may cause harm to aquatic organisms. Marine medaka (Oryzias melastigma) is a brackish fish, often used in ecotoxicology studies. In this study, the effect of norethisterone exposure on the transcriptome of marine medaka larvae was analyzed. Larvae were exposed to 10 ng/L NET for 24 h, then RNA-Seq was performed. Exposure to 10 ng/L NET resulted in 306 up-regulated and 516 down-regulated genes. An enrichment analysis revealed that differentially expressed genes (DEGs) were significantly enriched in metabolic and biosynthetic pathways, including DNA replication, proteasome, steroid biosynthesis, and other amino acid metabolism pathways. In the DNA replication pathway, all the DEGs were down-regulated, while in the steroid biosynthesis pathway, sqle, hmgcr, dhcr7, and dhcr24 were down-regulated. Quantitative real-time PCR (qPCR) was used to verify 12 DEGs, confirming that the validity of the RNA-Seq analysis. These results show that even low environmental concentrations of NET can lead to transcription level changes of genes related to fish growth and development, which may have adverse effects on the early development and growth of aquatic organisms. Highlights Transcriptomes from norethisterone-exposed marine medaka larvae were obtained A total of 822 differentially expressed genes were identified Norethisterone affected 155 pathways, including DNA replication.

In situ use of bivalves and passive samplers to reveal water contamination by microcystins along a freshwater-marine continuum in France

Cyanobacteria are a potential threat to aquatic ecosystems and human health because of their ability to produce cyanotoxins, such as microcystins (MCs). MCs are regularly monitored in fresh waters, but rarely in estuarine and marine waters despite the possibility of their downstream export. Over a period of two years, we monthly analyzed intracellular (in phytoplankton) and extracellular (dissolved in water) MCs at five stations along a river continuum from a freshwater reservoir with ongoing cyanobacterial blooms to the coast of Brittany, France. MCs were quantified using two integrative samplers placed at each site: solid phase adsorption toxin tracking (SPATT) samplers for collecting extracellular MCs and caged mussels (Anodonta anatina and Mytilus edulis) filter-feeding on MC-producing cyanobacteria. The MC transfer was demonstrated each year during five months at estuarine sites and sporadically at the marine outlet. SPATT samplers integrated extracellular MCs, notably at low environmental concentrations (0.2 µg/L) and with the same variant profile as in water. The mussel A. anatina highlighted the presence of MCs including at intracellular concentrations below 1 µg/L. M. edulis more efficiently revealed the MC transfer at estuarine sites than water samplings. Bivalves showed the same MC variant profile as phytoplankton samples, but with differential accumulation capacities between the variants and the two species. Using SPATT or bivalves can give a more accurate assessment of the contamination level of a freshwater-marine continuum, in which the MC transfer can be episodic. MC content in M. edulis represents a potent threat to human health if considering updated French guideline values, and particularly the total (free and protein-bound) MC content, highlighting the necessity to include cyanotoxins in the monitoring of seafood originating from estuarine areas.

Probability risk assessment of soil PAH contamination premised on industrial brownfield development: a case from China.

The harm of polycyclic aromatic hydrocarbons to human health and the natural environment has become an indisputable fact. Compared with other pollutants, PAHs are more toxic at low environmental concentrations, especially in industrialized environments. This study investigated the concentration distribution of soil PAHs at a well-known industrial production site in China and applied the Monte Carlo simulation method to assess the risk of cancer caused by the excessive accidental intake of PAHs in brownfield development environments. The results showed that the PAH content of the soil at the study site exceeded the local soil quality background value to varying degrees, and the excess rate ranged from 0.72 to 22.3%. There are serious health risks of BaP at the site, which has a 95th health risk percentile value of 1.12E-04. Those for BbF, InP, and DBA range from 1.0×10-6 to 1.0×10-4, and potential health risks occur. Moreover, the exposure duration and average carcinogenic time were the most influential parameters. The study has revealed that exposure to brownfield soil contaminated with PAHs increases the health risks. This is a representative study on the occurrence and concentration of PAHs in industrial brownfields in China, which can be adopted as a basis and evidence for pollution risk assessment of brownfield development.

Nanoplastics Identification in Complex Environmental Matrices: Strategies for Polystyrene and Polypropylene.

Identification of nanoplastics in complex environmental matrices remains a challenge. Despite the increase in nanoplastics studies, there is a lack of studies dedicated to nanoplastics detection, partially explained by their carbon-based structure, their wide variety of composition, and their low environmental concentrations compared to the natural organic matter. Here, pyrolysis coupled to a GCMS instrumental setup provided a relevant analytical response for polypropylene and polystyrene nanoplastic suspensions. Specific pyrolysis markers and their indicative fragment ions were selected and validated. Possible interferences with environmental matrices were explored by spiking nanoplastics in various organic matter suspensions (i.e., algae, soil natural organic matter, and soil humic acid) and analyzing an environmental suspension of nanoplastics. While a rapid polypropylene nanoplastics identification was validated, polystyrene nanoplastics require preliminary treatment. The strategies presented herein open new possibilities for the detection/identification of nanoplastics in environmental matrices such as soil, dust, and biota.

Bioelectrochemical systems for environmental remediation of estrogens: A review and way forward

Globally estrogenic pollutants are a cause of concern in wastewaters and water bodies because of their high endocrine disrupting activity leading to extremely negative impacts on humans and other organisms even at very low environmental concentrations. Bioremediation of estrogens has been studied extensively and one technology that has emerged with its promising capabilities is Bioelectrochemical Systems (BESs). Several studies in the past have investigated BESs applications for treatment of wastewaters containing toxic recalcitrant pollutants with a primary focus on improvement of performance of these systems for their deployment in real field applications. But the information is scattered and further the improvements are difficult to achieve for standalone BESs. This review critically examines the various existing treatment technologies for the effective estrogen degradation. The major focus of this paper is on the technological advancements for scaling up of these BESs for the real field applications along with their integration with the existing and conventional wastewater treatment systems. A detailed discussion on few selected microbial species having the unusual properties of heterotrophic nitrification and extraordinary stress response ability to toxic compounds and their degradation has been highlighted. Based on the in-depth study and analysis of BESs, microbes and possible benefits of various treatment methods for estrogen removal, we have proposed a sustainable Hybrid BES-centered treatment system for this purpose as a choice for wastewater treatment. We have also identified three pipeline tasks that reflect the vital parts of the life cycle of drugs and integrated treatment unit, as a way forward to foster bioeconomy along with an approach for sustainable wastewater treatment.

Characterization of Blighia sapida synthesized-copper nanoparticle and its application in periodic pharmaceutical effluent treatment

With the rapid increase in pharmaceutical wastewater treatment for diverse applications and to contribute to the understanding of suitability of nanoparticles (NPs) in pharmaceutical effluent treatment, this study was conceptualized. Here, we profiled the concentration of selected heavy metals (Cd, Cr, Pb, Cu and Ni) in pharmaceutical effluent samples over three sampling periods using atomic absorption spectroscopy and evaluated the effectiveness of B. sapida synthesized copper nanoparticles (Cu NPs) in pharmaceutical effluent treatment. The results showed that there was no significant (p > 0.05) difference in the heavy metals concentration of the pharmaceutical effluents across the three sampling periods. This observation could be attributed to the low environmental concentration of the metals that prevented significant leaching into the company’s water source through rainfall or the highly effective water treatment pathways that successfully reduced the metals concentration. Despite the observed increase in Cu ions in the treated samples due to the synthesized NPs, its concentration still conforms to the internationally accepted admissible limit in drinkable water. Studies seeking to understand the suitability and toxicological implications of use of the NP-treated effluents are highly encouraged and efforts are underway in this direction.