Simulated River Water Research Articles

Synergetic Combination of Bio‐Electrolytes and Bio‐Fluidic Channels as a Novel Resource of Sustainable Energy

AbstractExploration for sustainable energy resources is essential to minimize the dependence on fossil fuels and to improve environmental parameters. Here, the possibility of utilizing bio‐waste‐derived electrolytes as an electrical energy resource by placing them across semipermeable membranes prepared through parallel stacking of coir fibers is examined. The nanofluidic membrane (d‐CF‐V) prepared by modifying the inner walls of the bio‐fluidic channels with atomically thin layers of vanadium pentoxide (VO) shows excellent perm‐selectivity (t+ = 0.87, with 1000‐fold concentration difference) and electricity conversion efficiency (≈ 28.2%). With simulated sea and river water, the d‐CF‐V yields output energy up to 2.4 W m−2, similarly with mineral acid bases (0.5 m HCl and 0.01 m NaOH), the d‐CF‐V shows an energy output of 11.8 W m−2. The sun‐dried Garcinia morella (Kuji thekera), and charred peels of Musa balbisiana (banana) are used as sustainable sources of bio‐electrolytes, which in combination with permselective d‐CF‐V yielded a power density of ≈1.4 W m−2. By replacing standard Ag/AgCl electrodes with nanomaterials exhibiting contrasting charge transfer activities, oxidized carbon nanotube membrane (o‐CNT) and polyaniline (PANI) membrane the output voltage is enhanced from –127 to –568 mV and current output is increased from 10.2 to 51.5 µA.

Crystal orientation control in angstrom-scale channel membranes for significantly enhanced blue energy harvesting

Achieving high-performance blue energy harvesting from the interface between seawater and river water remains challenging, because the current ion-selective membrane suffers from a trade-off between ion permeability and selectivity. Here, we tackle this issue by manipulating the crystal orientations within metal–organic framework (MOF) MIL-178 membranes, including one with the a-axis perpendicular to the substrate, and the other with the b-axis similarly configured. We show that the MIL-178-a-oriented membrane exhibited over one order of magnitude faster ion transport than the MIL-178-b-oriented membrane, and one-dimensional angstrom-scale (∼3.2 Å) channels endow the former with ultrahigh ion selectivity. Consequently, the MIL-178-a-oriented membrane achieves an ultrahigh power density of ∼9.64 W/m2, with an unprecedented energy conversion efficiency of ∼38.5 % approaching the theoretical upper limit of 50 %, when simulated seawater and river water are mixed, surpassing all the reported non-oriented MOF-based membranes. This study presents a method for finely tuning preferred orientations within polycrystalline MOF membranes, enabling precise engineering of ultrahigh-performance osmotic energy conversion.

Two-dimensional distribution of arsenic species in the riparian zone regulated by As-Fe co-transformation under varying river water proportions and bicarbonate concentrations

Arsenic (As) contamination of groundwater is a major issue in global environmental health. In the riparian zone, mixing river water and groundwater with different substances is proposed to affect arsenic transformation and distribution. However, the distribution of arsenic species in the riparian zone and its co-transformation with iron under varying river water proportions and bicarbonate (HCO3–) concentrations remain unclear. The two-dimensional distributions of arsenic species, including exchangeable (Ex-As), carbonates-bounded (Carb-As), FeMn(hydr)oxide-bounded (Ox-As), organic-bounded (Om-As) and residual arsenic (Res-As), were investigated in three typical profiles of the riparian zone near the lower reaches of the Hanjiang River, China. The apparent enrichment of arsenic in the pore water, either As(III) and As(V), and in the sediment, mainly Carb-As and Ox-As, were observed in the profiles. The correlation analysis showed that the distributions of arsenic species in the riparian zone were primarily related to dissolved or total organic matter (DOC or TOC), Fe, HCO3–, dissolved oxygen (DO) and oxidation–reduction potential (Eh). Further batch experiments mixing simulated river water and groundwater with different proportions and HCO3– concentrations demonstrated that the forming of the arsenic-rich area in the riparian sediment was derived from the oxidation of Fe(II) and As(III) from groundwater, controlled by the varying DO from river water and HCO3– from organics degradation. These results provide more knowledge of the transforming process of arsenic in the riparian zone and a better understanding of the role of the riparian zone in arsenic restraint.

Dual-network fiber-hydrogel membrane for osmotic energy harvesting.

Osmotic energy harvesting was a promising way to alleviate energy crisis with reverse electrodialysis (RED) membrane-based technology. Charged hydrogel combined with other materials was an effective strategy to overcome problems, including restricted functional groups and complicated fabrication, but the effect of the respective charges of the two materials combined on the membrane properties has rarely been studied in depth. Herein, a new method was proposed that charged hydrogel was equipped with charged filter paper to form dual network fiber-hydrogel membrane for osmotic energy harvesting, which had excellent ion selectivity (beyond 0.9 under high concentration gradient), high ion transference number and energy conversion efficiency (beyond 32.5% under wide range concentration gradient), good property of osmotic energy conversion (∼4.84W/m2 under 50-fold KCl and ∼6.75W/m2 under simulated sea water and river water). Moreover, the power density was attributed to the surface-space charge synergistic effect from large amounts overlapping of electric double layer (EDL), so that the transmembrane ion transport was enhanced. It might be a valid mode to extensively develop the osmotic energy harvesting.

Influence of iron (hydr)oxide mineralogy and contents in aquifer sediments on dissolved organic carbon attenuations during aquifer storage and recovery

Aquifer storage and recovery (ASR) is a promising approach for managing water resources that enhances water quality through biogeochemical reactions occurring within aquifers. Iron (hydr)oxides, which are the predominant metallic oxides in soil, play a crucial role in degrading dissolved organic carbon (DOC), primarily through a process known as dissimilatory iron reduction (DIR). However, the efficiency of this reaction varies depending on the mineralogy and composition of the aquifer, and this understanding is essential for adequate water quality in ASR. The objective of this study is to investigate the impact of iron (hydr)oxide on acetate, as an organic carbon source, attenuation during the ASR. To achieve this, three sets of laboratory sediment columns were prepared, each containing a different type of iron (hydr)oxide minerals: ferrihydrite, goethite, and hematite. Following an acclimation period of 28 days to simulate the microcosm within an aquifer, the columns were continuously supplied with the simulated river water spiked with acetate (DOC 40–60 mg L−1), and the acetate concentration in the effluent was monitored. The result revealed that the column containing ferrihydrite achieved 97% acetate attenuation through DIR with anoxic conditions (DO < 0.1 mg L−1), while the goethite and hematite columns exhibited limited attenuation rates of 40 and 50%, respectively. Furthermore, the efficiency of acetate attenuation in the ferrihydrite columns increased with the content of ferrihydrite but experienced a rapidly declined at higher contents (3–4%), possibly due to the partial conversion of ferrihydrite to goethite as a result of the interaction between ferrihydrite and the Fe(II) produced during DIR. Additionally, an analysis of the microbial community demonstrated that microorganisms known to possess the ability to reduce iron (hydr)oxides under anaerobic conditions were abundant in the ferrihydrite columns.

Reductive sequestration of Cr (VI) by phosphorylated nanoscale zerovalent iron

The cracked phosphorylated nanoscale zerovalent iron (p-nZVI) has a strong electron selectivity towards the reductive removal of many heavy metal ions in waters. However, the unintended environmental risk after interactions with impurities or wastewater are not involved. Therefore, in this study, the phosphate group was successfully adsorbed into p-nZVI, and the cracked p-nZVI was successfully prepared with an optimal P/Fe ratio of 0.5%. The dosages of p-nZVI and temperatures were positively correlated with the removal rates. The removal process of Cr(VI) was more suitable by the Langmuir isothermal model（R2 > 0.99). The process of Cr (VI) (10, 20 and 40 mg/L) removal more fitted the pseudo first-order reaction model, while the process of Cr (VI) (60, 80 mg/L) removal more fitted the pseudo second-order reaction model. The Cr (VI) removal rates gradually decreased when the pH was increased. Dissolved oxygen slowed nanoiron reaction rates. The order of inhibition on the reactivity towards Cr(VI) was SiO32− > SO42− > PO43− > NO3− > HCO3−.The facilitation followed the order of Cd2+>Cu2+>Mg2+>Mn2+>Ca2+. Ca2+ showed an inhibitory effect, but all other cations showed different degrees of facilitation. The promotion effect is relatively similar in presence of Mn2+ or Mg2+. HA had a significant inhibitory effect. Environmental friendly p-nZVI had a good effect in simulated groundwater, seawater, river water and secondary effluent of the urban sewage treatment plant. The main pathway to remove Cr (VI) was in situ reduction by p-nZVI. The improved adsorption and reduction effect of p-nZVI on heavy metal ions in water was due to the structural change and the phosphate group.

Coal gasification crude slag based complex flocculants by two-step acid leaching process: synthesis, flocculation and mechanisms.

Coal gasification crude slag (CGCS) is the side-product of the coal gasification process, and its effective utilization has attracted great attention. A novel flocculant of poly-aluminum-ferric-acetate-chloride (PAFAC) was synthesized based on the recovery of CGCS by a two-step acid leaching process, namely HCl-acid leaching and HAc-acid leaching, which was optimized by an acid leaching liquor volume ratio of HCl to HAc of 3 : 2, polymerization pH of 3.5, and reaction temperature and time of 70 °C and 3.0 h, respectively. The performance of PAFAC was further evaluated by kaolin simulated wastewater, domestic sewage, river water, and aquaculture wastewater. The results revealed that PAFAC was feasible for the removal of turbidity, chemical oxygen demand (COD) and total phosphorus (TP). Moreover, PAFAC was characterized by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectrometry (XRF) and scanning electron microscopy (SEM), which proved that PAFAC was a kind of amorphous polyionic composite. Additionally, the acid leaching kinetics and flocculation mechanisms were further investigated. It was found that the acid leaching process was followed by the unreacted shrinkage core model, and the flocculation process was dominated by charge neutralization, adsorption bridging and precipitation net trapping. The work is expected to develop a new method for the safe disposal of CGCS and provide a novel way for the preparation of Fe-Al composite flocculants, especially, offering a potential strategy for the promotion of the additional value of the coal chemical industry.

Kelp Nanofiber‐Based Composite Membranes for Highly Efficient Osmotic Energy Conversion

AbstractThe blue osmotic energy harvesting based on the nanofiber‐based layered membranes has received tremendous attention. However, the most nanofiber‐based ion‐selective membranes are suffering from uneconomical, environmentally unfriendly characteristics and a long growth cycle, as well as insufficient power density. In this work, kelp cellulose nanofibers (KCNFs) from green and inexpensive kelp with short growth cycle are compounded with hydrophilic MXene nanosheets to prepare KCNF/MXene nanofluidic membranes. Notably, the KCNF/MXene‐40 (40 is the mass fraction of KCNF) membrane with an aligned nacre‐like nanostructure achieves 3.03‐fold increase in mechanical strength compared to the pure MXene membrane. The ingenious combination of the surface charge of the MXene nanosheets and the space charge formed by negatively charged KCNFs endows the KCNF/MXene‐40 membrane with enhanced cation selectivity (≈0.85), high energy conversion efficiency of 24.04% and high power density of 66.23 W m−2 in a 500‐fold concentration gradient, which has exceeded most reported state‐of‐the‐art 2D nanofluidic membranes. More importantly, the membrane exhibits the exceptional long‐term stability with relatively unchanged power density within 6000 s. Under the conditions of the natural seawater and simulated river water, the KCNF/MXene‐based generator deliveries an output power density of ≈10.56 W m−2.

Construction of metal-organic framework/cellulose nanofibers-based hybrid membranes and their ion transport property for efficient osmotic energy conversion

The development of advanced nanofluidic membranes with better ion selectivity, efficient energy conversion and high output power density remains challenging. Herein, we prepared nanofluidic hybrid membranes based on TEMPO oxidized cellulose nanofibers (T-CNF) and manganese-based metal organic framework (MOF) using a simple in situ synthesis method. Incorporated T-CNF endows the MOF/T-CNF hybrid membrane with a high cation selectivity up to 0.93. Nanoporous MOF in three-dimensional interconnected nanochannels provides massive ion transport pathways. High transmembrane ion flux and low ion permeation energy barrier are correlated with a superior energy conversion efficiency (36 %) in MOF/T-CNF hybrid membrane. When operating under 50-fold salinity gradient by mixing simulated seawater and river water, the MOF/T-CNF hybrid membrane achieves a maximum power density value of 1.87 W m−2. About 5-fold increase in output power density was achieved compared to pure T-CNF membrane. The integration of natural nanofibers with high charge density and nanoporous MOF materials is demonstrated an effective and novel strategy for the enhancement of output power density of nanofluidic membranes, showing the great potential of MOF/T-CNF hybrid membranes as efficient nanofluidic osmotic energy generators.

Artificial Sodium Channels for Enhanced Osmotic Energy Harvesting.

Inspired by the ion channels of electric eels, we can use biomimetic nanofluidic materials to harvest the osmotic power released by mixing seawater and river water. While biological ion channels have both cation/anion and inter-cation selectivity, previous nanofluidic materials neglected the latter. As a result, NaCl solutions were generally used to simulate river water, ignoring the fact that the dominating cation in river water is typically Ca2+. In this work, we show that the different ionic compositions of seawater and river water can be exploited to improve osmotic power density by employing biomimetic sodium selective materials. Inspired by a range of properties of biological sodium channels, we constructed artificial sodium channels with zeolitic imidazolate framework-65 crystals, which selectively transport Na+ but almost completely block Ca2+. Resultantly, the effective concentration gradient of seawater/river water is dramatically increased by preventing the major cations in the river water from participating in the ion diffusion. As a result, the osmotic power density can be increased by more than 1 order of magnitude. These results should open new avenues to develop high-performance osmotic generators and may advance other applications based on biomimetic ion channels such as neuromorphic information processing.

Spatio-temporal variation characteristics of stable isotopes of tap water and its potential as a proxy for surface water in Sichuan, China

The stability and safety of tap water are essential for human health and economic and social development. The stable isotopes can be used to reveal characteristics of tap water and link it with its source. In this paper, 1556 tap water samples were collected from Sichuan, China and the stable isotope ratios for these samples were determined. The δ2H ranges from −126.4 ‰ to −26.4 ‰, and the range of δ18O is −17.04 ‰ to −2.08 ‰, reflecting the tap water sources are affected by complex spatial features and changing meteorological elements. Stable isotopes in tap water usually reach the maximum values in summer, indicating that heavy isotope enrichment is easily achievable by the large amount of evaporation from water sources during the summer season. By using spatial interpolation and isoscapes, we can find that there is a strong correlation between both simulated tap water δ2H and river water δ2H, with the maximum difference not exceeding 10.0 ‰, while the overall mean relative error is 6 %. Consequently, it is feasible to use tap water isotopes as a proxy for surface water isotopes in representative watersheds where surface water is the main source of water. The study shows the variation characteristics and influencing factors of tap water isotopes and enriches the isotope database of tap water in China. Meanwhile, the utilize of stable isotopes in tap water as a proxy for surface water expands the application field of tap water stable isotopes and opens new perspectives for indirectly obtaining isotope data of surface water.

Optimized Adsorption of Pb(II) ION from Aqueous Solution Using Sharp Sand: Ann and RSM Modelling

Aim: This study was aimed at using sharp sand as an adsorbent to optimize the removal of Pb ionsfrom simulated water and water obtained from Enyigba River.&#x0D; Study Design: Adsorption experiment was designed using Response Surface Methodology (RSM). Artificial Neural Network (ANN) was also used to predict % Pb(II)removal.&#x0D; Place and Duration of Study: Department Of Pure and Industrial Chemistry, Nnamdi Azikiwe University, Awka, June 2012 to June 2023.&#x0D; Methodology: Sharp sand was modified with salicylic acid, noted as SSM and then characterized. Experiments were carried out by varying four adsorption factors: concentration, time, pH and temperature. Adsorption experiments were also done for equilibrium isotherm, kinetics and thermodynamic studies.&#x0D; Results: The modified sharp sand showed a high percentage of silicon. RSM and ANN predicted the sorption of Pb(II) well with R2 values &gt; 0.9. The optimal values for concentration, time, pH and temperature are 0.0125mg/l, 100sec, 2, 20oC respectively. Langmuir isotherm gave the better fit and adsorption was endothermic with positive ∆H. Adsorption followed second-order kinetics. FTIR analysis showed the presence of functional groups that were responsible for adsorption. Enyigba River water is slightly polluted with lead ions with concentrations higher than WHO standard.&#x0D; Conclusion: The adsorbent was able to remove over 70% of the metal ions from both the simulated and Enyigba River water.

Power-free bipolar membrane electrodialysis for acid-alkali production in river estuaries

Recent studies suggest that 2–2.6 TW blue energy can be harvested by mixing coastal seawater with freshwater world widely, but the extractable part was limited due to undesired development of conversion techniques. In this study, a novel power-free bipolar membrane electrodialysis process is proposed for the closed-loop utilization of salinity gradient energy and the salt resources in seawater. The system was evaluated using theoretical and experimental methods. Significance of the various membrane modules and operational conditions was evaluated. Based on fluid dynamics simulations and fluid online imaging technologies, a prototype electro-membrane reactor was fabricated to maximize the achievable energy and acid/base products. The acid production rate reached 6.9 mmol h−1 when feeding simulated seawater (30 g/L NaCl) and river water (1 g/L NaCl). The protocols provided in this work offer an effective route for developing advanced membrane processes for the harvesting of salinity gradient energy and acid-alkali production.

Characterization of Biodegradable Films Made from Taro Peel (Colocasia esculenta) Starch.

Studies of renewable polymers have highlighted starch's role to replace petroleum-based components to produce biodegradable films with plastic-like qualities. In this study, the novelty of taro peel starch (TPS) to produce such films using the casting technique is reported for the first time. A response surface method (RSM) approach was employed to optimize different concentrations of TPS (2.5-3.5%, w/w) and glycerol (25-35%, w/w) and investigate their effects on the physico-mechanical and water barrier properties of TPS films. TPS films showed a positive linear effect (p &lt; 0.05) for thickness (0.058-0.088 mm), opacity (1.95-2.67), water vapor permeability (0.06-0.09 g∙m/m2∙kPa∙h), and cubic effect (p &lt; 0.05) for moisture content (0.58-1.57%), which were linked to high starch concentrations when plasticized with glycerol. X-ray diffraction analysis of TPS films depicted "amorphous"-type crystalline structure peaks at 19.88°, while the thermogravimetric analysis of the film samples exhibited 75-80% of the weight loss of TPS film in the second phase between temperatures of 300 °C to 400 °C. All films exhibited homogenous, transparent surfaces with flexibility, and completely degraded in 5 days in simulated river water and composting soil environments, which confirmed TPS as a promising film polymer in food packaging.

Development of a System to Support the Analysis of Post-Calibration-Type Mass Spectrometric Target Screening Test Results and the Elucidation of Spilled Chemicals in a Simulated River Water Sample

Development of a System to Support the Analysis of Post-Calibration-Type Mass Spectrometric Target Screening Test Results and the Elucidation of Spilled Chemicals in a Simulated River Water Sample

Effects of temperature and light exposure on the decay characteristics of fecal indicators, norovirus, and Legionella in mesocosms simulating subarctic river water

Knowledge of the decay characteristics of health-related microbes in surface waters is important for modeling the transportation of waterborne pathogens and for assessing their public health risks. Although water temperature and light exposure are major factors determining the decay characteristics of enteric microbes in surface waters, such effects have not been well studied in subarctic surface waters. This study comprehensively evaluated the effect of temperature and light on the decay characteristics of health-related microbes [Escherichia coli, enterococci, microbial source tracking markers (GenBac3 & HF183 assays), coliphages (F-specific and somatic), noroviruses GII and Legionella spp.] under simulated subarctic river water conditions. The experiments were conducted in four different laboratory settings (4 °C/dark, 15 °C/dark, 15 °C/light, and 22 °C/light). The T90 values (time required for a 90 % reduction in the population of a target) of all targets were higher under cold and dark (2.6–51.3 days depending upon targets) than under warm and light conditions (0.6–3.5 days). Under 4 °C/dark (simulated winter) water conditions, F-specific coliphages had 27.2 times higher, and coliform bacteria had 3.3 times higher T90 value than under 22 °C/light (simulated summer) water conditions. Bacterial molecular markers also displayed high variation in T90 values, with the greatest difference between 4 °C/dark and 22 °C/light recorded for HF183 DNA (20.6 times) and the lowest difference for EC23S857 RNA (6.6 times). E. coli, intestinal enterococci, and somatic coliphages were relatively more sensitive to light than water temperature, but F-specific coliphages, norovirus, and all bacterial rDNA and rRNA markers were relatively more sensitive to temperature than light exposure. Due to the slow microbial decay in winter under subarctic conditions, the microbial quality of river water might remain low for a long time after a sewage spill. This increased risk associated with fecal pollution during winter may deserve more attention, especially when river waters are used for drinking water production.

Multiplexed Anodic Stripping Voltammetry Detection of Heavy Metals in Water Using Nanocomposites Modified Screen-Printed Electrodes Integrated With a 3D-Printed Flow Cell.

In this study, we present multiplexed anodic stripping voltammetry (ASV) detection of heavy metal ions (HMIs)—As(III), Cd(II), and Pb(II)—using a homemade electrochemical cell consisting of dual working, reference and counter screen-printed electrodes (SPE) on polyimide substrate integrated with a 3D-printed flow cell. Working and counter electrodes were fabricated by the screen-printing of graphite paste while the Ag/AgCl paste was screen-printed as a reference electrode (Ag/AgCl quasi-reference electrode). The working electrodes were modified with (BiO)2CO3-reduced graphene oxide (rGO)-Nafion [(BiO)2CO3-rGO-Nafion] and Fe3O4 magnetic nanoparticles (Fe3O4MNPs) decorated Au nanoparticles (AuNPs)-ionic liquid (IL) (Fe3O4-Au-IL) nanocomposites separately to enhance HMIs sensing. Electrochemical detection was achieved using square wave ASV technique. The desired structure of the flow electrochemical cell was optimized by the computational fluid dynamic (CFD). Different experimental parameters for stripping analysis of HMIs were optimized including deposition time, deposition potential and flow rate. The linear range of calibration curves with the sensing nanocomposites modified SPE for the three metal ions was from 0–50 μg/L. The limits of detection (S/N = 3) were estimated to be 2.4 μg/L for As(III), 1.2 μg/L for Pb(II) and 0.8 μg/L for Cd(II). Furthermore, the homemade flow anodic stripping sensor platform was used to detect HMIs in simulated river water with a 95–101% recovery, indicating high selectivity and accuracy and great potential for applicability even in complex matrices.

Synthesis of hybrid magnesium hydroxide/magnesium oxide nanorods [Mg(OH)2/MgO] for prompt and efficient adsorption of ciprofloxacin from aqueous solutions

The antibiotic ciprofloxacin (CIP) is recognized as a contaminant of emerging concern because its persistent occurrence in water accelerates the growth of deadly antimicrobial resistance genes (AMRs). For the first time, the conventional precipitation technique was thermally modified to produce hybrid magnesium hydroxide/magnesium oxide nanorods [Mg(OH)2/MgO] for efficient and rapid adsorption of CIP from water. The successful synthesis of Mg(OH)2/MgO was confirmed by the outcomes of TEM, EDS, XRD, and FTIR analysis. Mg(OH)2/MgO exhibited an extraordinary capability to adsorb CIP from water regardless of CIP initial concentration where more than 97% of 200 mg L−1 of CIP was promptly eliminated within 30 min by 0.1 g L−1 of Mg(OH)2/MgO under neutral pH and room temperature. These results clearly state that Mg(OH)2/MgO is at least 2-fold efficient and 20-fold faster in removing CIP than the reported nanomaterials with exceptional adsorption capacity higher than 1789 mg g−1. FTIR analysis for the spent Mg(OH)2/MgO revealed that bridging complexation with carboxylic group and electrostatic attraction with the positive amine group are the responsible mechanisms for CIP adsorption by Mg(OH)2/MgO. Moreover, simulated CIP-contaminated river water was efficiently treated by Mg(OH)2/MgO which proves the promising performance of Mg(OH)2/MgO in field scale applications.

Non-targeted analysis for organic components of microplastic leachates

Organic components of microplastic leachates were investigated in an integrated non-targeted analysis study that included statistical analysis on leachates generated under different leaching scenarios. Leaching experiments were undertaken with simulated gastric fluid (SGF), river water, and seawater with common polymer types, including polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polyester fabrics comprising both raw and recycled materials. Totals of 111.0 ± 26.7, 98.5 ± 20.3, and 53.5 ± 4.7 different features were tentatively identified as compounds in SGF, freshwater, and seawater leachates, respectively, of which 5 compounds were confirmed by reference standards. The leaching capacities of the media were compared, and the clusters of structurally related features leached in the same medium were studied. For leachates generated from raw and recycled plastics, volcano plots and Pearson's Chi-squared tests were used to identify characteristic features. More characteristic features (3−20) had an average intensity across all recycled plastics that were significantly higher (p < 0.05) than that (1–3) of raw plastics under different conditions. The results indicate that gastric solution is more likely to leach components from microplastics, and there exists the difference of leachate's organic composition between raw and recycled materials, providing new insights into understanding microplastic environmental effects.

Parallel artificial liquid membrane extraction of organophosphorus nerve agent degradation products from environmental samples

An emerging miniaturized high-throughput microextraction technique named Parallel artificial liquid membrane extraction (PALME) was, for the first time, investigated for the extraction of polar alkyl methylphosphonic acids (AMPAs) that are the degradation products of organophosphorus nerve agents. The effect of the key-parameters of the extraction method (nature of the membrane, of the extraction solvent, of the pH values of both donor and acceptor phases, agitation speed, extraction time, temperature and ionic strength) on the extraction recoveries was studied in spiked pure water samples. This led to extraction recoveries in the range of 25–102% for the 5 targeted analytes from water with enrichment factors in the range of 4.50–42.75.The developed PALME-LC-MS/MS method was first evaluated with spiked pure water. LOQs (S/N ≥ 10) were in the range of 0.009–1.141 ng mL−1, linearity above 0.9973 for all the AMPAs and with RSD values below 11%. This method was then applied on simulated waste water, river water and aqueous soil extracts. The achieved LOQs were in the range of 0.011–1.210, 0.013–1.196 and 0.016–6.810 ng mL−1, respectively. A detailed comparison of the performances of this PALME method with those of a previously developed hollow fiber liquid-phase microextraction methods already applied to AMPAs was done thus allowing to demonstrate the easy transfer of methods from HF-LPME to PALME. Moreover, the high-throughput potential of PALME was revealed since 192 samples were processed in parallel during 120 min (37.5 s/sample).