•A suspect chemical database containing 7,922 OPs were established based on the PubChem database.•A neoteric suspect screening and priority ranking strategy of typical OPs was developed.•566, 518, ...and 540 molecular formulas were detected in sediment, water, and indoor dust samples, respectively.•Three OPs candidates were tentatively identified and semiquantified.
Organophosphorus compounds (OPs) are widely used as flame retardants (FRs) and plasticizers, yet strategies for comprehensively screening of suspect OPs in environmental samples are still lacking. In this work, a neoteric, robust, and general suspect screening technique was developed to identify novel chemical exposures by use of ultra-high performance liquid chromatography-Q Exactive hybrid quadrupole-Orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS). We firstly established a suspect chemical database which had 7,922 OPs with 4,686 molecular formulas, and then conducted suspect screening in n = 50 indoor dust samples, n = 76 sediment samples, and n = 111 water samples. By use of scoring criteria such as retention time prediction models, we successfully confirmed five compounds by comparison with their authentic standards, and prioritized three OPs candidates including a nitrogen/fluorine-containing compound, that is dimethyl {1H-indol-3-yl3-(trifluoromethyl)anilinomethyl} phosphonate (DMITFMAMP). Given that the biodegradation half-life values in water (t1/2,w) of DMITFMAMP calculated by EPI Suite is 180 d, it is considered to be potentially persistent. This strategy shows promising potential in environmental pollution assessment, and can be expected to be widely used in future research.
The combined pollution of arsenic (As) and cadmium (Cd) are quite common in the polymetallic mining areas located in southern China. In the present study, field experiments were established for the ...purpose of exploring a simultaneous remediation strategy of rice variety-water management-contaminant immobilization on the As and Cd contamination in paddy soil. The obtained results revealed that the Maba Yinzhan was the best low-accumulation rice variety, with As and Cd concentrations of 0.54 and 0.16 mg kg
−1
, respectively, in the rice grains. On the basis of water management during heading stage, the treatment using 0.15 wt% lime plus 0.5 wt% ferro-ferric oxide (FO) decreased the As and Cd concentrations by 64.02% and 34.78%, respectively, in the grains. The results of this study potentially provide an effective remediation solution for the As/Cd contaminated soils in polymetallic mining areas.
Arsenic decontamination from groundwater is an urgent but still challenging task. Polystyrene-based hydrated ferric oxide (denoted as D201-HFO) nanocomposite is a new emerging current adsorbent for ...efficient arsenate removal in natural waters; the resulting materials can interact with arsenate, mainly driven by inner complexation and static interaction and the existing HA effects on adsorption was well investigated. Results reveals that low concentrations of HA (below 25 mg/L) coexistence led to negligible effects on As(V) removal, but high levels of HA (100 mg/L) exerted outstanding sorption competition to As(V) removal; kinetics results revealed the HA additions brought about the diffusion prolonging and capacity decline, due to the large molecule structure of HA. Column experiments further showed the slight decrease application capacity of 810 BV by HA additions, with satisfactory saturation capacity; significantly, the presence of HA also exerted negligible influences on regeneration performances. All the sorbents with or without HA could be well regenerated by binary alkaline and salt mixture.
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•TiO2 nanotubes showed high photocatalytic activity for microcystin-LR degradation.•Conjugated system and methoxy group in Adda chain are liable to be attacked by OH.•Conjugated ...system in Mdha amino acid is susceptible to be attacked by OH.•Carboxyl and amino groups of the peptides are inferred to be hydrolyzed.•Adda is proposed to be separated from heptapeptides, leaving alkyl derivatives.
Microcystins generated by Microcystis aeruginosa are commonly detected in freshwater bodies and their removal becomes an emerging field recently owing to the toxicity. Here we report the structural characterization of degradation products from the photocatalysis of microcystin-LR (MC-LR). To achieve efficient photocatalytic degradation of MC-LR, we fabricated highly ordered TiO2 nanotubes using anodization method. The surface morphology of TiO2 nanotubes depends primarily on the anodic voltage and the optimum value is 20V. Under UV irradiation, the concentration of MC-LR decreases by 84.6% when using TiO2 nanotubes anodized at 20V within 30min. The degradation intermediates of MC-LR are detected with mass spectrometry (MS) and seven main intermediates are observed in liquid chromatography mass spectrometry (LC/MS) chromatogram. We propose the possible structures of the intermediates of MC-LR and infer its possible degradation pathways. The results indicate that the conjugated double bond and methoxy group in the Adda chain, as well as the conjugated system in the Mdha amino acid, are susceptible to be initially attacked by hydroxyl radicals. In addition, it is deduced that the peptides undergo breakdown from Mdha, then their carboxyl and amino groups are stepwise hydrolyzed and the side chain of the amino acid is oxidized.
The sun and outer space are two crucial renewable thermodynamic resources that work together to maintain the delicate energy balance of our planet. The challenge lies in harvesting both resources ...synergistically and converting them into high-quality electricity. Here, we introduce a photovoltaic thermoelectric radiative cooling (PV-TE-RC) system. This system uses the full spectrum of the sun and the atmospheric window to generate electricity and achieve high-quality collaborative utilization of solar energy and space energy. Outdoor experiments have demonstrated the system’s capacity to operate efficiently around the clock. Notably, during the peak solar concentration, the thermoelectric generator (TEG) and the system achieved power outputs of 870 mW/m2 and 85.87 W/m2, respectively. We have further developed a three-dimensional transient coupled simulation model, which can accurately predict its operational limits. Therefore, this study provides practical insights and recommendations for large-scale and efficient collaborative power generation using these two thermodynamic resources.
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•The first instances of adding a photovoltaic to the RC-TE system•Generate electricity by synergistically harnessing two thermodynamic resources•Enables PV thermal management and boosts thermoelectric power generation•3D transient coupled simulation models accurately predict operating limits
Applied computing in engineering; Engineering.
Paddy soil in south China has long been haunted by the co-contamination of arsenic (As) and cadmium (Cd), resulting in the relatively high accumulation of As and Cd in rice, which puts humanity into ...a food safety dilemma. Therefore, it is paramount to restrain the migration of contaminants from soil to rice grains to cushion their impact on human health. However, the opposite biogeochemical behaviors of As and Cd in paddy soils under flooding condition make it a great challenge to simultaneously immobilize both As and Cd, particularly for the large-scale remediation. In this work, lime, Fe2O3, and Fe-Mn binary oxides (FM) were performed for immobilizing As and Cd in paddy soil at a field-scale experiment, and their associated mechanisms were discussed. Results showed that 0.10 wt% of Lime reduced Cd in grain (36.68%), 0.60 wt% of Fe2O3 decreased the accumulation of As and Cd (28.32% and 26.91%, respectively), and 0.60 wt% of FM significantly decreased As and Cd (42.42% and 36.49%, respectively). Analytical results of As speciation in rhizosphere soils demonstrated that FM played a dual role in oxidation and adsorption toward As immobilization. The DGT-measured As and Cd concentrations in rhizosphere soils showed that 0.60 wt% of FM significantly reduced the bioavailability of As and Cd in the paddy soil by 65.63% and 52.98%, respectively. Moreover, 0.60 wt% of FM promoted the formation of Fe/Mn-plaque on root surface, which significantly enhanced the adsorption of As and Cd upon Fe/Mn-plaque (44.06% and 32.14%, respectively) and further inhibited the uptake of As and Cd by rice. Hence, the mechanism for As and Cd immobilization by FM can be summarized: (1) oxidation of As(III) to As(V) and transformation and immobilization of As and Cd in rhizosphere soil and (2) promotion of Fe/Mn-plaque formation on root surface to retard the uptake of As and Cd by rice. These efforts attempt to set up a theory-to-practice solution for remediating As and Cd co-contamination in paddy soil.
Ninety-five soil samples (n = 95) were analyzed using an integrated suspect and non-target organophosphate ester (OPE) screening strategy. This suspect and non-target screening strategy allowed us to ...fully or tentatively identify 26 OPEs or OPE-like substances. Among these 26 newly identified contaminants, bisphenol A bis(diphenylphosphate) (BPABDP) exhibited the highest detection frequency of 83.2 %, with a concentration range of ND - 385 ng/g dry weight (dw). We also observed that BPABDP was significantly correlated with all other OPEs (p < 0.001 in all pairs), suggesting that BPABDP is widely used as a plasticizer and flame retardant in various commercial products. Another interesting finding was the discovery of four novel OPE structures with tentatively proposed chemical structures. Among these four non-target OPEs, (tert-butyl) phenyl bis(2,4-di-tert-butylphenyl) phosphate (TBPBDTBPP) shared a backbone structure very similar to that of the well-known OPE, tris(2,4-di-tert-butylphenyl) phosphate (TDTBPP). Detection frequency of this newly discovered OPE was high, up to 69.5 %, and it was significantly correlated with isodecyl diphenyl phosphate (IDDP), BPABDP, diphenyl 2-isopropylphenyl phosphate (2IPPDPP), and tricresyl phosphate (TCrP, p < 0.05 in all pairs), respectively. This study reported the most comprehensive suite of OPEs in soil samples, and 16 out of them were recognized in soil for the first time.
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•N = 95 soil samples were analyzed for OPEs via an integrated suspect and nontarget strategy;•This strategy allowed us fully or tentatively identify 26 OPEs or OPE like substances;•BPABDP exhibited the highest detection frequency with a concentration range of ND - 467 ng/g dw;•Sixteen out of 26 OPEs were reported in soil samples for the very first time;•There were clearly different OPE contamination patterns among different functional areas.
There is increasing scientific interest in environmental pollution and the effect on public health caused by organophosphate esters (OPEs). Using liquid chromatography coupled to a hybrid quadrupole ...Orbitrap high-resolution mass spectrometer, a novel, robust, and untargeted screening strategy for the identification of novel OPEs in indoor dust samples was presently developed based on the characteristic molecular fragmentation pathways, and 12 previously reported OPEs and six previously unrecognized OPEs were detected in the combined extracts of indoor dust samples, collected in Nanjing, eastern China. One of the six detected OPEs, bis-(2-ethylhexyl)-phenyl phosphate (BEHPP), was identified by comparison of unique LC and MS characteristics with a synthesized pure standard. Accurate concentrations of BEHPP were determined in n = 50 individual indoor dust samples with 100% detection frequency with a median concentration range of 50–1530 ng/g dry weight, which were generally greater or at least comparable to traditional OPEs, that is, triphenyl phosphate and 2-ethylhexyl diphenyl phosphate (EHDPP), in the same dust samples. Statistically significant, positive correlations were found for log-transformed concentrations of BEHPP versus EHDPP (r 2 = 0.7884, p < 0.0001), and BEHPP versus tris(2-ethylhexyl)phosphate (r 2 = 0.4054, p < 0.0001), suggesting their similar commercial applications and sources in the environment.
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•Persulfate salts significantly improved volumetric heating rate.•Recirculation brought more even volumetric elevation in temperature.•Convenient management of heating at ...recirculation-impacted zone.•More efficient and even volumetric degradation of phenanthrene.•A promising heat-activated persulfate ISCO process.
A combo system capable of simultaneous persulfate recirculation and low temperature electrical resistance heating (ERH) was developed for subsurface remediation of organic contaminants using heat-activated persulfate. First, dual-function injection/extraction-electrode wells were designed, and a laboratory-scale combo system was custom-build. Experiments in water tanks and sand tanks were then carried out to investigate the performance of the combo system, and study the impact of main operating parameters (persulfate dosage, recirculation rate, and phase voltage) on volumetric delivery and dispersion of heat and persulfate, and consequent volumetric oxidation of phenanthrene-spiked sand, a model compound of HOCs. The results indicate that the addition of persulfate salts could significantly improve volumetric heating rate, and application of recirculation brought more uniform elevation in temperature and enhanced volumetric degradation of phenanthrene in the recirculation-impacted zone. Overall, this study developed a promising combo system for the implementation of heat-activated persulfate ISCO.
Rare earth elements (REEs) have attracted much attention because of their unique physical and chemical properties. The root system is the plant organ most directly in contact with REEs, and it is ...critical to understand the mechanisms of interaction between the two. This paper investigates the effects of REEs on plant enrichment and fractionation, as well as on various developmental and toxicity indices of the root system. REEs are more likely to be deposited on the root surface under the influence of root secretion. The complexation between the two affects the uptake and fractionation of REEs and the altered pattern of root secretion. The toxicity mechanisms of REEs on plant root cells were lied in: (1) REEs generate reactive oxygen species after entering the plant, leading to oxidative stress and damage to plant cells; (2) REEs with higher charge-to-volume ratios compete for organic ligands with or displace Ca2+, further disrupting the normal function of plant root cells. It was shown that the sensitivity of inter-root microorganisms to REEs varied depending on the content and physicochemical properties of REEs. The paper also concluded with a meta-analysis of phytotoxicity induced by REEs, which showed that REEs affect plant physiological parameters. REEs, as a source of oxidative stress, triggered lipid peroxidation damage in plants and enhanced the activity of antioxidant enzymes, thus revealing the significant toxicity of REEs to plants. The phytotoxic effects of REEs increased with time and concentration. These results help to elucidate the ecotoxicology of rare earth-induced phytotoxicity.
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•REEs mainly accumulate in roots with LREEs easily moving into above-ground plants.•Stimulated by REEs, the composition and exudation of root secretions can be altered.•REEs affect root cell function by displacing Ca2+ and inducing ROS.•Interactions between root secretions, microbes, and REEs influence plant growth.•Meta-Analysis reveals the diverse mechanisms of REEs-induced phytotoxicity.
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