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1.
Environ Int ; 136: 105454, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32032889

RESUMO

Interest in the risks posed by trace concentrations of pharmaceuticals and personal care products (PPCPs) in surface waters is increasing, particularly with regard to potential effects of long-term, low-dose exposures of aquatic organisms. In most cases, the actual studies on PPCPs were risk assessments at screening-level, and accurate estimates were scarce. In this study, exposure and ecotoxicity data of 50 PPCPs were collected based on our previous studies, and a multiple-level environmental risk assessment was performed. The 50 selected PPCPs are likely to be frequently detected in surface waters of China, with concentrations ranging from the ng L-1 to the low-g L-1, and the risk quotients based on median concentrations ranged from 2046 for nonylphenol to 0 for phantolide. A semi-probabilistic approach screened 33 PPCPs that posed potential risks to aquatic organisms, among which 15 chemicals (nonylphenol, sulfamethoxazole, di (2-ethylhexyl) phthalate, 17ß-ethynyl estradiol, caffeine, tetracycline, 17ß-estradiol, estrone, dibutyl phthalate, ibuprofen, carbamazepine, tonalide, galaxolide, triclosan, and bisphenol A) were categorized as priority compounds according to an optimized risk assessment, and then the refined probabilistic risk assessment indicated 12 of them posed low to high risk to aquatic ecosystem, with the maximum risk products ranged from 1.54% to 17.38%. Based on these results, we propose that the optimized risk assessment was appropriate for screening priority contaminants at national scale, and when a more accurate estimation is required, the refined probability risk assessment is useful. The methodology and process might provide reference for other research of chemical evaluation and management for rivers, lakes, and sea waters.

2.
Environ Sci Technol ; 54(5): 2715-2725, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32003984

RESUMO

The benefits and disadvantages of hydrochar incorporation into soil have been heavily researched. However, the effect of hydrochar application on the soil microbial communities and the molecular structure of native soil organic carbon (SOC) has not been thoroughly elucidated. This study conducted an incubation experiment at 25 °C for 135 days using a soil column with 0.5 and 1.5% hydrochar-amended paddy soil to explore the interconnections between changes in soil properties and microbial communities and shifts in native SOC structure using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) and NMR after hydrochar application. Hydrochar addition decreased the labile SOC fraction by 15.6-33.6% and increased the stable SOC fraction by 10.3-27.0%. These effects were significantly stronger for 1.5% hydrochar-treated soil. Additionally, hydrochar addition induced the native SOC with 1.0-3.0% more carbon and 6.0-13.0% higher molecular weight. The SOC in hydrochar-amended soil contained more aromatic compounds but fewer carbohydrates and lower polarity. This was resulted by a statistically significant reduction in Sphingobacterium, which was active in polycyclic aromatic hydrocarbon degradation, and an increase in Flavobacterium, Anaerolinea, Penicillium, and Acremonium, which were the efficient decomposers of labile SOC. These findings will help elucidate the potential influence of hydrochar on the carbon biogeochemical cycle in the soil.


Assuntos
Microbiota , Solo , Carbono , Estrutura Molecular , Microbiologia do Solo
3.
Sci Total Environ ; 703: 134764, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31726300

RESUMO

Autochthonous dissolved organic matter (DOM) is increasingly released in lakes due to eutrophication, and thus affects the composition and environmental behaviors of DOM in eutrophic lakes. However, there are only limited studies on the molecular characteristics of autochthonous DOM and its influencing mechanisms. Herein, end-member DOM samples of macrophytes, algae, sediments and freshwater DOM samples in eutrophic lakes (Ch:Taihu and Dianchi) were collected and characterized by optical spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The results revealed the chemical structures of autochthonous DOM were more aliphatic and less oxidized, which was marked by increases in lipid compounds and decreases in the lignin components as compared to the allochthonous DOM-dominated freshwaters. More specially, algae-derived DOM contains more lipid compounds, while macrophyte-derived DOM was dominated by lignin and tannin compounds according to Van Krevelen plots. Sediment-derived DOM contained more N-containing compounds. The traditional optical indices indicated the relative aromaticity covaried with polyphenolic and polycyclic aromatics, whereas those reflecting autochthonous DOM covaried with more aliphatic compounds. Multivariate analysis of FT-ICR-MS data of end-members and freshwaters revealed the predominant terrestrial input to Lake Taihu and greater contribution of algae released DOM to Dianchi. This study provides critical information about the characteristics of autochthonous DOM at a molecular level and confirmed autochthonous DOM was compositionally distinct from allochthonous DOM. Overall autochthonous DOM should be gained more attention in the eutrophic lakes.

4.
J Biomol Struct Dyn ; 38(4): 1234-1241, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30880629

RESUMO

Communicated by Ramaswamy H. Sarma.

5.
J Hazard Mater ; 389: 121853, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-31874758

RESUMO

Chemical mixtures are a common occurrence in contaminated sediment and determining causal relationship between sediment contamination and adverse outcomes is challenging. The bioavailability and choice of bioassay endpoints played important roles in elucidating causality. As such, bioaccessibility-based XAD extraction and adverse outcome pathway (AOP) guided bioassays were incorporated into an effect-directed analysis to more effectively determine sediment causality. XAD extracts of sediments from urban waterways in Guangzhou, China were examined using cell viability bioassays with four human tumor cells from lung, liver, breast, and bone marrow. Pronounced effects to SH-SY5Y cells were noted, thus neurotoxicity was subsequently focused in the AOP-guided bioassays. Intracellular calcium influx, mitochondrial membrane potential inhibition, reactive oxygen species generation, and cell viability were utilized as evidence for neurotoxicity AOP-guided analysis. Suspect toxicants were identified in active fractions using GC-MS. Toxicity confirmation was performed by evaluating toxicity contributions of the candidates to the pathway. Cypermethrin, bisphenol A, galaxolide, tonalide, and versalide were found as the major stressors across key events of the studied pathway. Moreover, good correlations among key events validated the feasibility of method to predict in vivo response, suggesting that considering bioavailability and AOP improved environmental relevance for toxicant identification in a complex mixture.

6.
Bull Environ Contam Toxicol ; 103(6): 848-853, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31667530

RESUMO

In the present study, biochar particles (BPs) produced by the co-pyrolysis of sewage sludge and corncobs at temperatures of 300, 500, and 700°C were characterized. The Pb2+ adsorption properties and the heavy metal leaching toxicity rates of the BPs were investigated. It was found that the adsorption kinetics of the Pb2+ can be accurately described by a pseudo-second-order model, and the equilibrium adsorption data were well represented by both the Langmuir and the Freundilich Equations. The toxicity characteristic leaching procedure (TCLP) results indicated that the leaching concentrations of all the heavy metals were below the set limit of China's national standard (Identification Standard for Hazardous Waste Extraction Toxicity Identification, China National Standard, GB 5085.3-2007). The results of this study can successfully provide scientific support for future corncob treatment and sludge pollution control.


Assuntos
Carvão Vegetal/química , Chumbo/análise , Esgotos/química , Poluentes Químicos da Água/análise , Zea mays/química , Adsorção , China , Resíduos Perigosos/análise , Temperatura Alta , Cinética , Modelos Teóricos , Águas Residuárias/química , Purificação da Água/métodos
7.
Environ Int ; 133(Pt B): 105273, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31675557

RESUMO

Short-, medium-, and long-chain chlorinated paraffins (SCCPs, MCCPs, and LCCPs) are persistent in sediment and bioaccumulative in organisms in the coastal regions, and sewage treatment plants (STPs) play a crucial role in the control of emissions and risks of CPs in the aquatic environment. In this study, the occurrences of the three CP groups were simultaneously studied in a typical STP with anoxic/anaerobic/aerobic bioreactors as the core treatment units. MCCPs were the predominant CPs in wastewater samples tested, and SCCPs and LCCPs were in the similar concentrations. Proportions of LCCPs in solid samples increased steadily from 26% in influent to 53% in effluent, those of MCCPs decreased from 55% to 39%, while no obvious variations in the proportions (5.5-24%) of SCCPs were observed compared to the aqueous phase. The overall removal efficiencies were 93-97% for SCCPs, 75-89% for MCCPs, and 84-97% for LCCPs. A total of 50-67%, 25-64% and 55-92% of the initial mass loadings of SCCPs, MCCPs and LCCPs, respectively, were found in the dehydrated sludge, and 2.8-26% of the three CP groups were found in effluent. The removal pathway of three groups of CPs is dominated by sorption in the STP, especially for the longer chained and highly chlorinated CPs. Effluent discharge of STP is also an important source of CPs in the aqueous environment.


Assuntos
Hidrocarbonetos Clorados/química , Parafina/química , Esgotos/química , Poluentes Químicos da Água/química , China , Monitoramento Ambiental , Humanos
8.
Artigo em Inglês | MEDLINE | ID: mdl-31591803

RESUMO

Nanogels have been identified as outstanding nanocarrier candidates for drug delivery due to the desirable physiochemical properties and versatile applicability for diverse therapeutic molecules and imaging probes. One of the main challenges that hinder the clinical translation of nanogels is the low efficiency of drug transmitting to the target sites because of the impedance of complex biological barriers during the in vivo journey. The purpose of this review is to summarize the recent advances on the rational design and structure modulation of nanogels to overcome the barriers and challenges on the way to the site of action following various dosing modes. In particular, the functional moieties or domains were incorporated in the nanogels, allowing them to spontaneously regulate their structure and physiochemical properties to cross one or some of the multifaceted barriers. Importantly, the perspectives are presented in case of opportunities and challenges for the precise and efficacious therapeutic of nanogel formulations.

9.
Environ Sci Technol ; 53(22): 13495-13505, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31644877

RESUMO

Biomass, a renewable energy source, via available thermo-chemical processes has both engineering and environmental advantages. However, the understanding of the kinetics, evolved gases, and mechanisms for biomass pyrolysis is limited. We first propose a novel temperature response mechanism for the pyrolysis of sugar cane residue using thermogravimetric analysis-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS) combined with Gaussian model and two-dimensional correlation spectroscopy (2D COS). The existence and contribution of distinct peaks in TG-FTIR spectra were innovatively distinguished and quantified, and the temperature-dependent dynamics of gas amounts were determined using Gaussian deconvolution. The 2D-TG-FTIR/MS-COS results revealed for the first time that the primary sequential temperature responses of gases occurred in the order: H2O/CH4 > phenols/alkanes/aromatics/alcohols > carboxylic acids/ketones > CO2/ethers > aldehyde groups/acetaldehyde. Subtle sequential changes even occurred within the same gases during pyrolysis. The quantity dynamics and sequential responses of gases were fitted to the combined effects of the order-based, diffusion, and chemical reaction mechanisms for the component degradation. The combination of TG-FTIR-MS, Gaussian model, and 2D COS is a promising approach for the online monitoring and real-time management of biomass pyrolysis, providing favorable strategies for pyrolysis optimization, byproduct recovery, energy generation, and gas emission control in engineering and environmental applications.


Assuntos
Gases , Saccharum , Biomassa , Cinética , Pirólise , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
10.
Sci Total Environ ; 692: 660-668, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539974

RESUMO

Environmental behavior, bioavailability and risks posed by TiO2, nanomaterials (TiO2 NMs) in surface waters are affected by morphologies of the particles and geochemistry, including pH, inorganic and organic matter. Here, the adsorption, aggregation and sedimentation of TiO2 nanoparticles (TiO2 NPs) and nanotubes (TiO2 NTs) were investigated in the presence of Elliott Soil humic acid (HAE) and Suwannee River humic acids (HAS). The adsorption amount of HA on TiO2 NMs was inversely proportional to pH of solution. Maximum adsorption amount of HA on the surface of TiO2 NMs follows the order TiO2 NPs + HAE (236.05 mg/g) > TiO2 NTs + HAE (146.05 mg/g) > TiO2 NTs + HAS (70.66 mg/g) > TiO2 NPs + HAS (37.48 mg/g). Stability of TiO2 NPs and TiO2 NTs largely depended on their isoelectric point, morphology and solution pH in the absence of HA. Dispersion of TiO2 NMs was enhanced with solution pH deviated from the isoelectric point of nanomaterials due to electrostatic repulsion. Moreover, tubular structures of TiO2 NTs with higher length-diameter ratio seem to aggregate more easily than dose sphere-like TiO2 NPs. This might be due to their spherical structure enhancing steric repulsion. Notably, the adsorption of HA led to disagglomeration and significant stability of TiO2 NPs and TiO2 NTs due to steric hindrance under varying solution pH. In addition, adsorption time, concentration and sources of HA also influenced suspension/sedimentation behavior of TiO2 NPs and TiO2 NTs, and aromatic-rich HAE stabilized TiO2 NMs suspension more aggressively than aliphatic-rich HAS.

11.
Environ Manage ; 64(3): 366-380, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31377846

RESUMO

To obtain a general understanding of heavy metal contamination in peri-urban agricultural soils in China, this study investigates the concentrations of eight heavy metals, i.e., Cd, Pb, Zn, As, Cu, Cr, Hg, and Ni, in the peri-urban agricultural soils of 31 provincial capital cities in China. The data were obtained via exhaustive literature searches in both the Web of Science and China National Knowledge Infrastructure (CNKI) as well as from statistical yearbooks published in China. To evaluate the pollution status of each city and identify a variety of potential sources, various contamination indexes, e.g., the enrichment factor (EF), geoaccumulation index (Igeo), and integrated pollution index (IPI), were calculated based on the peri-urban agricultural soil dataset. The results of the analysis of the heavy metal concentrations, EF values and Igeo values showed that the peri-urban agricultural soils were enriched in most heavy metals, and Cd and Hg concentrations greatly exceeded the Chinese Environmental Protection Administration (CEPA) guidelines. The IPI results showed that 15 of the 31 cities, i.e., 48%, exhibited varying extents of heavy metal pollution. Although the mean IPI value for peri-urban agricultural soils in all cities (0.83) was slightly lower than that for urban soil (0.9), the IPI values for peri-urban agricultural soils from 65% of the cities were greater than those for urban soils, indicating that peri-urban agricultural soils are more polluted than urban soils in these large cities. These results are important for guiding future research on heavy metal pollution in peri-urban agricultural soils of presently expanding Chinese cities.


Assuntos
Metais Pesados , Poluentes do Solo , China , Cidades , Monitoramento Ambiental , Medição de Risco , Solo
12.
Water Res ; 165: 114991, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31442757

RESUMO

Progestins (PGs) are a group of steroid hormones known to have endocrine-disrupting effects. These compounds can enter the aquatic environment via the discharge of treated or untreated wastewater and the disposal of sludge from sewage treatment plants (STPs); thus, their removal in STPs are of great importance. The present study simultaneously investigated the occurrences and fates of 62 PGs in a municipal STP in Beijing, China. Progesterone (P) and its metabolites were found to be the predominant compounds, with total dissolved concentrations of 1866 ng/L in the influent. About 11 P metabolites were newly detected, accounting for 25-55% and 75-91% of the total concentrations in wastewater and sludge, respectively. For the other three groups of PGs derived from different parent compounds, P derivatives were first detected in the STP with the highest concentration in the wastewater and sludge, followed by 19-nortestosterone (NT) derivatives and 17α-hydroxyprogesterone (17α-OHP) derivatives. The removal efficiencies in the dissolved phase of wastewater were relatively high for P and its metabolites (95-99%) and P derivatives (91-99%). And the relative persistence of NT (68-99%) and 17α-OHP derivatives (79-99%) was observed during the wastewater treatment processes. Mass balance analysis showed that the lost mass proportions were as high as 41-99%, the mass fractions in sludge were in the range of 0-55%, and 0.24-25% of the initial mass loadings was present in the effluent. These results indicated that biodegradation was the major removal mechanism of PGs in the STP.


Assuntos
Esgotos , Poluentes Químicos da Água , Pequim , China , Monitoramento Ambiental , Progestinas , Eliminação de Resíduos Líquidos , Águas Residuárias
13.
Environ Sci Technol ; 53(16): 9462-9471, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31353896

RESUMO

The spatial and temporal distributions of short-, medium-, and long-chain chlorinated paraffins (SCCPs, MCCPs, and LCCPs) were studied in sediment cores and surface sediment from nine lakes in China. The highest total CP concentrations in surface sediment were found in the plateau lakes of southwest China, followed by lakes in the northeast, east, and remote northwest. The concentrations of three CP groups in cores showed an increasing trend from the 1970s to 2014, with the most rapid increase occurring from the late 2000s to 2014, consistent with the statistics on historical production of CPs in China. The three CP groups showed site-specific profiles in sediments from the nine lakes, and their percentages changed with sedimentary years. In sediment samples with dated year after 1980, MCCPs were dominant in sediment from Lakes Sihailongwan maar, Taihu, Erhai, and Chenghai, and LCCPs were predominant compounds in the other five lakes. The proportions of LCCPs rapidly increased after 1980, reflecting the increasing production and usage of LCCPs in China. The total burdens of ∑SCCPs, ∑MCCPs, and ∑LCCPs in sediment prior to 2006 were estimated to be 0.26-5100, 0.29-21000, and 0.07-4300 kg, respectively, which were 1.4-440-fold higher than those of ∑PBDEs.


Assuntos
Hidrocarbonetos Clorados , Parafina , China , Monitoramento Ambiental , Sedimentos Geológicos , Lagos
14.
J Mass Spectrom ; 54(8): 655-666, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177597

RESUMO

Soluble extractives in wood function to protect living trees from destructive agents and also contribute to wood color and fragrance. Some extractive components have biological activities with medical applications. They also play important roles in wood processing and related applications. To increase the knowledge of wood chemistry, maple and oak were extracted by water. Ultraviolet/visible (UV/vis) spectroscopy indicated the presence of a phenolic compound, resorcinol, in maple extractives having higher molecular mass and more aromatic components than oak extractives. Negative and positive electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS) identified thousands of formulas in the two samples in the m/z range of 200 to 800. They mainly fall into the lignin-like, carbohydrate-like, and tannin-like compound categories. The top 25 peaks (ie, formulas) with the highest relative magnitude in negative ESI represented nearly 50% of the summed total spectral magnitude of all formulas assigned in the maple and oak extractives. Furthermore, the base peak (ie, most abundant peak) accounted for about 14% of the total abundance in each wood sample. Literature comparisons identified 17 of 20 formulas in the top five peaks of the four spectra as specific bioactive compounds in trees and other plants, implying the potential to explore utilization of maple and oak extractives for functional and medicinal applications. The various profiling of the top 25 peaks from the two samples also suggested the possible application of FT-ICR-MS for detecting chemical markers useful in profiling and identification of wood types and sources.

15.
Environ Pollut ; 252(Pt A): 657-665, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31185354

RESUMO

Both essential and toxic metal contaminants impact agricultural crops by bioaccumulation in plants. The goal of this study was to evaluate the tissue-level spatial distribution of metal(loids) in corn seeds (Zea mays, L.) from contaminated corn fields near the Xikuangshan (XKS) antimony mine in Hunan, China, and compared them with corn (Zea mays everta L., popcorn) grown in a farm in Amherst, MA that practices sustainable farming as a control. How toxic and essential metals translocate through the roots and shoots during early stages of germination was also investigated. The cleaned corn seed samples were mounted in resin blocks and longitudinally dissected into thin sections. The laser ablation parameters were optimized, and the instrument was calibrated using tomato leaf standard reference material (NIST SRM 1573a) in a pellet form. Tissue level distributions of metal(loid)s As, Cd, Hg, Sb and Zn in corn seeds collected were determined using (LA-ICP-MS). Seeds from the control farm were germinated and their roots and shoots were analyzed to determine tissue level concentrations and their spatial distributions. It was found that seeds from the XKS mine region in China had higher overall concentration of all elements analyzed due to metal(loids) absorbed from contaminated mine soils. Metal(loids) concentrations were highest in the embryo (∼360 mg/kg) and pericarp (∼0.48 mg/kg) compared with the endosperm of corn seeds. Essential element Zn was found in the embryo and emerging coleoptile and radicle. Finally, in both roots and shoots, element concentrations were highest proximally to the tip cap compared to distal concentrations and later translocated to distal tissue regions. This study offers unique insights of metal(loid) bioaccumulation and translocation in corn and thus is better able to track metal(loids) contaminants trafficking in our food systems.


Assuntos
Sementes/química , Poluentes do Solo/análise , Oligoelementos/análise , Zea mays/química , Agricultura , China , Produtos Agrícolas , Germinação , Metais/análise , Folhas de Planta/química , Raízes de Plantas/química , Solo , Oligoelementos/toxicidade , Zinco/toxicidade
16.
Environ Sci Pollut Res Int ; 26(21): 21463-21474, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31127516

RESUMO

Environmental behavior, bioavailability, and risks posed by Fe3O4, magnetic nanoparticles (Fe3O4 NPs) in surface waters are affected by complex geochemistry, including pH and inorganic and organic matter. This work provides a systematic analysis of adsorption of fulvic acid (FA) on surfaces of Fe3O4 NPs with adsorption kinetics, adsorption thermodynamic, and adsorption isotherm. Adsorption of FA on surfaces of Fe3O4 NPs is consistent with assumptions of Langmuir and Freundlich adsorption isotherm models. The adsorption amount of FA was inversely proportional to solution pH, and the maximum amount is 128.6 mg g-1. Adsorption of FA on surfaces of Fe3O4 NPs is a spontaneous endothermic process. FA plays an important role in aggregation and suspension/sedimentation behavior of Fe3O4 NPs in aquatic environmental. With continuous adsorption of FA, electrostatic repulsion between the particles and the steric hindrance of FA significantly decreased aggregation and increased suspension of Fe3O4 NPs. The results of FTIR and XPS indicated that FA was adsorbed on Fe3O4 NPs mainly through chemical reactions, and carbohydrates particularly play an important role in adsorption.


Assuntos
Benzopiranos/química , Nanopartículas de Magnetita/química , Adsorção , Cinética , Magnetismo , Modelos Químicos , Eletricidade Estática , Termodinâmica
17.
Sci Total Environ ; 659: 1437-1447, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096354

RESUMO

In this study, molecular compositions of cyanobacteria, suspended matter, and surface sediments in the Dianchi Lake, a highly eutrophic lake, were investigated by solution and solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. A solution-state 31P NMR spectral analysis of NaOH-EDTA-extracted samples revealed the presence of orthophosphate (ortho-P, 48.5%-91.2% of the total extracted phosphate), orthophosphate monoester (mono-P, 7.3%-43.9%), orthophosphate diester (diester-P, 0.9%-3.9%), and pyrophosphate (pyro-P, 0.7%-5.5%). The organic phosphorus (Po) distribution in suspended matters and cyanobacteria was relatively similar but different from surface sediments. The inorganic phosphorus (Pi) distribution in suspended matters and surface sediments was slightly similar. Results of the solid-state 31P NMR spectral analysis of non-extractable residue showed that cyanobacteria and suspended matter contain a large proportion of Po and poly-P. For surface sediment, only metal-bonded pyro-P and a high proportion of ortho-P were detected. The solid-state 31P NMR spectra results of extracted residual indicated that several of the pyro-P bound to metals and other Pi or Po compounds associated with mineral phases in suspended matter and surface sediment are non-extractable. This result revealed that a high proportion of biogenic phosphorus is bioavailable. These results verify the process of biogenic poly-P regeneration in the Dianchi Lake given that Po, poly-P, and pyro-P are predominant in cyanobacteria and can be released into lake water through chemical and biological degradation, thus further worsening eutrophication.


Assuntos
Monitoramento Ambiental/métodos , Fósforo/análise , Poluentes Químicos da Água/análise , China , Eutrofização , Sedimentos Geológicos/química , Lagos/química , Compostos de Fósforo/análise
18.
Environ Sci Technol ; 53(9): 5151-5158, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30955331

RESUMO

Microplastics (MPs) in aquatic organisms are raising increasing concerns regarding their potential damage to ecosystems. To date, Raman and Fourier transform infrared spectroscopy techniques have been widely used for detection of MPs in aquatic organisms, which requires complex protocols of tissue digestion and MP separation and are time- and reagent-consuming. This novel approach directly separates, identifies, and characterizes MPs from the hyperspectral image (HSI) of the intestinal tract content in combination with a support vector machine classification model, instead of using the real digestion/separation protocols. The procedures of HSI acquisition (1 min) and data analysis (5 min) can be completed within 6 min plus the sample preparation and drying time (30 min) where necessary. This method achieved a promising efficiency (recall >98.80%, precision >96.22%) for identifying five types of MPs (particles >0.2 mm). Moreover, the method was also demonstrated to be effective on field fish from three marine fish species, revealing satisfying detection accuracy (particles >0.2 mm) comparable to Raman analysis. The present technique omits the digestion protocol (reagent free), thereby significantly reducing reagent consumption, saving time, and providing a rapid and efficient method for MP analysis.


Assuntos
Plásticos , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental , Peixes
19.
Environ Sci Pollut Res Int ; 26(16): 15989-15999, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30963435

RESUMO

Total (all forms of inorganic and organic) concentrations of mercury (Hg) and selenium (Se) were measured in dorsal muscle and eggs of wild fishes from two shallow lakes in China: Tai Lake (Ch: Taihu; TL) and Baiyangdian Lake (BYDL). Hazard quotients (HQs) were calculated by dividing concentrations of Se or Hg in muscle or eggs of fishes by threshold concentrations for effects expressed as tissue residue toxicity reference values (TR-TRVs). Concentrations of Hg in whole bodies of fishes were estimated by concentrations in muscle. Based on concentrations of Hg in whole body, HQs for fishes in TL and BYDL were less than 1.0, which suggests little to moderate potential for effects on these fishes and unaccepted adverse effects of Hg are unexpected for adult fishes. HQs of Se in muscle of common carp from TL were closed to 1.0, and 27% of HQs based on concentrations of Hg in eggs of fishes from BYDL exceeded 1.0. Potential hazard due to Hg on common carp in TL and reproductive effects of Se on fishes from BYDL exhibited need for concern. Ratios of molar concentrations of Se to Hg were greater than 1.0. Thus, there might be some protective effects of Se on effects of Hg on fishes in TL and BYDL.


Assuntos
Ecotoxicologia/métodos , Peixes , Mercúrio/toxicidade , Selênio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Carpas , China , Monitoramento Ambiental , Lagos , Mercúrio/análise , Músculos/química , Especificidade de Órgãos , Óvulo/química , Selênio/análise , Poluentes Químicos da Água/análise
20.
Chemosphere ; 226: 381-387, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30947047

RESUMO

With the rapid development of the industrialization and urbanization, the urban environment was heavily contaminated by metals. Therefore, studies on health risk assessment of exposure to metals for urban population is necessary and urgent, especially for children, who are more susceptible to environmental pollution due to their undeveloped immune system. Moreover, ingestion has been proved to be the most important pathway of human metals exposure. Therefore, typical metals, including Lead(Pb), Cadmium(Cd), Arsenic(As), Chromium(Cr), and Manganese(Mn), were analyzed in duplicated diet, drinking water, and soil in this study. The integrated risks of oral exposure to these metals for the local children were then evaluated on a field sampling and measured child-specific exposure factors basis. Results showed that the studied urban environments were polluted by metals to a certain degree. Food ingestion was the largest, which accounted for 66.7%-98.4%. Furthermore, soil ingestion was also a non-negligible exposure route, which accounted for 29.7% for Pb. The combined oral non-carcinogenic and carcinogenic risks all exceeding the corresponding maximum acceptable levels. The non-carcinogenic risk was mainly attributed to the food ingestion of As and Cr, and the soil ingestion of As, while, the carcinogenic risk was mainly attributed to the food ingestion of As and Cr, and the soil ingestion of Cr. This study emphasizes attentions should be paid to children in urban areas due to the potential adverse health risk associated with metals via oral exposure pathway.


Assuntos
Monitoramento Ambiental/métodos , Poluição Ambiental/efeitos adversos , Metais Pesados/química , Medição de Risco/métodos , Criança , Pré-Escolar , China , Feminino , Humanos , Masculino , Metais Pesados/análise , População Urbana
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