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1.
Environ Sci Technol ; 58(2): 1048-1054, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38157561

RESUMO

Tebuconazole (TEB), a widely used and persistent pesticide, has garnered attention due to its frequent detection in sediments worldwide. This widespread occurrence has raised concerns about potential dietborne toxicity to benthic crustaceans, as they may ingest contaminated particles in their habitat. While bioaccumulation studies indicate the importance of TEB ingestion for benthic crustaceans, limited data exist on direct dietborne toxicity testing. This study investigated the diet-related toxicity of TEB by subjecting a benthic ostracod, Heterocypris incongruens, to a 6 day toxicity test under dietary and combined exposures. Subsequently, the importance of dietary exposure for TEB toxicity was uncovered, followed by quantification of relative dietborne toxicity contributions using a modified concentration-additive model. Results revealed that the dietary route was more toxicologically significant than the aqueous route in equilibrium. The dietborne lethal concentration (LC50) for TEB on H. incongruens was 200 (170-250) mg/kg, with an 80% relative dietborne toxicity contribution. To gain comprehensive insights into dietborne significance, toxicity data were collected from previous studies involving different pollutants to calculate relative contributions. Finally, the correlation between dietborne toxicity and the partitioning coefficient was analyzed to understand the pollutant behavior and its toxic impact when ingested through the diet.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Animais , Crustáceos , Testes de Toxicidade/métodos , Triazóis/toxicidade , Poluentes Ambientais/toxicidade , Água , Poluentes Químicos da Água/toxicidade
2.
Environ Sci Technol ; 58(31): 13760-13771, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39051920

RESUMO

China's unprecedented rapid urbanization has dramatically reshaped the urban built environment, disrupting the thermal balance of cities. This disruption causes the urban heat island (UHI) effect, adversely affecting urban sustainability and public health. Although studies have highlighted the remarkable impacts of the built environment on UHIs, the specific effects of its various structures and components remain unclear. In this study, a multidimensional remote sensing data set was used to quantify the atmospheric UHIs across 335 Chinese cities from 1980 to 2020. In conjunction with stocks of three end-use sectors and three material groups, the impacts of gridded material stocks on UHI variations were analyzed. The findings reveal that building stocks exert a predominant influence in 48% of cities. Additionally, the extensive use of metal and inorganic materials has increased thermal stress in 220 cities, leading to an average UHI increase of 0.54 °C. The effect of organic materials, primarily arising from mobile heat sources, is continuously increasing. Overall, this study elucidates the effect of the functional structure and material composition of urban landscapes on UHIs, highlighting the complexities associated with the influence of the built environment on the urban heat load.


Assuntos
Ambiente Construído , Cidades , Temperatura Alta , Urbanização , China
3.
Environ Res ; 245: 118017, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38157965

RESUMO

As the largest beer producer and consumer in the world, China's endeavors to reduce solid waste generation (SWG) and carbon emissions (CEs) in the course of beer production assume paramount significance. This study aims to assess the SWG and CEs in beer production within China at both national and provincial levels, and further delves into the spatial distribution characteristics and evolving patterns across the country. Key findings of the study include:(1) Peak SWG and CEs were recorded in 2013, reaching 861.62 million tons and 2315.10 tCO2e, respectively, followed by a consistent decline. (2) Among the three types of solid waste, spent grain exhibited the highest generation rate, contributing to 94.38% of the total. (3) The emergence of China's beer industry dates back to the 1980s in the northeastern region, expanding to the southeastern and the Yangtze River Basin during the 1990s, ultimately extending nationwide. (4) The spatial distribution of beer production revealed significant regional disparities and notable industry concentration. Notably, many provinces witnessed reduced CEs from beer production starting in 2015, although the extent of reduction varied in different provinces. These findings serve as a scientific foundation for formulating emission reduction strategies in beer producing and offer insights for other food industries in China.


Assuntos
Carbono , Resíduos Sólidos , Resíduos Sólidos/análise , Carbono/análise , Cerveja/análise , Indústrias , China , Dióxido de Carbono/análise , Desenvolvimento Econômico
4.
Environ Res ; 231(Pt 1): 116109, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37178751

RESUMO

The scarcity of carbon sources presents a significant challenge for the bio-treatment of rural domestic wastewater (RDW). This paper presented an innovative approach to address this issue by investigating the supplementary carbon source through in-situ degradation of particulate organic matter (POM) facilitated by ferric sulfate modified sludge-based biochar (SBC). To prepare SBC, five different contents of ferric sulfate (0%, 10%, 20%, 25%, and 33.3%) were added to sewage sludge. The results revealed that the pore and surface of SBC were enhanced, providing active sites and functional groups to accelerate the biodegradation of protein and polysaccharide. During the 8-day hydrolysis period, the concentration of soluble chemical oxidation demand (SCOD) increased and peaked (1087-1156 mg L-1) on the fourth day. The C/N ratio increased from 3.50 (control) to 5.39 (25% ferric sulfate). POM was degraded the five dominant phyla, which were Actinobacteriota, Firmicutes, Synergistota, Proteobacteria, and Bacteroidetes. Although the relative abundance of dominant phyla changed, the metabolic pathway remained unchanged. The leachate of SBC (<20% ferric sulfate) was beneficial for microbes, but an excessive amount of ferric sulfate (33.3% ferric sulfate) could have inhibition effects on bacteria. In conclusion, ferric sulfate modified SBC holds the potential for the carbon degradation of POM in RDW, and further improvements should be made in future studies.


Assuntos
Esgotos , Águas Residuárias , Esgotos/microbiologia , Carbono , Bactérias
5.
J Clin Biochem Nutr ; 73(1): 61-76, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37534099

RESUMO

High-fat consumption promotes the development of obesity, which is associated with various chronic illnesses. Mitochondria are the energy factories of eukaryotic cells, maintaining self-stability through a fine-tuned quality-control network. In the present study, we evaluated high-fat diet (HFD)-induced changes in mitochondrial ultrastructure and dynamics protein expression in multiple organs. C57BL/6J male mice were fed HFD or normal diet (ND) for 24 weeks. Compared with ND-fed mice, HFD-fed mice exhibited increased body weight, cardiomyocyte enlargement, pulmonary fibrosis, hepatic steatosis, renal and splenic structural abnormalities. The cellular apoptosis of the heart, liver, and kidney increased. Cellular lipid droplet deposition and mitochondrial deformations were observed. The proteins related to mitochondrial biogenesis (TFAM), fission (DRP1), autophagy (LC3 and LC3-II: LC3-I ratio), and mitophagy (PINK1) presented different changes in different organs. The mitochondrial fusion regulators mitofusin-2 (MFN2) and optic atrophy-1 (OPA1) were consistently downregulated in multiple organs, even the spleen. TOMM20 and ATP5A protein were enhanced in the heart, skeletal muscle, and spleen, and attenuated in the kidney. These results indicated that high-fat feeding caused pathological changes in multiple organs, accompanied by mitochondrial ultrastructural damage, and MFN2 and OPA1 downregulation. The mitochondrial fusion proteins may become promising targets and/or markers for treating metabolic disease.

6.
Environ Sci Technol ; 55(12): 7939-7948, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34047553

RESUMO

Organic pollutants with high solid-water equilibrium partition coefficients are adsorbed into solid particles and are easily ingested by benthic organisms, potentially causing dietborne toxicity. Whether dietborne toxicity is more important than waterborne toxicity for such chemicals remains to be determined. In this study, we identify the most relevant uptake route for the toxicity of two alkylphenols, 4-tert-butylphenol (4tBP), and 4-tert-octylphenol (4tOP). To achieve this, 6-day toxicity tests under two exposure conditions, namely dietary exposure (clean water + contaminated food) and combined exposure (contaminated water + contaminated food) were conducted on a benthic ostracod, Heterocypris incongruens. The toxicologically important exposure routes were confirmed by the consistency of dietary and aqueous dose-response relationships under different exposure conditions. During the test, frequent renewal of water and food was performed to reduce variability in the exposure conditions. The results showed that, under the equilibrium condition, the dietary exposure route was toxicologically more important than the aqueous route for 4tBP, whereas the waterborne exposure route was more important than the dietary exposure route for 4tOP. This study provides a novel approach to identify the most relevant uptake pathways for chemical toxicity, which better explains the importance of exposure routes in toxicity effects.


Assuntos
Crustáceos , Poluentes Químicos da Água , Animais , Fenóis/toxicidade , Testes de Toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
7.
J Environ Sci (China) ; 76: 359-367, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30528027

RESUMO

Microcystis panniformis is a bloom forming species with flat panniform-like colonies. This species was recently found in Lake Taihu, China. To specifically characterize M. panniformis based on isolated strains, morphological examination on colonial transition and genetic examination are needed. Three M. panniformis strains isolated from a water bloom sample in Lake Taihu were characterized by molecular analysis and toxin quantification. Phylogenetic analysis based on both 16S rRNA gene and internal transcribed spacer (ITS) between 16S and 23S rRNA genes were performed and compared to facilitate easy identification of the species. Relatively high similarities (98%-99%) were shown in 16S rDNA sequences between the strains of M. panniformis and those of other Microcystis species, whereas the similarities for ITS sequences were 88%-95%. In the phylogenetic tree based on the 16S rDNA sequences, the M. panniformis and M. aeruginosa strains were intermixed together with no clear division, whereas all of the M. panniformis strains were clustered together in a single clade based on the ITS sequences based phylogenyetic tree. The mcyE gene was detected in all three strains, and microcystin was determined by high-performance liquid chromatography. The molecular detection and toxin production of M. panniformis strains are of great significance for the environmental risk assessment of Microcystis blooms.


Assuntos
Monitoramento Ambiental , Lagos/microbiologia , Microcistinas/análise , Microcistinas/biossíntese , Microcystis/metabolismo , Toxinas Biológicas/análise , Toxinas Biológicas/biossíntese , China , Microcystis/genética , Filogenia , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética
8.
Waste Manag Res ; 33(11): 1005-14, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26416851

RESUMO

To evaluate the effects of different remediation methods on heavy metals contaminated recycled gravel, three immobilization agents (monopotassium phosphate, lime, nano-iron) and two mobilization agents (glyphosate, humic acid (HA)) were studied and compared. Results indicated that nano-iron powder was found to be more effective to immobilize Zn, Cu, Pb and Cd. Meanwhile, glyphosate presents a higher mobilization effect than HA with removal rates of about 66.7% for Cd, more than 80% for Cr, Cu and Zn, and the highest removal percentage of 85.9% for Cr. After the mobilization by glyphosate, the leaching rates of Zn, Cu and Cr were about 0.8%, and below 0.2% for Pb and Cd. The leaching rates after nano-iron powder treatment were 1.18% for Zn, 0.96% for Cr, 0.61% for Cu, 0.45% for Pb and Cd not detected. The formation and disappearance of metal (Zn/Cu/Cr/Pb/Cd) compounds were firmly confirmed through X-ray diffraction and scanning electron microscopy analyses on crystalline phases and morphological surface structures.


Assuntos
Materiais de Construção/análise , Poluentes Ambientais/análise , Recuperação e Remediação Ambiental/métodos , Metais Pesados/análise , Reciclagem , Gerenciamento de Resíduos , Microscopia Eletrônica de Varredura , Difração de Raios X
9.
J Hazard Mater ; 476: 135046, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-38964038

RESUMO

Emerging contaminants pose a potential risk to aquatic ecosystems in the Pearl River Basin, China, owing to the high population density and active industry. This study investigated samples from eight sewage treatment plants, and five surface water bodies of related watersheds. To screen the risk of emerging contaminants (ECs), and clarify their sources, this study calculated the risk quotient of detected chemical and performed source identification/apportionment using the positive matrix factorization method. In total, 149 organic pollutants were identified. Pharmaceuticals showed significant concentrations in sewage treatment plant samples (120.87 ng/L), compared with surface water samples (1.13 ng/L). The ecological risk assessment identified three chemicals with a heightened risk to aquatic organisms: fipronil sulfide, caffeine, and roxithromycin. Four principal sources of contaminants were identified: pharmaceutical wastewater, domestic sewage, medical effluent, and agricultural runoff. Pharmaceutical wastewater was the primary contributor (60.4 %), to the cumulative EC concentration and to ECs in sewage treatment plant effluent. Agricultural drainage was the main source of ECs in surface water. This study provides a strategy to obtain comprehensive information on the aquatic risks and potential sources of EC species in areas affected by artificial activities, which is of substantial importance to pollutant management and control.


Assuntos
Monitoramento Ambiental , Rios , Esgotos , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Rios/química , China , Esgotos/análise , Medição de Risco , Preparações Farmacêuticas/análise , Águas Residuárias/análise , Águas Residuárias/química , Eliminação de Resíduos Líquidos
10.
J Hazard Mater ; 476: 135109, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-38972204

RESUMO

To overcome challenges in assessing the impact of environmental factors on heavy metal accumulation in soil due to limited comprehensive data, our study in Yangxin County, Hubei Province, China, analyzed 577 soil samples in combination with extensive big data. We used machine learning techniques, the potential ecological risk index, and the bivariate local Moran's index (BLMI) to predict Cr, Pb, Cd, As, and Hg concentrations in cultivated soil to assess ecological risks and identify pollution sources. The random forest model was selected for its superior performance among various machine learning models, and results indicated that heavy metal accumulation was substantially influenced by environmental factors such as climate, elevation, industrial activities, soil properties, railways, and population. Our ecological risk assessment highlighted areas of concern, where Cd and Hg were identified as the primary threats. BLMI was used to analyze spatial clustering and autocorrelation patterns between ecological risk and environmental factors, pinpointing areas that require targeted interventions. Additionally, redundancy analysis revealed the dynamics of heavy metal transfer to crops. This detailed approach mapped the spatial distribution of heavy metals, highlighted the ecological risks, identified their sources, and provided essential data for effective land management and pollution mitigation.


Assuntos
Monitoramento Ambiental , Aprendizado de Máquina , Metais Pesados , Poluentes do Solo , Poluentes do Solo/análise , Metais Pesados/análise , Medição de Risco , China , Monitoramento Ambiental/métodos , Solo/química
11.
Eur J Pharmacol ; 959: 176085, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37806539

RESUMO

Despite the great clinical benefits of statins in cardiovascular diseases, their widespread use may lead to adverse muscle reactions associated with mitochondrial dysfunction. Some studies have demonstrated that statins provide substantial improvement to skeletal muscle health in mice. Our previous study found that oral treatment with atorvastatin (Ator, 3 mg/kg) protected myocardial mitochondria in high-fat diet (HFD)-fed mice. Therefore, this study aimed to explore the influence of low-dose Ator (3 mg/kg) on mitochondria in skeletal muscle under cholesterol overload. Male C57BL/6J mice were fed a HFD for 18 weeks and orally administered Ator (3 mg/kg) during the last 12 weeks. Ator treatment had no effects on elevated serum cholesterol and glucose levels in HFD-fed mice. Serum creatine kinase levels and the cross-sectional area of muscle cells were not affected by HFD feeding or Ator treatment. Increased expression of PINK1-LC3 II (activated mitophagy), MFN2 (fusion), and PGC-1α (biogenesis) proteins was induced in the skeletal muscles of HFD-fed mice. Treatment with Ator inhibited PINK1 and LC3 II protein expression, but further promoted MFN1, MFN2, and OPA1 expression. The impairments in mitochondrial quality and morphology in HFD-fed mice were attenuated by treatment with Ator. Furthermore, Ator treatment enhanced glucose oxidation capacity and restored ATP production in the skeletal muscles of HFD-fed mice. The study reveals that low-dose Ator has a protective effect on muscle mitochondria in mice, likely through inhibiting mitophagy and enhancing mitochondrial fusion. This suggests that skeletal muscle mitochondria may be one of low-dose Ator-mediated protective targets.


Assuntos
Dieta Hiperlipídica , Inibidores de Hidroximetilglutaril-CoA Redutases , Camundongos , Masculino , Animais , Dieta Hiperlipídica/efeitos adversos , Atorvastatina/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Camundongos Endogâmicos C57BL , Mitocôndrias , Mitocôndrias Musculares , Músculo Esquelético/metabolismo , Autofagia , Glucose/metabolismo , Colesterol/metabolismo , Proteínas Quinases/metabolismo
12.
Biomed Pharmacother ; 157: 114024, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36402030

RESUMO

Although statins are shown to have cardiac pleiotropic effects independent of lowering cholesterol, the underlying mechanism remains unclear. Mitochondrial dysfunction induced by increased fatty acid oxidation (FAO) is the culprit in the development of cardiac hypertrophy and dysfunction. This study was to explore whether the cardiac pleiotropic effects of atorvastatin were associated with FAO regulation, with a specific focus on carnitine palmitoyltransferase 1 (CPT1). High-fat diet (HFD)-fed mice and palmitic acid (PA)-stimulated neonatal rat primary cardiomyocytes (NRCMs) were treated with atorvastatin, with or without FAO modulators, signal transducer and activator of transcription 3 (STAT3) agonist, and inhibitor. Atorvastatin (3 mg/kg) did not reduce serum cholesterol levels in HFD-fed mice but ameliorated mitochondrial dysfunction and cardiac hypertrophy. In vitro, atorvastatin and the FAO inhibitor alleviated PA-induced mitochondrial dysfunction and cardiomyocyte hypertrophy. However, the FAO enhancer eliminated atorvastatin's protective effects. Furthermore, atorvastatin decreased CPT1 and FAO levels and prevented STAT3 phosphorylation and nuclear translocation. STAT3 inhibitor had the same inhibitory effects as atorvastatin on CPT1, FAO levels, and cardiomyocyte hypertrophy, whereas STAT3 agonist disrupted these effects of atorvastatin. Our results demonstrate that atorvastatin decreases myocardial FAO by inactivating the p-STAT3/CPT1 signaling pathway, which improves lipid overload-induced mitochondrial dysfunction and cardiac hypertrophy in a cholesterol-independent manner. This is the first study to explore the cardiac pleiotropic effects of atorvastatin with respect to FAO. However, whether atorvastatin regulates FAO in the cardiac hypertrophy model induced by other variables has not been investigated in this work, and this is expected to be performed in the future.


Assuntos
Carnitina O-Palmitoiltransferase , Fator de Transcrição STAT3 , Ratos , Camundongos , Animais , Carnitina O-Palmitoiltransferase/metabolismo , Fator de Transcrição STAT3/metabolismo , Atorvastatina/farmacologia , Cardiomegalia/metabolismo , Miócitos Cardíacos , Ácido Palmítico/farmacologia , Mitocôndrias , Ácidos Graxos/metabolismo
13.
Chemosphere ; 275: 129954, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33631402

RESUMO

The harvesting of algal sludge from eutrophic lakes, including the large quantity of organic matters, has the potential to be used as valuable products through the process of resource recovery. This study investigates the fatty acid production potential from algal sludge via anaerobic fermentation under different pH values. The results indicated that the recovery of short-chain fatty acids (SCFAs) was the highest (3269.25 ± 32.89 mg·COD/L) at pH 11 after 7 days of fermentation. The SCFAs concentration at pH value 11 was 6.24, 1.27, 4.90, and 0.53 times higher compared with that at pH value 3, 5, 7, and 9, respectively. The SCFAs production was continually increased from day 1 to day 7 at pH value 7, 9, and 11. Much fewer middle- and long-chain fatty acids were produced compared with SCFAs. Gross. fatty acid production was the highest at pH 11. The concentrations of soluble protein and polysaccharide were the highest at pH 11, implying that the disruption of algal cells could have a high value at pH 11. The polysaccharide concentration was the lowest at pH 7. The fluorescence excitation-emission matrix profile implied that the disruption of algal cells was the greatest at pH 11. Methane production was greatest at pH 7 and 9. Overall, the results of this study revealed that a pH of 11 was optimal for the recovery of SCFAs from algal sludge due to the higher cell disruption, suitable ORP condition for SCFAs production and inhibition of methanogens.


Assuntos
Ácidos Graxos Voláteis , Esgotos , Anaerobiose , Fermentação , Concentração de Íons de Hidrogênio
14.
Sci Total Environ ; 702: 134993, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31726336

RESUMO

Since the establishment of the whole-contact sediment toxicity test using Heterocypris incongruens in 2012, this user-friendly method has been widely used for the assessment of many kinds of solid samples, such as sediment, soil, compost, and sewage sludge. There are two endpoints for this method: mortality and growth inhibition. Currently, there is no standard toxicity threshold established for the endpoint of growth inhibition. However, there is evidence showing that the calcite saturation state of the overlying water, which might be different among various samples, influences the growth and survival of H. incongruens. Thus, it is necessary to characterize the influence of the calcite saturation state to ensure that the test results are reliable and comparable among different samples. In the present study, we created artificial sediments comprised of quartz sand and 0-20% calcite particulates to manipulate the calcite saturation state in the overlying water and performed the test using H. incongruens for 6 d. The results show that a low calcite saturation state inhibited the growth of H. incongruens but had no effect on survival rate. The growth of ostracods was linearly related to the calcite saturation index of the overlying water. Additionally, a formula for artificial sediment consisting of 10% calcite and 90% quartz sand for the H. incongruens toxicity test was proposed. This study helps to distinguish H. incongruens growth inhibition caused by calcite saturation from that caused by toxicity.


Assuntos
Carbonato de Cálcio/química , Crustáceos/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Fenômenos Biológicos , Sedimentos Geológicos/química , Esgotos , Solo , Testes de Toxicidade , Poluentes Químicos da Água/normas
15.
Sci Rep ; 8(1): 10139, 2018 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-29973662

RESUMO

Postpartum depression (PPD) is a common mental health problem that causes maternal suffering and various negative consequences for offspring. The pathogenesis of PPD and the causes of consequences for offspring remain largely unknown. Here, we applied RNA sequencing to sequence the whole transcriptomes of peripheral blood mononuclear cells (PBMCs) from PPD patients (Edinburgh Postnatal Depression Scale [EPDS] score ≥13) and control subjects (EPDS = 0). We found that PPD was positively correlated with multiple genes involved in energy metabolism, neurodegenerative diseases and immune response, while negatively correlated with multiple genes in mismatch repair and cancer-related pathways. Remarkably, genes associated with appetite regulation and nutrient response were differentially expressed between PPD and control subjects. Then, we employed a postnatal growth retardation model by repeated immobilization stress (IS) stimulation to maternal mice. The expression of appetite regulation and nutrient response-related genes in the PBMCs of IS mice and in the hypothalamus of their offspring were also affected. In conclusion, this study provides a comprehensive characterization of the PBMCs transcriptome in PPD and suggests that maternal stress may affect appetite regulation and nutrient response in the hypothalamus of offspring mice.


Assuntos
Depressão Pós-Parto/genética , Transcriptoma , Adulto , Animais , Depressão Pós-Parto/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos ICR , Monócitos/metabolismo
16.
Environ Sci Pollut Res Int ; 22(12): 9332-44, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25601613

RESUMO

Total concentrations of heavy metals (Cu, Zn, Pb, Cr, Cd, and Ni) were measured among 63 samples of construction and demolition (C&D) wastes collected from chemical, metallurgical and light industries, and residential and recycled aggregates within China for risk assessment. The heavy metal contamination was primarily concentrated in the chemical and metallurgical industries, especially in the electroplating factory and zinc smelting plant. High concentrations of Cd were found in light industry samples, while the residential and recycled aggregate samples were severely polluted by Zn. Six most polluted samples were selected for deep research. Mineralogical analysis by X-ray fluorescence (XRF) spectrometry and X-ray diffraction (XRD), combined with element speciation through European Community Bureau of Reference (BCR) sequential extraction, revealed that a relatively slight corrosion happened in the four samples from electroplating plants but high transfer ability for large quantities of Zn and Cu. Lead arsenate existed in the acid extractable fraction in CI7-8 and potassium chromium oxide existed in the mobility fraction. High concentration of Cr could be in amorphous forms existing in CI9. The high content of sodium in the two samples from zinc smelter plants suggested severe deposition and erosion on the workshop floor. Large quantities of Cu existed as copper halide and most of the Zn appeared to be zinc, zinc oxide, barium zinc oxide, and zincite. From the results of the risk assessment code (RAC), the samples from the electroplating factory posed a very high risk of Zn, Cu, and Cr, a high risk of Ni, a middle risk of Pb, and a low risk of Cd. The samples from the zinc smelting plant presented a high risk of Zn, a middle risk of Cu, and a low risk of Pb, Cr, Cd, and Ni.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/química , Metais Pesados/química , Metais Pesados/toxicidade , China , Resíduos Industriais , Indústrias , Reciclagem , Medição de Risco
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