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1.
J Environ Manage ; 370: 122562, 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39305885

RESUMEN

The transport behavior of combined organic pollutants in soil and groundwater has attracted significant attention in recent years. Research on the influence of humic acid (HA) on organic pollutant transport behavior mainly focuses on the study of the mobile phase HA, with less research on the adsorbed phase HA, especially regarding its interaction with combined pollutants. To enhance understanding of the regulation of co-transport and retention of combined pollutants by adsorbed phase HA, in this study, tests were conducted to investigate how toluene (TOL) and dichloromethane (DCM) are transported in the presence of adsorbed phase HA at different pH levels and ionic strengths. As the proportions of HA-coated sand increased, so did its adsorption capacity for TOL and DCM, which can be attributed to adsorbed phase HA providing more adsorption sites compared to plain sand, thereby reducing the transport potential of the pollutants. The presence of both TOL and DCM facilitated their mutual transportation due to competitive adsorption controlled by the adsorbed phase HA content in the porous medium. Furthermore, it was observed that pH levels influenced the transport behavior of TOL and DCM when adsorbed phase HA was present since adsorbed phase HA transformation into mobile phase was regulated by pH levels. The transport patterns can be effectively simulated using the chemical nonequilibrium two-site sorption model in HYDRUS-1D, accurately reflecting the retardation coefficients and transport distances based on model parameters. This work sheds new light on the regulatory role of adsorbed phase HA in TOL and DCM transport under diverse hydrochemical conditions, with implications for accurately depicting the behavior of combined pollutants, optimizing the remediation strategies and improving remediation efficiency in contaminated sites.

2.
Bioresour Technol ; 384: 129356, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37336445

RESUMEN

Composting experiment of swine manure, adding with yellow phosphorus slag(YPS) at 5% (w/w), was conducted in an industrial-scale reactor covered with semi-permeable membrane. During 27 days of composting, the changes in temperature, compost quality and phosphorus(P) speciation of products were monitored. Results indicated that the temperature of compost pile was sharply increased on day 2, and the thermophilic period lasted for 15 days. The dynamics in germination index(GI), pH, nutrient contents, etc. of products were in line with conventional composting process. For P distribution, the contents of total-P and citric acid extracted-P(CAP) of products were increased during composting, while that of Olsen-P was decreased. HCl extracted inorganic P(HCl-Pi), a slowly release fraction of P, was dominated in the product, which showed an increasing trend during the composting. These results suggest that the industrial-scale composting with novel YPS additive can be accomplished, and its product contains abundant slowly released P.


Asunto(s)
Compostaje , Suelo , Animales , Porcinos , Suelo/química , Estiércol , Fósforo , Temperatura
3.
Artículo en Inglés | MEDLINE | ID: mdl-36767132

RESUMEN

Microbial biodegradation is considered as one of the most effective strategies for the remediation of soil contaminated with polycyclic aromatic hydrocarbons (PAHs). To improve the degradation efficiency of PAHs, PAH-degrading consortia combined with strengthening remediation strategies was used in this study. The PAH biodegrading performance of seven bacterial consortia constructed by different ratios of Mycobacterium gilvum MI, Mycobacterium sp. ZL7 and Rhodococcus rhodochrous Q3 was evaluated in an aqueous system containing phenanthrene, pyrene, benzo[a]pyrene and benzo[b]fluoranthene. Bacterial consortium H6 (Q3:ZL7:MI = 1:2:2) performed a high degrading efficiency of 59% in 8 days. The H6 was subsequently screened to explore its potential ability and performance to degrade aged PAHs in soils from a coking plant and the effects of strengthening strategies on the aged PAH degradation, including the addition of glucose or sodium dodecyl benzene sulfonate (SDBS) individually or as a mixture along immobilization of the inoculant on biochar. The highest degradation efficiencies, which were 15% and 60% for low-molecular-weight (LMW) PAHs and high-molecular-weight (HMW) PAHs, respectively, were observed in the treatment using immobilized microbial consortium H6 combined with the addition of glucose and SDBS after 24 days incubation. This study provides new insights and guidance for future remediation of aged PAH contaminated soils.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , Hidrocarburos Policíclicos Aromáticos/análisis , Biodegradación Ambiental , Consorcios Microbianos , Suelo , Contaminantes del Suelo/análisis , Bacterias/metabolismo , Microbiología del Suelo
4.
Sci Total Environ ; 789: 147937, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34049148

RESUMEN

The rapid socioeconomic development has led to severe pollution of urban soils by heavy metals. It is vital to identify and quantify the factors that affect trace-element pollution for better preventing and managing soil pollution. In this study, we collected 179 surface soil samples from Zhangzhou City in a coastal area of south China to determine the concentration of seven heavy metals (As, Cr, Cu, Hg, Ni, Pb, and Zn) and used the Nemerow Pollution Index (Pn) to estimate the level of heavy metal pollution in soils. Eighteen environmental factors, including six natural factors (e.g. soil properties, surface topography) and twelve anthropogenic factors (e.g. industry, road network, land use types and landscape pattern), were evaluated with the geodetector statistical method. The results indicate that the heavy metal contamination of soils in Zhangzhou City was highly heterogeneous. We found that the primary influencing factors for heavy metal concentrations were soil organic matter content, agriculture activities, and landscape pattern. Furthermore, the nonlinear relationship between the primary factors and their interaction factors enhanced soil contamination by the heavy metals. Among the anthropogenic factors, landscape pattern enhanced Pn the most when interacting with natural factor. In addition, the buffer zone should be considered when evaluating the effects of factors such as land use and landscape pattern, because the interactions between landscape pattern and slope aspect produce a maximum effect, accounting for 31.0% of the Pn value on the scale of 800 m. Based on this analysis, we identified the key factors of heavy metal pollution in the soils of Zhangzhou City and proposed strategic procedures for effective soil pollution prevention and treatment in the future.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , China , Ciudades , Monitoreo del Ambiente , Metales Pesados/análisis , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis
5.
J Hazard Mater ; 388: 122037, 2020 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-31951992

RESUMEN

Thiol-modified rice straw biochar (RS) was prepared by an esterification reaction with ß-mercaptoethanol and used for the remediation of Cd and Pb polluted soils. Modified biochar was characterized through elemental analysis, BET analysis, FE-SEM, FT-IR and XPS. These analytical results revealed that thiol groups were successfully grafted onto the surface of the biochar and were involved in metal ion complexation. Batch sorption experiments indicated that Cd2+ and Pb2+ sorption onto RS described well by a pseudo second order kinetic model and a Langmuir isotherm. The maximum adsorption capacities for Cd2+ and Pb2+, in the single-metal systems, were 45.1 and 61.4 mg g-1, respectively. In the binary-metal systems, RS selectively adsorbed Cd2+ over Pb2+. Cd2+ and Pb2+ were removed mainly through surface complexation. In the soil incubation experiments (28 days), RS reduced the available Cd by 34.8-39.2 %; while, RS reduced the available Pb by 8.6 %-11.1 %. This research demonstrates RS as a potentially effective amendment for the remediation of heavy metal polluted soils.


Asunto(s)
Cadmio/química , Carbón Orgánico/química , Restauración y Remediación Ambiental/métodos , Plomo/química , Contaminantes del Suelo/química , Compuestos de Sulfhidrilo/química , Adsorción
6.
Environ Pollut ; 263(Pt A): 114580, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33618458

RESUMEN

The bioaccessibility of arsenic and its speciation are two important factors in assessing human health risks exposure to contaminated soils. However, the effects of human gut microbiota on arsenic bioaccessibility and its speciation are not well characterized. In this study, an improved in vitro model was utilized to investigate the bioaccessibility of arsenic in the digestive tract and the role of human gut microbiota in the regulation of arsenic speciation. For all soils, arsenic bioaccessibility from the combined in vitro model showed that it was <40% in the gastric, small intestinal and colon phases. This finding demonstrated that the common bioaccessibility approach assuming 100% bioaccessibility would overestimate the human health risks posed by contaminated soils. Further to this, the study showed that arsenic bioaccessibility was 22% higher in the active colon phase than that in the sterile colon phase indicating that human colon microorganisms could induce arsenic release from the solid phase. Only inorganic arsenic was detected in the gastric and small intestinal phases, with arsenate [As(V)] being the dominant arsenic species (74%-87% of total arsenic). Arsenic speciation was significantly altered by the active colon microbiota, which resulted in the formation of methylated arsenic species, including monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)] with low toxicity, and a highly toxic arsenic species monomethylarsonous acid [MMA(III)]. Additionally, a high level of monomethylmonothioarsonic acid [MMMTA(V)] (up to 17% of total arsenic in the extraction solution) with unknown toxicological properties was also detected in the active colon phase. The formation of various organic arsenic species demonstrated that human colon microorganisms could actively metabolize inorganic arsenic into methylated arsenicals and methylated thioarsenicals. Such transformation should be considered when assessing the human health risks associated with oral exposure to soil.


Asunto(s)
Arsénico , Arsenicales , Microbioma Gastrointestinal , Microbiota , Contaminantes del Suelo , Arsénico/análisis , Humanos , Suelo , Contaminantes del Suelo/análisis
7.
Environ Geochem Health ; 41(4): 1811, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29282623

RESUMEN

Unfortunately, in the original publication of the article, Prof. Yong Sik Ok's affiliation was incorrectly published. The author's affiliation is as follows.

8.
Environ Geochem Health ; 41(4): 1755-1766, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28550600

RESUMEN

Arsenic-containing water poses a serious threat to human health. In this study, two types of Fe-modified rice straw biochars [(Fe-impregnated biochar (FeIm char) and pre-modified rice straw biochar (PMRS char)] were prepared, in which three ratios [1, 5, and 10% (w/w)] of Fe modification were evaluated, resulting in six different Fe-modified biochars. Then, a series of adsorption experiments, using single- and binary-metal solutions of As(V) and Cd(II), were conducted to investigate the performances of modified biochars on metal adsorption compared to pristine rice straw biochar (RS char). Results indicated Fe modification improved the As(V) adsorption capacity of biochar. PMRS char showed higher adsorption of As(V) than FeIm char. At the 5% Fe modification ratio (FMR), the As(V) removal by PMRS char (at 10 g/L dosage) from 100 mg/L As(V) solution was approximately 69.6%, which was higher than 46.1% of FeIm char or 22.6% of RS char. In contrast, the adsorption of Cd(II) was decreased after modified at 5 or 10% FMR. Interestingly, for treating solution containing As(V) and Cd(II) together, the adsorption of As(V) onto FeIm char or PMRS char prepared at 5 or 10% FMR remained higher than that onto RS char, while the simultaneous removal of Cd(II) ion by either modified biochar was kept over 50%. Thus, the finding of this study suggested Fe-modified biochars, especially prepared via the pyrolysis of FeCl3 pre-soaking rice straw, could be a promising adsorbent for the remediation of complex As(V)-containing wastewater.


Asunto(s)
Arseniatos/química , Cadmio/química , Carbón Orgánico/química , Hierro/química , Oryza/química , Adsorción , Arsénico , Tallos de la Planta/química , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos
9.
J Agric Food Chem ; 66(18): 4710-4715, 2018 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-29633616

RESUMEN

Shrimp, a popular and readily consumed seafood, contains high concentrations of arsenic. However, few studies have focused on whether arsenic in the shrimp could be transformed during the cooking process and gastrointestinal digestion. In this study, a combined in vitro model [Unified Bioaccessibility Research Group of Europe (BARGE) Method-Simulator of Human Intestinal Microbial Ecosystem (UBM-SHIME)] was used to investigate arsenic bioaccessibility and its speciation in raw and cooked shrimps. The results showed that the cooking practices had little effect on the arsenic content and speciation. Bioaccessibility of arsenic in raw shrimp was at a high level, averaging 76.9 ± 4.28 and 86.7 ± 3.74% in gastric and small intestinal phases, respectively. Arsenic speciation was stable in all of the shrimp digestions, with nontoxic arsenobetaine (AsB) being the dominated speciation. The cooking practice significantly increased the bioaccessibility of arsenate ( p < 0.05) in shrimp digests, indicating the increase of the potential health risks.


Asunto(s)
Arsénico/química , Arsénico/metabolismo , Mariscos/análisis , Animales , Disponibilidad Biológica , Culinaria , Crustáceos/metabolismo , Digestión , Mucosa Gástrica/metabolismo , Calor , Humanos , Mucosa Intestinal/metabolismo , Modelos Biológicos
10.
Arch Toxicol ; 92(3): 1023-1035, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29222745

RESUMEN

Exposure to ambient particulate matter (PM) has been linked to the increasing incidence and mortality of lung cancer, but the principal toxic components and molecular mechanism remain to be further elucidated. In this study, human lung adenocarcinoma A549 cells were treated with serial concentrations of water-extracted PM10 (WE-PM10) collected from Beijing, China. Our results showed that exposure to 25 and 50 µg/ml of WE-PM10 for 48 h significantly suppressed miR-26a to upregulate lin-28 homolog B (LIN28B), and in turn activated interleukin 6 (IL6) and signal transducer and activator of transcription 3 (STAT3) in A549 cells, subsequently contributing to enhanced epithelial-mesenchymal transition and accelerated migration and invasion. In vivo pulmonary colonization assay further indicated that WE-PM10 enhanced the metastatic ability of A549 cells. In addition, luciferase reporter assay demonstrated that 3' untranslated region of LIN28B was a direct target of miR-26a. Last but not the least, the key toxic contribution of metals in WE-PM10 was confirmed by the finding that removal of metals through chelation significantly rescued WE-PM10-mediated inflammatory, carcinogenic and metastatic responses. Taken together, miR-26a could act as the tumor suppressor in PM10-related lung cancer, and PM10-bound metals promoted lung cancer cell metastasis through downregulation of miR-26a that directly mediated LIN28B expression.


Asunto(s)
Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , MicroARNs/genética , Material Particulado/toxicidad , Proteínas de Unión al ARN/genética , Células A549 , Animales , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Humanos , Inflamación/inducido químicamente , Inflamación/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Masculino , Metales/análisis , Metales/toxicidad , Ratones Endogámicos BALB C , Material Particulado/química , Proteínas de Unión al ARN/metabolismo , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
11.
Chemosphere ; 182: 316-324, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28501571

RESUMEN

The inoculation of rice straw biochar with PAH-degrading Mycobacterium gilvum (1.27 × 1011 ± 1.24 × 1010 cell g-1), and the subsequent amendment of this composite material to PAHs contaminated (677 mg kg-1) coke plant soil, was conducted in order to investigate if would enhance PAHs biodegradation in soils. The microbe-biochar composite showed superior degradation capacity for phenanthrene, fluoranthene and pyrene. Phenanthrene loss in the microbe-biochar composite, free cell alone and biochar alone treatments was, respectively, 62.6 ± 3.2%, 47.3 ± 4.1% and non-significant (P > 0.05); whereas for fluoranthene loss it was 52.1 ± 2.3%; non-significant (P > 0.05) and non-significant (P > 0.05); and for pyrene loss it was 62.1 ± 0.9%; 19.7 ± 6.5% and 13.5 ± 2.8%. It was hypothesized that the improved remediation was underpinned by i) biochar enhanced mass transfer of PAHs from the soil to the carbonaceous biochar "sink", and ii) the subsequent degradation of the PAHs by the immobilized M. gilvum. To test this mechanism, a surfactant (Brij 30; 20 mg g-1 soil), was added to impede PAHs mass transfer to biochar and sorption. The surfactant increased solution phase PAH concentrations and significantly (P < 0.05) reduced PAH degradation in the biochar immobilized M. gilvum treatments; indicating the enhanced degradation occurred between the immobilized M. gilvum and biochar sorbed PAHs.


Asunto(s)
Biodegradación Ambiental , Carbón Orgánico/química , Micobacterias no Tuberculosas/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Contaminantes del Suelo/metabolismo , Suelo/química , Absorción Fisicoquímica , Microbiología del Suelo , Tensoactivos/farmacología
12.
J Hazard Mater ; 321: 47-53, 2017 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-27607932

RESUMEN

Lab scale and single stage high solid anaerobic digestion of sewage sludge spiked with freshly synthesized nanoscale zero valent iron (nZVI) and commercial iron powder (IP) under mesophilic condition (37±1°C) was performed. The effects of both additives on methane yield, and pharmaceutical and personal care product (PPCP) removal were investigated. Results showed that methane yield was increased by 25.2% and 40.8% in the presence of nZVI (0.1%) and IP (1.6%), respectively. Removal efficiencies of chemical oxygen demand were 54.4% and 66.2% in the presence of nZVI and IP, respectively, which were higher compared to the control group (44.6%). In addition, most PPCPs could be partly or completely removed during the anaerobic digestion process. The application of nZVI and IP showed positive impact on the removal of chlorinated PPCPs (p<0.05), but did not show significant impact on other PPCPs (p>0.05). Our finding suggests that the application of nZVI and IP in anaerobic digestion could be a promising way to enhance methane yield but had less improvement on PPCP degradation.


Asunto(s)
Cosméticos/análisis , Hierro/química , Metano/biosíntesis , Nanopartículas/química , Preparaciones Farmacéuticas/análisis , Aguas del Alcantarillado , Contaminantes Químicos del Agua/análisis , Bacterias Anaerobias/metabolismo , Reactores Biológicos/microbiología , Polvos , Aguas del Alcantarillado/química , Aguas del Alcantarillado/microbiología , Purificación del Agua/métodos
13.
Environ Pollut ; 216: 819-825, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27368131

RESUMEN

Much research has considered the influence of biochars on the availability and phytoaccumulation of potentially toxic elements (PTEs) from soil. However, the vast majority of these studies use, what are arguably, unrealistic and unpractical amounts of biochar (10, 50 and even up to 100 t/ha). To offer a more realistic insight into the influence of biochar on PTE partitioning and phytoaccumulation, a field study, using modest rates of biochar application (1.5, 3.0 t/ha), was undertaken. Specifically, the research investigated the influence of sewage sludge biochar (SSBC) on the accumulation of Cd into rice (Oryza sativa L.) grown in Cd contaminated (0.82 ± 0.07 mg/kg) paddy soil. Results indicated, Cd concentrations in rice grains to significantly (p < 0.05) decrease from 1.35 ± 0.09 mg/kg in the control to 0.82 ± 0.07 mg/kg and 0.80 ± 0.21 mg/kg in the 1.5 t/ha and 3.0 t/ha treatments, respectively. Accordingly, the hazardous quotient (HQ) indices for Cd, associated with rice grain consumption, were also reduced by ∼40%. SSBC amendment significantly (p < 0.05) increased grain yields from 1.90 ± 0.08 g/plant in the control to 2.17 ± 0.30 g/plant and 3.40 ± 0.27 g/plant in the 1.5 t/ha and 3.0 t/ha treatments, respectively. Thus, the amendment of SSBC to contaminated paddy soils, even at low application rates, could be an effective approach to mitigate Cd accumulation into rice plants, to improve rice grain yields, and to thereby improve food security and protect public health.


Asunto(s)
Cadmio/metabolismo , Carbón Orgánico/química , Oryza/metabolismo , Contaminantes del Suelo/metabolismo , Contaminación Ambiental , Aguas del Alcantarillado/química , Suelo/química
14.
Huan Jing Ke Xue ; 37(9): 3413-3422, 2016 Sep 08.
Artículo en Chino | MEDLINE | ID: mdl-29964775

RESUMEN

Index of Biological Integrity (IBI) is a scientific tool used to evaluate health of aquatic ecosystems. IBI associates anthropogenic influences with biological activity in the water body, and is formulated using data developed from biosurveys. Compared with other biotic assemblage indicators of water quality, little attention has been paid to the application of microbial community in ecosystem health assessment for groundwater bodies so far. An approach based on microbiome index of biotic integrity was developed to assess groundwater ecosystem health in this study. The method based on Illumina high-throughput DNA sequencing was applied to achieve the information of microbial community. The key environmental factors were selected based on CCA analysis and the optimized values were calculated for defining the taxonomic genera sensitive and resistant to these factors. The resulting candidate biotic factors were used to construct microbiome index of biotic integrity (M-IBI) evaluating system. The results showed among the studied sample sites from groundwater of Baogang rare earth tailings, 33.3% of samples were at "Great" level, 16.7% at "Good" level, most of samples (41.7%) at "moderate" level and 8.3% at "Bad" level. The ecosystem healthy status of the sample sites near the tailings was affected by human disturbances, while the samples far away the tailings were at healthy level. The results of the groundwater ecosystem healthy assessment based on M-IBI system had a good match with the groundwater quality standard based on chemical properties. It indicated that M-IBI could be a potential index to evaluate the health of groundwater ecosystem.


Asunto(s)
Monitoreo del Ambiente , Agua Subterránea/microbiología , Microbiota , Microbiología del Agua , Calidad del Agua , China , Ecosistema , Minería , Contaminantes Químicos del Agua
15.
Environ Technol ; 36(24): 3148-58, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26075798

RESUMEN

The feasibility of converting food waste into nematocidal biofertilizer by nematophagous fungus Paecilomyces lilacinus (P. lilacinus) was investigated. The culture conditions of P. lilacinus were optimized through response surface methodology. Results showed that fermentation time, the amount of food waste, initial pH and temperature were most important factors for P. lilacinus production. The P. lilacinus production under optimized conditions was 10(9.6 ± 0.3) conidia mL⁻¹. After fermentation, the chemical oxygen demand concentration of food waste was efficiently decreased by 81.92%. Moreover, the property evaluation of the resultant food waste as biofertilizer indicates its high quality with reference to the standard released by the Chinese Ministry of Agriculture. The protease activity and nematocidal ability of P. lilacinus cultured by food waste were 10.8% and 27% higher than those by potato dextrose agar, respectively.


Asunto(s)
Fertilizantes/análisis , Hypocreales/fisiología , Paecilomyces/fisiología , Residuos Sólidos/análisis , Tylenchoidea/microbiología , Animales , Fermentación , Hypocreales/citología , Hypocreales/enzimología , Hypocreales/crecimiento & desarrollo , Paecilomyces/citología , Paecilomyces/enzimología , Paecilomyces/crecimiento & desarrollo , Control Biológico de Vectores , Enfermedades de las Plantas/prevención & control
16.
J Microbiol Biotechnol ; 24(4): 534-44, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24448165

RESUMEN

The effects of microbial iron reduction and oxidation on the immobilization and mobilization of copper were investigated in a high concentration of sulfate with synthesized Fe(III) minerals and red earth soils rich in amorphous Fe (hydr)oxides. Batch microcosm experiments showed that red earth soil inoculated with subsurface sediments had a faster Fe(III) bioreduction rate than pure amorphous Fe(III) minerals and resulted in quicker immobilization of Cu in the aqueous fraction. Coinciding with the decrease of aqueous Cu, SO4(2-) in the inoculated red earth soil decreased acutely after incubation. The shift in the microbial community composite in the inoculated soil was analyzed through denaturing gradient gel electrophoresis. Results revealed the potential cooperative effect of microbial Fe(III) reduction and sulfate reduction on copper immobilization. After exposure to air for 144 h, more than 50% of the immobilized Cu was remobilized from the anaerobic matrices; aqueous sulfate increased significantly. Sequential extraction analysis demonstrated that the organic matter/sulfide-bound Cu increased by 52% after anaerobic incubation relative to the abiotic treatment but decreased by 32% after oxidation, indicating the generation and oxidation of Cu-sulfide coprecipitates in the inoculated red earth soil. These findings suggest that the immobilization of copper could be enhanced by mediating microbial Fe(III) reduction with sulfate reduction under anaerobic conditions. The findings have an important implication for bioremediation in Cucontaminated and Fe-rich soils, especially in acid-mine-drainage-affected sites.


Asunto(s)
Cobre/metabolismo , Hierro/metabolismo , Minerales/química , Microbiología del Suelo , Suelo/química , Biodegradación Ambiental , Biota , Electroforesis en Gel de Gradiente Desnaturalizante , Oxidación-Reducción
17.
J Environ Monit ; 14(12): 3111-7, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23092998

RESUMEN

Xiamen is one of China's most rapidly developing metropolises. The objectives of the present study were: (1) to establish the levels and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in soil across the Xiamen metropolis, (2) to evaluate the extent to which PAH concentrations were elevated in the high urbanization area (HUA) of the island and how these compared with those in the low urbanization area (LUA) of the mainland, and (3) to evaluate the PAH hazard based upon their Carcinogenic Potential (CP), defined as toxicity equivalence of ∑PAHs. Twenty two alternative relative carcinogenic potency schemes were used and compared. Results demonstrated PAH concentrations to be greatly elevated across the entire metropolis. Significantly, the most enriched compounds represented the greatest concern with respect to carcinogenicity. The CP of more than 25% of the industrial samples from the island surpassed the Canadian guidance threshold value (600 µg kg⁻¹) for an excess lifetime cancer risk (ELCR) of 1 in 10⁻6. While soil samples from the remaining land uses on the island were all below this threshold, PAH levels in soil were nonetheless elevated (enrichment factors of between 4.1 ± 1.9 and 16.3 ± 12.4 in the HUA, and between 1.3 ± 0.7 and 10.8 ± 4.4 in the LUA). Results relating to agricultural locations on the island indicated 75% of the samples in HUA and 28% of the samples in LUA to be above the USEPA guidance value for BaP (15 µg kg⁻¹). Given the exceptionally high population density on the island there is a need for further research to evaluate multiple pathway PAH exposure risks.


Asunto(s)
Carcinógenos/toxicidad , Hidrocarburos Policíclicos Aromáticos/toxicidad , Contaminantes del Suelo/toxicidad , Carcinógenos/análisis , China , Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Medición de Riesgo , Suelo/química , Contaminantes del Suelo/análisis , Urbanización
18.
Environ Monit Assess ; 149(1-4): 291-302, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18274872

RESUMEN

The short-term responses and mechanisms of antioxidants in moss Hypnum plumaeforme subjected to single or combined Pb and/or Ni stress has been revealed in this study, in order to clarify (1) the relationship between the stress intensity and antioxidant fluctuation, (2) the difference between single and combined stress, and (3) the possibility of biomonitoring by the application of antioxidant fluctuation under stress. The results showed that the stress induced dose dependent formation of reactive oxygen species (ROS) and subsequent lipid peroxidation. Total chlorophyll (Chl) content and superoxide dismutase (SOD) activity were initiated under lower stress but were inhibited under higher stress. Both single and combined stress decreased catalase (CAT) activity but increased peroxidase (POD) activity, indicating POD in the moss played an important role in resisting the oxidative stress induced by Pb and Ni. The accumulation of (.)O2(-) and H2O2 in H. plumaeforme was respectively related to the low activity of SOD and the decreased activity of CAT. The study indicated that Pb and Ni had synergistic effect in inducing the oxidative stress in moss H. plumaeforme, especially under the combination of high concentration of Ni (0.1, 1.0 mM) and Pb. POD and CAT activity, as well as H2O2 and MDA content, which increased or decreased regularly with a dose dependent under Pb and Ni stress, could be used as an effective indicator in moss biomonitoring, especially in the case of light pollution caused by heavy metals without the changes in the appearance of mosses.


Asunto(s)
Antioxidantes/química , Briófitas/química , Plomo/química , Níquel/química , Catalasa/metabolismo , China , Peróxido de Hidrógeno/química , Peroxidación de Lípido , Estrés Oxidativo , Peroxidasas/metabolismo , Especies Reactivas de Oxígeno/química , Superóxido Dismutasa/metabolismo
19.
Environ Monit Assess ; 156(1-4): 91-8, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18636336

RESUMEN

An investigation of the behavior and availability of heavy metals (HMs), i.e., Cu, Zn, Ni, Pb, Cr, and Cd, based on the analysis of correlation between HMs and physical and chemical properties of coastal soils developed from alluvial deposits in Shanghai, China, has been conducted, in order to reveal the effect of the soil formation and development and the unsuited human activities on the activities and mobility of HMs in agricultural soils. The results showed that (1) the soils still meet the needs of plant growth due to the moderate fertility with a soil texture of silty loam although the content of organic matters is lower, (2) total heavy metal content had a increase trend from the inland area to the coastal area, indicating the impact of alluvial deposits related to the soil formation on the distribution of HMs; (3) a significant positive correlation was found between HMs and some soil properties (i.e., clay content, cation exchange capacity, organic matters, total Phosphorous content, etc.), indicating that the regulation of these properties could give some great effect on the behavior and availability of HMs; (4) the positive correlation among Cu, Zn, Ni, and Cd, and between Pb and Cr is very significant, suggesting the most similar, if not the same, origins of HMs; These findings are helpful to the soil remediation, fertility adjustment, and plant cultivation.


Asunto(s)
Monitoreo del Ambiente , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Suelo/análisis , Cadmio/análisis , Cromo/análisis , Cobre/análisis , Plomo/análisis , Níquel/análisis , Zinc/análisis
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