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1.
J Environ Manage ; 366: 121688, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38971059

RESUMEN

Heavy metals (HMs) contained terrestrial ecosystems are often significantly display the antibiotic resistome in the pristine area due to increasing pressure from anthropogenic activity, is complex and emerging research interest. This study investigated that impact of chromium (Cr), nickel (Ni), cobalt (Co) concentrations in serpentine soil on the induction of antibiotic resistance genes and antimicrobial resistance within the native bacterial community as well as demonstrated their metabolic fingerprint. The full-length 16S-rRNA amplicon sequencing observed an increased abundance of Firmicutes, Actinobacteriota, and Acidobacteriota in serpentine soil. The microbial community in serpentine soil displayed varying preferences for different carbon sources, with some, such as carbohydrates and carboxylic acids, being consistently favored. Notably, 27 potential antibiotic resistance opportunistic bacterial genera have been identified in different serpentine soils. Among these, Lapillicoccus, Rubrobacter, Lacibacter, Chloroplast, Nitrospira, Rokubacteriales, Acinetobacter, Pseudomonas were significantly enriched in high and medium HMs concentrated serpentine soil samples. Functional profiling results illustrated that vancomycin resistance pathways were prevalent across all groups. Additionally, beta-lactamase, aminoglycoside, tetracycline, and vancomycin resistance involving specific bio-maker genes (ampC, penP, OXA, aacA, strB, hyg, aph, tet(A/B), otr(C), tet(M/O/Q), van(A/B/D), and vanJ) were the most abundant and enriched in the HMs-contaminated serpentine soil. Overall, this study highlighted that heavy-metal enriched serpentine soil is potential to support the proliferation of bacterial antibiotic resistance in native microbiome, and might able to spread antibiotic resistance to surrounding environment.

2.
J Environ Manage ; 352: 120015, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38194873

RESUMEN

The most common construction material used in Taiwan is concrete, potentially contaminated by geologic heavy metals (HMs). Younger children spend much time indoors, increasing HM exposure risks from household dust owing to their behaviors. We evaluated arsenic (As), cadmium (Cd), and lead (Pb) concentrations in fingernails among 280 preschoolers between 2017 and 2023. We also analyzed HM concentrations, including As, Cd, Pb, chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn), in 90 household dust and 50 road dust samples from a residential area where children lived between 2019 and 2021 to deepen the understanding of sources and health risks of exposure to HMs from household dust. The average As, Cd, and Pb concentrations in fingernails were 0.12 ± 0.06, 0.05 ± 0.05, and 0.95 ± 0.77 µg/g, respectively. Soil parent materials, indoor construction activities, vehicle emissions, and mixed indoor combustion were the pollution sources of HMs in household dust. Higher Cr and Pb levels in household dust may pose non-carcinogenic risks to preschoolers. Addressing indoor construction and soil parent materials sources is vital for children's health. The finding of the present survey can be used for indoor environmental management to reduce the risks of HM exposure and avoid potential adverse health effects for younger children.


Asunto(s)
Arsénico , Metales Pesados , Humanos , Preescolar , Cadmio , Monitoreo del Ambiente , Polvo/análisis , Plomo , Metales Pesados/análisis , Cromo , Medición de Riesgo , Suelo , China , Ciudades
3.
Environ Geochem Health ; 45(8): 6267-6286, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37289259

RESUMEN

Health risk assessments of exposure to mercury (Hg) from soils via ingestion and inhalation are indispensable for Taiwanese people living in the vicinity of Hg-contaminated sites. In this study, anthropogenic soils were collected from various polluted sources in Taiwan. In vitro oral and inhalation bioaccessible fractions of Hg were analyzed to avoid from overestimating the exposure risk. Discrepancies in oral and inhalation bioaccessible levels of Hg in soils were found using different in vitro assays with different pH levels and chemical compositions. The freshly contaminated soil (soil S7) polluted by chlor-alkali production activity sampled before the site was remediated had the highest total Hg concentration of 1346 mg/kg, with the highest oral bioaccessibility of 26.2% as analyzed by SW-846 Method 1340 and inhalation bioaccessibility of 30.5% as analyzed by modified Gamble's solution. The lesser extent of aging of Hg in soil S7 increased the Hg availability for humans, which was also found based on results of a sequential extraction procedure. Results of the hazard quotient showed that soil ingestion was the main pathway causing non-carcinogenic risks for children and adults. Children were also exposed to higher risks than were adults due to higher frequencies of hand-to-mouth behaviors and lower body weights. Furthermore, hazard index results adjusted for oral and inhalation bioaccessible Hg were lower than those obtained based on the total Hg content; however, an unacceptable value of the non-carcinogenic risk (> 1) for children living near soil S7 was still observed. This study suggests that children living near sites polluted for a short period of time may suffer potential renal effects regardless of the bioaccessibility. Our findings provide suggestions for decision makers on setting new strategies for managing risks of Hg-contaminated soils in Taiwan.


Asunto(s)
Mercurio , Contaminantes del Suelo , Adulto , Niño , Humanos , Mercurio/análisis , Taiwán , Contaminación Ambiental/análisis , Suelo/química , Medición de Riesgo , Riñón , Contaminantes del Suelo/análisis , Monitoreo del Ambiente
4.
Proc Natl Acad Sci U S A ; 116(14): 6891-6896, 2019 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-30877251

RESUMEN

Belowground organisms play critical roles in maintaining multiple ecosystem processes, including plant productivity, decomposition, and nutrient cycling. Despite their importance, however, we have a limited understanding of how and why belowground biodiversity (bacteria, fungi, protists, and invertebrates) may change as soils develop over centuries to millennia (pedogenesis). Moreover, it is unclear whether belowground biodiversity changes during pedogenesis are similar to the patterns observed for aboveground plant diversity. Here we evaluated the roles of resource availability, nutrient stoichiometry, and soil abiotic factors in driving belowground biodiversity across 16 soil chronosequences (from centuries to millennia) spanning a wide range of globally distributed ecosystem types. Changes in belowground biodiversity during pedogenesis followed two main patterns. In lower-productivity ecosystems (i.e., drier and colder), increases in belowground biodiversity tracked increases in plant cover. In more productive ecosystems (i.e., wetter and warmer), increased acidification during pedogenesis was associated with declines in belowground biodiversity. Changes in the diversity of bacteria, fungi, protists, and invertebrates with pedogenesis were strongly and positively correlated worldwide, highlighting that belowground biodiversity shares similar ecological drivers as soils and ecosystems develop. In general, temporal changes in aboveground plant diversity and belowground biodiversity were not correlated, challenging the common perception that belowground biodiversity should follow similar patterns to those of plant diversity during ecosystem development. Taken together, our findings provide evidence that ecological patterns in belowground biodiversity are predictable across major globally distributed ecosystem types and suggest that shifts in plant cover and soil acidification during ecosystem development are associated with changes in belowground biodiversity over centuries to millennia.


Asunto(s)
Biodiversidad , Modelos Biológicos
5.
Environ Res ; 197: 110994, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33713714

RESUMEN

Gallium (Ga), indium (In), and thallium (Tl) are emerging soil contaminants. Profile distribution of total content and available form as well as assessing the contamination degree of these elements in highly-weathered soils have not been studied. Consequently, the aim of this study was to determine the distribution of total (HF-digestion) and available (EDTA-extracted form) content of Ga, In, and Tl in eleven soil profiles collected from aged fluvial materials on the Quaternary terraces representing highly-weathered soils (Ultisols and Oxisols) in Taiwan as affected by soil properties. We also assessed the soils contamination degree using indices including enrichment factor (EF), geo-accumulation index (Igeo), and pollution loading index (PLI). The total element content varied from 9460 to 2340 µg kg-1 for Ga, 4.77-37.1 µg kg-1 for In, and from 55.7 to 206 µg kg-1 for Tl. The elements showed different profile distribution in the soils. Soil contamination degree was low in all profiles according to the Igeo and PLI values, but the contamination degree according to the EF was severe for Ga and minor or moderate for In in selected horizons of some profiles. The median content of EDTA-extracted Ga, In, and Tl accounted for 24.0, 8.70, and 5.1% of the total content, respectively. The available Ga and Tl can be predicted by a function of total element and clay using multivariate linear regression analysis. The available In was not able to be predicted by a significant fit of the regression with total In and the studied soil properties, and thus we require more assessment approaches of In availability for the soils in the future.


Asunto(s)
Galio , Contaminantes del Suelo , Monitoreo del Ambiente , Indio , Suelo , Contaminantes del Suelo/análisis , Taiwán , Talio/análisis
6.
Geomorphology (Amst) ; 288: 164-174, 2019 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-31293283

RESUMEN

In high-standing islands of the Western Pacific, typhoon-triggered landslides occasionally strip parts of the landscape of its vegetative cover and soil layer and export large amounts of biomass and soil organic carbon (OC) from land to the ocean. After such disturbances, new vegetation colonizes the landslide scars and OC starts to reaccumulate. In the subtropical mountains of Taiwan and in other parts of the world, bamboo (Bambusoideae) species may invade at a certain point in the succession of recovering landslide scars. Bamboo has a high potential for carbon sequestration because of its fast growth and dense rooting system. However, it is still largely unknown how these properties translate into soil OC re-accumulation rates after landslide disturbance. In this study, a chronosequence was established on four former landslide scars in the Central Mountain Range of Taiwan, ranging in age from 6 to 41 years post disturbance as determined by landslide mapping from remote sensing. The younger landslide scars were colonized by Miscanthus floridulus, while after approx. 15 to 20 years of succession, bamboo species (Phyllostachys) were dominating. Biomass and soil OC stocks were measured on the recovering landslide scars and compared to an undisturbed Cryptomeria japonica forest stand in the area. After initially slow re-vegetation, biomass carbon accumulated in Miscanthus stands with mean annual accretion rates of 2 ± 0.5 Mg C ha-1 yr-1. Biomass carbon continued to increase after bamboo invasion and reached ~40% of that in the reference forest site after 41 years of landslide recovery. Soil OC accumulation rates were ~2.0 Mg C ha-1 yr-1, 6 to 41 years post disturbance reaching ~64% of the level in the reference forest. Our results from this in-situ study suggest that recovering landslide scars are strong carbon sinks once an initial lag period of vegetation re-establishment is overcome.

7.
Environ Res ; 167: 240-247, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30059858

RESUMEN

Children may be exposed to environmental contaminants through incidental ingestion of soil resulting from hand-to-mouth contact. We measured soil adherence to the skin among 86 children from four kindergartens and one elementary school in Taiwan. Rinse water samples were collected from the hands, forearms, feet and lower legs of children after they had engaged in assigned activity groups (pre-activity, indirect contact and direct contact) from two different soil textures groups: sand and clay. We found that the soil loadings significantly differed between the different soil textures, body parts, activities, and clothing groups. Measured soil loadings for hands of pre-activity, indirect contact activity, and direct contact activity groups were 0.0069, 0.0307 and 0.153 mg cm-2, respectively, for the group playing on sand and 0.0061, 0.0116 and 0.0942 mg cm-2, respectively, for the group playing on clay. To facilitate the use of soil adherence data in exposure assessments, we provided a new and simple way to group activities based on the intensity of children's interactions with soil. The adherence data from this study can help enhance existing information based on soil-to-skin adherence factors used to assess children's exposure to soil contaminants during their play activities.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Piel/efectos de los fármacos , Contaminantes del Suelo/análisis , Niño , Humanos , Juego e Implementos de Juego , Taiwán
8.
J Environ Manage ; 186(Pt 2): 151-157, 2017 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26928072

RESUMEN

Serpentine soils may be natural sources of metal leaching and pollution. In this study, two contrasting serpentine soils from Taiwan and Austria were selected to evaluate the leaching potential of geogenic nickel (Ni). We applied selective sequential extractions and dissolution kinetics with three inorganic acids (HCl, HNO3, and H2SO4) and three organic acids (citric, acetic, and oxalic acids) in concentrations ranging from 0.05 to 10 mM to determine the release rate of Ni in the soils with respect to pH and acid types. Chlorite and serpentine were the major Ni-bearing minerals in the studied soils. Ni was dominantly bound in unavailable forms within these silicate minerals, but smaller fractions of acid-soluble, Fe-Mn oxide-bound, and organically bound Ni represented more labile Ni sources in the soils. The release rate of Ni from the soils increased with decreasing pH in all acids. However, the organic acids caused stronger pH dependences than the inorganic acids, likely because of ligand-promoted dissolution. The maximum total rate of Ni dissolution occurred with citric acid in both soils. The dissolution of Ni strongly increased when the ionic strength in the background solutions increased. We observed marked differences in dissolution rates and ligand effects between the Austrian and Taiwanese soils, which reflect differences in labile Ni pools, especially in the organically bound fraction. Our results demonstrate that labile fractions control the leaching potential of Ni in serpentine soils and that Ni associated with soil organic matter may contribute to leaching at moderately acidic pH levels.


Asunto(s)
Níquel/análisis , Contaminantes del Suelo/análisis , Austria , Disponibilidad Biológica , Fraccionamiento Químico , Cloruros/química , Concentración de Iones de Hidrógeno , Cinética , Níquel/farmacocinética , Concentración Osmolar , Suelo/química , Contaminantes del Suelo/farmacocinética , Taiwán
9.
Environ Geochem Health ; 39(6): 1325-1334, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28229256

RESUMEN

We investigated the extractability of nickel (Ni) in serpentine soils collected from rice paddy fields in eastern Taiwan to evaluate the bioavailability of Ni in the soils as well as for demonstrating the health risks of Ni in rice. Total Ni concentrations in the soils ranged were 70.2-2730 mg/kg (mean, 472 mg/kg), greatly exceeding the natural background content and soil control standard in Taiwan. Available Ni concentration only accounts for <10% of total soil Ni content; 0.1 N HCl-extractable Ni was the more suitable index for Ni bioavailability in the soil to rice than was diethylenetriaminepentaacetic acid (DTPA)-extractable Ni. The accumulation ability of rice roots was much higher than that of its shoots; however, compared with those reported previously, our brown and polished rice samples contained much higher Ni concentrations, within the ranges of 1.50-4.53 and 2.45-5.54 mg/kg, respectively. On the basis of the provisional tolerable Ni intake for adults recommended by the World Health Organization (WHO), daily consumption of this rice can result in an excessive Ni intake.


Asunto(s)
Productos Agrícolas/metabolismo , Níquel/metabolismo , Oryza/metabolismo , Contaminantes del Suelo/metabolismo , Contaminantes Químicos del Agua/metabolismo , Adulto , Disponibilidad Biológica , Quelantes/química , Exposición Dietética , Humanos , Níquel/química , Níquel/aislamiento & purificación , Ácido Pentético/química , Estructuras de las Plantas/metabolismo , Medición de Riesgo , Contaminantes del Suelo/química , Contaminantes del Suelo/aislamiento & purificación , Taiwán , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación
10.
Environ Geochem Health ; 39(2): 391-401, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27316918

RESUMEN

Crops grown in metal-rich serpentine soils are vulnerable to phytotoxicity. In this study, Gliricidia sepium (Jacq.) biomass and woody biochar were examined as amendments on heavy metal immobilization in a serpentine soil. Woody biochar was produced by slow pyrolysis of Gliricidia sepium (Jacq.) biomass at 300 and 500 °C. A pot experiment was conducted for 6 weeks with tomato (Lycopersicon esculentum L.) at biochar application rates of 0, 22, 55 and 110 t ha-1. The CaCl2 and sequential extractions were adopted to assess metal bioavailability and fractionation. Six weeks after germination, plants cultivated on the control could not survive, while all the plants were grown normally on the soils amended with biochars. The most effective treatment for metal immobilization was BC500-110 as indicated by the immobilization efficiencies for Ni, Mn and Cr that were 68, 92 and 42 %, respectively, compared to the control. Biochar produced at 500 °C and at high application rates immobilized heavy metals significantly. Improvements in plant growth in biochar-amended soil were related to decreasing in metal toxicity as a consequence of metal immobilization through strong sorption due to high surface area and functional groups.


Asunto(s)
Carbón Orgánico , Restauración y Remediación Ambiental/métodos , Metales Pesados/farmacocinética , Contaminantes del Suelo/farmacocinética , Disponibilidad Biológica , Biomasa , Cloruro de Calcio/química , Fraccionamiento Químico , Fabaceae , Germinación , Solanum lycopersicum/crecimiento & desarrollo , Metales Pesados/análisis , Metales Pesados/toxicidad , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Sri Lanka , Temperatura
11.
J Air Waste Manag Assoc ; 64(9): 1013-20, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25282998

RESUMEN

When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Mercurio/química , Metales Pesados/química , Contaminantes del Suelo/química , Fraccionamiento Químico , Calor
12.
ScientificWorldJournal ; 2014: 309396, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25295297

RESUMEN

This study compared the extractability of Cd, Cu, Ni, Pb, and Zn by 8 extraction protocols for 22 representative rural soils in Taiwan and correlated the extractable amounts of the metals with their uptake by Chinese cabbage for developing an empirical model to predict metal phytoavailability based on soil properties. Chemical agents in these protocols included dilute acids, neutral salts, and chelating agents, in addition to water and the Rhizon soil solution sampler. The highest concentrations of extractable metals were observed in the HCl extraction and the lowest in the Rhizon sampling method. The linear correlation coefficients between extractable metals in soil pools and metals in shoots were higher than those in roots. Correlations between extractable metal concentrations and soil properties were variable; soil pH, clay content, total metal content, and extractable metal concentration were considered together to simulate their combined effects on crop uptake by an empirical model. This combination improved the correlations to different extents for different extraction methods, particularly for Pb, for which the extractable amounts with any extraction protocol did not correlate with crop uptake by simple correlation analysis.


Asunto(s)
Brassica/química , Metales Pesados/análisis , Población Rural , Contaminantes del Suelo/análisis , Suelo/química , Brassica/metabolismo , Metales Pesados/metabolismo , Contaminantes del Suelo/metabolismo , Taiwán
13.
ScientificWorldJournal ; 2014: 602197, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25548787

RESUMEN

Food demand and soil sustainability have become urgent issues recently because of the global climate changes. This study aims to evaluate the application of a biochar produced by rice hull, on changes of physiochemical characteristics and erosion potential of a degraded slopeland soil. Rice hull biochar pyrolized at 400°C was incorporated into the soil at rates of 2.5%, 5%, and 10% (w/w) and was incubated for 168 d in this study. The results indicated that biochar application reduced the Bd by 12% to 25% and the PR by 57% to 92% after incubation, compared with the control. Besides, porosity and aggregate size increased by 16% to 22% and by 0.59 to 0.94 mm, respectively. The results presented that available water contents significantly increased in the amended soils by 18% to 89% because of the obvious increase of micropores. The water conductivity of the biochar-amended soils was only found in 10% biochar treatment, which might result from significant increase of macropores and reduction of soil strength (Bd and PR). During a simulated rainfall event, soil loss contents significantly decreased by 35% to 90% in the biochar-amended soils. In conclusion, biochar application could availably raise soil quality and physical properties for tilth increasing in the degraded mudstone soil.


Asunto(s)
Carbón Orgánico/química , Fenómenos Químicos , Conservación de los Recursos Naturales , Sedimentos Geológicos/química , Suelo/química , Carbono/análisis , Geografía , Oryza/química , Oryza/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Taiwán , Residuos , Agua/química
14.
Water Environ Res ; 86(4): 331-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24851329

RESUMEN

The fate of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) in the water column, sediment, and macrophytic plants as well as a total phosphorus eutrophication model were evaluated by a field monitoring program in the LungLuanTan wetland-reservoir system in Taiwan. Zinc and Cd were found to have the highest and lowest partition coefficients, respectively. The levels of heavy metals in the sediment of the wetland were highest in the dry season. In fresh plant tissues and sediment, Cd had the highest bioconcentration factor during the study period. Furthermore, the results obtained using the total phosphorus model with time-variable volumes for reservoir eutrophication and observed values were in reasonable agreement. Based on the modeling results, appropriate watershed management strategies are proposed to restore the wetland-reservoir water quality.


Asunto(s)
Monitoreo del Ambiente/métodos , Eutrofización , Sedimentos Geológicos/análisis , Metales Pesados/metabolismo , Fósforo/metabolismo , Plantas/metabolismo , Contaminantes Químicos del Agua/metabolismo , Técnicas de Apoyo para la Decisión , Eichhornia/metabolismo , Lagos , Metales Pesados/análisis , Modelos Químicos , Estaciones del Año , Taiwán , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Humedales
15.
J Environ Manage ; 117: 58-64, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-23353878

RESUMEN

A greenhouse experiment was used to test the applicability of [S,S]-Ethylenediaminedisuccinic acid (EDDS) and nitrilotriacetic acid (NTA) at rates of 2.5 mmol kg(-1) and 5.0 mmol kg(-1), respectively, to increase the uptake of Cd by water spinach (Ipomoea aquatic Forsk) in soils with 2.5-30 mg Cd kg(-1). The addition of EDDS and NTA significantly increased water soluble Cd in soils. However, the Cd concentration in the root and shoot was higher in the NTA treatment than in the EDDS treatment. No instance of Cd hyperaccumulation was observed; however, the 5.0 mmol kg(-1) NTA treatment for soil with 30 mg Cd kg(-1) caused the Cd concentration to increase to 86 mg kg(-1), which is close to the critical concentration (100 mg kg(-1)) of a hyperaccumulator. The total Cd uptake in the treatments of EDDS and NTA for soils with 2.5, 5.0, and 10 mg Cd kg(-1) was acceptable, and was higher than the control. The level of 5.0 mmol kg(-1) EDDS was excessively high for enhanced phytoextraction in soils with 20 and 30 mg Cd kg(-1). Water spinach for Cd phytoextraction is a viable alternative to using herbaceous hyperaccumulators.


Asunto(s)
Cadmio/química , Etilenodiaminas/química , Ipomoea/metabolismo , Ácido Nitrilotriacético/química , Contaminantes del Suelo/química , Succinatos/química , Biodegradación Ambiental , Biomasa , Cadmio/metabolismo , Ipomoea/crecimiento & desarrollo , Contaminantes del Suelo/metabolismo
16.
Artículo en Inglés | MEDLINE | ID: mdl-23947715

RESUMEN

In situ immobilization of heavy metals using reactive or stabilizing materials is a promising solution for soil remediation. Therefore, four agronomic and industrial by-products [wood biochar (WB), crushed oyster shell (OS), blast furnace slag (BFS), and fluidized-bed crystallized calcium (FBCC)] and CaCO3 were added to acidic soil (Cd = 8.71 mg kg(-1)) at the rates of 1%, 2%, and 4% and incubated for 90 d. Chinese cabbage (Brassica chinensis L.) was then planted in the soil to test the Cd uptake. The elevation in soil pH caused by adding the by-products produced a negative charge on the soil surface, which enhanced Cd adsorption. Consequently, the diethylenetriamine pentaacetic acid (DTPA)-extractable Cd content decreased significantly (P < 0.05) in the incubated soil. These results from the sequential extraction procedure indicated that Cd converted from the exchangeable fraction to the carbonate or Fe-Mn oxide fraction. The long-term effectiveness of Cd immobilization caused by applying the 4 by-products was much greater than that caused by applying CaCO3. Plant shoot biomass clearly increased because of the by-product soil amendment. Cd concentration in the shoots was < 10.0 mg kg(-1) following by-product application, as compared to 24 mg kg(-1) for plants growing in unamended soil.


Asunto(s)
Brassica/metabolismo , Cadmio/metabolismo , Restauración y Remediación Ambiental/métodos , Contaminantes del Suelo/metabolismo , Suelo/química , Adsorción , Agricultura , Animales , Biodegradación Ambiental , Residuos Industriales/análisis , Taiwán
17.
Sci Total Environ ; 893: 164895, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37321509

RESUMEN

Tea (Camellia sinensis) is a widespread beverage plant that prefers aluminum-enriched acidic soils. However, rare earth elements (REEs) might be highly phyto-available in these soils. With the increasing demands for REEs in high-technology industries, understanding the dynamics of REEs in the environment is essential. Thus, this study identified the total concentration of REEs in the root-zone soils and corresponding tea buds (n = 35) collected from tea gardens in Taiwan. Additionally, the labile REEs in the soils were extracted with 1 M KCl, 0.1 M HCl, and 0.05 M ethylenediaminetetraacetic acid (EDTA) to elucidate the fractionation tendency of REEs in the soil-plant system and the relationships between REEs and Al in the tea buds. The concentration of light REEs (LREEs) was higher than those of medium REEs (MREEs) and heavy REEs (HREEs) in all soil and tea bud samples. According to the upper continental crust (UCC) normalization, MREEs and HREEs were more abundant than LREEs in the tea buds. Furthermore, REEs remarkably increased with increasing Al in the tea buds, whereas the linear correlations between Al and MREEs and HREEs were stronger than between LREEs. Compared with LREEs, the extractabilities of MREEs and HREEs by all single extractants in the soils were higher, coinciding with their higher UCC-normalization-based enrichments in the tea buds. Moreover, the 0.1 M HCl- and 0.05 M EDTA-extractable REEs were affected by soil properties and significantly correlated with the total REEs in the tea buds. The concentration of REEs in the tea buds was successfully predicted by empirical equations of extractable REEs with 0.1 M HCl and 0.05 M EDTA, as well as general soil properties including pH, organic carbon, dithionite-citrate-bicarbonate-extractable iron, aluminum, and phosphorus. However, this prediction should be further verified using many soil and tea types in the future.


Asunto(s)
Metales de Tierras Raras , Contaminantes del Suelo , Suelo , Disponibilidad Biológica , Taiwán , Ácido Edético , Aluminio , Metales de Tierras Raras/análisis , Ácidos , Contaminantes del Suelo/análisis ,
18.
Sci Total Environ ; 850: 158087, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-35981572

RESUMEN

The release dynamics and mobilization of geogenic Ni, Co, and Cr in serpentine paddy soils under fluctuating redox conditions have not yet been well studied. Here we investigated the release dynamics of Cr, Co, and Ni and controlling factors (e.g., Fe, Mn, Mg, Cl-, PO43-, SO42-, and dissolved organic carbon (DOC)) in a geogenic-contaminated serpentine soil under wide range of redox potential (EH) changes. The effects of re-oxidation process have been also investigated. The soil was incubated for 28 days and EH was controlled from oxidation (+200 mV) to reduction (-200 mV) and re-oxidation (+240 mV) using a microcosm setup in duplicates. The slurry pH increased, along with decreasing EH. The average concentration of dissolved Co (17.1-23.6 µg L-1) decreased under low EH/high pH and vice versa. The average concentration of dissolved Cr decreased sharply from 624 µg L-1 to 54.4 µg L-1 with decreasing EH from +200 mV to 0 mV and the associated increase of pH from 7.8 to 8.5; then, it was constant around 24.5 µg L-1. Concentration of dissolved Ni was lower (73.5-84.6 µg L-1) under high EH at the first week of incubation; then, increased to 108.5 µg L-1 under low EH (-200 mV); thereafter, increased more at the end up to 124.5 µg L-1 at high EH (+240 mV), because of the pH decrease. A factor analysis identified that Cr and Co formed one group with Mn and Mg, while Ni was clustered together with Cl-, DOC, and SO42-. This indicates that the redox-induced release dynamic of Cr and Co was mainly governed by MnMg compounds, while the release of Ni was mainly affected by the aliphatic compounds of DOC and the redox chemistry of chlorides and sulfur in this soil. The re-oxidation increased the mobilization of Ni and Co and did not affect the release of Cr. These findings suggest that the redox-induced mobilization of geogenic Co, Ni, and Cr from soil to water in serpentine rice soils should be considered due to the high solubility and thus the associated bioavailability and potential environmental and human health risks, when such metal-enriched soils will be used for agricultural flood-dry cycle systems.


Asunto(s)
Contaminantes del Suelo , Humanos , Oxidación-Reducción , Suelo/química , Contaminantes del Suelo/análisis , Azufre , Agua/análisis
19.
J Environ Qual ; 51(5): 1083-1095, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35833602

RESUMEN

Air pollutants pose risks to human health, especially in densely populated cities. We compared the interception of suspended particles and metal elements by four sidewalk tree species with different leaf surface wettability (based on contact angle), leaf area, and phenology in Taipei, Taiwan. Suspended particles were enriched 2.0-2.5 times in throughfall relative to rainfall due to wash-off of suspended particles deposited on leaf surfaces during rainless periods. The enrichment in throughfall was greater in tree species with larger leaf areas. Despite greater concentrations of suspended particles in rainfall during the low-leaf-area period, enrichment was greater in the high-leaf-area period, indicating that leaf area was a key factor affecting canopy interception of pollutants. Throughfall enrichment of suspended particles positively correlated with water quantity, indicating that air pollutants intercepted by tree canopies were not fully washed off by rainfall. Annually, ∼830 g of suspended particles were intercepted and washed off from one tree canopy, with a crown area of 42 m2 . Scaling up, a rough estimate of 72.7 Mg of suspended particles were intercepted annually by the 90,000 sidewalk trees in Taipei City. Copper, chromium, and aluminum were enriched in throughfall compared with rainfall. However, lead was depleted in throughfall, indicating greater interception than wash-off. Based on our results, leaf area and length of foliated period are key characteristics affecting canopy interception of particulate matter and associated metal elements, whereas leaf surface wettability is of secondary importance.


Asunto(s)
Contaminantes Atmosféricos , Árboles , Contaminantes Atmosféricos/análisis , Aluminio , Cromo , Ciudades , Cobre , Humanos , Material Particulado/análisis , Hojas de la Planta/química , Taiwán , Agua
20.
Front Microbiol ; 13: 959080, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36118214

RESUMEN

Plant growth-promoting rhizobacteria (PGPR) are microorganisms that promote plant health and play a critical role in sustainable agriculture. As a PGPR, Rhodopseudomonas palustris strain PS3, when applied as a microbial inoculant, exhibited beneficial effects on a variety of crops. In this study, we investigated the effects of PS3 on tomato growth, soil properties, and soil microbiota composition in an organic field. The results demonstrated that PS3 inoculation significantly improved the yield of marketable tomato fruit (37%) and the postharvest quality (e.g., sweetness, taste, vitamin C, total phenolic compounds, and lycopene). Additionally, soil nutrient availability (35-56%) and enzymatic activities (13-62%) also increased. We detected that approximately 107 CFU/g soil of R. palustris survived in the PS3-treated soil after harvest. Furthermore, several bacterial genera known to be associated with nutrient cycling (e.g., Dyella, Novosphingobium, Luteimonas, Haliangium, and Thermomonas) had higher relative abundances (log2 fold change >2.0). To validate the results of the field experiment, we further conducted pot experiments with field-collected soil using two different tomato cultivars and obtained consistent results. Notably, the relative abundance of putative PGPRs in the genus Haliangium increased with PS3 inoculation in both cultivars (1.5 and 34.2%, respectively), suggesting that this genus may have synergistic interactions with PS3. Taken together, we further demonstrated the value of PS3 in sustainable agriculture and provided novel knowledge regarding the effects of this PGPR on soil microbiota composition.

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