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1.
Water Res ; 171: 115395, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31918386

RESUMEN

Stormwater harvesting (SWH) provides multiple benefits to urban water management. Other than providing water for human use, it also reduces the volume of polluted stormwater discharge to the environment. There are currently no methods available to quantify the additional environmental benefits, which could encourage greater uptake of the practice. This paper investigates a number of factors (climate and catchment characteristics, pollutant reduction targets, etc.) that could impact upon the benefits of SWH for pollution reduction through sensitivity analyses. A method was developed and tested for quantification of the pollution mitigation benefits by SWH under different scenarios. A novel indicator, Impervious Area Offset (IAO), was proposed to reflect the additional impervious area that can be left untreated to achieve the equivalent pollution load reduction targets due to the introduction of SWH. Results indicate significant correlations (p < 0.01) between IAO values and extraction rate (proportion of total annual runoff removed due to the harvesting system and water use substitution), system type, and pollutant reduction targets. The proposed linear empirical relationships between IAO values and extraction rate for different types of system configurations and pollution reduction targets were well represented by observed linear regression (average R2 = 0.98 for all tested scenarios). Empirical relationships were validated successfully against different scenarios, with differences between predicted IAO and baseline IAO values being only ±4.5% for the majority of the validation scenarios. Using this simple and reliable method to rapidly quantify SWH benefits can further add to the growing business case of adopting SWH practices.


Asunto(s)
Movimientos del Agua , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Contaminación Ambiental , Lluvia , Agua
2.
Bioresour Technol ; 301: 122804, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31982297

RESUMEN

Biodiesel is one of the best promising candidates in response to the energy crisis, since it has the capability to minimize most of the environmental problems. Microalgae, as the feedstock of third-generation biodiesel, are considered as one of the most sustainable resources. However, microalgae production for biodiesel feedstock on a large scale is still limited, because of the influences of lipid contents, biomass productivities, lipid extraction technologies, the water used in microalgae cultivation and processes of biomass harvesting. This paper firstly reviews the recent advances in microalgae cultivation and growth processes. Subsequently, current microalgae harvesting technologies are summarized and flocculation mechanisms are analyzed, while the characteristics that the ideal harvesting methods should have are summarized. This review also summarizes the environmental pollution control performances and the key challenges in future. The key suggestions and conclusions in the paper can offer a promising roadmap for the cost-effective biodiesel production.


Asunto(s)
Microalgas , Biocombustibles , Biomasa , Contaminación Ambiental , Floculación
3.
Environ Technol ; 41(5): 556-565, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30052142

RESUMEN

Dust emission from the bauxite residue drying areas is of great concern for its serious environmental and health impacts. The application of polymer stabilizers is a promising approach to mitigate such issues. However, limited studies have been done on their application on red sand and the investigation of the effect of polymers on penetration resistance, which is a key mechanical property closely related to the dust control performance. Stabilizers reduce the dust emission potential by forming a crust on the surface of treated material. This paper investigates the relationship of crust properties and dust control performance by applying synthetic (polyacrylamide) and natural (xanthan gum and guar gum) polymers. Results illustrated that the water retention property of treated sand is greatly improved after the application of stabilizers. The thickness of the formed crust decreases with stabilizer concentration. Results from wind tunnel simulation illustrated that the polymer stabilizer offers nearly 8 times longer protective period than water when used as a stabilizing agent. Cationic PAM performed the best, and cationic guar gum outperformed anionic xanthan gum. The penetration resistance is proved in this study to be a primary index for predicting dust control performance of polymer stabilizers.


Asunto(s)
Óxido de Aluminio , Polvo , Contaminación Ambiental , Polímeros , Agua
4.
Environ Technol ; 41(3): 277-286, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29969373

RESUMEN

Jet fuel may be released in the environment either by in-flight fuel jettisoning (fuel dumping) or accidentally from spills and leaks, and eventually can reach subsurface formations where it can remain as long-term source of pollution. Remediation of aquifers contaminated by jet fuels is not a trivial task. This experimental study examined the effectiveness of a water-soluble, DNA-protein-based biodegradable non-living catalyst, with commercial name GreenZyme® for the remediation of water saturated porous media polluted with jet fuel (JP-5). Also for comparison purposes, the commercial surfactant sodium dodecyl sulfate (SDS) was used. Bench scale experiments were conducted in a glass column packed with glass beads. The migration of JP-5 in the glass column under various conditions, with and without the presence of GreenZyme® was monitored by a well-established photographic method. Digital photographs of the packed column were captured under fluorescent lighting. The fluorescent intensity of JP-5 dyed with Red Oil O within the column was analyzed using the Matlab Image Processing Toolbox. The colour intensities were converted to concentrations via appropriate calibration curves. The experimental results suggested that GreenZyme® was an efficient biosurfactant capable of enhancing significantly the migration of JP-5 in the glass column, which performed considerably better that SDS under the experimental conditions of this study.


Asunto(s)
Contaminación Ambiental , Hidrocarburos , Porosidad , Dodecil Sulfato de Sodio , Tensoactivos , Agua
6.
Waste Manag ; 102: 710-721, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31805444

RESUMEN

In order to reduce emissions of CO2 from cement production and avoid severe environmental pollution from the deposition of mine waste, this study investigated the possibility of utilizing mine tailings as supplementary cementitious materials (SCM) for partially replacement of cement in concrete. This study provides a characterization study of mine tailings to evaluate their potential for contributing chemically or physically as SCM. 13 mine tailing samples were characterized in regards to chemical composition (XRF, Loss on Ignition, CaCO3 and pH), mineralogical content (XRD) and physical characteristics (Grain size distribution, Specific Surface Area, SEM-analysis). The characterization study showed five mine tailings to possess potential chemical contribution as SCM based on their chemical composition (SiO2, Al2O3, Fe2O3 and CaO) and amorphous content. Three mine tailings showed potential physical contribution as SCM based on grain size and grain morphology. The remainder mine tailing characteristics suggest that their potential as SCM may be improved by pretreatment such as milling and/or thermal treatment.


Asunto(s)
Contaminación Ambiental , Dióxido de Silicio , Materiales de Construcción
7.
Bioresour Technol ; 298: 122468, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31839494

RESUMEN

The difficulty of separating the powdered biochar from the environmental medium may lead to secondary pollution and hinder the large-scale application of biochar as an adsorbent. An effective strategy to solve this bottleneck is to introduce transition metals and their oxides into the biochar matrix, creating easily separable magnetic biochar. Magnetic biochar is also effective for the removal of pollutants from aqueous solution. This review comprises a systematic analysis of 109 papers published in recent years (From 2011 to June 2019), and summarises the synthetic methods and raw materials required for magnetic biochar preparation. The basic physicochemical properties of magnetic biochar are expounded, together with findings from relevant studies, and the application of magnetic biochar as an adsorbent or catalyst in environmental remediation are summarised. Other applications of magnetic biochar are also discussed. Finally, some constructive suggestions are given for the future direction of magnetic biochar research.


Asunto(s)
Restauración y Remediación Ambiental , Contaminantes del Suelo , Adsorción , Carbón Orgánico , Contaminación Ambiental , Fenómenos Magnéticos , Suelo
8.
Chemosphere ; 239: 124724, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31505447

RESUMEN

Combination of sulfuric acid modified bagasse activated carbon-bone biochar beads and Acinetobacter indicus screened from petroleum contaminated soil was the best condition for gaseous methyl tert-butyl ether (MTBE) removal. It was found that H2SO4 modified bagasse AC in powder form had higher adsorption capacity (989.33 mg g-1) than that in bead form (1.94 mg g-1). In addition, bone biochar in powder form (3.51 mg g-1) also had higher adsorption capacity than that in bead form (1.63 mg g-1). This was the fact that material beads contained high moisture content that inhibited the penetration of gaseous MTBE into the material. And a mixed material of H2SO4 modified bagasse AC-bone biochar beads had the highest adsorption capacity (2.22 mg g-1) compared to individual H2SO4 modified bagasse AC beads (1.94 mg g-1) and bone biochar beads (1.63 mg g-1) due to a mixed material had more rough surface and high surface area on its material. So, gaseous MTBE can penetrate through this material more easily. Although the maximum adsorption capacity of H2SO4 modified bagasse AC in powder form was the highest but microorganism cannot sustain and survive in this form for a long time. Therefore, the material beads were more suitable for microorganism to grow and degrade gaseous MTBE. Microorganism can degrade MTBE and caused no secondary wastes. Moreover, A. indicus was a novel strain for MTBE removal that has not been previously reported. Therefore, a combination of A. indicus-mixed material beads was a good choice for MTBE removal in a biofilter system.


Asunto(s)
Acinetobacter/metabolismo , Celulosa/química , Carbón Orgánico/química , Éteres Metílicos/química , Acinetobacter/aislamiento & purificación , Adsorción , Biodegradación Ambiental , Células Inmovilizadas , Contaminación Ambiental , Gases , Éteres Metílicos/aislamiento & purificación , Éteres Metílicos/metabolismo , Petróleo , Microbiología del Suelo , Ácidos Sulfúricos/química , Administración de Residuos/métodos
9.
Chemosphere ; 239: 124809, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31527008

RESUMEN

Honey is a highly nutritious natural product widely produced and consumed by people in Shirak and Syunik regions of Armenia. Unlike Shirak, Syunik is under the impact of mining industry. Since the environmental pollution can adversely impact the safety of honey and entail a probable risk to human health, it is important to evaluate the presence of potentially toxic trace elements in honey samples from both regions and draw comparisons. This study assesses the dietary exposure to trace elements and persistent organic pollutants through the intake of honey for the first time among people in Shirak and Syunik regions. 24-hour dietary recall method was used to investigate the consumption of honey. The presence of seven trace elements (Pb, Cd, As, Hg, Cu, Zn, and Ni) and persistent organic pollutants (hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT) and its metabolites) were determined in honey samples using atomic absorption spectrometry and gas chromatography-mass spectrometry, respectively. In several samples, the concentrations of Cu were above the maximum allowable level. Non-carcinogenic risk values did not exceed the acceptable level, while carcinogenic risk values for Ni and As exceeded the risk level of 10-6 in both regions. Moreover, among the persistent organic pollutants, only the concentration of DDT in honey from Shirak was above the European Union maximum residue level.


Asunto(s)
Carcinógenos/análisis , DDT/análisis , Exposición Dietética/análisis , Miel/análisis , Medición de Riesgo/métodos , Oligoelementos/análisis , Armenia , Contaminantes Ambientales/análisis , Contaminación Ambiental/análisis , Miel/toxicidad , Humanos , Metales Pesados/análisis , Minería , Espectrofotometría
10.
Chemosphere ; 240: 124846, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31550594

RESUMEN

Cadmium (Cd) precipitation and dissolution in pore water is associated with dissolved organic carbon (DOC)-induced reduction-oxidation of sulfur (S) under waterlogging and is vital for controlling the bioavailability in paddy soil. A 120-day soil incubation experiment, including application of sulfur (S, 30 mg kg-1) and wheat straw (W, 1.0%) alone or in combination (W + S) into Cd-contaminated paddy soil under waterlogging, was conducted to investigate the dynamic of dissolved Cd and its relationship with DOC, S2-, Fe2+, pH, Eh and pe + pH in soil pore water. The results showed that the lowest dissolved Cd concentration was observed in the W + S-treated soil pore water among all treatments when the soil Eh remained at lower values during the period of 15-60 days of incubation, which could be attributed to CdS precipitation and/or co-precipitation of Cd absorbed by FeS2 because of the reduction in sulfur. The application of S resulted in a Cd rebound in the pore water irrespective of W addition when the Eh began to increase from its lowest values during the period of 45-75 days of incubation, and SOB genera were observed in the S added soil. This could be attributed to re-dissolution of the precipitated Cd in soils under the SOB-driven oxidation of sulfide such as CdS and FeS2. In conclusion, DOC-driven reduction-oxidation of sulfur controls Cd dissolution in the pore water of Cd-contaminated paddy soil under waterlogging conditions. Further studies are required to investigate the interaction of sulfur and SOM-induced DOC on Cd bioavailability in rice-planted paddy soils.


Asunto(s)
Cadmio/uso terapéutico , Contaminación Ambiental/efectos adversos , Contaminantes del Suelo/química , Azufre/uso terapéutico , Cadmio/farmacología , Azufre/farmacología , Agua
11.
Chemosphere ; 240: 124845, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31561162

RESUMEN

In the paper, hydrothermally (HT) treated, sulfuric acid (H2SO4), and hydrochloric acid (HCl) washed fly ashes (FA) were used to examine the applied effects with and without biochar (BC) on the bioavailability of heavy metals (HMs) and growth of maize (Zea mays L.) plants in coal-mining contaminated soil. Addition of BC in combination with these processed fly ashes (PFA) significantly increased the soil pH, EC, and soil organic carbon (SOC). Individual application of BC and PFA increased the available contents of Mg, Mn, and Fe, while the combination of BC and PFA significantly decreased the bioavailability of HMs in soil compared to control. The BC + HT-FA and BC + H2SO4-FA were most efficient treatments followed by BC + HCl-FA in promoting plant growth parameters (i.e., fresh and dry biomass, root and shoot lengths), reduction in the uptake of HMs and increase in the uptake of macronutrients. The results established that the combined application of BC and PFA synergistically increased HMs immobilization and maize biomass yields. The lowest transfer rate (TR), bioconcentration factor (BCF), and translocation factor (TF) for Cr, Co, Ni, Cu, Zn, Cd, and Pb were detected in BC + HT-FA, followed by BC + H2SO4-FA and BC + HCl-FA treatments after 60 days of maize crop harvesting. It could be suggested that using BC along with PFA as a soil stabilizer may be a promising source to immobilize HMs in a coal-mining contaminated soil.


Asunto(s)
Carbón Orgánico/química , Ceniza del Carbón/química , Minas de Carbón/métodos , Contaminación Ambiental/efectos adversos , Metales Pesados/química , Contaminantes del Suelo/química , Suelo/química , Zea mays/química , Disponibilidad Biológica
12.
Chemosphere ; 240: 124828, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31568944

RESUMEN

Biochar has been recommended as a multi-beneficial amendment for the in situ remediation of heavy metals contaminated soils due to its high recalcitrance, stability, specific surface area and retention capacity, which leads to a long-lasting influence on the immobilization of soil contaminants. The influence of biochar on the availability of heavy metals such as copper is not fully understood and may be related to a change in copper association with soils fractions. Therefore, a long-time laboratory incubation study was set up as a completely randomized design to test the effect of biochar from different sources (coconut husks-CHB, orange bagasse-OBB and sewage sludge-SSB) at two rates of application (30 and 60 t ha-1) on the distribution of copper in a copper-contaminated soil after 24 months incubation. Copper distribution was evaluated through a sequential extraction procedure that fractionated copper into five fractions: F1 (soluble and exchangeable), F2 (specifically bound), F3 (organic matter bound), F4 (Fe and Mn oxide bound) and F5 (residual). Copper availability, soil pH and organic matter were also evaluated. Corn seeds were germinated in the incubated biochar soil to investigate the effect of biochar on seed germination and plantlets characteristics. All biochars increased soil pH and the concentration of oxidizable organic matter, and reduced copper availability after the 24 months incubation. CHB caused a discrete influence on copper distribution among soil fractions. OBB30 increased F1 (54.5%), F3 (24.0%), F4 (32.2%) and F5 (64.1%), and reduced F2 (39.8%); OBB60 reduced F1 (61.8%), F2 (16.5%) and F3 (16.0%) and increased F4 (18.0%) and F5 (84.4%). SSB30 strongly reduced Cu concentration in F1 (96.2%), F2 (34.0%), and F3 (22.2%), and increased F4 (54.4%); SSB60 reduced F1 (57.5%) and F3 (59.4%). Considering the high stability of biochar, the association of copper to the organic fraction leads to a long-time reduction in copper availability in the contaminated soil, which can reduce the cost and increase the efficiency of the remediation process. SSB reduced seed germination but produced vigorous and well-developed plantlets. Therefore, with proper production procedure to reduce the volatile matter content, SSB may not interfere with seed germination and has the greatest potential to be used for the remediation of copper-contaminated sites.


Asunto(s)
Carbón Orgánico/química , Cobre/química , Contaminación Ambiental/efectos adversos , Semillas/química , Contaminantes del Suelo/química , Suelo/química , Zea mays/química , Germinación
13.
Sci Total Environ ; 702: 134455, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31733547

RESUMEN

Microplastics are ubiquitous environmental contaminants leading to inevitable human exposure. Even so, little is known about the effects of microplastics in human health. Thus, in this work we review the evidence for potential negative effects of microplastics in the human body, focusing on pathways of exposure and toxicity. Exposure may occur by ingestion, inhalation and dermal contact due to the presence of microplastics in products, foodstuff and air. In all biological systems, microplastic exposure may cause particle toxicity, with oxidative stress, inflammatory lesions and increased uptake or translocation. The inability of the immune system to remove synthetic particles may lead to chronic inflammation and increase risk of neoplasia. Furthermore, microplastics may release their constituents, adsorbed contaminants and pathogenic organisms. Nonetheless, knowledge on microplastic toxicity is still limited and largely influenced by exposure concentration, particle properties, adsorbed contaminants, tissues involved and individual susceptibility, requiring further research.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Contaminación Ambiental/estadística & datos numéricos , Humanos
14.
Sci Total Environ ; 702: 134725, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31734607

RESUMEN

The increase in artificial light at night (ALAN) is a global concern, while the pattern of ALAN pollution inside urban areas has not yet been fully explored. To fill this gap, we developed a novel method to map fine-scale ALAN pollution patterns in urban bird habitats using high spatial resolution ALAN satellite data. First, an ALAN pollution map was derived from JL1-3B satellite images. Then, the core habitat nodes (CHNs) representing the main habitats for urban birds to inhabit were identified from the land cover map, which was produced using Gaofen2 (GF2) data, and the high probability corridors (HPCs), indicating high connectivity paths, were derived from Circuitscape software. Finally, the ALAN patterns in the CHNs and HPCs were analysed, and the mismatch index was proposed to evaluate the trade-off between human activity ALAN demands and ALAN supply for the protection of urban birds. The results demonstrated that 115 woodland patches covering 4149.0 ha were selected as CHNs, and most of the CHNs were large urban parks or scenic spots located in the urban fringe. The 2923 modelled HPCs occupying 1179.2 ha were small remaining vegetation patches and vegetated corridors along the major transport arteries. The differences in the ALAN pollution patterns between CHNs and HPCs were mainly determined by the characteristics of the green space patches and the light source types. The polluted regions in the CHNs were clustered in a few regions that suffered from concentrated and intensive ALAN, while most of the CHNs remained unaffected. In contrast, the 727 HPCs were mainly polluted by street lighting was scattered and widely distributed, resulting a more varying influence to birds than that in the CHNs. Relating patterns of the ALAN to bird habitats and connectivity provides meaningful information for comprehensive planning to alleviate the disruptive effects of ALAN pollution.


Asunto(s)
Aves , Ecosistema , Monitoreo del Ambiente , Contaminación Ambiental , Luz , Animales , Ciudades
15.
Water Res ; 168: 115121, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31605833

RESUMEN

Plastic debris and marine microplastics are being discharged into the ocean at an alarming scale and have been observed throughout the marine environment. Here we report microplastic in sediments of the Challenger Deep, the deepest known region on the planet, abyssal plains and hadal trenches located in the Pacific Ocean (4900 m-10,890 m). Microplastic abundance reached 71.1 items per kg dry weight sediment. That high concentrations are found at such remote depths, knowing the very slow sinking speed of microplastics, suggests that supporting mechanisms must be at-play. We discuss cascading processes that transport microplastics on their journey from land and oceanic gyres through intermediate waters to the deepest corners of the ocean. We propose that hadal trenches will be the ultimate sink for a significant proportion of the microplastics disposed in the ocean. The build-up of microplastics in hadal trenches could have large consequences for fragile deep-sea ecosystems.


Asunto(s)
Plásticos , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente , Contaminación Ambiental , Océanos y Mares
16.
Chemosphere ; 239: 124707, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31479912

RESUMEN

Site soils with persistent cyanide compounds (primarily iron-cyanide complex) pose potential hazards to the environment and require remediation before redevelopment. This study evaluated the possibility of thermal treatment on remediation of cyanide-contaminated soils via batch heating experiments spanning a wide temperature range (200-500 °C). The change with operation variables of total cyanide and some reaction intermediates (e.g. CN-) was analyzed in order to elucidate the optimal variables that guarantee cyanide removal while generating no hazardous byproducts. Temperature, heating time and cyanide species have been found to be important parameters influencing removal/destruction of cyanide in soils. For soils bearing K3[Fe(CN)6] and K4[Fe(CN)6], a removal efficiency of >99.9% can be obtained with temperatures over 350 °C at 1 h, while for samples bearing Fe4[Fe(CN)6]3, a higher temperature (>450 °C) is needed to obtain an equivalent efficiency. During heating, the iron-cyanide complexes decomposed, releasing highly toxic free cyanides, which will subsequently be oxidized. However, a small percentage of free cyanide can always be detected as a result of incomplete oxidation, thus caution should be taken to minimize the accumulation of free cyanide during thermal treatment.


Asunto(s)
Cianuros/análisis , Restauración y Remediación Ambiental/métodos , Contaminantes del Suelo/análisis , Temperatura Ambiental , Cianuros/química , Contaminación Ambiental/prevención & control , Ferrocianuros/análisis , Ferrocianuros/química , Oxidación-Reducción , Contaminantes del Suelo/química
17.
Chemosphere ; 239: 124706, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31493754

RESUMEN

The remediation effect of organic acids in heavy metal contaminated soil was widely studied. However, the comprehensive evaluation of organic acids on micro-ecological environment in heavy metal contaminated soil was less known. Herein, this experiment was conducted to investigate the impact of malic acid, citric acid and oxalic acid on soil fertility, cadmium (Cd) speciation and ecotoxicity in contaminated soil. Especially, to evaluate the ecotoxicity of Cd, high-throughput sequencing was used to investigate the soil bacterial community structure and diversity after incubation with organic acids. The results showed that obvious changes in soil pH were not observed. Whereas, the contents of available phosphorus (Olsen-P) and alkali hydrolysable nitrogen (Alkeline-N) evidently increased with a significant difference. Furthermore, compared to control, the proportion of acetic acid-extractable Cd increased by 3.06-6.63%, 6.11-9.43% and 1.91-6.22% respectively in the groups amended with malic acid, citric acid and oxalic acid, which indicated that citric acid did better in improving the availability of Cd than malic acid and oxalic acid. In terms of biological properties, citric acid did best in bacteria count increase, enzyme activities and bacterial community structure improvement. Accordingly, these results provided a better understanding for the influence of organic acids on the micro-ecological environment in Cd contaminated soil, based on physicochemical and biological analysis.


Asunto(s)
Cadmio/toxicidad , Ácidos Carboxílicos/farmacología , Restauración y Remediación Ambiental/métodos , Microbiología del Suelo , Contaminantes del Suelo/química , Bacterias/efectos de los fármacos , Cadmio/análisis , Cadmio/química , Ácidos Carboxílicos/química , Ácido Cítrico/química , Ácido Cítrico/farmacología , Ecotoxicología , Contaminación Ambiental/análisis , Malatos/química , Malatos/farmacología , Ácido Oxálico/química , Ácido Oxálico/farmacología , Suelo/química , Contaminantes del Suelo/análisis
18.
Chemosphere ; 240: 124910, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31561159

RESUMEN

The micronucleus test has been applied for more than three decades in tadpoles, generating an early warning of environmental quality. In this study, we reviewed 48 articles on the micronucleus test in tadpoles, published between 1987 and 2018. The findings reveal that pesticides have been the main topic discussed in the induction of micronucleus and other nuclear abnormalities in anuran larvae to the detriment of the widespread use of compounds used in agriculture. In addition to pesticides, a number of other xenobiotic agents have been targeted for genotoxic damage, such as heavy metals, radiation and wastewater. An appeal is reported to environmental contaminants, which when released naturally into the environment or because of human activities may contaminate aquatic habitats, threatening populations of tadpoles that depend on these environments for their survival. Larvae can bioaccumulate these contaminants that cause progressive impacts, ranging from DNA damage to metamorphosis delays, as well as malformations. We found that Argentina is the main driving force for the application of this test in anuran larvae along with Brazil. Different erythrocyte malformations have been reported for the erythrocyte nuclear abnormalities test, binucleated cells, nuclear buds, notched, lobed, reniform, nuclear bebbled, anucleated, picnotic and apoptotic cells are the most cited. In summary, the presence of chemical or physical agents, along with other disturbances of the habitat, can have a significant impact on the life history of the species, contributing to the decline of anuran populations.


Asunto(s)
Anuros/genética , Ecotoxicología/tendencias , Eritrocitos/efectos de los fármacos , Larva/efectos de los fármacos , Larva/genética , Pruebas de Micronúcleos , Agricultura , Animales , Argentina , Brasil , Daño del ADN , Ecosistema , Monitoreo del Ambiente/métodos , Contaminación Ambiental , Eritrocitos/patología , Eritrocitos/fisiología , Metales Pesados/toxicidad , Metamorfosis Biológica/efectos de los fármacos , Publicaciones Seriadas , Contaminantes Químicos del Agua/toxicidad
19.
Chemosphere ; 239: 124496, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31505446

RESUMEN

Electrical resistance heating (ERH) is a promising thermal remediation method for treating volatile soil pollutants. However, the remediation of soil contaminated by polycyclic aromatic hydrocarbons (PAHs) based on lab-scale ERH devices must be extensively studied to determine the factors affecting the remediation. Therefore, this study used a lab-scale ERH equipment to investigate the influence factors of ERH, PAH removal efficiency, and changes in soil properties through the treatment process. The results suggested that moisture and salinity were basic factors affecting electric conductive capability; heating 15 g of soil to the target temperature required at least 4 g solution of 0.1% salt. Meanwhile, higher electric strength can ensure heating efficiency and maximum temperature. The removal efficiency of PAHs, which is highly related to boiling point, was significantly affected by its benzene rings and bond structure; during 90 min ERH treatment, more than 40% of the pollutants were removed synchronously with the evaporation of water. Hence, co-boiling with water was confirmed to be the primary mechanism of ERH. The influence of the treatment on soil properties (organic matter, particle size, fertility, enzymatic activity) was limited, suggesting that soil functionality can be retained by ERH.


Asunto(s)
Contaminación Ambiental/análisis , Restauración y Remediación Ambiental/métodos , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes del Suelo/análisis , Suelo/química , Impedancia Eléctrica , Calefacción , Calor , Temperatura de Transición
20.
Sci Total Environ ; 701: 134945, 2020 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-31734483

RESUMEN

The extensive use of nitrogen (N) fertilizers implicates a paradox: while fertilizers ensure the supply of a large amount of food, they cause negative environmental externalities, including reduced biodiversity, and eutrophic streams and lakes. Moreover, such fertilizers may also result in a major public health hazard: increased antibiotic resistance. This article discusses the critical implications of perturbations in N cycle caused by excessive use of fertilizers and resulting policy implications as they relate to ecosystem services. While there are solutions such as cover crops, these solutions are expensive and inconvenient for farmers. We advocate the use of biological fixation (BF) for staple crops-microbiome mediated natural supply of fixed N. This would involve engineering a microbiome that can be grown cheaply and at industrial scale. Fertilizers resulting from such innovation are termed as "biofertilizers" in this article. Following a qualitative cost-benefit analysis broken down by key stakeholders and a quick exploration of policy frameworks as they relate to the advancement of biofertilizers, we propose a practical pathway of where and how research investments should be directed to make such a solution feasible. We make five policy recommendations for decision-makers to facilitate a successful trajectory for this solution: (1) Future agricultural science should seek to understand how BF might be employed as a practical and efficient strategy. This effort would require that industry and the government partner to establish a pre-competitive research laboratory equipped with the latest state-of-the-art technologies that conduct metagenomic experiments to reveal signature microbiomes and form novel symbiotic connections. (2) To have a smooth ride in the market, ag-bio companies should: (i) create awareness among farmers; (ii) impart skills to farmers in testing and using biofertilizers, and (iii) conduct extensive field tests and more research in studying the scalability potential of such fertilizers. (3)The United States Department of Agriculture (USDA) and state governments should provide research and development (R&D) tax credits to biotech companies specifically geared towards R&D investments aimed at increasing the viability of BF and microbiome engineering. (4) To control agricultural pollution in the biosphere, federal governments should consider passing a Clean Agriculture Act (CAA), including a specific clause that regulate the use of chemical fertilizers. (5) Governments and the UN Food and Agriculture Organization (FAO) should coordinate Biological Advanced Research in Agriculture (BARA)-a global agricultural innovation initiative for investments and research in biological fixation and ethical, legal, and social implications of such innovation. While biological fixation will be central in BARA, we envision it to conduct research around other agricultural innovations as well, such as increasing photosynthetic efficiency.


Asunto(s)
Contaminación del Aire/análisis , Productos Agrícolas , Política Ambiental , Nitrógeno/análisis , Agricultura , Contaminación del Aire/legislación & jurisprudencia , Contaminación del Aire/estadística & datos numéricos , Biodiversidad , Conservación de los Recursos Naturales , Producción de Cultivos , Ecosistema , Contaminación Ambiental , Fertilizantes
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