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Farm and product carbon footprints of China’s fruit production—life cycle inventory of representative orchards of five major fruits Texto completo
2016
Yan, Ming | Cheng, Kun | Yue, Qian | Yan, Yu | Rees, R. M. (Robert M.) | Pan, Genxing
Understanding the environmental impacts of fruit production will provide fundamental information for policy making of fruit consumption and marketing. This study aims to characterize the carbon footprints of China’s fruit production and to figure out the key greenhouse gas emissions to cut with improved orchard management. Yearly input data of materials and energy in a full life cycle from material production to fruit harvest were obtained via field visits to orchards of five typical fruit types from selected areas of China. Carbon footprint (CF) was assessed with quantifying the greenhouse gas emissions associated with the individual inputs. Farm and product CFs were respectively predicted in terms of land use and of fresh fruit yield. Additionally, product CFs scaled by fruit nutrition value (vitamin C (Vc) content) and by the economic benefit from fruit production were also evaluated. The estimated farm CF ranged from 2.9 to 12.8 t CO₂-eq ha⁻¹ across the surveyed orchards, whereas the product CF ranged from 0.07 to 0.7 kg CO₂-eq kg⁻¹ fruit. While the mean product CFs of orange and pear were significantly lower than those of apple, banana, and peach, the nutrition-scaled CF of orange (0.5 kg CO₂-eq g⁻¹ Vc on average) was significantly lower than others (3.0–5.9 kg CO₂-eq g⁻¹ Vc). The income-scaled CF of orange and pear (1.20 and 1.01 kg CO₂-eq USD⁻¹, respectively) was higher than apple, banana, and peach (0.87~0.39 kg CO₂-eq USD⁻¹). Among the inputs, synthetic nitrogen fertilizer contributed by over 50 % to the total greenhouse gas (GHG) emissions, varying among the fruit types. There were some tradeoffs in product CFs between fruit nutrition value and fruit growers’ income. Low carbon production and consumption policy and marketing mechanism should be developed to cut down carbon emissions from fruit production sector, with balancing the nutrition value, producer’s income, and climate change mitigation.
Mostrar más [+] Menos [-]Vertical profile, source apportionment, and toxicity of PAHs in sediment cores of a wharf near the coal-based steel refining industrial zone in Kaohsiung, Taiwan Texto completo
2016
Chen, Chih-Feng | Chen, Chiu-Wen | Ju, Yun-Ru | Dong, Cheng-Di
Three sediment cores were collected from a wharf near a coal-based steel refining industrial zone in Kaohsiung, Taiwan. Analyses for 16 polycyclic aromatic hydrocarbons (PAHs) of the US Environmental Protection Agency priority list in the core sediment samples were conducted using gas chromatography–mass spectrometry. The vertical profiles of PAHs in the core sediments were assessed, possible sources and apportionment were identified, and the toxicity risk of the core sediments was determined. The results from the sediment analyses showed that total concentrations of the 16 PAHs varied from 11774 ± 4244 to 16755 ± 4593 ng/g dry weight (dw). Generally, the vertical profiles of the PAHs in the sediment cores exhibited a decreasing trend from the top to the lower levels of the S1 core and an increasing trend of PAHs from the top to the lower levels of the S2 and S3 cores. Among the core sediment samples, the five- and six-ring PAHs were predominantly in the S1 core, ranging from 42 to 54 %, whereas the composition of the PAHs in the S2 and S3 cores were distributed equally across three groups: two- and three-ring, four-ring, and five- and six-ring PAHs. The results indicated that PAH contamination at the site of the S1 core had a different source. The molecular indices and principal component analyses with multivariate linear regression were used to determine the source contributions, with the results showing that the contributions of coal, oil-related, and vehicle sources were 38.6, 35.9, and 25.5 %, respectively. A PAH toxicity assessment using the mean effect range-median quotient (m-ERM-q, 0.59–0.79), benzo[a]pyrene toxicity equivalent (TEQᶜᵃʳᶜ, 1466–1954 ng TEQ/g dw), and dioxin toxicity equivalent (TEQᶠⁱˢʰ, 3036–4174 pg TEQ/g dw) identified the wharf as the most affected area. The results can be used for regular monitoring, and future pollution prevention and management should target the coal-based industries in this region for pollution reduction.
Mostrar más [+] Menos [-]Application of modified attapulgite in phthalate acid ester-contaminated soil: Effects on phthalate acid ester dissipation and the composition of soil microbial community Texto completo
2016
Gao, Jun | Shi, Yi-ying | Zhou, Hai-feng | Ren, Xu-qin | Ji, Huai
The effects of modified attapulgite (MA) on the dissipations of the plasticizers di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) in soil, as well as on the composition of soil microbial community, were studied. DBP, DEHP (50 mg kg⁻¹ in soil, respectively), and MA (1, 5, and 10 % in soil) were mixed thoroughly with soil and incubated for 60 days. DBP- and DEHP-contaminated soils without MA were used as the controls. Both of DBP and DEHP residues in bulk soils and four soil fractions were measured at five incubation times 1, 7, 15, 30, and 60 days, and their dissipation kinetic equations were analyzed. The microbial phospholipid fatty acid (PLFA) concentrations were also measured at the end of experiment. Our results showed that the effect of modified attapulgite on DBP dissipation was related to its dosage in soil. The DEHP dissipation was both inhibited by MA at the 5 and 10 % rates in soils. The application of MA changed the content percentages but did not change the concentration order of phthalate acid esters (PAEs) in soil particle-size fractions. The total microbial PLFA content was significantly increased by 5 and 10 % MA in the contaminated soils. Meanwhile, the gram-negative (GN)/gram-positive (GP) ratios increased when MA was applied at the dosages of 5 and 10 % in DBP and 10 % in DEHP-contaminated soils. Principal component analysis (PCA) indicated that the change of bacteria PLFA, especially the GN bacterial PLFA, depended on the dosages of MA added into soil. The application of MA into soil has a positive effect on reducing the eco-toxicity of PAEs in soil based on the analysis of the soil microbial PLFA.
Mostrar más [+] Menos [-]Biomonitoring of agricultural workers exposed to pesticide mixtures in Guerrero state, Mexico, with comet assay and micronucleus test Texto completo
2016
Carbajal-López, Yolanda | Gómez-Arroyo, Sandra | Villalobos Pietrini, Rafael | Calderón-Segura, María Elena | Martínez Arroyo, Amparo
The aim of this study was to evaluate the genotoxic effect of pesticides in exfoliated buccal cells of workers occupationally exposed in Guerrero, Mexico, using the comet assay and the micronucleus test. The study compared 111 agricultural workers in three rural communities (Arcelia 62, Ajuchitlan 13, and Tlapehuala 36), with 60 non-exposed individuals. All the participants were males. The presence of DNA damage was investigated in the exfoliated buccal cells of study participants with the comet assay and the micronucleus (MN) test; comet tail length was evaluated in 100 nuclei and 3000 epithelial cells of each individual, respectively; other nuclear anomalies such as nuclear buds, karyolysis, karyorrhexis, and binucleate cells were also evaluated. Study results revealed that the tail migration of DNA and the frequency of MN increased significantly in the exposed group, which also showed nuclear anomalies associated with cytotoxic or genotoxic effect. No positive correlation was noted between exposure time and tail length and micronuclei frequencies. No significant effect on genetic damage was observed as a result of age, smoking, and alcohol consumption. The MN and comet assay in exfoliated buccal cells are useful and minimally invasive methods for monitoring genetic damage in individuals exposed to pesticides. This study provided valuable data for establishing the possible risk to human health associated with pesticide exposure.
Mostrar más [+] Menos [-]Biohythane production from organic wastes: present state of art Texto completo
2016
Roy, Shantonu | Das, Debabrata
The economy of an industrialized country is greatly dependent on fossil fuels. However, these nonrenewable sources of energy are nearing the brink of extinction. Moreover, the reliance on these fuels has led to increased levels of pollution which have caused serious adverse impacts on the environment. Hydrogen has emerged as a promising alternative since it does not produce CO₂ during combustion and also has the highest calorific value. The biohythane process comprises of biohydrogen production followed by biomethanation. Biological H₂ production has an edge over its chemical counterpart mainly because it is environmentally benign. Maximization of gaseous energy recovery could be achieved by integrating dark fermentative hydrogen production followed by biomethanation. Intensive research work has already been carried out on the advancement of biohydrogen production processes, such as the development of suitable microbial consortium (mesophiles or thermophiles), genetically modified microorganism, improvement of the reactor designs, use of different solid matrices for the immobilization of whole cells, and development of two-stage process for higher rate of H₂ production. Scale-up studies of the dark fermentation process was successfully carried out in 20- and 800-L reactors. However, the total gaseous energy recovery for two stage process was found to be 53.6 %. From single-stage H₂ production, gaseous energy recovery was only 28 %. Thus, two-stage systems not only help in improving gaseous energy recovery but also can make biohythane (mixture of H₂ and CH₄) concept commercially feasible.
Mostrar más [+] Menos [-]Plant responses to a phytomanaged urban technosol contaminated by trace elements and polycyclic aromatic hydrocarbons Texto completo
2016
Marchand, Lilian | Sabaris, Celestino-Quintela | Desjardins, Dominic | Oustrière, Nadège | Pesme, Eric | Butin, Damien | Wicart, Gaetan | Mench, Michel
Medicago sativa was cultivated at a former harbor facility near Bordeaux (France) to phytomanage a soil contaminated by trace elements (TE) and polycyclic aromatic hydrocarbons (PAH). In parallel, a biotest with Phaseolus vulgaris was carried out on potted soils from 18 sub-sites to assess their phytotoxicity. Total soil TE and PAH concentrations, TE concentrations in the soil pore water, the foliar ionome of M. sativa (at the end of the first growth season) and of Populus nigra growing in situ, the root and shoot biomass and the foliar ionome of P. vulgaris were determined. Despite high total soil TE, soluble TE concentrations were generally low, mainly due to alkaline soil pH (7.8–8.6). Shoot dry weight (DW) yield and foliar ionome of P. vulgaris did not reflect the soil contamination, but its root DW yield decreased at highest soil TE and/or PAH concentrations. Foliar ionomes of M. sativa and P. nigra growing in situ were generally similar to the ones at uncontaminated sites. M. sativa contributed to bioavailable TE stripping by shoot removal (in g ha⁻¹ harvest⁻¹): As 0.9, Cd 0.3, Cr 0.4, Cu 16.1, Ni 2.6, Pb 4, and Zn 134. After 1 year, 72 plant species were identified in the plant community across three subsets: (I) plant community developed on bare soil sowed with M. sativa; (II) plant community developed in unharvested plots dominated by grasses; and (III) plant community developed on unsowed bare soil. The shoot DW yield (in mg ha⁻¹ harvest⁻¹) varied from 1.1 (subset I) to 6.9 (subset II). For subset III, the specific richness was the lowest in plots with the highest phytotoxicity for P. vulgaris.
Mostrar más [+] Menos [-]Antioxidant defense gene analysis in Brassica oleracea and Trifolium repens exposed to Cd and/or Pb Texto completo
2016
Bernard, F. | Dumez, S. | Brulle, F. | Lemière, S. | Platel, A. | Nesslany, F. | Cuny, D. | Deram, A. | Vandenbulcke, F.
This study focused on the expression analysis of antioxidant defense genes in Brassica oleracea and in Trifolium repens. Plants were exposed for 3, 10, and 56 days in microcosms to a field-collected suburban soil spiked by low concentrations of cadmium and/or lead. In both species, metal accumulations and expression levels of genes encoding proteins involved and/or related to antioxidant defense systems (glutathione transferases, peroxidases, catalases, metallothioneins) were quantified in leaves in order to better understand the detoxification processes involved following exposure to metals. It appeared that strongest gene expression variations in T. repens were observed when plants are exposed to Cd (metallothionein and ascorbate peroxidase upregulations) whereas strongest variations in B. oleracea were observed in case of Cd/Pb co-exposures (metallothionein, glutathione transferase, and peroxidase upregulations). Results also suggest that there is a benefit to use complementary species in order to better apprehend the biological effects in ecotoxicology.
Mostrar más [+] Menos [-]How contamination sources and soil properties can influence the Cd and Pb bioavailability to snails Texto completo
2016
Pauget, Benjamin | Gimbert, Frédéric | Coeurdassier, Mickael | Druart, Coline | Crini, Nadia | de Vaufleury, Annette
To better understand the fate of metals in the environment, numerous parameters must be studied, such as the soil properties and the different sources of contamination for the organisms. Among bioindicators of soil quality, the garden snail (Cantareus aspersus) integrates multiple sources (e.g. soil, plant) and routes (e.g. digestive, cutaneous) of contamination. However, the contribution of each source on metal bioavailability and how soil properties influence these contributions have never been studied when considering the dynamic process of bioavailability. Using accumulation kinetics, this study showed that the main assimilation source of Cd was lettuce (68 %), whereas the main source of Pb was the soil (90 %). The plant contribution increased in response to a 2-unit soil pH decrease. Unexpectedly, an increase in the soil contribution to metal assimilation accompanied an increase in the organic matter (OM) content of the soil. For both metals, no significant excretion and influence of source on excretion have been modelled either during exposure or depuration. This study highlights how the contribution of different sources to metal bioavailability changes based on changes in soil parameters, such as pH and OM, and the complexity of the processes that modulate metal bioavailability.
Mostrar más [+] Menos [-]Simultaneous removal of potent cyanotoxins from water using magnetophoretic nanoparticle of polypyrrole: adsorption kinetic and isotherm study Texto completo
2016
Hena, S. | Rozi, R. | Tabassum, S. | Huda, A.
Cyanotoxins, microcystins and cylindrospermopsin, are potent toxins produced by cyanobacteria in potable water supplies. This study investigated the removal of cyanotoxins from aqueous media by magnetophoretic nanoparticle of polypyrrole adsorbent. The adsorption process was pH dependent with maximum adsorption occurring at pH 7 for microcystin-LA, LR, and YR and at pH 9 for microcystin-RR and cylindrospermopsin (CYN). Kinetic studies and adsorption isotherms reflected better fit for pseudo-second-order rate and Langmuir isotherm model, respectively. Thermodynamic calculations showed that the cyanotoxin adsorption process is endothermic and spontaneous in nature. The regenerated adsorbent can be successfully reused without appreciable loss of its original capacity.
Mostrar más [+] Menos [-]Effects of doping amounts of potassium ferricyanide with titanium dioxide and calcination durations on visible-light degradation of pharmaceuticals Texto completo
2016
Lin, Justin Chun Te | de Luna, Mark Daniel G. | Gotostos, Mary Jane N. | Lü, Mingjun
Acetaminophen (ACT) is one of the most frequently detected pharmaceuticals in aqueous environments, and treatment of ACT were generally carried out by photocatalytic degradations under high energy UV irradiation. In this study, potassium ferricyanide was utilized as a quadruple-elemental dopant in a TiO₂ photocatalyst in order to enhance its visible-light activity. Two critical parameters (amounts of dopants and durations of calcination) of the synthesis of the photocatalyst by a sol–gel method were systematically evaluated. Crystal structure of the doping TiO₂ was examined by X-ray diffraction while the effects of the two parameters on the photocatalytic activity were elucidated by various characterizations. Increasing the amount of dopant or the duration of calcination red-shifted the UV–vis DRS of the doped TiO₂. The estimated band gap energy of the doped TiO₂ decreased slightly as the amount of dopant increased, but it increased as the duration of calcination increased. The FT-IR yielded characteristic peaks that revealed the effects of the two parameters, whereas the SEM images revealed the morphological evolutions of each effect. The photocatalyst, synthesized at optimum conditions was able to remove 99.1 % acetaminophen with rate constant of 7.9 × 10⁻³ min⁻¹, which was 4.88 times greater than virgin TiO₂. In general, this study not only optimized synthetic conditions of the new visible-light active photocatalyst for ACT degradation but also presented characterizations conducted by SEM, XRD, UV–vis DRS, and FTIR to elucidate the relationship between modified structure and the photocatalytic activity. Graphical abstract Effects of doping amounts of K₃[Fe(CN)₆] and calcunation duration on visible light absorbance of TiO₂ photocatalysts
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