Уточнить поиск
Результаты 1-8 из 8
Biochar significantly reduced fumigant emissions and benefited germination and plant growth under field conditions
2022
Wang, Qiuxia | Gao, Suduan | Wang, Dong | Cao, Aocheng
Soil fumigation continues to play an important role in soil disinfection, but tools to significantly reduce emissions while providing environmental benefits (e.g., biochar) are lacking. The objective of this study was to determine the effects of biochar products on fumigant 1,3-dichloropropene (1,3-D) and chloropicrin (CP) emissions, their distribution and persistence in soil, nematode control, and potential toxicity to plants in a field trial. Treatments included three biochar products [two derived from almond shells (ASB) at either 550 or 900 °C pyrolysis temperature and one from coconut shells (CSB) at 550 °C] at 30 and 60 t ha⁻¹, a surface covering with a low permeability film (TIF), and no surface covering (control). A mixture of 1,3-D (∼65%) and CP (∼35%) was injected to ∼60 cm soil depth at a combined rate of 640 kg ha⁻¹. All biochar treatments significantly reduced emissions by 38–100% compared to the control. The ASB (900 °C) at both rates reduced emissions as effectively as the TIF (by 99–100%). Both fumigant emission reduction and residue in surface soil were positively correlated with biochar's adsorption capacity while cucumber germination rate and dry biomass were negatively correlated with residual fumigant concentrations in surface soil. This research demonstrated the potential and benefits of using biochar produced from local orchard feedstocks to control fumigant emissions. Additional research is needed to maximize the benefits of biochar on fumigant emission reductions without impacting plant growth.
Показать больше [+] Меньше [-]Colony field test reveals dramatically higher toxicity of a widely-used mito-toxic fungicide on honey bees (Apis mellifera)
2021
Fisher, Adrian | DeGrandi-Hoffman, Gloria | Smith, Brian H. | Johnson, Meredith | Kaftanoglu, Osman | Cogley, Teddy | Fewell, Jennifer H. | Harrison, Jon F.
Honey bees (Apis mellifera) and other pollinator populations are declining worldwide, and the reasons remain controversial. Based on laboratory testing, fungicides have traditionally been considered bee-safe. However, there have been no experimental tests of the effects of fungicides on colony health under field conditions, and limited correlational data suggests there may be negative impacts on bees at levels experienced in the field. We tested the effects of one of the most commonly used fungicides on colony health by feeding honey bee colonies pollen containing Pristine® (active ingredients: 25.2% boscalid, 12.8% pyraclostrobin) at four levels that bracketed concentrations we measured for pollen collected by bees in almond orchards. We also developed a method for calculating per-bee and per-larva dose. Pristine® consumption significantly and dose-dependently reduced worker lifespan and colony population size, with negative health effects observed even at the lowest doses. The lowest concentration we tested caused a 15% reduction in the worker population at an estimated dosage that was three orders of magnitude below the estimated LD₁₅ values for previous acute laboratory studies. The enhanced toxicity under field conditions is at least partially due to activation of colonial nutritional responses missed by lab tests. Pristine® causes colonies to respond to perceived protein malnutrition by increasing colony pollen collection. Additionally, Pristine induces much earlier transitioning to foraging in individual workers, which could be the cause of shortened lifespans. These findings demonstrate that Pristine® can negatively impact honey bee individual and colony health at concentrations relevant to what they experience from pollination behavior under current agricultural conditions.
Показать больше [+] Меньше [-]A Two-Step Approach to Eliminate Pesticides and Estrogens from a Wastewater and Reduce Its Phytotoxicity: Adsorption onto Plant-Derived Materials and Fungal Degradation
2016
Loffredo, Elisabetta | Castellana, Giancarlo | Taskin, Eren
In this study, adsorption and biodegradation were exploited sequentially to remove the herbicide fenuron, the insecticide carbaryl and the estrogens 17β-estradiol (E2) and 4-tert-octylphenol (OP) from a municipal landfill leachate (MuLL). In the first step, we used spent coffee grounds, almond shells, a biochar and potato dextrose agar to adsorb the compounds spiked in MuLL at a concentration of 1 mg L⁻¹. After only 3 days, any adsorbent removed from MuLL the totality of E2 and OP, averagely more than 95 % of carbaryl and 62 % of fenuron (81 % after 7 days). In the second step, the adsorbents collected from MuLL after 7 days were inoculated with the fungi Bjerkandera adusta and Irpex lacteus, separately. After 7 days, the maximum degradation occurred for OP in any treatment being averagely 78 and 74 % using B. adusta and I. lacteus, respectively. After 15 days, the average percentages of fenuron, carbaryl, E2 and OP degraded were, respectively, 75, 76, 88 and 88 % using B. adusta, and 74, 79, 85 and 89 % using I. lacteus. Residual estrogenicity in the adsorbents, tested with the recombinant yeast assay, was strictly related to residual E2, thus indicating a negligible contribution from the other contaminants and/or degradation products. The 7-day treatment of MuLL with the adsorbents caused a significant abatement of MuLL phytotoxicity on flax (2.5 times seedling elongation with coffee grounds, compared to MuLL) and a huge stimulation of rapeseed respect to water (biomass almost doubled), thus suggesting a possible worthwhile recycling of this wastewater in agriculture.
Показать больше [+] Меньше [-]Sustainable valorization of recycled low-density polyethylene and cocoa biomass for composite production
2021
de Araújo Veloso, Maria Cecíllia Ramos | Scatolino, Mário Vanoli | Gonçalves, Maria Margarida Boavida Pontes | Valle, Mara Lúcia Agostini | de Paula Protásio, Thiago | Mendes, Lourival Marin | Junior, José Benedito Guimarães
The development of products from wastes such as plastic and lignocellulosic materials brings great advantages from the economic and sustainable point of view. The use of waste, previously destined for disposal, enables the changes in production patterns, and prevents major environmental problems. This research investigated the inclusion of different contents of cocoa almond husk on the properties of composites with recycled low-density polyethylene (LDPE) matrix. The composites were produced by extrusion process with proportions: 0%, 10%, 20%, 30%, and 40% of cocoa waste reinforcement in the polymer matrix. The density of the composites decreased (from 0.81 to 0.61 g/cm³) with the addition of the lignocellulosic waste in the matrix. The hygroscopicity was increased, however, at considerably low levels (0.17 to 2.68 %). There was a decrease in composite strength and elongation, becoming the material more rigid. The use of the cocoa waste for composites production is feasible to use since it can be adapted to the required application and still incorporate additives requested for specific purposes. This research demonstrated that is possible the combination of recycled low-density polyethylene and lignocellulosic wastes for the production of materials with high added value.
Показать больше [+] Меньше [-]Adsorption of Lead and Cadmium from Aqueous Solution by Using Almond Shells
2009
Mehrasbi, Mohammad Reza | Farahmandkia, Zohreh | Taghibeigloo, Bahareh | Taromi, Azra
The potential of almond shells was assessed for adsorption of heavy metal ions such as Pb²⁺ and Cd²⁺ from aqueous solution. Almond shells were pretreated separately with 0.4 mol/L NaOH, 0.4 mol/L HNO₃, and distilled water and their adsorption abilities were compared. Batch adsorption experiments were carried out as a function of the initial ion concentration, pH, and adsorbent dosage. Adsorption isotherms of metal ions on adsorbents were determined and correlated with common isotherm equations such as Langmuir, Freundlich, and BET models. The alkali-modified almond shells had adsorption capacities for Pb²⁺ from 2 to 9 mg/g and for Cd²⁺ from 2 to 7 mg/g, which was much higher than acid- and water-pretreated adsorbents. Experimental results showed that the best pH for adsorption was 5-6 and the adsorption values decreased with lowering pH. Isotherm models indicated the best fit for Langmuir model for alkali-modified almond shells. In comparing the parameters of the models, it was observed that the affinity of almond shells for adsorption of lead is stronger than affinity for adsorption of cadmium.
Показать больше [+] Меньше [-]A critical approach to the toxic metal ion removal by hazelnut and almond shells
2018
Cataldo, Salvatore | Gianguzza, Antonio | Milea, Demetrio | Muratore, Nicola | Pettignano, Alberto | Sammartano, Silvio
The adsorption capacity of ground hazelnut (HS) and almond (AS) shells towards Pb(II) and Cd(II) has been studied at pH = 5, in NaNO₃ and NaCl ionic media, in the ionic strength range 0.05–0.5 mol L⁻¹. Kinetic and equilibrium experiments were carried out by using the Differential Pulse Anodic Stripping Voltammetry technique to check the amount of the metal ion removed by HS and AS materials. Different kinetic and equilibrium equations were used to fit experimental data and a statistical study was done to establish the suitable model for the data fitting. A speciation study of the metal ions in solution was also done in order to evaluate the influence of the ionic medium on the adsorption process. TGA-DSC, FT-IR, and SEM-EDX techniques were used to characterize the adsorbent materials. The mechanism of metal ions adsorption was explained on the basis of the results obtained by the metal ions speciation study and the characterization of materials.
Показать больше [+] Меньше [-]Mutagenicity assessment of aerosols in emissions from domestic combustion processes
2016
Canha, Nuno | Lopes, Isabel | Vicente, Estela Domingos | Vicente, Ana M. | Bandowe, Benjamin A Musa | Almeida, Susana Marta | Alves, Célia A.
Domestic biofuel combustion is one of the major sources of regional and local air pollution, mainly regarding particulate matter and organic compounds, during winter periods. Mutagenic and carcinogenic activity potentials of the ambient particulate matter have been associated with the fraction of polycyclic aromatic hydrocarbons (PAH) and their oxygenated (OPAH) and nitrogenated (NPAH) derivatives. This study aimed at assessing the mutagenicity potential of the fraction of this polycyclic aromatic compound in particles (PM₁₀) from domestic combustion by using the Ames assays with Salmonella typhimurium TA98 and TA100. Seven biofuels, including four types of pellets and three agro-fuels (olive pit, almond shell and shell of pine nuts), were tested in an automatic pellet stove, and two types of wood (Pinus pinaster, maritime pine, and Eucalyptus globulus, eucalypt) were burned in a traditional wood stove. For this latter appliance, two combustion phases—devolatilisation and flaming/smouldering—were characterised separately. A direct-acting mutagenic effect for the devolatilisation phase of pine combustion and for both phases of eucalypt combustion was found. Almond shell revealed a weak direct-acting mutagenic effect, while one type of pellets, made of recycled wastes, and pine (devolatilisation) presented a cytotoxic effect towards strain TA100. Compared to the manually fired appliance, the automatic pellet stove promoted lower polyaromatic mutagenic emissions. For this device, only two of the studied biofuels presented a weak mutagenic or cytotoxic potential.
Показать больше [+] Меньше [-]Orchard management under the effects of climate change: implications for apple, plum, and almond growing
2019
Gitea, Manuel Alexandru | Gitea, Daniela | Tit, Delia Mirela | Purza, Lavinia | Samuel, Alina Dora | Bungău, Simona | Badea, Gabriela Elena | Aleya, Lotfi
The authors analyzed certain species and varieties of fruit tree in which applied crop technology is used and also undergoes the effects of climate change. The aim is to extend productive crop varieties, resistant to disease and pests, in order to obtain superior yields. The research was conducted in orchards located in northwestern Romania (on 8.59 ha), intensively cultivated with apple, plum, and almond species. The blooming period of the species and fruit production was studied in 2009, the first year of the farm’s commercial production, and then compared to figures from 2016 to see the changes that occurred. Climatic conditions were studied throughout the period of existence of the farm (2002–2016). To determine the influence of the climatic factor on the blooming and production periods, respectively, every year is considered having pre-blooming, blooming, and ripening periods. It was found that climate change influences the annual biological cycle of the trees: the vegetative rest period of the trees shortens, the tree vegetation begins earlier in the spring, and the blooming period is advanced by as much as 10 days compared to normal cultivated varieties. All these factors have direct repercussions on the quantity of production.
Показать больше [+] Меньше [-]