Search results for "Nitrogen"

Microstructural and associated chemical changes during the composting of a high temperature biochar: Mechanisms for nitrate, phosphate and other nutr…

2018

Recent studies have demonstrated the importance of the nutrient status of biochar and soils prior to its inclusion in particular agricultural systems. Pre-treatment of nutrient-reactive biochar, where nutrients are loaded into pores and onto surfaces, gives improved yield outcomes compared to untreated biochar. In this study we have used a wide selection of spectroscopic and microscopic techniques to investigate the mechanisms of nutrient retention in a high temperature wood biochar, which had negative effects on Chenopodium quinoa above ground biomass yield when applied to the system without prior nutrient loading, but positive effects when applied after composting. We have compared non-co…

Nutrient recovery from wastewater treatment by ultrafiltration membrane for water reuse in view of a circular economy perspective

2022

The study aims to recover nitrogen from wastewater by employing ultrafiltration membrane in water reuse for agriculture purpose. To such aim, a new reclaimed water quality index (RWQI) is proposed and applied including an innovative protocol for its assessment. Specifically, the influence of filtration and backwashing times for an ultrafiltration system aimed to nutrient recovery has been analyzed. The final goal was to pin down the trade-off between operation costs and effluent quality. Results show that backwashing time play a crucial role in reducing the operation costs; indeed, low values (i.e., 0.5 min) lead to an increase in the number of required chemical cleanings and consequently o…

Design and performance of BNR activated sludge systems with flat sheet membranes for solid-liquid separation

2007

The use of immersed membranes for solid-liquid separation in biological nutrient removal activated sludge (BNRAS) systems was investigated at lab scale. Two laboratory-scale BNR activated sludge systems were run in parallel, one a MBR system and the other a conventional system with secondary settling tanks. Both systems were in 3 reactor anaerobic, anoxic, aerobic UCT configurations. The systems were set up to have, as far as possible, identical design parameters such as reactor mass fractions, recycles and sludge age. Differences were the influent flow and total reactor volumes, and the higher reactor concentrations in the MBR system. The performances of the two systems were extensively mo…

Nutri-priming as an efficient means to improve the agronomic performance of molybdenum in common bean (Phaseolus vulgaris L.).

2019

International audience; Microelements play important roles in improving crop productivity and quality. Two traditional methods of providing micronutrients are soil and foliar application, yet the cost involved and phytotoxicity risks poses a major challenge in most global agricultural areas. Nutri-priming represents thus a very promising and viable alternative to ensure that the plants' requirements for micronutrients are met. This paper explores the Mo-priming effects on the germination, growth and yield components of common bean (Phaseolus vulgaris L.). In order to accomplishthis research objective, our study is divided in two phases. The first phase seeks to determine the effects of two …

Biological nutrients removal and recovery

2020

The combined effects of CO2, ozone and drought on rubisco and nitrogen metabolism of young oak trees (Quercus petraea) A phytotron study

1998

Abstract In this phytotron experiment we investigated the influence of increased CO 2 , O 3 and drought on the content of soluble proteins and some enzymes of carbon and nitrogen metabolism. We found that the amounts of soluble proteins and the large subunit of the rubisco per fresh weight in young oak leaves declined under conditions of increasing levels of CO 2 and after temporary water stress. The activities of nitrite reductase and glutamine synthetase were reduced when O 3 and CO 2 levels were raised.

Use of Sentinel-2 Satellite for Spatially Variable Rate Fertiliser Management in a Sicilian Vineyard

2022

Satellites can be used for producing maps of within-field crop and soil parameters and, consequentially, spatially variable rate crop input application maps. The plant vegetative vigour index (i.e., Normalised Difference Vegetation Index—NDVI) and the leaf water content index (i.e., Normalised Difference Water Index—NDWI) maps were used to study—through both time and space—the phenological phases of two plots, with Syrah and Nero d’Avola grapevine varieties, in a Sicilian vineyard farm, located in Naro (Agrigento, Sicily, Italy). The aim of this work is to produce spatially variable rate nitrogen fertiliser maps to be applied in the two vineyard plots under stu…

[3+2] Cycloaddition reaction of 1H-phosphorinium-3-olate and 1-methylphosphorinium-3-olate with methyl acrylate: A DFT study

2016

Abstract A density functional theory study was performed on the [3+2] cycloaddition (32CA) reaction of 1H-phosphorinium-3-olate and 1-methylphosphorinium-3-olate with methyl acrylate. The thermodynamic and kinetic parameters were analysed by considering the regio- and stereoisomeric pathways in gas phase and solvents. The geometries indicate that the transition states are slightly more advanced and asynchronous in ethanol. Electron localisation function topological analysis of the bonding changes along the most favourable reaction pathway associated with the 32CA reaction of 1H-phosphorinium-3-olate with methyl acrylate indicates that the reaction takes place through a two-stage one-step me…

Triazolopyridines. Part 30. Hydrogen transfer reactions; pyridylcarbene formation

2013

The transfer hydrogenation reaction of (1,2,3)triaz olo(1,5-a)pyridines with Pd/C/Zn or Pd(OH) 2/C/Zn in water, ethanol or water/ethanol mixture ha s been explored. 4,5,6,7-Tetrahydro- triazolopyridines were obtained in good to medium yields. In addition, under the same conditions 2-substituted pyridines were also formed as a resul t of intermediate pyridylcarbene formation, by triazole ring opening and loss of nitrogen.

Constrained formation of 2-(1-(arylimino)ethyl)-7-arylimino-6,6-dimethylcyclopentapyridines and their cobalt(ii) chloride complexes: synthesis, chara…

2015

A series of 2-(1-(arylimino)ethyl)-7-arylimino-6,6-dimethylcyclopentapyridine derivatives (L1-L5) was synthesized, and individually reacted with cobalt(II) chloride to form the corresponding cobalt chloride complexes (C1-C4). These compounds were characterized, and the single crystal X-ray diffraction for two representative cobalt complexes was carried out. The molecular structures indicate that 2,7-bis(arylimino)cyclopentapyridines act as tridentate ligands; however, one of the Co-N coordinative bonds is weak due to the spatial separation of nitrogen atoms. Upon activation with either MAO or MMAO, all cobalt complexes exhibit catalytic activities toward ethylene. Polymerization takes place…