conformational redistribution of honey components following different storage conditions

The present study aims at the investigation of the changes in water distribution among the organic components of selected honey samples following honey storage at different temperatures. Results, achieved by application of fast field cycling NMR relaxometry, revealed that the organic constituents were homogeneously distributed within the whole samples stored at room temperature. Conversely, after four months of refrigeration at 4°C, the organic systems were included in persistent clusters, as a consequence of the water release due to the larger stability of the intramolecular interactions over the intermolecular ones. The new conformational arrangements of the honey constituents entailed enhancement of honey moisture content. For this reason, it can be suggested that honey refrigeration prior to storage at room temperature may be detrimental for its long-term storage. In fact, higher risk of fermentation may occur once the sample is warmed after the first refrigeration step

Conformational Redistribution of Honey Components following Different Storage Conditions

The present study aims at the investigation of the changes in water distribution among the organic components of selected honey samples following honey storage at different temperatures. Results, achieved by application of fast field cycling NMR relaxometry, revealed that the organic constituents were homogeneously distributed within the whole samples stored at room temperature. Conversely, after four months of refrigeration at 4°C, the organic systems were included in persistent clusters, as a consequence of the water release due to the larger stability of the intramolecular interactions over the intermolecular ones. The new conformational arrangements of the honey constituents entailed enhancement of honey moisture content. For this reason, it can be suggested that honey refrigeration prior to storage at room temperature may be detrimental for its long-term storage. In fact, higher risk of fermentation may occur once the sample is warmed after the first refrigeration step

Efficiency of biochar for reducing mobility of inorganic contaminants

Anthropogenic activities have produced numerous sites with extensive contamination close to residential areas. Several physicochemical and biological remediation methods exist for remediation of metal contaminated soils and lands, such as soil washing, soil flushing, phytoremediation, and electrokinetics. Biochar (biologically derived charcoal) is produced by pyrolysis of biomasses under low oxygen conditions, and it can be applied for recycling organic waste in soils. The main objectives of the present study were to determine the possible use of biochar from forest ersidues (Populus nigra) in order to achieve a stabilization of inorganic contaminants by adsorption processes. Adsorption of copper by biochar from dilute solutions showed a closer agreement with the Langmuir isotherm in a concentration range 25-500 mM. The decontamination by biochar is very suitable because the treatment is passive and does not require specialized equipment or extensive labor as compared to other remediation methods. Moreover, biochar is also a possible carbon sink due to its long term storage in environment, thereby favouring mitigation of the anthropic impact on environment

Structure alteration of a sandy-clay soil by biochar amendments

The aim of the present study was to investigate structure alterations of a sandy-clay soil upon addition of different amounts of biochar (f (bc) ). All the f (bc) samples were analyzed by high energy moisture characteristic (HEMC) technique and H-1 nuclear magnetic resonance (NMR) relaxometry. HEMC was applied in order to evaluate aggregate stability of biochar-amended soil samples. H-1 NMR relaxometry experiments were conducted for the evaluation of the pore distributions through the investigation of water dynamics of the same samples. The HEMC technique revealed improvement in aggregate stability through measurements of the amount of drainable pores and the stability ratio. The latter increased as the amount of biochar was raised up. The H-1 NMR relaxometry revealed a unimodal T (1) distribution for both the sole sandy-clay soil and the biochar. Conversely, a bimodal T (1) distribution was acquired for all the different f (bc) samples. Improvement in aggregate stability was obtained as biochar was progressively added to the sandy-clay soil. A dual mechanism of water retention has been hypothesized. In particular, intra-aggregate porosity was indicated as the main responsible for molecular water diffusion when f (bc) comprised between 0 and 0.33. Conversely, inter-aggregate porosity resulted predominant, through swelling processes, when f (bc) overcame 0.33

Regeneration of cellulose by water addition to phosphoric acid/cellulose mixture

In the last years, phosphoric acid has been increasingly considered as a simple and economic solvent for cellulose pretreatment before its degradation to glucose. Cellulose swells in 71–80% phosphoric acid solutions, whereas at higher H3PO4 concentrations dissolution appears to occur. In addition, it is reported that regenerated cellulose is more easily fermentable to bioethanol. The aim of the present study was to elucidate the mechanism for cellulose regeneration following treatment with phosphoric acid at room temperature. CPMAS 13C NMR spectra revealed a downfield shift of the 13C NMR signals from the regenerated cellulose as compared to the crystalline one. CPMAS 31P NMR spectroscopy showed presence of organic phosphate in the regenerated cellulose. These results suggested that cellulose regeneration consisted in the precipitation of a phosphorylated polymer. Fast field cycling NMR relaxometry confirmed such hypothesis. In fact, the correlation time of water saturated crystalline cellulose was shorter than that measured for the water saturated regenerated cellulose. The phosphate groups bound to the regenerated cellulose surface allow restriction of water mobility, thereby producing longer correlation times. Finally turbidimetric analyses revealed that the mechanism of regeneration consisted in a first reduction of the colloidal cellulose size followed by aggregation, colloidal size increment and flocculation. This study is of paramount importance to understand how phosphoric acid interact with cellulose in order to address its possible uses in biomass transformation for bioenergy purposes

BIOCHAR SURFACE PROPERTIES THROUGH APPLICATION OF AN INNOVATIVE NMR TECHNIQUE: FAST FIELD CYCLING RELAXOMETRY

Biochar is a carbonaceous material obtained by pyrolysis of biomass feedstocks. It is applied to soils in order to improve fertility and mitigate greenhouse-gases emissions. In fact, from the one hand, biochar changes physical-chemical soil properties, thereby affecting soil fertility. From the other hand, biochar is resistant to chemical and biochemical degradation. For this reason, its use allows carbon sequestration in soils and consequent reduction of carbon dioxide to the atmosphere. Here, dynamics of water at the liquid-solid interface of water saturated biochars is discussed. Results revealed that water dynamics is affected by the nature of biochar parent biomasses. Moreover, biochar chemical physical properties are affected by conditions for their production. It was understood that water undergoes to an inner-sphere interaction mechanism with biochar surface through formation of weak unconventional hydrogen bonds. Recognition of the interaction mechanisms between water and biochar is of paramount importance in order to understand why biochar soil amendments improve soil fertility and crop production

Effects of pyrolysis conditions on the thermal transformation of chicken manure into char

Biochar is a fine-grained and highly porous carbonaceous substance, arising from the pyrolitic decomposition of natural or synthetic organic materials. It is lately applied to soils to favorably affect soil physico-chemical properties, such as water and nutrient retention and cation exchange capacity (CEC). The extent of the effect of biochar on crop productivity is very variable due to the different biophysical interactions and processes that occur when it is applied to soils. Char properties are greatly influenced by both natures of feedstock and process conditions. An accurate characterization of biochar is crucial to evaluate the possibility to amend soil with such material by avoiding environmental damages. The aim of this work was the chemical-physical characterization of biochar from chicken manure in order to investigate its potentiality either as fertilizer or as metal bio-sorbent in soil remediation procedures. Biochar was produced at different temperatures and residence times into a heating muffle. Then, evaluation of carbon, hydrogen and nitrogen contents, transversal relaxation time (T2) by NMR as well as metal content such as Na, K, Fe, Cu, Mn, Al, Ca, Mg, and Pb has been achieved. Environmental Scanning Electron Microscopy (ESEM), Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) studies have been also carried out. Elemental Analysis revealed a decrease in the C, H, N content with increasing Pyrolysis Temperature (PT). These changes appeared not to be dependent upon residence time (RT) in the furnace. The ash content increased from 46.09% in 300°C-obtained biochar to 66.54% in 600°C-obtained biochar. TG profiles from biochars pyrolized at the same PT but at different RT were similar, while there were statistically significant differences among biochars obtained at increasing temperatures. From TG and DSC curves, the presence of one or two main different processes, each corresponding to a mass-loss step, was recognised. Biochar samples can be divided into different groups depending on their distinctive thermal behavior. For samples obtained below 450°C, the first mass loss occurred between 180°C and 350°C. It can be attributed to the destruction of alkyl systems, CH and amino groups. The second mass loss is comprised in the range 350-600°C and corresponds to the thermo-oxidation of aromatic, mono or polycyclic, rings as well as decarboxilation. Samples produced above 500°C revealed only one single process supporting the evidence that biochar produced at higher temperatures contain mainly aromatic compounds. 450°C-produced biochars showed intermediate characteristics. T2-NMR results revealed an increase in all relaxation times with PT. The shift of T2 towards higher values is an indication of the presence of water into larger pores and suggests that char treated at higher temperatures may contain larger-sized pores. According to our results, the chemical composition and the physical structure of chicken manure biochar vary mainly depending on process temperature. During pyrolysis, biochar loses volatile compounds gaining more stability. Biochar formation can be described as an aromatic growth and polymerization process, resulting in carbon enrichment. In addition, porosity development is achieved as volatile matter is removed. The high ash content of this kind of char has both positive and negative implications. The ash contains important plant nutrients (K, Ca, Mg) and a very basic pH, which are generally positive traits. However, they can be detrimental if biochar is applied at high concentrations or on alkaline/calcareous soils

Preliminary identification and quantification of steroid hormones in the red palm weevil, Rhynchophorus ferrugineus

In the present preliminary study, we used a gas chromatography–mass spectroscopy (GC-MS) method to identify and quantify steroid hormones, their precursors and metabolites in whole body of red palm weevil (RPW) R. ferrugineus adults. We identified a total of seven steroids by single ion monitoring mode (SIM) analysis and compared them to the National Institute of Standards and Technology (NIST) library. The steroids include: dehydroepiandrosterone (DHEA), estrone, estradiol-17β, testosterone, progesterone, cortisol and cholesterol, whereas pregnenolone, pregnan-20-one-17-hydroxy and corticosterone were not detected. This study shows that some invertebrate groups seem to use partially or totally comparable hormones to vertebrates and produce vertebrate-type steroids with functional roles. However, some steroids of the endocrine system of invertebrates are still lacking or yet to be identified in most phyla

EVALUATION OF INORGANIC CONTAMINANT REMOVAL FROM AQUEOUS SOLUTIONS USING PYROLIZED CHICKEN MANURE, CONIFER AND POPLAR WOOD AS ADSORBENT

Anthropogenic activities alter the natural flow of materials and introduce novel chemicals into the environment thereby causing serious soil and water pollution. Indeed, many industries produce aqueous effluents containing toxic substances, especially heavymetals. The presence of these contaminants in the environment is a great issue because of their toxicityand bioaccumulation ability which affect human life and the environment. Various physicochemical and biological techniques have been used to remove the heavy metals from waste waters, including chemical precipitation, ion exchange, chemical coagulation, electrolytic methods, membrane processes, and adsorption. Biochar is a carbonaceous material obtained from the pyrolysis of plant and animal biomasses. Due to its high porosity, it could be a potential alternative to the existing conventional technologies for the removal and/or recovery of metal ions from aqueous solutions. The aim of this work was the chemical-physical characterization of biochar produced from chicken manure (CM), conifers and poplar wood wastes in order to assess their ability in the removal of heavy metal from aqueous solutions. Chemical-physical characterization of the different CM chars was conducted by cross polarization magic angle spinning (CPMAS) 13 C NMR spectroscopy and NMR relaxometry together with a comparative study between the removal efficiencies of Cu(II), Ni(II) andPb(II) from synthetic wastewater by using adsorption onto biochars surfaces. From adsorption studies, it was observed that conifer biochar did not significantly adsorbed metals. This behavior is probably due to his own chemical characteristics, since it’s quite hydrophobic and probably its surface lacks functional groups able to bind ions. Conversely, chicken manure biochar proved to have the highest removal efficiencies for all the metals considered, in the order Pb(II)>Cu(II)>Ni(II) ions. In conclusion, different chars have different physicochemical characteristics so they should be addressed to different uses. For example, conifer char should not be used for remediation since it’s not effective in removing inorganic metals from aqueous solutions. The most effective in remediation was chicken manure biochar, probably thanks to the presence of nitrogen on its surface. In fact, nitrogen has a free electronic doublet/pair able to interact with cation. Finally, char metals absorption involves both a physical and a chemical mechanism and further studies should be addressed to explain it

Biotossine nei Mitili: Effetti dell’Acido Domoico sull’attività colinesterasica in Tapes philippinarum, Venus gallina e Glycimeris glycimeris (Lamellibranchia, Mollusca)

L’acido domoico (AD) è una biotossina che si accumula principalmente in animali che filtrano acque contaminate da diatomee dei generi Nitzschia e Pseudo-nitschia. L’incremento delle fioriture di diatomee ed i conseguenti casi di intossicazione per ingestione di molluschi contaminati sono fenomeni che da più di un decennio si manifestano anche in Italia, rappresentando motivo di seria preoccupazione per la salute pubblica e per l’economia dell’industria ittica. L’acido domoico è il responsabile dell’“Amnesic Shellfish Poisoning” (ASP), i cui sintomi si manifestano sia a livello gastrointestinale che neurologico. Le proprietà neurotossiche dell'acido domoico sono dovute alla sua azione agonista sui recettori degli aminoacidi eccitatori (acido glutammico e aspartico) e sulla trasmissione sinaptica. I dati sulla tossicologia dell’acido domoico sono comunque ancora limitati, inoltre sono state condotte ancora poche ricerche sugli effetti di tale biotossina sugli organismi marini. In questo lavoro sono stati condotti esperimenti di esposizione in vitro ad acido domoico su Tapes philippinarum, Venus gallina e Glycimeris glycimeris al fine di valutare i suoi effetti sull’attività colinesterasica. I risultati hanno mostrato un incremento dell’attività enzimatica in tutte e tre le specie di molluschi. Tapes philippinarum e Venus gallina sono state le specie più sensibili all’azione dell’acido domoico con un incremento percentuale di attività enzimatica maggiore del 60%