Low Concentrations Of Heavy Metals Research Articles

English

The coastal flanks of Mt Etinde is wedged between the sea and the southwestern slope of Mt Cameroon. The only fresh water resources available for multipurpose uses in this area are mountain springs and streams that drain volcanic materials. To access the sources, processes and assess the ecological risk associated with hydrochemicals and heavy metals in these mountain water resources, 18 water samples were collected in different seasons at 4 locations between may 2009 and december 2010 for major ions and heavy metals determination. The sampled waters ranged from neutral to slithly alkaline, weakly mineralized and dominated by Ca–Mg–HCO3 water type irrespective of season. The hydrochemical ratios revealed ions chemistry mostly influenced by geogenic source of silicate rock weathering and atmospheric inputs. Sampled waters had low concentration of heavy metals which are less mobile in the aqueous phase, controlled by hydraulic condition. Geochemical processes of  mineral dissolution and reverse ion exchange coupled with hydrodynamic processes of flushing at the weathering front and soil leaching are the main controls on the water chemistry in the area. Despite agricultural and other anthropogenic activities, quality indices in the study area indicate the absence of anthropogenic inputs.   Key words: Major ions, heavy metals, rocks weathering, soil leaching, water quality assessment.

Accumulation of heavy metals in ducks exposed to heavy metals-contaminated water

The objective of this study was to determine the bioaccumulation of heavy metals (HM) (Cu, Zn, Hg, Pb and Cd) in 15 tissues (brain, breast muscle, sternum, thigh muscle, femur, blood, heart, lung, gizzard, liver, intestine, spleen, pancreas, bile and kidney) of domestic ducks exposed to HM-contaminated water with levels equal to values specified in the column B of QCVN 40:2011/BTNMT. The experiment was a completely randomized design with two treatments: without exposure to HM (CT) and with exposure to HM (ET). Each treatment was replicated 3 times. Ducks were randomly allocated to the treatments with a stocking density of 10 ducks per cage and reared for 8 weeks. The results showed that concentrations of HM, particularly toxic metals such as Hg, Pb and Cd, in all tissues of duck in the CT were lower than those in the ET. The highest levels of HM in tissues were found in the liver and kidney. In the ET, Pb levels in kidney and bone and Cd levels in liver and kidney exceeded the permissible exposure limit according to the guidance of the Ministry of Health of Vietnam and the European Commission. This study demonstrated that the accumulation of HM in duck tissues could happen even though ducks were exposed to relatively low concentrations of HM in water. Thus, further investigation on the bioaccumulation of HM in farmed ducks as well as wild water-birds should be conducted in the near future.

Pyrolysis of Solid Digestate from Sewage Sludge and Lignocellulosic Biomass: Kinetic and Thermodynamic Analysis, Characterization of Biochar

This study investigates the pyrolysis behavior and reaction kinetics of two different types of solid digestates from: (i) sewage sludge and (ii) a mixture of sewage sludge and lignocellulosic biomass—Typha latifolia plant. Thermogravimetric data in the temperature range 25–800 °C were analyzed using Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose kinetic methods, and the thermodynamic parameters (ΔH, ΔG, and ΔS) were also determined. Biochars were characterized using different chemical methods (FTIR, SEM–EDS, XRD, heavy metal, and nutrient analysis) and tested as soil enhancers using a germination test. Finally, their potential for biosorption of NH4+, PO43−, Cu2+, and Cd2+ ions was studied. Kinetic and thermodynamic parameters revealed a complex degradation mechanism of digestates, as they showed higher activation energies than undigested materials. Values for sewage sludge digestate were between 57 and 351 kJ/mol, and for digestate composed of sewage sludge and T. latifolia between 62 and 401 kJ/mol. Characterizations of biochars revealed high nutrient content and promising potential for further use. The advantage of biochar obtained from a digestate mixture of sewage sludge and lignocellulosic biomass is the lower content of heavy metals. Biosorption tests showed low biosorption capacity of digestate-derived biochars and their modifications for NH4+ and PO43− ions, but high biosorption capacity for Cu2+ and Cd2+ ions. Modification with KOH was more efficient than modification with HCl. The digestate-derived biochars exhibited excellent performance in germination tests, especially at concentrations between 6 and 10 wt.%.

Differential Zn and Mn sensitivity of microalgae species from genera Bracteacoccus and Lobosphaera.

One of the most common pollutants in natural ecosystems is heavy metals. Algae are sensitive to the action of heavy metals. This allows to use algae to assess the toxicity of heavy metals, bioindication, and during phycoremediation. This study examines the effect of different Zn and Mn concentrations (1.0, 5.0, 25.0, 50.0, 500.0, 1000.0 mg L-1) on green algae Bracteacoccus minor and Lobosphaera incisa in a chronic bioassay. The results of this study showed that the toxic effect of Zn and Mn on B. minor and L. incisa begins to manifest itself at the lowest of the studied metal concentrations-1 mg L-1. The critical concentration of Zn, which leads to the complete death of B. minor and L. incisa, is 50.0 and 500.0 mg L-1, and Mn is 1000.0 mg L-1 and 500.0 mg L-1, respectively. It was found that principal component (PC) 1 accounts for 60.47% of the total variance and reflects changes associated with low concentrations of heavy metals (up to 5.0 mg L-1). PC2 accounts for 27.95% of the total variance. PC2 is mostly associated with high concentrations of ions of heavy metals. Thus, the effect of Zn and Mn concentrations up to 5 mg L-1and above 50 mg L-1on B. minor and L. incisa has a different character. At the same time, the response of the studied algae species to the action of Zn and Mn has individual differences. In general, B. minor is more resistant to Mn, while L. incisa is more resistant to Zn.

Assessing the water quality of Suva foreshore for the establishment of estuary and marine recreational water guidelines in the Fiji Islands.

The Standards for water quality in Fiji defined in the Environment Management Regulations 2007 only relate to effluent discharge into the environment. Urbanisation is contributing to wastewater contamination in receiving estuary and marine recreational waters, thus requiring specific guidelines. To create a baseline for this, a sampling programme with relevant physico-chemical and biological parameters was implemented at 3 sites along the Suva foreshore, for 8 consecutive months, during low and high tides. Analysis was done in triplicates, using standard methods approved for the examination of water and wastewater. In the absence of relevant Fiji guidelines, the results were compared with ANZECC (2000) guidelines for estuary and marine waters. Low DO levels, high COD, TN, NH3, TP, OP and heavy metal concentrations were measured in all 3 sites. For instance, TN and NH3 concentrations as high as 4.44 ±0.99 mg/L and 2.58 ± 0.89 mg/L respectively were recorded in Wailea river (Site 2). The colony counts for the TC, FC and E. coli were in most cases above the limits. These results confirm that wastewater discharges add to the inherent levels of parameters in receiving water bodies and support the need for specific, robust Fiji standards to better monitor water quality in foreshore areas.

Assessment of heavy metal pollution and water quality characteristics of the reservoir control reaches in the middle Han River, China

The systematic and scientific assessments on heavy metal pollutions and water quality characteristics are greatly important to protecting the river and coastal eco-environment. In this paper, sediment size, organic matter, total nitrogen, total phosphorus, and heavy metal contents were analyzed by collecting surface sediments and surface water in the reservoir control reach of the middle Han River. Besides, sediment enrichment factor and sediment pollution index were used to evaluate the heavy metal pollution, and enrichment analysis and redundancy analysis were applied to analyze the sources of heavy metals in sediments. The results show a low heavy metal content in the surface water, and the water quality is graded as a Good level. The average enrichment factor of Cd in surface sediments reached 4.63. Zn and Cu also showed significant enrichment in the tributary sediments, whose content far exceeded the background value of soil elements. Thus, the potential ecological risk of heavy metals was at a medium level. Statistical analysis and enrichment factors showed that the accumulation of heavy metals in sediments was affected by pollutant input and reservoir regulation, and it was urgent to conduct an integrated regulation of the heavy metals in river sediment. This study provided an insight into the understanding of feasible assessment for heavy metal contaminated sediment.

The effect of heavy metals on sulfur autotrophic short-cut denitrification

A batch experiment was used to investigate the influence of common heavy metals Cr(VI), NI(II), Cu(II) on sulfur autotrophic short-cut denitrification. Experimental results show that low concentrations (1-3 mg/L) of heavy metals have little effect on sulfur autotrophic shortcut denitrification, and high concentrations (4-10 mg/L) of heavy metals have obvious effects on sulfur autotrophic short-cut denitrification. Inhibition. The doserape model is used to fit the doseeffect curve of heavy metals, and the IC50 is used to judge the toxicity. The order of the IC50 of each heavy metal is: Cr(VI)>NI(II)>Cu(II). The effects of two heavy metals in the binary system of Cu(II) and NI(II) are antagonistic.

Quantification of Some Heavy Metals in Hair of Dairy Cows Housed in Different Areas from Sicily as a Bioindicator of Environmental Exposure-A Preliminary Study.

Simple SummaryHeavy metals are considered one of the most critical pollutants that contaminate the environment through anthropogenic or natural activities. Animals are very good indicators of environmental pollution as they inhabit the same space as humans and are exposed to the same pollutants. The levels of selected heavy metals in hair samples of Holstein dairy cows are evaluated in this study. The gathered results would emphasize the usefulness of hair samples as possible bioindicators of heavy metal exposure that, in the long term, could be harmful to the final consumer. Moreover, this study gives an overview about the scenario of anthropogenic activity effects on heavy metal accumulation in dairy cows from Ragusa, a peculiar Sicilian province particularly dedicated to cow breeding for milk production.The objective of this preliminary study was to evaluate the levels of selected heavy metals in hair samples of Holstein dairy cows reared on agricultural soils characterized by grassland subjected to anthropogenic impacts. Ninety Holstein-Friesian cows were enrolled in the study and divided into six groups according to farm origin. From each animal, hair samples were collected in order to determine the content of aluminum, chromium, iron, copper, zinc, arsenic, cadmium, and lead. One-way analysis of variance was applied to assess statistically significant differences in the studied heavy metals among the six groups. A significant effect of groups (p < 0.05) on all tested heavy metals was observed. In this study, the low concentration of heavy metals in the hair of the studied animals led us to think that the cows were subjected to low levels of these compounds, preventing them from bioaccumulating. Although the current study provides only preliminary results, it highlights the importance of investigating the concentration of heavy metals in cow hair to improve the health and welfare of both humans and animals.

Long-Term Cultivation of a Native Arthrospira platensis (Spirulina) Strain in Pozo Izquierdo (Gran Canaria, Spain): Technical Evidence for a Viable Production of Food-Grade Biomass

Microalgae cultivation is a promising alternative to traditional agriculture in arid—semi-arid areas. The aim of this study is to assess the viability of long-term cultivation of native Arthrospira platensis in Gran Canaria. Maximum culture productivity (0.08 g/L/day) and optimal concentration range (0.6–0.9 g/L) were firstly determined in 8000 L raceway under a greenhouse. Afterwards, a stable productivity of 0.06 g/L/day (6.0 g/m2/day) was obtained by reusing the culture medium during 26 days of cultivation, with consistent biomass biochemical composition. Outdoor temperature and daily solar irradiation ranged between 17.9–30.7 °C and 79.2–274.8 W/m2, while culture pH and salinity were in the range 9.42–10.77 and 11.2–14.9 g/L, respectively. Protein (&gt;60%), potassium (1.8 g/100 g) and C-phycocyanin (7.2%) content is in the high-range of commercial Spirulina, which makes BEA 1257B promising for food and extraction of natural pigments/antioxidants. The dried biomass complies with international standards for human consumption, because of low heavy metal content and no pathogens presence. Product quality can be improved by reducing ash (≃12%) and sodium (1.5%) content through biomass washing optimization and/or further dewatering step. Other microorganisms can be prevented by high alkaline conditions and mild chemical treatments. These results pave the way for a sustainable microalgae-based blue bioeconomy in the Canary Islands.

A Comparative Study on Opto-Thermal Properties of Natural Clay Bricks Incorporating Dredged Sediments

The brick industry is currently facing a shortage of natural resources. Despite this, the demand for construction bricks is progressively increasing. Alternative materials, such as dredged sediments and solid organic waste, have been recently proposed as options to replace natural clay in brick manufacturing. Potential exploitation of dredged sediments in clay bricks is evaluated in this study. The chemical composition of the mixtures and the opto-thermal properties of brick samples, which differed for the dredged sediment content (from 10% to 50% of the clay weight), were investigated. Chemical analyses detected lower concentrations of heavy metals in bricks incorporating dredged sediments (DS). Negligible variations in thermal conductivity, thermal diffusivity, and specific heat were observed by increasing the amount of DS in the mixture. In particular, the thermal conductivity values ranged between 0.45 ± 0.03 W m−1 K−1 (DS-50) and 0.50 ± 0.03 W m−1 K−1 (DS-30). Conversely, the color shift value and spectral reflectance in the infrared field were found directly proportional to the concentration of DS. Using dredged sediments as building material demonstrated to be a solution to the problem of their disposal and the scarcity of raw materials, reducing the global warming score by up to 2.8%.

Mixed metal oxide anodes used for the electrochemical degradation of a real mixed industrial wastewater

Mixed industrial wastewaters are often highly contaminated with heavy metals and organic pollutants. Treating these mixed wastewaters requires many stagewise unit operations. Our work investigates using an electrochemical oxidation-in-situ coagulation (ECO-IC) process as a pre-treatment step toward the efficient treatment of real mixed industrial wastewater rich with heavy metals and organic contaminants. The process degraded organic contaminants in the wastewater via anodic electrochemical oxidation. Simultaneously, heavy metals were precipitated in the solution by coagulants (iron hydroxides) formed in-situ by cathode-generated hydroxyl ions reacting with the significant amounts of dissolved iron in the wastewater. IrO2–RuO2 mixed metal oxide anodes were identified as the best electrodes for organic compound degradation demonstrating 97% degradation of methyl orange (MO) as a model compound within 15 min. These anodes were used to treat real industrial wastewater produced from the industrial cleaning of train tanker cars transporting industrial solvents. The electrochemical treatment experiments resulted in a treated solution with a lower heavy metal content, achieving 96% reduction in Fe and 30% reduction in As content. Only moderate decreases in organic content were observed up to a maximum of 13% reduction in total organic carbon after 1 h of treatment. Electrochemical treatment of the mixed industrial wastewater produced greater effective diameter of the suspended particles and distinct sediment, liquid, and suspended foam phases that could be easily separated for further treatment. ECO-IC shows promise as an efficient and chemical-free method to coagulate heavy metals in real industrial wastewaters and could be an effective pre-treatment in their separation.

Levels of Hydroquinone, Selected Heavy Metals (Hg, Pb, As) and Chemical requirements in Some Skin Lightening Creams Sold in Mbarara Municipality

In this study, Skin-lightening creams commonly sold in Mbarara municipality were analyzed for chemical parameters (pH, thermal stability and fatty substance content), total hydroquinone, Lead, Mercury, and Arsenic contents. Total heavy metal content was determined by atomic absorption spectrophotometry. The levels of hydroquinone were determined using High Performance liquid chromatography (HPLC). All the creams showed detectable mean levels of mercury, ranging from 0.07±0.01ppm to 0.33±0.01ppm. Only 26.31% of the creams showed detectable levels of lead and 15.79% creams recorded detectable levels of arsenic. The mean levels of hydroquinone ranged from 0.54±0.02% to 4.47±0.02%. All the creams passed the thermal stability and fatty substance content tests. However, all the creams had very low pH values below the recommended 4.5- 8.5 pH ranges by Uganda National Bureau of Standards (UNBS). The levels of mercury, arsenic and lead in the samples were less than the UNBS, European Union and US Food and Drug Administration’s acceptable limits. Only 84.2% of the cream samples analyzed contained hydroquinone levels higher than the recommended WHO limit of 2%. The use of such creams may lead to serious health hazards. While the low concentrations of heavy metals detected in the cream samples analyzed do not pose any potential risk to consumers, repeated application of these creams may cause a cumulative effect over prolonged exposure. The low pH values may cause skin irritations. Therefore, the community needs to be sensitized on the implications of using skin lightening creams and UNBS should conduct periodic analysis to ascertain the levels of hydroquinone, heavy metals, and chemical requirements of skin lightening creams sold in Uganda as well as encourage manufacturers to state the exact bleaching agents in their creams.

Heavy Metal Potential of Domestic Biological Wastewater Treatment Plant Sludge

The use of sludge as fertilizers helps to the recycling of nutrients to the environment due to its beginning from wastewater and therefore relatively high content of nutrients and organic matter. However, wastewater does also contain hazardous compounds like heavy metals and micro pollutants which eventually are separated to the sludge during the treatment processes at the wastewater treatment plant. In order to improve the sludge quality, source tracking is a relatively cheap and effective way to find and eliminate hazardous compounds and prevent them from ending up in the sludge. The aim with this thesis was to investigate the fertilizer potential in sludge from wastewater treatment plant. The sludge is analyzed in terms of nutrient and heavy metal contents as well as physiochemical parameters. In order to determine the potential as fertilizer, the quality of the sludge is compared with other fertilizer alternatives, other sludge types and regulations for sludge use in agriculture. The work with sludge quality improvements in Gaborone is also investigated. Sludge from different stages along the treatment processes were collected in order to see differences in quality related to the treatment. The results shows that the samples of primary an aerobically treated sludge tend to have higher heavy metal content than the secondary sludge. The quality of the dry sludge samples indicates lower nutrient content than both the primary and secondary sludge, but similar heavy metal content. The analysis of dry sludge from indicates a low nutrient value and high heavy metal content in comparison to other selected fertilizer options and sludge from other. The processes for removal of nutrients from the wastewater are an important factor for the nutrient content in the sludge. Keywords wastewater; fertilizers; nutrients; sludge treatment

The influence of heavy metals on the shape and asymmetry of wings of female Polistes nimpha (Hymenoptera, Vespidae) living on contaminated sites

The aim of the present study was to determine the fluctuating asymmetry of the first pair of wings in females Polistes nimpha (Christ, 1791) living in an environment contaminated with heavy metals. The average concentration of Zn, Cd and Pb in the bodies of the insects varied depending on the distance from the source of contamination, reaching the highest values on the site closest to the source of contamination and the lowest at the most distant site. As a result of the morphometric analyses, significant differences were found in the asymmetry values of the first pair of wings depending on the level of Zn, Cd, Pb accumulated by the wasps. In the case of shape asymmetry, differences were found for all the effects studied (year of capture and site). Significant differences were also found in the size of wings between individuals captured on Sites 1 and 2 and those caught on Site 3. Specimens caught on site characterized by the lowest concentration of heavy metals in the topsoil, proved to be significantly larger than the insects collected on the other sites. There were no differences in the size of individuals between the different years of capture. Based on the results obtained by us, it can be assumed that the wings of P. nimpha females may become a useful object in studying the impact of environmental stress of Zn, Cd and Pb pollution on the symmetry of their wings.

Roughcast analysis as a new method of environmental research

The aim of this study is to show purpose of roughcast analysis as a new useful tool for research of the condition of the environment. Samples of roughcast were collected from buildings in 6 different cities of Europe (Cracow, Lublin, Warsaw, Lviv, Monchegorsk and Murmansk) and their compositions were examined with scanning electron microscope, ICP-OAS and ASA methods. Also, binocular magnifier was used. The samples were investigated for heavy metals presence. The result shows that despite the deposition of particles is bigger on horizontal surface, the vertical layer of roughcast accumulate significant amounts of impurities and heavy metals. The composition and content of metals differ accordingly to automotive traffic nowadays and in the past, existence of road hubs, industrial districts and historical manufactures. Samples from Cracow show high content of non-ferrous metals and nickel, whereas content of copper was significantly higher in Monchegorsk. In Lublin and Lviv, their agricultural past contributed to significantly lower heavy metal content Determination of heavy metals contents in roughcast can be used to evaluate anthropogenic impact in the cities through the years and to help to protect cities’ population from negative consequences of living in urban areas.

Optimal Operating Conditions for Adsorption of Heavy Metals from an Aqueous Solution by an Agriculture Waste

The aim of this work is to detect the best operating conditions that effect on the removal of Cu2+, Zn2+, and Ni2+ ions from aqueous solution using date pits in the batch adsorption experiments. The results have shown that the Al-zahdi Iraqi date pits demonstrated more efficient at certain values of operating conditions of adsorbent doses of 0.12 g/ml of aqueous solution, adsorption time 72 h, pH solution 5.5 ±0.2, shaking speed 300 rpm, and smallest adsorbent particle size needed for removal of metals. At the same time the particle size of date pits has a little effect on the adsorption at low initial concentration of heavy metals. The adsorption of metals increases with increasing the initial of metal concentration while above the 85 ppm, the removal efficiency was decreased. The phenomenon of adsorption of heavy metals on to Al-Zahdi Iraqi Date pits is exothermic process. The maximum adsorption capacity according to the Langmuir equation was 0.21, 0.149, and 0.132 mmol/g for Cu2+, Zn2+, and Ni2+ respectively. The adsorption equilibrium was well described by the Freundlich model. The results of Freundlich constants indicated that the adsorption capacity and adsorption intensity of Copper is larger than the Zinc and Nickel. The intraparticle diffusion was involved is this process but it is not the controlling step. The results of this study may inspire to find the optimal operating conditions for adsorption and develop that with large-scale production to clean the polluted water with heavy metals.

Black locust flowers: antioxidant extraction kinetics, reducing capacity, mineral composition, and antioxidant activity

The impact of solvent polarity on the kinetics, reducing capacity, antioxidant activity, and mineral composition of black locust (Robinia pseudoacacia) flowers extracts obtained by ultrasound-assisted extraction was investigated. The DPPH assay and the Folin-Ciocalteu method were applied to define the antioxidant activity and reducing capacity of the extracts, respectively. The mineral content was defined using the ICP-OES method. Ponomaryov and non-stationary diffusion models were used for modeling the extraction of antioxidants. The obtained results showed that antioxidant activity, phenolic and mineral contents of the extracts were varied significantly depending on the solvent polarity. The highest reducing capacity (3.78 g gallic acid equivalent per 100 g dry weight) had the 50% (v/v) methanol extract, while the strongest antioxidant activity (IC50 = 0.3381 mg/mL) was found in the 50% (v/v) ethanol extract. HPLC analysis showed that water as a solvent had the highest extraction capacity for vanillic acid and catechin hydrate. ICP-OES analysis confirmed that the black locust flower extracts are rich in macroelements (Ca, Na, Mg, K) with low content of heavy metals (Pb, Cd). The 50% (v/v) ethanol extract had the highest amount of macroelements, predominantly potassium (10.49 g/kg). The prepared extracts due to good antioxidant activity, high phenolic and mineral content, and low heavy metal contents can be considered useful for further human uses.

Potential Uses of Stormwater Runoff Sedimentgs Retained in a Constructed-Wetland/Storage-Tank

Objective: The goal of this work was to establish the quality conditions of the sediments retained in a constructed-wetland/storage-tank, which are to be used as productive material. Materials and methods: Sediments were collected every fortnight for five months in 2016, with sediment traps specially designed for the study case, to analyze particle size distribution, total organic carbon, and heavy metals concentrations. Sediment and hydrological data processing were performed using principal component analysis and multiple correspondence analysis. Results: The maximum measured concentrations were 110.80 mg/kg, 263.25 mg/kg, 798.85 mg/kg, and 3067 mg/kg for Cr, Cu, Pb, and Zn respectively; for total organic carbon was 20.6 mg. The sediment particles were considered thin (D50 &lt; 150μm). Interesting relationships between rainfall and sediment characteristics were found. In shorter dry seasons, higher particle diameter, lower concentrations of heavy metals, and higher concentrations of total organic carbon were seen. Conclusions: Sediments are suitable for use in activities such as land remediation, vegetation of soils that are not for agricultural use, and as materials for ornamental and recreational areas. It is possible to use the sediments in embankments as tolerable soil for fillings of concrete structures and culverts in the core or foundation area.

The chemical composition of pollen, staminate catkins, and honey of Castanea sativa Mill.

The chemical composition of pollen and honey primarily depends on the botanical and geographical origin of the species, as well as other factors – climatic conditions, soil type, plant species, etc. The present study was to knowledge the biochemical profile of pollen, staminate catkins, and honey samples of Castanea sativa Mill. which were examined under conditions of Ukraine. Proteins are the major components of pollen and staminate catkins (169.0 ±1.60 g.kg-1 and 69.8 ±1.67 g.kg-1, respectively), while saccharides are predominant in honey samples (38.0 ±1.32 g.kg-1 fructose, 32.5 ±0.68 glucose g.kg−1 and 6.1 ±0.06 g.kg-1 sucrose). Glutamic acid (13.30 g.kg-1), aspartic acid (13.05 g.kg-1), and proline (12.45 g.kg-1) were predominant nonessential amino acids in the chestnut pollen. The content of macro and microelements was found in the pollen and staminate catkins much higher than in the honey. All Castanea sativa samples are a very valuable source of potassium as the main mineral element contained in pollen (7400 mg.kg-1), staminate catkins (7760 mg.kg-1), and honey (981 mg.kg-1). Microelements such as manganese and iron prevailed in pollen (478 mg.kg-1 Mn and 461 mg.kg-1 Fe), and staminate catkins (247 mg.kg-1 Mn and 109 mg.kg-1 Fe), and heavy metals (Hg, Sr, Sn, Sb, Li) are present only in the pollen samples with the most abundant Sr (12.8 mg.kg-1) and Sn (1.9 mg.kg-1) content and can be used as indicator suggesting the environmental pollution status in the region. Regarding the vitamin content, vitamin C was the most represented in all samples. Obtained results indicate that chestnut is species with important constituents such as amino acids and vitamins, with low content of heavy metals and high content of biogenic elements that may be used in phytotherapy and phytopharmacology.

Soil heterogeneity within a vineyard impacts the beta but not the alpha microbial agro-diversity

Here we investigate the effect of agricultural integrated management on soil microbial diversity within a vineyard with a history (20 years) of exposure to frequent applications of fertilizers and pesticides each season. Considering that these practices were mainly directed to the target plant (i.e. grapevine) and its surrounding area, we expected that these practices have influenced the soil alpha and beta bacterial and fungal diversity differently. Soil samples were collected from three different sites: row, inter-row (space between vines rows) and headland.The soil microbial community was investigated by targeted amplicon sequencing of the 16SrRNA gene (for bacteria) and the ITS region (for fungi), and the chemical and physical soil properties have been characterized.Soil samples collected in row and inter-row were chemically and microbiologically different from the headland soil (PERMANOVA: row/inter-row vs headland P ≤ 0.01), exhibiting this latter a significantly lower concentration of heavy metals. This soil heterogeneity seemed to play a crucial role in the variation of species diversity of microbial communities among sites (i.e. beta-diversity). In contrast, the mean species diversity in each site (i.e. alpha-diversity) did not change among the sites.The sole variation of the beta-diversity could indicate a possible turnover of soil microbial communities to agricultural practices without compromising the alpha-diversity values.