Humic acids extracted from compost as amendments for Fenton treatment of diesel-contaminated soil

In this study, we investigate the performance of a Fenton-like process carried out adding as amendments humic acids extracted from compost obtained from or     

“Modern agriculture” transfers many pesticides to watercourses: a case study of a representative rural catchment of southern Brazil

Environmental Science and Pollution Research - The total cultivated area in Brazil reached to 62 million ha in 2018, with the predominance of genetically modified soybean and corn (36 and 17...     

The Influence of Linear Elements on Plant Species Diversity of Mediterranean Rural Landscapes: Assessment of Different Indices and Statistical Approaches

This paper mainly aims to study the linear element influence on the estimation of vascular plant species diversity in five Mediterranean landscapes modeled as land cover patch mosaics. These landscapes have several core habitats and a different set of linear elements -habitat edges or ecotones, roads or railways, rivers, streams and hedgerows on farm land- whose plant composition were examined. Secondly, it aims to check plant diversity estimation in Mediterranean landscapes using parametric and non-parametric procedures, with two indices: Species richness and Shannon index.Land cover types and landscape linear elements were identified from aerial photographs. Their spatial information was processed using GIS techniques. Field plots were selected using a stratified sampling design according to relieve and tree density of each habitat type. A 50×20 m² multi-scale sampling plot was designed for the core habitats and across the main landscape linear elements. Richness and diversity of plant species were estimated by comparing the observed field data to ICE (Incidence-based Coverage Estimator) and ACE (Abundance-based Coverage Estimator) non-parametric estimators.The species density, percentage of unique species, and alpha diversity per plot were significantly higher (p < 0.05) in linear elements than in core habitats. ICE estimate of number of species was 32% higher than of ACE estimate, which did not differ significantly from the observed values. Accumulated species richness in core habitats together with linear elements, were significantly higher than those recorded only in the core habitats in all the landscapes. Conversely, Shannon diversity index did not show significant differences.     

Preparation of 2-mercaptobenzothiazole-derivatized mesoporous silica and removal of Hg(ii) from aqueous solution

Mesoporous silicas (SBA-15 and MCM-41) have been functionalized by two different methods. Using the heterogeneous route the silylating agent, 3-chloropropyltriethoxysilane, was initially immobilized onto the mesoporous silica surface to give the chlorinated mesoporous silica Cl-SBA-15 or Cl-MCM-41. In a second reaction a multifunctionalized N,S donor compound (2-mercaptobenzothiazol) was incorporated to obtain the functionalized silicas denoted as MBT-SBA-15-Het and MBT-MCM-41-Het. Using the homogeneous route, the functionalization was achieved via the one step reaction of the mesoporous silica with an organic ligand containing the chelating functions, to give the modified mesoporous silicas denoted as MBT-SBA-15-Hom or MBT-MCM-41-Hom. The functionalized mesoporous silicas were employed as adsorbents for the regeneration of aqueous solutions at pH 6 contaminated with Hg(ii) at room temperature. Results obtained indicate that mercury adsorption was higher in the mesoporus silicas prepared by the homogeneous method, and the maximum adsorption value (0.24 +/- 0.02 mmol Hg(ii) g(-1)) was obtained for MBT-SBA-15-Hom. The chemically stability in acid medium of the functionalized silicas, possibility its regeneration washing with concentrate HCl, resulting in the reuse of the adsorbent material for several cycles.     

Challenges for modelling and integrating environmental performances in concept design: the case of an automotive component lightweighting

The objective of this paper is to discuss the main barriers for modelling and integrating the environmental performances in the automotive concept design. Incorporating environmental assessment in the early design phase of a vehicle component is known as an important challenge that car makers need to face in order to develop more sustainable design solutions; in this regard, the Life Cycle Assessment is the most widespread methodology for the environmental assessment and comparison of alternatives. The present work illustrates the combination of such methodology with the traditional design procedure at two different levels of the component design phase, material choice and concept design. In particular, the potential benefits originated by a lightweight solution for the automotive component Throttle Body are evaluated by considering environmental and technical implications at the same level. The case study shows that a multi-disciplinary approach for design effectively allows the integration of the environmental issue in the company’s established procedures. However, interpretation of results is still a challenging aspect due to the inevitable contradicting elements which should not discourage to develop comprehensive sustainability assessment within the early design stage.     

Effect of fireworks on ambient air quality in Malta

Religious festivals (festas) in the densely populated Maltese archipelago (Central Mediterranean) are ubiquitous during summer when 86 of them are celebrated between June and October, each involving the burning of fireworks both in ground and aerial displays over a period of 3 days or longer per festival. We assessed the effect of fireworks on the air quality by comparing PM₁₀ and its content of Al, Ba, Cu, Sr and Sb which materials are used in pyrotechnic compositions. PM₁₀ was collected mainly from two sites, one in Malta (an urban background site) and the other in Gozo (a rural site) during July–August 2005 when 59 feasts were celebrated and September–October 2005 when only 11 feasts occurred. For both Malta and Gozo, PM₁₀ and metal concentration levels measured as weekly means were significantly higher during July–August compared to September–October and there exist strong correlations between PM₁₀ and total metal content. Additionally, for Malta dust, Al, Ba, Cu and Sr correlated strongly with each other and also with total concentration of all five metals. The same parameters measured in April 2006 in Malta were at levels similar to those found in the previous October. Ba and Sb in dust from the urban background site in Malta during July–August were at comparable or higher concentration than recently reported values in PM₁₀ from a heavily-trafficked London road and this suggests that these metals are locally not dominated by sources from roadside materials such as break liner wear but more likely by particulate waste from fireworks. Our findings point to the fact that festa firework displays contribute significantly and for a prolonged period every year to airborne dust in Malta where PM₁₀ is an intractable air quality concern. The presence in this dust of elevated levels of Ba and especially Sb, a possible carcinogen, is of concern to health.     

Phenol depletion by thermally activated peroxydisulfate at 70°C

The ability of thermal activated peroxydisulfate (PS) of mineralizing phenol at 70 °C from contaminated waters is investigated. Phenol in concentrations of 10⁻⁴ to 5 × 10⁻⁴ M is quantitatively depleted by 5 × 10⁻³ to 10⁻² M activated PS in 15 min of reaction. However, mineralization of the organic carbon is not observed. Instead, an insoluble phenol polymer-type product is formed. A reaction mechanism including the formation of phenoxyl radicals and validated by computer simulations is proposed. High molecular weight phenolic products are formed by phenoxyl radical H-abstraction reactions. This is not the case for the room temperature degradation of phenol by sulfate radicals where sulfate addition to the aromatic ring mainly leads to the generation of hydroxycyclohexadienyl radicals leading to hydroxybenzenes and oxidized open chain products. Therefore, a change in the reaction mechanism is observed with increasing temperature, and thermal activation of PS at 70 °C does not lead to the mineralization of phenol. Thus PS activation at 70 °C may be considered a potential method to reduce the load of phenol in polluted waters by polymerization.     

Lactational exposure to phthalates in Southern Italy

BackgroundPhthalates, reproductive toxicants in animals, are synthetic chemicals with ubiquitous human exposures because of their extensive use, with potential detrimental health effects. Infants are considered to represent a population at increased risk, as they are exposed early in life to several different sources of exposure to phthalates.Objectives and methodsLittle information exists on phthalate exposure through breast milk from different geographic areas. By means of a LC/LC–MS/MS method we tested the presence of several different phthalate metabolites in breast milk from 62 healthy mothers living in Southern Italy.ResultsThe simple monoesters mono-isobutyl phthalate (MiBP) (median 18.8 μg/l) and mono(2-ethylhexyl) phthalate (MEHP) (median 8.4 μg/l) were present in all milk samples, whereas mono-n-butyl phthalate (MnBP) (median 1.5 μg/l) and mono-benzyl phthalate (MBzP) (median < 0.3 μg/l) were found in 64.5% and 43.5% of the samples, respectively. Among the oxidative metabolites of DEHP and DiNP only mono(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP) and monoisononyl phthalate with one hydroxyl group (OH-MiNP) were detectable in one and 13 samples (21%), respectively.ConclusionsThese findings indicate that exposure to phthalates through breast milk in Southern Italian infants is comparable to that of other countries, thus confirming that human milk may represent an additional potential source of phthalate exposure in a population at increased risk. However, different milk concentrations of MiBP may suggest a different pattern of usage of di-iso-butyl phthalate in Europe, as compared to USA, whereas for the first time, we detected an oxidative DiNP metabolite, whose significance remains unclear.     

Festuca arundinacea,glutathione S-transferase and herbicide safeners: A preliminary case study to reduce herbicidal pollution

The expression of glutathione S-transferase (GST) activity in Festuca arundinacea was investigated in response to the following herbicide safeners: benoxacor, cloquintocet-mexyl, fenchlorazol-ethyl, fenclorim, fluxofenim and oxabetrinil. All the above compounds enhanced the GST activity tested towards the “model” substrate 1-chloro-2,4-dinitrobenzene (CDNB). Assays of GST activity towards the herbicides terbuthylazine (N ²-tert-butyl-6-chloro-N ⁴-ethyl-1,3,5-triazine-2,4-diamine) and butachlor (N-butoxymethyl-2-chloro-2′,6′-diethylacetanilide) as substrates also showed the ability of the safeners to enhance the enzyme activity towards both these herbicides, with the exception of cloquintocet-mexyl for the enzyme activity towards butachlor. As a consequence of the above effects at a macro-scale level, decreased herbicide accumulation and persistence were ascertained in response to the addition of the safener benoxacor to both terbuthylazine and butachlor treatments. These results are discussed in terms of capacity of benoxacor to induce herbicide detoxification in Festuca arundinacea with a view to utilizing them in reducing herbicide pollution.     

Carbon deposition in soil rhizosphere following amendments with compost and its soluble fractions, as evaluated by combined soil-plant rhizobox and reporter gene systems

We determined the organic carbon released by roots of maize plants (Zea mays L.) when grown in soils amended with compost and its soluble fractions. In rhizobox systems, soil and roots are separated from the soil of a lower compartment by a nylon membrane. Treatments are applied to the upper compartment, while in the lower compartment luminescent biosensors measure the bioavailable organic carbon released by roots (rhizodeposition). The rhizobox-plants systems were amended with a compost (COM), its water extract (TEA), the hydrophobic (HoDOM) and hydrophilic (HiDOM) fractions of the dissolved organic matter (DOM) extracted from the compost. After root development, the lower untreated compartments were sampled and sliced into thin layers. The bioavailable organic carbon in each layer was assessed with the lux-marked biosensor Pseudomonas fluorescens 10586 pUCD607, and compared with total organic carbon (TOC) analyses. The TOC values ranged between 8.4 and 9.6 g kg(-1) and did not show any significant differences between bulk and rhizosphere soil samples in any treatment. Conversely, the biosensor detected significant differences in available C compounds for rhizosphere soils amended with various organic materials. Concentrations of available organic compounds in the first 2 mm of soil rhizosphere were 1.69 (control), 1.09 (COM), 2.87 (HiDOM), 4.73 (HoDOM) and 2.14 (TEA)micromol Cg(-1) soil g(-1) roots. The applied rhizobox-biosensor integrated method was successful in detecting and quantifying effects of organic amendments on organic carbon released by maize plant roots. This approach may become important in assessing the carbon cycle in agricultural soils and soil-atmosphere compartments.