Gasification of the char derived from distillation of granulated scrap tyres

This work reports the effect of pressure on the steam/oxygen gasification at 1000 °C of the char derived from low temperature-pressure distillation of granulated scrap tyres (GST). The study was based on the analysis of gas production, carbon conversion, cold gas efficiency and the high heating value (HHV) of the product. For comparison, similar analyses were carried out for the gasification of coals with different rank.In spite of the relatively high ash (≈12 wt.%) and sulphur (≈3 wt.%) contents, the char produced in GST distillation can be regarded as a reasonable solid fuel with a calorific value of 34 MJ kg⁻¹. The combustion properties of the char (E_A ≈ 50 kJ mol⁻¹), its temperature of self-heating (≈264 °C), ignition temperature (≈459 °C) and burn-out temperature (≈676 °C) were found to be similar to those of a semi-anthracite.It is observed that the yield, H₂ and CO contents and HHV of the syngas produced from char gasification increase with pressure. At 0.1 MPa, 4.6 Nm³ kg_char⁻¹ of syngas was produced, containing 28% v/v of H₂ and CO and with a HHV around 3.7 MJ Nm⁻³. At 1.5 MPa, the syngas yield achieved 4.9 Nm³ kg_char⁻¹ with 30% v/v of H₂-CO and HHV of 4.1 MJ Nm⁻³. Carbon conversion significantly increased from 87% at 0.1 MPa to 98% at 1.5 MPa.It is shown that the char derived from distillation of granulated scrap tyres can be further gasified to render a gas of considerable heating value, especially when gasification proceeds at high pressure.     

Fetoplacental discrepancy involving structural abnormalities of chromosome 8 detected by prenatal diagnosis

We describe the finding of three cell lines involving different structural abnormalities of chromosome 8 detected in a prenatal diagnosis. Chorionic villi sampling (CVS) was performed on a pregnant woman because of advanced maternal age. Semidirect cytogenetic analysis showed a mos46,XX,i(8q)/46,XX,del(8)(p11.2) karyotype, confirmed by fluorescence in situ hybridization (FISH). Amniocentesis was subsequently performed, and the karyotype obtained was 46,XX,dup(8)(p23p11.2). The pregnancy was terminated; pathologic findings included clubfeet, clenched left hand, subcutaneous edema and bilateral hydrocephalus. Molecular studies using chromosome 8 microsatellites performed on parents' blood and fetal tissues revealed a maternal meiotic origin of the inv dup(8p) with deletion of the distal p23 region and duplication of the remaining 8p. We propose a model to explain the cytogenetic findings, which includes a first maternal meiotic error giving rise to a large dicentric isochromosome 8 present in the ovum, a second error in one of the first zygote divisions with misdivision of the dicentric 8 giving rise to a cell line with del(8p) confined to the trophoblast and another cell line with inv dup(8p) confined to the fetal tissue and a third error in the trophoblast giving rise to a further cell line with isochromosome 8q. Copyright © 2003 John Wiley & Sons, Ltd.     

Controlling risks of P water pollution by sorption on soils,pyritic material,granitic material,and different by-products: effects of pH and incubation time

Environmental Science and Pollution Research - Batch experiments were used to test P sorbent potential of soil samples, pyritic and granitic materials, mussel shell, mussel shell ash, sawdust, and...     

Removal of organochlorine pesticides from lindane production wastes by electrochemical oxidation

This study is focused on the effective removal of recalcitrant pollutants hexaclorocyclohexanes (HCHs, isomers α, β, γ, and δ) and chlorobenzenes (CBs) present in a real groundwater coming from a landfill of an old lindane factory. Groundwater is characterized by a total organic carbon (TOC) content of 9 mg L^?1, pH₀?=?7, conductivity?=?3.7 mS cm^?1, high salt concentration (SO₄^2?, HCO₃^?, Cl^?), and ferrous iron in solution. The experiments were performed using a BDD anode and a carbon felt (CF) cathode at the natural groundwater pH and without addition of supporting electrolyte. The complete depletion of the four HCH isomers and a mineralization degree of 90% were reached at 4-h electrolysis with a current intensity of 400 mA, the residual TOC (0.8 mg L^?1) corresponding mainly to formic acid. A parallel series reaction pathway was proposed: HCHs and CBs are transformed into chlorinated and hydroxylated intermediates that are rapidly oxidized to non-toxic carboxylic acids and/or mineralized, leading to a rapid decrease in solution pH.     

Effects of arbuscular mycorrhizal fungi on Agrostis capillaris grown on amended mine tailing substrate at pot,lysimeter, and field plot scales

Applied research programs in the remediation of contaminated areas can be used also for gaining insights in the physiological and ecological mechanisms supporting the resistance of plant communities in stress conditions due to toxic elements. The research hypothesis of this study was that in the heavily contaminated but nutrient-poor substrate of mine tailing dams, the beneficial effect of inoculation with arbuscular mychorrizal fungi (AMF) is due to an improvement of phosphorus nutrition rather than to a reduction of toxic element transfer to plants. A concept model assuming a causal chain from root colonization to element uptake, oxidative stress variables, and overall plant development was used. The methodological novelty lies in coupling in a single research program experiments conducted at three scales: pot, lysimeter, and field plot, with different ages of plants at the sampling moment (six subsets of samples in all). The inoculation with AMF in expanded clay carrier had a beneficial effect on the development of plants in the amended tailing substrate heavily contaminated with toxic elements. The effect of inoculation was stronger when the quantity of expanded carrier was smaller (1 % vs. 7 % inoculum), probably because of changes in substrate features. The improvement of plant growth was due mainly to an improvement in phosphorus nutrition leading to an increase of protein concentration and decrease of oxidative stress enzyme activity (superoxide dismutase and peroxidase). In a single data subset, an effect of inoculation on the uptake of several toxic elements could be proved (decrease of As concentration in plant roots correlated with a decrease of oxidative stress independent from the effect of P concentration increase). The multi-scale approach allowed us to find differences between the patterns characterising the data subsets. These subset-specific patterns point out the existence of physiological differences between plants in different development states (as a result of sampling at different plant ages). From an applied perspective, conclusions are drawn with respect to the use of plants in the monitoring programs of contaminated areas and the use of inoculation with AMF in the remediation of tailing dams.     

Alkylphenols and polycyclic aromatic hydrocarbons in eastern Mediterranean Spanish coastal marine bivalves

This paper reports the first results on alkylphenol pollution in edible bivalves from the Spanish coast. Two sampling campaigns (July 2006 and July 2007) were carried out to determine the concentration of nonylphenol (NP), octylphenol (OP), and eight polycyclic aromatic hydrocarbons (PAHs) in wild mussels (Mytilus galloprovincialys) and clams (Donax trunculus) at 14 sampling sites along the eastern Mediterranean Spanish coast. The results show that NP is the predominant alkylphenol, being the port of Valencia the most polluted area (up to 147 ??g/kg wet weight in clams). Moving away from the ports the concentration of NP in bivalves decreased. OP concentration was below its detection limit in most of the studied areas and its maximum concentration (6 ??g/kg w/w) was measured in clams from the port of Sagunto. The presence of low levels of PAHs was observed in most of the studied areas. The total PAHs concentration (i.e., sum of the eight measured PAHs) achieved a maximum value of 10.09 ??g/kg w/w in the north coast of Valencia city. The distribution pattern of the individual PAHs showed that both pollution sources petrogenic and pyrolytic were present in the sampled areas. Fluoranthene was the most abundant PAH in mussels while benzo(b)fluoranthene in clams. The maximum concentration of 10 ??g/kg w/w for benzo(a)pyrene established by the European Commission was never reached, indeed sampled bivalves showed concentrations 10 times lower than this reference value. Thus, they can be considered safe for human consumption. Despite the low contamination levels, the results show an overall pollution of bivalves by alkylphenol and PAHs as well as an increment in the number of polluted areas from 2006 to 2007. Thus, periodical sampling campaigns should be carried out to monitor the long-term tendency of these toxic and persistent pollutants.     

Managing environmental knowledge through unlearning in Spanish hospitality companies

The Spanish hospitality industry is facing environmental challenges which require organizations and individuals to learn new skills and practices and create new environmental knowledge. Understanding the nature and role of prior knowledge for sustainable development is a necessary step towards understanding if new environmental practices will be adopted successfully. This research focuses on unlearning and its impact on environmental knowledge by carrying out an empirical investigation of the unlearning context in 127 Spanish hospitality companies. The findings indicate that a process for consolidating emergent understandings would appear to be an intermediary step between the forgetting of old knowledge and the application of new environmental knowledge. Consequently, it is important that managers provide an appropriate unlearning context to support the openness of individuals to new ideas and environmental awareness. Otherwise, individuals may be fearful of or confused by the prospect of unlearning old habits and routines.     

No detectable impact of small-scale disturbances on ‘blue carbon’ within seagrass beds

Seagrass meadows are among the most efficient and long-term carbon sinks on earth, but disturbances could threaten this capacity, so understanding the impacts of disturbance on carbon stored within seagrass meadows—‘blue carbon’—is of prime importance. To date, there have been no published studies on the impacts of seagrass loss on ‘blue carbon’ stocks. We experimentally created several kinds of small-scale disturbances, representative of common grazer and boating impacts, within seagrass (Zostera nigracaulis) meadows in Port Phillip Bay (Australia) and measured the impacts on sediment organic carbon stocks (‘C _org’, and other geochemical variables—%N, δ¹³C, δ¹⁵N). Disturbance had no detectable effect on C _org levels within seagrass sediments, even for high-intensity disturbance treatments, which remained bare (i.e. no seagrass recovery) for 2 years after the disturbance. These findings challenge the widely held assumption that disturbance and concomitant loss of seagrass habitat cause release of carbon, at least for small-scale disturbances. We suggest that larger (e.g. meadow scale) disturbances may be required to trigger losses of ‘blue carbon’ from seagrass meadows.