Comparative life cycle assessment study on environmental impact of oil production from micro-algae and terrestrial oilseed crops.

In this study the LCA methodology is applied in order to satisfy two goals: i) to evaluate the hot spots in site-specific production chain of biodiesel from terrestrial and micro-algae feedstock; ii) to compare quantitatively, utilizing primary data, the impacts of the first generation in respect to the third generation bio-fuels. Results show that micro-algae are neither competitive yet with traditional oil crops nor with fossil fuel. The use of renewable technologies as photovoltaics and biogas self production might increase the competitiveness of micro-algae oil. Further investigations are however necessary to optimize their production chain and to increase the added value of co-products.

Thermal desorption of polychlorobiphenyls from contaminated soils and their hydrodechlorination using Pd- and Rh-supported catalysts.

This paper reports about a combined technology for soil remediation from PCBs using the thermal desorption technique coupled with the catalytic hydrogenation of recovered PCBs. The reactor is a bench scale rotating desorption furnace through which nitrogen is flushed and used as carrier gas of desorbed PCBs. The latter are condensed into an hexane or hexane-acetone (1:1 v/v) solution that is then hydrogenated using phosphate-supported Pd or Rh as catalyst. The analysis of the treated soil, under variable operative conditions (temperature and desorption time), shows that the total (99.8%) decontamination from PCBs occurs. The recovery yield of the desorbed PCBs is better than 75% and the subsequent hydrogenation reaches 63% of the collected PCBs in 5h or 100% in 12h.

Supercritical fluid extraction of polycyclic aromatic hydrocarbons from marine sediments and soil samples.

Supercritical fluid extraction (SFE) was used to extract polycyclic aromatic hydrocarbons (PAH) from a certified sample of marine sediment. This sample contains a great number of organic pollutants that are present in low concentrations. The extractions were carried out at 50 and 80 degrees C, at a pressure varying from 230 to 600 bar and using CO2 in the supercritical phase and the effect of three organic modifiers (methanol, n-hexane and toluene), added at 5%/vol, at the same temperature and pressure conditions, were then considered. PAHs were characterized by GC-MS and the recover yield was estimated for 6 PAHs that were representative of those present in the sample, according to their molecular weight and to the number of condensed rings. The analytical conditions giving the best recovery efficiency were used on an unpolluted soil sample spiked with 11 PAHs of environmental importance at a concentration similar to that certified for the sediment sample. An increase in the yield of recovered PAHs, using methanol as co-solvent, was observed while higher temperatures caused a negative effect on the quantity of recovered pollutants. The recovery yield for PAHs from the spiked soil sample was measured and found to be greater than 90%. Better recoveries were obtained for those compounds with higher molecular weight.

Solid state dehalogenation of PCBs in contaminated soil using NaBH4.

In this work we present the results of an experimental study on the abatement of polychlorinated biphenyl (PCBs) in contaminated soil using a high energy milling technique, that promotes a reaction only by impact between milling bodies. A sample of soil from a controlled landfill was treated with powdered NaBH(4) using two different hydride/soil ratios (5 and 2.5% w/w). The efficiency of the dehalogenation/hydrogenation reaction was studied as a function of the milling time (3.5 up to 30 h). After each run, the total PCBs content and the production of inorganic chloride were measured. The complete abatement was obtained with a starting PCBs concentration of about 2600 mg/kg. The residual PCBs concentration resulted to be <0.2 mg/kg. The final products of the treatment were biphenyl and NaCl. Other toxic or hazardous organic by-products were not generated. Boron was found as boric acid.

Catalysis research of relevance to carbon management: progress, challenges, and opportunities.

The goal of the "Opportunities for Catalysis Research in Carbon Management" workshop was to review within the context of greenhouse gas/carbon issues the current state of knowledge, barriers to further scientific and technological progress, and basic scientific research needs in the areas of H2 generation and utilization, light hydrocarbon activation and utilization, carbon dioxide activation, utilization, and sequestration, emerging techniques and research directions in relevant catalysis research, and in catalysis for more efficient transportation engines. Several overarching themes emerge from this review. First and foremost, there is a pressing need to better understand in detail the catalytic mechanisms involved in almost every process area mentioned above. This includes the structures, energetics, lifetimes, and reactivities of the species thought to be important in the key catalytic cycles. As much of this type of information as is possible to acquire would also greatly aid in better understanding perplexing, incomplete/inefficient catalytic cycles and in inventing new, efficient ones. The most productive way to attack such problems must include long-term, in-depth fundamental studies of both commercial and model processes, by conventional research techniques and, importantly, by applying various promising new physicochemical and computational approaches which would allow incisive, in situ elucidation of reaction pathways. There is also a consensus that more exploratory experiments, especially high-risk, unconventional catalytic and model studies, should be undertaken. Such an effort will likely require specialized equipment, instrumentation, and computational facilities. The most expeditious and cost-effective means to carry out this research would be by close coupling of academic, industrial, and national laboratory catalysis efforts worldwide. Completely new research approaches should be vigorously explored, ranging from novel compositions, fabrication techniques, reactors, and reaction conditions for heterogeneous catalysts, to novel ligands and ligation geometries (e.g., biomimetic), reaction media, and activation methods for homogeneous ones. The interplay between these two areas involving various hybrid and single-site supported catalyst systems should also be productive. Finally, new combinatorial and semicombinatorial means to rapidly create and screen catalyst systems are now available. As a complement to the approaches noted above, these techniques promise to greatly accelerate catalyst discovery, evaluation, and understanding. They should be incorporated in the vigorous international research effort needed in this field.

Copper(II) catalysis in cyanide conversion into ethyl carbamate in spirits and relevant reactions.

The role of copper(II) species in the oxidation of inorganic cyanide to cyanate and in the conversion of cyanate or urea into ethyl carbamate was investigated. The oxidation process has been shown to be independent from the dissolved oxygen. Elemental analysis and infrared spectroscopy have shown the formation of a mixed copper carbonate/hydroxide in the process of oxidation of cyanide to cyanate in water/ethanol. The complexation to Cu(II) of cyanate formed upon cyanide oxidation makes the former more susceptible to nucleophilic attack from ethanol, with conversion into ethyl carbamate. Comparatively, urea has a minor role with respect to cyanide in the formation of ethyl carbamate. Therefore, the urea present in some samples of Brazilian sugar cane spirit (cachaça) has been shown to have almost no influence on the ethyl carbamate content of cachaças, which comes essentially from cyanide. Fe(II,III) affords results similar to those found with Cu(II). Some suggestions are presented to avoid ethyl carbamate formation in spirits during distillation.

Catalytic properties of phenol carboxylase. In vitro study of CO2: 4-hydroxybenzoate isotope exchange reaction.

Phenol is metabolized in a denitrifying bacterium in the absence of molecular oxygen via para-carboxylation to 4-hydroxybenzoate (biological Kolbe-Schmitt synthesis). The enzyme system catalyzing the presumptive carboxylation of phenol, tentatively named 'phenol carboxylase', catalyzes an isotope exchange between 14CO2 and the carboxyl group of 4-hydroxybenzoate (specific activity 0.1 mumol 14CO2 incorporated into 4-hydroxybenzoate x min-1 x mg-1 cell protein) which is considered a partial reaction of the overall enzyme catalysis; 14C from [14C]phenol was not exchanged into 4-hydroxybenzoate ring positions to a significant extent. The 14CO2 isotope exchange reaction was studied in vitro. The reaction was dependent on the substrates CO2 and 4-hydroxybenzoate and required K+ and Mn2+. The actual substrate was CO2 rather than HCO3-. The apparent Km values were 1 mM dissolved CO2, 0.2 mM 4-hydroxybenzoate, 2 mM K+, and 0.1 mM Mn2+. The cationic cocatalysts could be substituted by ions of similar ionic radius: K+ could be replaced to some extent by Rb+, but not by Li+, Na+, Cs+, or NH4+; Mn2+ could be replaced to some extent by Fe2+ greater than Mg2+, Co2+, but not by Ni2+, Zn2+, Ca2+, or Cu2+. The exchange reaction was not strictly specific for 4-hydroxybenzoate, however it required a p-hydroxyl group; derivatives of 4-hydroxybenzoate with OH, CH3 or Cl substituents in m-position did react, whereas those with substitutions in the o-position were inactive or were inhibitory. The enzyme was induced when cells were grown on phenol, but not on 4-hydroxybenzoate. Comparison of SDS/PAGE protein patterns of cells grown on phenol or 4-hydroxybenzoate revealed several additional protein bands in phenol-grown cells. The possible role of similar enzymes in the anaerobic metabolism of phenolic compounds is discussed.

In vitro cisplatin effects on phagocyte functions.

The effects of cis-diamminedichloroplatinum (II) (cisplatin), a drug used in cancer chemotherapy, on the oxidative metabolism, endocytosis, chemotaxis and exocytosis of guinea-pig polymorphonuclear leukocytes were studied. All these functions were negatively influenced, but the same effect (50% inhibition) was observed at different drug concentrations (3 X 10(-5) M for chemotaxis, 10(-4) M for O2 consumption by FMLP and beta-glucuronidase release, 10(-3) M for O2 consumption by PMA and for zymosan engulfment). The effects of the drug can be explained by its ability to bind to membrane proteins, essentially to -SH groups.

Biological activity of metal complexes. I. Interaction of pt(II), pd(II) and rh(I) complexes with E. coli strains and with mice LS fibroblasts in vitro.

The effects of a number of Pt(II, Pd(II) and Rh(I) complexes against cultures of Escherichia coli (strains B, H10178, uvra-, recA-) and cultures of mice LS Fibroblasts were tested. Most of the compounds showed higher cytotoxic activity than the cis-Pt(NH3)2Cl2, the compound at present on clinical trial as antittumour drug. A new model of active compound is proposed.