Direct oxidation of methane to oxygenates over heteropolyanions

Partial oxidation of methane to formaldehyde and methanol was studied at atmospheric pressure in the temperature range of 700-750 °C using heteropolycompound catalysts （NH4）6HSiMo11FeO40, （NH4）4PMo11FeO39, and H4PMo11VO40, which were prepared and characterized by various analysis techniques such as infrared, visible UV, XRD and DTA. O2 or N2O was used as the oxidizing agent, and the principal products of the reaction were CH3OH, CH2O, CO, CO2, and water. The conversion and the selectivity of products depend strongly on the reaction temperature, the nature of oxidizing agent, and the composition of catalyst.

Fire and People in Three Rural Communities in Kabylia (Algeria): Results of a Survey

This research was conducted to investigate about the causes of wildfires in three municipalities of the Tizi Ouzou and Bouira provinces, in Kabylia. Unknown forest fire causes account for 80% of total in Algeria, with a peak of about 99% in Kabylia, the most forested region in the country but also the most severely affected by wildfires. The three study areas exhibit a rather high forestry ratio (40% on average) but also a very high population density, up to 300 people per km2, living in a multitude of small hamlets, near or inside the domanial forests and exerting an enormous pressure on them. Survey was carried out on people (N = 300) randomly selected in nine hamlets (thaddarth) through ad hoc questionnaires (134 possible replies) filled with face-to-face interviews. Factorial Correspondence Analysis was used to process data (300 × 134 replies in total). Fires result mainly voluntary (52.95%): pastoral fires to renew pastures (11.30%), political fires as security counter-terrorism measure (11.24%), uncontrolled garbage burning (6.83%). Negligent fires account for 41.79%: carelessly tossed cigarette butts (9.13%), agricultural works (burning of cut bush, stubble burning, 7.03%), restart of fire (6.83%) and forest activities in the forest (6.31%). Results depict a common core of fires due to the pressure on the domanial forests, on which traditional use of fire (pastoralism) and national security needs (counter-terrorism) dominate.

Degradation of direct azo dye by Cucurbita pepo free and immobilized peroxidase

Enzymatic decolourization of the azo dye, Direct Yellow （DY 106） by Cucurbita pepo （courgette） peroxidase （CP） is a complex process, which is greatly affected by pH, temperature, enzyme activity and the concentrations of H202 and dye. Courgette peroxidase was extracted and its performance was evaluated by using the free-CP （FCP） and immobilized-CP （ICP） forms in the decolourization of DY106. Immobilization of peroxidase in calcium alginate beads was performed according to a strategy aiming to minimize enzyme leakage and keep its activity at a maximum value by optimizing sodium alginate content, enzyme loading and calcium chloride concentration. The initial conditions ~it which the highest DY106 decolourization yield was obtained were found at pH 2, temperature 20~C, H202 dose 1 mmol/L （FCP） and 100 mmol/L （ICP）. The highest decolourization rates were obtained for dye concentrations 50 mg/L （FCP） and 80 mg/L （ICP）. Under optimal conditions, the FCP was able to decolorize more than 87% of the dye within 2 min. While with ICP, the decolourization yield was 75% within 15 rain. The decolourization and removal of DY106 was proved by UV-Vis analysis. Fourier transform infrared （FF-IR） spectroscopy analysis was also performed on DY106 and enzymatic treatment precipitated byproduct.