توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Evaluation of Anthropogenic Impacts on Soiland Regolith Materials Based on BCR Sequential Extraction Analysis Alimohammad
نویسنده(ها): ، ، ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، ششم،شماره۱، Winter ۲۰۱۲، سال
تعداد صفحات: ۱۰
This study was conducted in Assaluyeh region, southwest of Iran to show utilization and efficiency of sequential extraction analysis in environmental impact studies using soil and related regolith materials as sample media. In order to investigate distribution of heavy metals, optimized BCR (Community Bureau of Reference) sequential extraction analysis method was used. In this caseeight representative samples which state all types of different regolith materials in the area were investigated. Total concentration and chemical partitioning of a number of elements (Pb, Cu, Zn, Cr, Mn and Fe) were studied to cover all spectral from typical anthropogenic elements, lead and copper, elements of assumed mixed origin, chromium and zinc, to mostly lithogenic elements, iron and manganese. Results stated that the concentrations of each chemical phase extracted from samples are below the total concentration of each element.The results could be used to establish best media indicators for environmental studies with dependence on type of elements determined in regolith material. Using sequential extraction analysis, the association of particular elements with geochemical phases in soils and related materials was investigated as well asthe importance of particular phases in the scavenging of heavy metals. Results showed that the organic and sulphide phase was less important in scavenging mechanism –in spite of industrial and petrochemical activities in the study area– than exchangeable and carbonate fraction, which showed to be most important phase with respect to metal scavenging capacity.

۲Examining a Hybrid plug–flow Pilot reactor for Anaerobic Digestion of Farm–Based Biodegradable
نویسنده(ها): ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، ششم،شماره۱، Winter ۲۰۱۲، سال
تعداد صفحات: ۱۰
Plug–flow digesters with periodic loading mechanism are more enthusiastic than fully mechanized digestion plants for the majority of small or medium scale farms according to the costs and operational complexities. A dual–compartment plug–flow reactor equipped with a passive heating system was designed and experimentally operated by purpose of demonstrating a simple and low cost technology for handling the biodegradable agricultural wastes. The reactor was successfully started up with pig feces as feedstock under a quasi–continuous loading and semi–dry condition with an average total solids content of 12.8% inside the digester and an average organic loading rate of 2.06kg–VS\(m3.d). The start–up phase was followed by co–digestion of pig feces and pre–treated cotton stalk. Even though the digester actually worked at a temperature range 12 to 30% below the optimal mesophilic level, acceptable rates of methane generation and VS destruction were observed. The biogas and methane yield were measured for single digestion stage as 0.332 and 0.202 m3\(kg–added VS) and for co–digestion stage as 0.482 and 0.325 m3\(kg–added VS) respectively. The cumulative biogas production data demonstrated a reasonable correlation (R2 over 0.99) with a simplified consecutive kinetic model.
نمایش نتایج ۱ تا ۲ از میان ۲ نتیجه