heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

The circulation of dust suspended in the air is among the most significant environmental problems in the various regions of the world. However, the primary source of the dust present in the atmosphere is fine-grained particles and These tiny particles are more frequent in arid and semi-arid areas. The Tabas Masina Playa in Iran is one of the regions prone to dust production due to warm and dry ...

The operation of sand transport by erosive winds and its sedimentation around the obstacles such as plants leads to the appearance of the eco-geomorphologic phenomenon of nebka dunes in dry seasons of Golestan province. This study aims to identify the physicochemical characteristics of nebka sediments and compare its results with adjacent lands. Hence, the grain size distribution and morph...

Soil or relative percentage of sand, silt and clay reflects some texture characteristics such as permeability, water holding capacity, CEC, and soil behavior in return to the plow and other tillage operations is very important. The study area covers an area of 1715.4 hectares, near the Aiej soil dam, East of Jooneghan city, Chaharmahal and Bakhtiari Province. For this study, 40 disturbed soil s...

In recent years, due to the overpopulation, serious water shortages, and need to consume more water, the use of wastewater treatment plant has attracted lots of attention. When the pollution load is not high, biofilm reactors are commonly used for the purpose. In this study, the porous concrete as a bed biofilm in reducing pollution load of wastewater was investigated. In order to evaluate poro...

The research results indicated that wet and dry dust deposition is a function of geographical characteristics. The seasonal wet and dry dust deposition and Fine Particles (PM 2.5) correlation in Iran with elevation, latitude and longitude results that the maximum correlation belongs to height, followed by latitude and longitude; meanwhile height and latitude are strongly and reversely correlate...