Calcium sulfate (CaSO4) is one of the most common evaporites found in earth’s crust. It can be as four main variations: gypsum (CaSO4∙2H2O), bassanite (CaSO4∙0.5H2O), soluble anhydrite, and insoluble anhydrite (CaSO4), being key difference hydration state mineral. Naica giant crystals’ growth starts from a supersaturated solution delicate thermodynamic balance close to equilibrium, where form n...

Many soil amendments are used to remediate paddy soils polluted with heavy metals, including arsenic (As) and lead (Pb). This study was conducted assess the efficacy of three inorganic amendments, such as calcium carbonate (CaCO3), sulfate (CaSO4), ferrous (FeSO4), on As Pb co-contaminated soils. The were applied alone and/or in combinations compare theirs for stabilization rice growth. In addi...

The degree of III-CaSO4 to II-CaSO4 transition was estimated on wet specimens, 25 mm in diameter and 50 mm high, prepared from a gypsum-bonded investment for quick casting. After 30 min from mixing the specimens were heated in a 700 degrees C furnace until a specimen temperature of 200 degrees C to 700 degrees C was reached. The estimation was made by measuring mass changes of the specimens bef...

The dehydration of gypsum CaSO4.2H20 has been studied, at negligible water vapour pressure, by in situ infrared (IR) spectroscopy and by thermogravimetry to determine whether intermediate phases (CaSO4.nH20) exist, other than the hemihydrate with n=0.5, and also to compare the mechanism of the dehydration process when measured by two techniques with very different correlation lengths. Thermogra...

The crystalline substances are the most used for Thermoluminescent Dosimetry (TLD) purposes. The crystalline structure allows for a controlled impurification with activators in order to improve their dosimetric parameters. The activators introduced into the crystalline network [1], enhance the number of electrons and hole traps inside the forbidden band. In the first step, immediately after the...

The formation of deposits on heat transfer surfaces is the main hurdle in optimum operation of thermal desalination units. It is, therefore, common practice to operate these units i.e. MSF under sub-atmospheric pressure to boil saline water below saturation temperature of which depositions occurs. However this comes with high price-tag for excessive use of energy for pumping. Alternative and en...

Plaster, made of calcium sulfate hemihydrate (CaSO4•½H2O) and/or γ-anhydrite (CaSO4) is obtained by dehydration gypsum (CaSO4·2H2O) at 100–200 °C. When mixed with water, it dissolves while new crystals precipitate. Plaster's microstructures affect its reactivity and setting properties, but are poorly understood due to confusion between polycrystalline structures in the literature. Through a mul...

water and soil pollution by human pathogenic bacteria draw attention of many researchers. duration of bacterial survival for reach to the soil and water resources is very important. current study focused on the effects of caco3 and caso4 compounds on escherichia coli survival. using caco3, caso4 compounds and fine sand particles (

The biofloculant production potential of a consortium of Streptomyces and Brachybacterium species were evaluated. Optimum bioflocculant yields (g/L) and flocculation activities (%) were observed for the following preferred nutritional sources: glucose (56%; 2.78 ± 0.15 g/L), (NH4)2NO3 (53%; 2.81 ± 0.37 g/L) and CaSO4 · H2O (47%; 2.19 ± 0.13 g/L). A Plackett-Burman design revealed the critical f...