oxidative coupling of methane has been studied over (mn+a+w)/sio2 catalysts in a continuous–flow microreactor, where a represents an alkali ion of li, na, k or cs having different weight percents. the main aim of this study is to find the role of alkali ions in interaction between mn and w species with sio2 to make a proper structure for catalyzing oxidative coupling of methane (ocm) reaction. ...

Water scarcity and imbalances in irrigation drainage are the main factors leading to soil salinization arid areas. There is a recognized need for effective measures prevent improve saline−alkali land. The principal objective of this project was investigate effects on desalination farmland process improving saline–alkali soils; these included subsurface pipe (SPD) open ditch (ODD). results tests...

Abstract Purpose Adsorbent amendment to contaminated sediments is one in situ remediation method decrease the bioaccessibility of pollutants from sediments. In this work, alkali-activated blast furnace slag (BFS) granules were used a field experiment at Lake Kivijärvi (Finland). The lake was heavily affected by mining accident 2012, which released significant peak load metals and sulfate. purpo...

Bacterial leaching of an As-containing pyrite concentrate produced acidic (pH < 1) leachates. During the leaching, the bacteria solubilized both As and Fe, and these two elements were distributed in solution-phase and solid-phase products. Jarosite and scorodite were the exclusive crystalline products in precipitate samples from the bacterial leaching of the sulfide concentrate.

The changes in cell surface properties associated with alkali stress can significantly disrupt cell metabolism and structures, preventing effective interactions between bacterial cells and their environment. Listeria monocytogenes is known to display an adaptive response to alkali stress that enhances its capacity to more effectively survive subsequent severe alkali challenge. In this study, we...

In this paper, the composite additive of CaF2/CaO was used to extract vanadium from stone coal, and the effect of roasting and leaching kinetics were studied. The purpose of this manuscript is to realize and improve the vanadium recovery from stone coal using the composite additive. The experimental results indicated that the roasted clinker can be obtained under the conditions of CaF2/CaO at a...

Reduction of migration of fecal coliforms (FC) and streptococci (FS) by limiting the leaching in effluent-irrigated soil was tested in lysimeters packed with quartz sand without or with added biosolids compost or with one of two clayey soils. The 200-L, 70-cm-deep lysimeters were either planted with a Eucalyptus camaldulensis or an Oroblanco citrus tree (in the sand only), or not planted. The E...

Kinetics of the chemical leaching of chalcocite from a low-grade copper ore in a ferric sulfate medium was investigated using the constrained least square optimization technique. The experiments were carried out for different particle sizes in both the reactor and column at constant Eh, pH, and temperature. The leaching rate increased with increase in the temperature. About 50% of the Cu recove...

Colemanite is one of the most important underground riches of Turkey, having approximately 60% of the world boron deposits, and it has a large portion in the deposits. In this study, chemical leaching and biological leaching methods were used for production of boric acid from colemanite (2CaO · 3B3O3 · 5H2O) (Emet-Kütahya, Turkey). Oxalic acid concentration, temperature, stirring time and solid...

Ground granulated blast furnace slag (ggbs), can reduce the alkali load in concrete, despite its relatively high alkali content. Most research has been devoted to the efficacy of slag with an alkali content of less than 1.0% and this is reflected in guidance documents. A comparative assessment was made of the effect, if any, of the alkali level of ggbs on potential alkali-silica reactivity. Exp...