A bench work study was carried out to investigate the use of kaolinitic clay containing 29.4% Al2O3 extremely abundant in Saudi Arabia for the production of pure alumina by calcination at 700 o C for 1h (recommended by previous investigators) then leached by hydrochloric acid. The effects of leaching temperature (25 o C to boiling temperature), period of activation (10-150 minutes), acid concen...

At present, all kinds of municipal solid waste incineration (MSWI) fly ash stabilization technology has been reported and successfully applied in many countries. However, leaching procedures are very different that the technologies lack uniform standard, and it is even impossible to predict the long-term stabilization. Geochemical model can explain the environmental stabilization based on chemi...

In nitrogen (N)-limited systems, the potential to sequester carbon depends on the balance between N inputs and losses as well as on how efficiently N is used, yet little is known about responses of these processes to changes in plant species richness, atmospheric CO2 concentration ([CO2]), and N deposition. We examined how plant species richness (1 or 16 species), elevated [CO2] (ambient or 560...

Accurate descriptions of P leaching are important because excess P applied to soils can enter surface water via leaching and subsurface transport, thereby negatively impacting water quality. The objectives of this study were to monitor P leaching in soils with a long-term history of waste application, relate soil solution P concentrations to soil P status, and quantify P leaching losses. Soil s...

The decline in water quality in Lake Taupo has been attributed to nitrogen (N) leaching from surrounding land areas. Pastoral agriculture has been identified as a significant contributor to this N transfer to the lake through animal urine deposition. There is therefore an immediate need for new management options to reduce N losses. The objective of this study was to measure the effectiveness o...

The effects of ferrous and ferric iron as well as redox potential on copper and iron extraction from the copper flotation concentrate of Sarcheshmeh, Kerman, Iran, were evaluated using shake flask leaching examinations. Experiments were carried out in the presence and absence of a mixed culture of moderately thermophile microorganisms at 50 ̊C. Chemical leaching experiments were performed in the...

Several widely used techniques for the fabrication of three dimensional (3D) scaffolds utilize the particulate leaching method to achieve a porous structure. This method involves the selective leaching of a mineral or an organic compound to generate pores. However, scaffolds prepared by this technique tend to exhibit limited interconnectivity. Therefore, to enhance the interconnectivity of the ...

The results of studies on the separation of platinum(IV) ions by solvent extraction from aqueous solutions after leaching of spent catalysts have been reviewed. The following processes have been discussed: acid leaching of spent catalysts and solvent extraction of platinum(IV) ions by using organophosphorous acids, amines and oximes as the extractants. In hydrometallurgical leaching of spent au...

Eutrophication, a major problem in many fresh and brackish waters, is largely caused by nonpoint-source pollution by P from agricultural soils. This lysimeter study examined the influence of P content, physical properties, and sorption characteristics in topsoil and subsoil on P leaching measured during 21 mo in 1-m-long, undisturbed soil columns of two clay and two sandy soils. Total P losses ...

Drainage and deforestation turned Southeast (SE) Asian peat soils into a globally important CO2 source, because both processes accelerate peat decomposition. Carbon losses through soil leaching have so far not been quantified and the underlying processes have hardly been studied. In this study, we use results derived from nine expeditions to six Sumatran rivers and a mixing model to determine l...