Invertase was immobilised on microporous montmorillonite K-10 via adsorption and covalent binding. The immobilised enzymes were tested for sucrose hydrolysis activity in a batch reactor. Km for immobilised systems was greater than free enzyme. The immobilised forms could be reused for 15 continuous cycles without any loss in activity. After 25 cycles, 85% initial activity was retained. A study ...

The influence of adsorption-desorption phenomena and distribution of pore sizes on lhe leaching beh.viour of two herbicides, thiazafluron (highly polar, nonionic) and clopyralid (anionic) in three soils has been studied. Adsorption d.ta, obtained by b.tch equilibriwn, were fitted to Freundlich equation and Kf values calculated. Pore size distribution of the soils was studied by mercury porosime...

an approach to recycle precious metals of cathode materials from spent lithium cobalt oxide batteries by using organic citric acid and hydrogen peroxide has been studied in this paper. the effects of molar ratio, solid-liquid ratio, reaction time and temperature on leaching efficiency of cobalt were investigated respectively. meanwhile the leaching kinetics equation of cobalt was established, a...

Bioleaching is a technique for reducing the heavy metal content of coal ash by using bacteria, fungi, or yeast. Previous studies in bioleaching discussed factors affecting process, but as yet there little information on challenges microorganisms. Therefore, this study aimed to obtain comprehensive regarding use microorganisms bioleaching. Heavy concentrations are low, and metals diverse. The co...

In regions like south of “ khouzestan” that water table are high, under the effect of water rise moving through capillary fringe and its vaporize,  the salts move to soil surface and cause salin or salin and sodic soils. Leaching assign as one of those adjustment soils methods. In order to investigate the leaching process and draw the curves of desalinization and dealkalization in region of Dar...

however, the conventional gold recovery process is cyanidation, due to the recent environmental laws; researchers are looking for alternative methods for the recovery of gold. furthermore, the copper anode slime is one of the most important secondary sources of gold (about 1200 ppm). so, the main objective of the current work is gold separation from copper anode slime as a rich secondary source...

The mechanisms by which potentially soluble inorganic nutrients are retained and eventually recycled within ecosystems have been characterized by many studies. Substantial amounts of potentially soluble organic nutrients are also released as plants grow, die, and decompose. In this study, a conceptual model was developed which shows the pools and signi®cant processes generating and consuming di...

In this Study, vanadium recovery from the steelmaking converter slag was studied. Salt roasting-basic leaching is the process which was applied to separate and extract vanadium from steel making slag. Ground slag was roasted after mixing with determined quantities of sodium carbonate. The effect of time and temperature of roasting and sodium carbonate content were studied. The optimum temperatu...

Batch tests indicated that arsenic (As) leaching is significantly affected by the calcium concentration in fly ash in the alkaline pH range. Arsenic leaching from low calcium fly ash from eastern bituminous coal increased with increase of pH in the alkaline pH range (pH 7 – 12). Fly ash from eastern bituminous coal with a slightly higher calcium content exhibited an arsenic leaching peak at pH ...