Generation of aqueous foams and fiber foams in a stirred tank

Unveiling the organic nature of phosphogypsum foam: Insights into formation dynamics, pollution load, and contribution to marine pollution in the Southern Mediterranean Sea

The foamability of dissolved phosphogypsum from the phosphate fertilizer factories of Gabes (SE Tunisia) is a spectacular phenomenon that has not yet been thoroughly studied. The main objective of this research was to investigate the organic properties of phosphogypsum foam (PGF) to understand its formation process, determine the origin of its enhanced radiochemical contaminants load, and identify its role in pollutants dispersion in marine environment of the Southern Mediterranean Sea. This study identified PGF as an unnatural, surfactant-stabilized, and ephemeral aqueous foam. PGF-forming process comprises three main steps: (i) formation (through phosphogypsum dissolution), (ii) stabilization (facilitated by organic surfactants and gypsum crystals), and (iii) destabilization (geochemical (involving the dissolution of the PGF skeleton gypsum) and/or mechanical (influenced by wind and wave action)). The amphiphilic nature of PGF organic matter and the presence of specific organic groups are responsible for its high toxic contaminants load. PGF contributes, through its elevated pollutants content and its ability to migrate far from its source, to the marine dispersion of industrial toxic radiochemical contaminants. It is therefore recommended to mitigate the environmental and health risks associated with PGF, including banning the discharge of untreated phosphogypsum and other industrial wastes into the coastal environment of Gabes.

Hamdi H, Dareb Shaban A. The Effect of Chicken Gallus gallus (Domestics) feathers on the sorption properties of polyurethane foam

A comparative absorption capability analysis was conducted using adapted polyurethane foam as crude oil Sorbents. The used Crude oil has been brought from the west of the Qurna city oil field with A.P.I. equals 22.2- 27. API measures how heavy or light a petroleum liquid is compared to water; crude oil's sorption and absorption ratio amounts are investigated. The findings demonstrate that the absorption ratio of fluff feather to wing feather is very distinct. The fluff feather absorbed much more crude oil than the wings. Moreover, much crude oil absorption causes the three types of feathers to plunge into crude oil. Owing to the disparity of the capillary structures of pure and modified polyurethane and the particular arrangement of the feathers, the absorption of modified polyurethane foam is beyond pure foam. The absorption ratio is saturated at (240-270) % (where the modified foam releases some additional volume of crude oil rather than the saturation ratio). Because of the cross-link density inside the modified foam, the last results were clarified. Also, we analyzed the effect of 10 holes on the absorption ratio in which the absorption is less than the unpinned ratio. Keywords: Chicken feather, Qurna, West Qurna oil field, Iraqi crude oil, polyurethane, capillary structure.

Dynamic generation of aqueous foams and fiber foams in a mixing tank

Mixing tanks are employed in paper and pulp industries to generate aqueous foams and fiber foams. The aim of the present study was to investigate the effect of impeller geometry on dynamic foam generation in a 60 L mixing tank. Three impeller geometries including two radial—Rushton turbine (RT), Bakker turbine (BT6), one axial high solidity pitched blade turbine (HSPBT), and four dual impeller combinations were investigated. Compressed air, water and sodium dodecyl sulphate were used as gas phase, liquid phase and surfactant, respectively, to generate aqueous foam. 1% mass consistency softwood fiber was used to generate fiber foam. The change in aqueous foam density for any given impeller was limited to ± 40 kg/m3 indicating foam density was dictated by impeller type rather than power input. Single impellers generated bubbly liquids whereas dual impellers generated low-density aqueous foams. Besides, stable foam was produced even at low power input compared to single impellers due to increase in impeller swept volume and blade contact area. Addition of fibers increased the foam density by ~ 100–150 kg/m3 and reduced the half-life time by almost threefold for all impellers due to lower air content and higher bubble size. Placement of high shear impeller (BT6) at bottom and down-pumping axial impeller (HSPBT) on top generated fine bubbles.