Development of eco-friendly porous fired clay bricks using pore-forming agents: a review.

Today, clay bricks are facing technological challenges and are uncompetitive compared to materials such as concrete. Their performance must be improved if they are to stand up to the competition. Increasing environmental concerns over the accumulation of unmanaged wastes from agricultural or industrial productions have made these good candidates for incorporation into building materials to improve their performance. This process leads to the formation of pores in the bricks, producing lightweight and sustainable building materials. This paper reviews the different pore-forming agents from renewable or mineral resources as described in the literature. It also presents the impact of pore-forming agents on the physical, mechanical and thermal properties of clay bricks.

Oil removal from water by sorption on hydrophobic cotton fibers. 2. Study of sorption properties in dynamic mode.

The recovery of oil from an oil-in-water emulsion, during a flow through a bed of cotton rendered hydrophobic by acylation of cellulose was defined by sorption and coalescence phenomena. During percolation, the column "hold-up" (difference between injected and rejected oil) became constant at the equilibrium volume, i.e., as soon as the instant oil concentration in the effluent (C) was equal to the oil concentration in the initial emulsion (C0). This equilibrium permitted the measurement of the cotton sorption capacity (SC), which increased with C0 up to the cotton saturation. The oil-water separation improved at a lower temperature, lower flow, a deeper medium, and larger oil drops. The system was modeled as a piston flow-through in order to generalize the results.

Oil removal from water by selective sorption on hydrophobic cotton fibers. 1. Study of sorption properties and comparison with other cotton fiber-based sorbents.

Hydrophobic cotton fibers, obtained by acylation of cellulose with fatty acid using microwaves radiations, have a high selective affinity for vegetable or mineral oil, fuel, and petroleum, in aqueous medium. Their sorption capacity (SC) (weight of liquid picked up by a given weight of sorbent) is about 20 g/g, after draining. They are reusable after simple squeezing, and their SC reaches a constant value, ca. 12 g/g. Moreover, this product is stable in water, whereas raw cotton can develop molds, after oil sorption. Besides, it is also biodegradable.