“Process and absorbent material for absorption of organic pollutants from aqueous solutions”
The present invention relates to an adsorbent material and to a process for obtaining it, used to reduce the level of organic pollutants in aqueous solutions, at ambient temperature and atmospheric pressure. The adsorbent demonstrates adsorption capacity, evaluated in a batch system, against organic micro-pollutants of industrial origin (demonstrated by phenol adsorption) and against organic micro-pollutants from the pharmaceuticals and personal care products category.
(Demonstrated by ibuprofen adsorption).
The adsorbent made according to the invention removes the mentioned disadvantages, in that it is presented in the form of powder, having a specific surface between 35..55 m2/g, the size of the crystallites below 25 nm and the method of obtaining it consists of two stages. In the first stage, in 600 ml demineralized water containing 31..60 grams of Ca(NO3)2•4H2O and BaCl2•6H2O mixture solution in the ratio Ca:Ba = 9:1..1:9 and 200..500 ml NH4OH (25%), add a solution of (NH4)2HPO4 (35..50 grams in 600 ml water), under mechanical stirring and at a temperature of 65..90°C, at a constant pH. After 3..8 hours of reaction, the precipitate is separated by filtration, washed with demineralized water and drained. 50..250 ml of ethanol is added to the obtained material, and the gel thus obtained is dried in a vacuum oven for 24..48 hours. In the second stage, the material obtained according to the previously described steps is calcined, at a temperature of 250..600°C, calcination time 1..5 hours. After calcination, the material is mortared in an agate mortar until particle sizes below 20 μm are obtained (determined by sieving on a 20 μm mesh sieve).