Polyvalent pollution removal composition and use thereof

Abstract

A pollution removal composition includes: (a) at least one silica gel; and (b) at least one wood-derived absorbent agent, characterized in that the silica gel has a grain-size distribution of between 60 and 500 ym and a density of between 150 and 400 kg/m.sup.3. A pollution removal method using the composition is also described.

Claims

1. A pollution removal composition consisting of: (a) at least one silica gel, and (b) at least one wood derived absorbing agent, and (c) optionally at least one additive selected from the group consisting of pH indicator agents, scents, dyes, flow improvers, bulking agents and mixtures thereof, said silica gel having a particle size from 60 to 500 m and a mass density from 150 to 380 kg/m.sup.3; and the mass ratio between the silica gel and the wood derived absorbing agent being from 95:5 to 60:40; thereby said composition has an absorption capacity from 5 L to 90 L per 1 kg of said composition and allows removal of a pollution removal residue without leaving a residue bonded to a surface on which a liquid pollutant has spread.

2. The composition according to claim 1, wherein said silica gel has an absorption capacity from 1 L to 10 L per 1 Kg of said silica gel.

3. The composition according to claim 1, wherein said wood derived absorbing agent is selected from wood sawdust, wood chips, wood powder, chopped straw, ground corn, cellulose, hemicellulose, lignin, and mixtures thereof.

4. The composition according to claim 1, wherein the pH indicator agent is selected from tropaeolin, thymol blue, bromocresol purple, bromophenol blue, Congo red, neutral red, phenolphthalein, thymolphthalein, alizarin yellow R, and mixtures thereof.

5. The composition according to claim 1, wherein said silica gel is present in an amount ranging from 60% to 95% by total weight of the composition.

6. The composition according to claim 1, wherein said pH indicator agent is present in an amount ranging from 0.001% to 0.1%.

7. The composition according to claim 1, consisting of: from 60 to 95% by weight of the weight of the silica gel composition; from 5 to 40% by weight of the weight of the wood derived absorbent composition; from 0 to 2% by weight of the weight of at least one additive of the composition.

8. The composition according to claim 7, wherein the additive is a pH indicator agent.

9. The composition according to claim 1, wherein said silica gel has an absorption capacity from 1 L to 10 L per 1 Kg of said silica gel.

10. A method of pollution removal comprising the following steps: 1) adding the composition according to claim 1 on a liquid pollutant spread over a surface; 2) waiting until the liquid pollutant is absorbed by the composition; 3) optionally, checking the pH of the residue obtained in Step 2); 4) repeating Steps 1) to 3) until complete absorption of the liquid pollutant and the formation of a solid residue; and 5) picking up the residue.

Description

EXAMPLES

(1) In the examples below, the following commercial products are used:

(2) Tixosil 68: silica gel marketed by Rhodia having a particle size of 200 m and a mass density of 300 kg/cm.sup.3.

(3) Lignocel C250: wood derived absorbent, marketed by JRS Pharma.

(4) Sepiolite: Mediterranean natural clay absorbent.

(5) Unisafe: Synthetic absorbent marketed by Okotec based on silica and super absorbent polymer.

Example 1

(6) 1-1. Formulation

(7) A pollution removal composition XY027-01 was prepared by mixing Tixosil 68 and Lignocel C250 in a weight ratio of 80/20.

(8) Then, to this mixture were added:

(9) TABLE-US-00001 Tropaeolin 0.01% Thymol blue 0.02%
the % are % by weight relative to the weight of the mixture Tixosil 68/Lignocel C250.

(10) 1-2. Liquid Absorption Test

(11) The absorption test was performed successively with the following polluting liquids: 98% H.sub.2SO.sub.4, 100% HNO.sub.3, 65% HNO.sub.3, 50% soda, 30% ammonia, water, 0.9% NaCl, 40% H.sub.2O.sub.2, 13% bleach, oil, HCl 5N, NaOH 5N, EtOAc, toluene, formaldehyde, formic acid, and EtOH, using, on the one hand, the composition prepared above and, on the other hand, for comparison purposes with the sepiolite and Unisafe according to the following protocol: 1) 1 L liquid to be cleaned up is put in a glass container; 2) 100 g of the composition is added into said container. Once the mixture is homogenized, the state (liquid or solid) of the mixture is checked. 3) Steps 1) and 2) are repeated until a solid residue is obtained. 4) Once a solid residue is obtained, said residue is picked up with a shovel.

(12) The results of the absorption test are shown in FIG. 1.

(13) It should be noted that whatever the pollutants and their concentrations, the composition of the present invention showed better absorption efficiency than the currently marketed products.

(14) Furthermore, the cost of treatment using the composition according to the invention compared to the cost of treatment using the currently marketed compositions is considerably reduced. On average, it is reduced by more than 50% compared to the cost incurred by using of the Unisafe product, and by more than 75% compared to the cost incurred by using sepiolite.

(15) In conclusion, the composition can absorb different polluting liquids at different concentrations using a minimum amount of product and at a lower cost than currently marketed products. In addition, the composition is not hazardous (non-toxic, non-irritating, non-allergenic and non ecotoxic), unlike some currently marketed products.