CELLULAR GLASS AS INERTIZATION ALTERNATIVE FOR THE EXHAUSTED COMPOSITE ADSORPTION MATERIAL RESULTED FROM THE REMOVAL OF ARSENIC FROM WASTE WATERS

Cellular glass is an insulation material that Competes with polymeric and fibrous insulators on the market, having significant advantages such as the constant insulation efficiency, fire protection, corrosion and moisture resistance and long term dimensional stability. The present paper proposes a green solution to harness the exhausted composite adsorption material resulted from the removal of arsenic from wastewaters, by vitrification using two types of common recycled glasses: window panes and cathode ray tubes (CRT). Based on the high carbon amount present in the exhausted adsorption material, it was used as porogen material for cellular glasses. The apparent porosity, determined using the saturation under vacuum method, ranged between 40.25 - 62.15%. The optimal porous microstructure, having small uniform pores (under 150 gm) and narrow dimensional scattering, was obtained using both exhausted adsorption material and silicon carbide. The hydrolytically stability, measured according to the ISO 719/1985, classifies all the investigated glasses in HGB1-HGB3 stability classes. The arsenic, lead and iron ions leachability were determined in accordance with the American Extraction Procedure Toxicity Test. No discernable losses of arsenic or lead (in the case of samples containing CRT recycled glass) were measured, regardless of time or environment's pH. The amount of iron extracted after 28 days was very low, ranging from 0 to 0,056 % of the total iron. The thermal conductivity of the obtained cellular glasses range from 0.092 to 0.133 W/mK, classifying them as insulators. These results confirm the viability of the proposed alternative for immobilizing the exhausted adsorption material containing arsenic together with common recycled glasses as cellular glasses having high chemical stability and good thermal conductivity with multiple economic advantages