Adsorção de Fósforo em coluna de leito fixo utilizando como adsorvente o concreto aerado autoclavado

Abstract

Civil construction waste is underused due to lack of knowledge and interest in its possible uses, leading to landfill disposal. In addition, the excess of phosphorus in effluents, along with their lack of treatment, has been increasing the level of water bodies’ eutrophication, disturbing the ecosystem. This research aimed to test autoclaved aerated concrete in order to adsorb phosphorus from wastewater. Other works’ high rate of heavy metal adsorption justifies the use of this material considering it an efficient adsorbent. Physicochemical characterizations of the autoclaved aerated concrete were carried out and a statistical planning based on the batch optimal conditions previously tested was elaborated. The tests were carried out in a fixed bed column, due to its great similarity with real effluents on an industrial scale, in addition to its low cost and relatively simple technique. The solution to be treated was prepared to contain 10mg/L of phosphorus, and the amount of adsorbent material in the column, as well as the affluent flow rate varied. The experiments showed that both factors are significant influencers on the adsorption efficiency. In the best scenario analyzed, autoclaved aerated concrete was able to adsorb 98.7% of the phosphorus during the initial 45 minutes of the experiment. Both Thomas and Yoon-Nelson’s models were respectively used to predict maximum adsorption capacity and the breakthrough time, with an R² varying between 0.86 and 0.94. The results obtained in this study suggest that autoclaved aerated concrete has great potential for the application of phosphorus removal from contaminated water.