Análise da utilização de cerâmica vermelha como adsorvente na remoção de fósforo em solução aquosa

Abstract

Considering phosphate rock reserves scarcity, in this work was evaluated the use of ceramic residue as an alternative low-cost adsorbant. Reusing this waste represents a sustainable alternative to its disposal. It was evaluated the potential of 5 granulometric bands of the material in the removal of phosphorus from aqueous solution. The adsorbents were physico-chemically characterized by its granulometry (materials retained in the bands 0.6 mm - 1.2 mm; 1.21 mm - 2.4 mm; 2.41 mm - 4.8 mm; 4.81 mm – 6.3 mm and 6.31 mm – 9.5 mm were studied), moisture content, volatile and ash content, real specific mass, X-Ray diffractometry, Thermogravimetric and Differential thermal analysis, mercury intrusion porosimetry, specific surface area (Blaine) and quantity of fixed Calcium Hydroxide (modified Chapelle test). The kinetic assays were carried out based on the statistical design elaborated with central composite rotational design (CCRD), varying ceramic mass and initial concentration of phosphorus for each of the studied bands.The kinetic data obtained were adjusted to the pseudo-first and pseudo-second order Lagergren models. The efficiency of adsorption of phosphorus varied from 23.9% to 45.73% between 0.6 mm - 1.2 mm; 14.73% to 39,83% between 1.21 mm - 2.4 mm; 11.78% to 35.40% between 2.41 mm - 4.8 mm; 6.73% to 30.83% between 4.81 mm – 6.3 mm and 3.81% to 27.83% between 6.31 mm – 9.5 mm, whit different values of mass and initial concentration of phosphorus. The adsorption kinetics data were better fitted to the pseudosecond order model with R² higher than 0.97 for most of the investigated granulometries. Thus, it was concluded that the ceramic residue can be adopted as an alternative adsorbent with efficiency values similar to activated carbon.