Síntese e caracterização de adsorvente sustentável a partir de lodo de ETA e casca de laranja: aplicação para remoção de corante reativo azul BF 5G

This study produced and characterized a mixed adsorbent material from Water Treatment Plant (WTP) sludge and orange peel waste (Citrus sinensis (L.) Osbeck) for use in the removal of Reactive Blue BF 5G dye from aqueous solutions. The pellets were thermally treated at 950ºC. The material produced, named MAT, was characterized for its chemical and surface properties using XRF, XRD, FTIR, SEM, BET, PZ, and pH-PCz. The results reveal that MAT showed promising chemical and mineralogical composition for adsorption, with a predominance of silica (>45%) and aluminum (>30%), a mesoporous and rough surface, negative charge under neutral conditions, and a buffering effect at pH 5.7. The dye removal efficiency of MAT was evaluated in terms of solution pH, temperature, contact time, and MAT mass. The results showed that MAT exhibited adsorption capacity and removal efficiency with the best performance at pH 3. The process was favorable at room temperature and rapid, using just one unit of the pellet. However, the adsorption capacity was lower than expected (q < 0.26 mg g⁻¹), suggesting that sintering at lower temperatures might be more suitable to optimize its effectiveness.