Produção do carvão ativado, a partir das podas do Ziziphus Joazeiro e avaliação da utilização no tratamento de efluentes residenciais de Crateús

Abstract

The objective of this study was to evaluate the effectiveness of activated carbon obtained from the pruning of Ziziphus joazeiro for the treatment of domestic wastewater in Crateús, Ceará. The production of the activated carbon was based on the optimized conditions previously determined by Pereira (2021), using a Central Composite Rotational Design (CCRD) in conjunction with Response Surface Methodology (RSM), which enabled the production of carbon with lower cost and higher adsorptive efficiency. Subsequently, biofilters were constructed using stone materials, coconut fiber, and the synthesized activated carbon. The physicochemical analyses of the effluent showed that the biofilter with activated carbon was effective, resulting in an 87.7% reduction in biochemical oxygen demand (BOD), 35% in sulfates, and 27% in alkalinity. The morphological analysis of the activated carbon through Scanning Electron Microscopy (SEM) revealed a rough surface, irregular structure, and high porosity, with an average grain size of 3.46 µm and an average pore diameter of 21 nm, suggesting a predominance of mesopores. This configuration enhances adsorption efficiency. Furthermore, an increase in porosity was observed compared to the precursor material, demonstrating the effectiveness of the activating agent and the thermal process used. It can be concluded that plant-based activated carbon, especially that produced from Ziziphus joazeiro, represents a viable, sustainable, and technically efficient option for wastewater treatment.