Arsenic bioadsorption from groundwater using Guadua angustifolia Kunth flour
Description
Introduction. Arsenic in groundwater requires low-cost treatment options suitable for decentralised application. Objetives. This study evaluated total arsenic bioadsorption from groundwater using Guadua angustifolia Kunth flour, considering biosorbent dose, contact time, removal efficiency and adsorption capacity. Materials and Methods. Culms were processed by drying, milling and sieving without chemical activation. Batch assays were performed with 250 mL of groundwater containing 0.081 mg L-1 arsenic. A 4 x 3 quantitative factorial design tested 1, 3, 6 and 10 g L-1 flour at 30, 60 and 90 min, with duplicate runs. Final arsenic, removal and adsorption capacity were calculated, followed by factorial analysis of variance, Tukey comparison and quadratic regression. Results. Final arsenic decreased as dose and time increased. The best experimental condition, 10 g L-1 and 90 min, reached 0.008 ± 0.001 mg L-1 and 90.13 ± 0.70% removal. The factorial model was significant, and the quadratic model showed high predictive performance, with no significant lack of fit. Numerical optimisation predicted 9.5965 g L-1 and 86.4404 min for 0.008 mg L-1. Conclusions. Guadua flour showed operational potential as a minimally processed biosorbent for reducing arsenic in groundwater within the tested domain.