Avaliação ecotoxicológica do Bisfenol a e sua remoção em água utilizando a biomassa ativada de Ingá-cipó (Inga edulis)

Abstract

Bisphenol A (BPA) is a substance used in the production of plastics and resins and is recognized for causing harmful effects on the environment and human health. As an endocrine disruptor, BPA can cause hormonal alterations, reproductive problems, and impacts on the growth and metabolism of aquatic organisms and humans. In this context, the search for effective strategies that enable its removal represents a current challenge. In this study, the toxicity of BPA to freshwater organisms was investigated before and after the application of adsorption techniques, using activated biomass from Inga edulis bark as the adsorbent material. Acute toxicity assays were conducted with Daphnia similis and Ceriodaphnia silvestrii to determine CE50 values (24 and 48 h), and with Chironomus sancticaroli to determine the CL50 (96 h). The mean CE50 values (24 and 48 h) for D. similis were 10.50 and 8.89 mg L⁻¹, respectively; for C. silvestrii, they were 5.64 and 3.63 mg L⁻¹, respectively; while for C. sancticaroli, the CL50 (96 h) was 3.32 mg L⁻¹. After determining the CE50 and CL50 values for BPA, the optimization of adsorption parameters was carried out, including kinetics, pH, isotherms, and optimal dosage. The biomass was previously characterized using SEM, FTIR, TG, CHN, BET, XPS, and point of zero charge (PZC) analyses, which confirmed structural modifications and the presence of functional groups relevant to the activation and adsorption processes. The adsorption assays demonstrated a significant reduction in BPA concentration in the samples, with removal efficiencies ranging from 38% to 61%. In addition, BPA concentrations before and after the adsorption process were quantified by electrochemical techniques and UV–Vis spectrophotometry. When the treated samples were re-exposed to the test organisms, survival rates of 100% for D. similis at 24 h and 80% at 48 h, 100% for C. silvestrii at both exposure periods (24 and 48 h), and 98% for C. sancticaroli at 96 h were observed, evidencing a substantial reduction in BPA toxicity after treatment. The results indicate that activated I. edulis bark biomass has high potential as an ecological and efficient adsorbent material, capable of significantly reducing BPA concentration and toxicity in aquatic environments, thus contributing to the development of sustainable alternatives for the treatment of contaminated waters.