Cadmium bioadsorption in contaminated surface water using Moringa oleifera seed flour
Description
Introduction. Cadmium in surface water requires low-complexity treatment options for field-derived matrices. Objetives. This study evaluated Cd bioadsorption from contaminated surface water using chemically unmodified Moringa oleifera Lam. seed flour. Materials and Methods. Mature seeds were washed, dehulled, dried at 65 °C for 24 h, milled and sieved through No. 50 mesh. The biosorbent was characterised by proximate analysis and FTIR-ATR. Batch assays used a 4 x 3 factorial design with doses of 1, 5, 10 and 15 g L⁻¹ and contact times of 30, 60 and 90 min, with duplicates. Results. The initial Cd concentration was 0.046 mg L⁻¹. The flour contained 35.18 g 100 g⁻¹ carbohydrates, 27.71 g 100 g⁻¹ protein, 27.40 g 100 g⁻¹ fat, 6.34 g 100 g⁻¹ moisture and 3.37 g 100 g⁻¹ ash. FTIR-ATR identified N-H, O-H, C-H, C=O and C-O bands. The best tested condition was 10 g L⁻¹ for 30 min, reducing Cd to 0.00460 mg L⁻¹ and reaching 90.00% removal. The quadratic model was significant, p < 0.001, with R² = 99.84%, adjusted R² = 99.80%, predicted R² = 99.71% and non-significant lack of fit. Conclusions. Moringa oleifera seed flour offers an accessible biosorbent for Cd reduction in surface water, with validation needed for regeneration, leaching and matrix variability.