Cadmium bioadsorption in contaminated surface water using Moringa oleifera seed flour

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.