Olive Stone Biosorption Dataset — raw data and reproducible analysis scripts for "Electrostatic selectivity of NaOH-modified olive stone: robust Pb(II) removal, dose-dependent Cd(II) uptake, and limited As(V) retention"

This dataset contains all raw experimental data and reproducible analysis scripts supporting the study on biosorption of cationic Pb(II), Cd(II) and anionic As(V) onto NaOH-modified olive stone (Olea europaea L.). CONTENTS:- Physicochemical characterisation of native (NC) and NaOH-treated (CT) biosorbent: ash, iron, phosphorus, Ca+Mg, FTIR spectra (3551 points), point of zero charge.- Two factorial batch experiments (pH × particle size and dose × particle size) with n = 2 replicates per cell.- Single-metal kinetic experiments (7 time points per metal, 3 metals).- Fixed-bed column breakthrough experiments for As(V), Cd(II), and Pb(II).- Dose-dependent equilibrium uptake data.- Reproducible analysis scripts (R and Python) that regenerate ANOVA tables, effect sizes, non-linear kinetic fits (PFO, PSO, IPD), and Thomas-model parameters reported in the manuscript. FOLDER STRUCTURE: 01_characterization/ — chemical composition, pHPZC, FTIR 02_batch_experiments/ — factorial ANOVA datasets 03_kinetics/ — kinetic data and fitted parameters 04_fixed_bed_column/ — breakthrough curves and Thomas parameters 05_equilibrium_uptake/ — dose-dependent uptake 06_reproducibility/ — Data S1 analysis scripts (R and Python) Reproducibility verified: Table 1a, Table 1b, Table S7, and Table 4 (Cd, Pb) of the manuscript are regenerated exactly by the provided scripts. A minor numerical discrepancy in the As(V) Thomas fit is documented transparently in the README. Full documentation (README.md), license (CC BY 4.0), and SHA-256 manifest included in the archive. Related publication: Associated manuscript submitted to Journal of Environmental Management. Funding: CONCYTEC/PROCIENCIA, Peru, Contract No. 365-2019-FONDECYT.