This work reports the abstractive potential of Parkia Biglobosa seed waste (PSW) and Parkia Biglobosa cellulosic extract (PBCE) for the removal of Cr(VI), Pb(II), methylene blue (MB) and congo red (CR) from aqua system. Physicochemical analyses carried out for these biomaterials were proximate analysis, Fourier transform infra red (FTIR) Spectrophotometry and scanning electron microscopy (SEM). The FTIR data showed that-O-H,-C=C- ,-C=O,-C:C-and-S-H functional groups were responsible for the sequestration of Cr(VI), Pb(II), MB and CR from aqua system. The equilibrium data fitted best to Langmuir isotherm model with the highest adsorption obtained for MB, being 1498.42 mg/g at 298 K and 403.23 mg/g at 298 K for PSW and PBCE respectively. Pseudo-second order model gave the best fits for the kinetic data among two other kinetic models used. The PSW and PBCE biomaterials demonstrated good potentials for the removal of toxic Cr(VI), Pb(II), MB and CR from aqua systems.

This research enthusiastically highlights the bio-adsorption of methylene blue (MB) by local, poultry, NaOH and citric acid modified ubiquitous eggshell (LES, NLES, CLES, PES, NPES and CPES) adsorbents. The microstructures of these adsorbents indicated that they had some surface functional moieties that were responsible for the adsorption of MB. The Langmuir isotherm and PSO model best fit the experiment data. The largest Langmuir monolayer adsorption capacity ${q_{max}}$, was 242.47 mg/g, with the largest MB initial concentration of 400 mg/L. This was a clear indication and a confirmation that MB adsorption by the powdered eggshells was chemisorptive. Moreover, the values of $F$, the thickness of the boundary layer/film were $\gt 0$, showing that the rate limiting step for the adsorption process was controlled by more than one diffusion mechanism. The values of $\Delta {G^\circ }$ for the adsorption of MB by the adsorbents indicated that the adsorption reactions were all non-feasible and non-spontaneous. The values for $\Delta {S^\circ }$ (J/K/mol) for LES, NLES and CPES for the uptake of MB showed decrease in the chaos or degree of randomness of the adsorption reactions, and the reverse was the case for PES, NPES and CLES for the uptake of MB, which showed increase in the chaos or degree of randomness of the adsorption. The adsorption of MB by LES, NLES and CPES gave $\Delta {H^\circ }$(kJ/mol) values which were indicative of endothermic nature of the adsorption systems, and the reverse was the case for the uptake of MB by PES, NPES and CLES, which was indicative of the exothermic nature of the adsorption systems.