New facile benign agrogenic-nanoscale titania material—Remediation potential for toxic inorganic cations

A new facile benign (eco-friendly) Nauclea diderrichii agrowaste-nanoscale titania hybrid adsorbent (TND) used in the sequestration of Cr(III) and Pb(II) ions is reported in this paper. Surface characterization techniques such as thermogravimetric analysis (TG), X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) surface area and porosimetric analyses indicated that N. diderrichii agrowaste (NDS) was successfully modified with nano-titania. TG analysis proved that modification of N. diderrichii agrowaste with nano-titania improved its thermal stability and rate of metal ion uptake. Pseudo-second order kinetic equation gave better fit to experimental data than pseudo-first order kinetic equation. The adsorption capacity of NDS and TND adsorbents for Cr(III) were 5.57 mg/g and 6.21 mg/g, respectively. Also, the amounts of Pb(II) sequestered by NDS and TND adsorbents were 6.82 mg/g and 7.49 mg/g, respectively. Also, the initial sorption rates of Cr(III) and Pb(II) by TND adsorbent was higher than for NDS adsorbent, making TND material a better adsorbent for toxic metal ions removal from aqueous effluents than NDS adsorbent.