Access to fresh water

its availability

and its quality are a global challenge to humanity

largely due to human activities in the environment. Thus

global water security has been jeopardized

requiring urgent remediation to safeguard our very existence. Hence

a novel and facilely engineered zirconium and polyethylenimine adsorbent based on tiger nut residue (TNR) was prepared

and its adsorptive capabilities towards a model dyestuff and nutrient were invested through a batch adsorption method. The developed adsorbent

zirconium-polyethylenimine-engineered tiger nut residue (TNR@PEI-Zr) was characterised by scanning electron microscopy

Fourier-transform infrared spectroscopy

X-ray diffraction analysis

and X-ray photoelectron spectroscopy to understand its morphology and surface chemistry and predict its adsorption mechanism. TNR@PEI-Zr had a pH point of zero charge (pH

zpc

) of 6.7. The introduction of salts inhibited the removal efficiency of Alizarin red (AR) and phosphate (PO

4

3-

) in the order of HCO

3

-

SO

4

2-

Cl

-

. Increasing temperatures (293-313 K) favoured the adsorption process at pH 3. The Langmuir mode

l suited the adsorption processes of both AR and PO

4

3-

implying homogenous and monolayer removal of pollutants with a maximal capacity of 537.8 mg·g

-1

and 100.5 mg·g

-1

at a dose of 0.01 g

respectively. The rate-determining steps of AR and PO

4

3-

followed a pseudo-second-order kinetic model and were thermodynamically spontaneous with an increase in randomness at the solid-solution interface. The adsorbent’s recyclability was notable and outperformed most adsorbents in terms of removal efficiency. TNR@PEI-Zr was found to be stable

and its use in practical wastewater decontamination was effective

ecologically acceptable and free of secondary pollution problems.