Adsorption of 4-Nitrophenol (PNP) Using Pilli Nut Shell Active Carbon

  • F. O. Nwosu Department of Industrial Chemistry, Faculty of Physical Sciences, University o Ilorin, Ilorin, Nigeria
  • F. A. Adekola
  • A. O. Salami


An economically feasible technology for the removal of pollutants from wastewater is adsorption. Active carbon was prepared by single stage method via chemical impregnation of Pili Nut-Shell with orthophosphoric acid and activation at a temperature of 450 oC using precursor-acid ratio of 1:4 for a period of 2 h. The effects of initial concentration, contact time, adsorbent dose and pH on the uptake of 4-nitrophenol (PNP) using Pili nut-based active carbon (PAC) were determined. The PAC maximum adsorption capacity value (190.39 mg/g) was obtained at an initial concentration of 1000 mg/L and was found to be greater than that of a commercial granular active carbon, CGAC (166.97 mg/g) at an initial concentration of 800 mg/L. The BET surface area and total pore volume of PAC (960 m2/g, 0.422 cm3/g) respectively were also greater than that of CGAC (426.3 m2/g, 0.208 cm3/g). The pore size distribution of the PAC (2.842 nm) classifies it to be within range of super-microporous and as such could be used for toxic gas removal as well as small liquid molecules. The Langmuir isotherm best described the adsorption of PNP onto PAC while Pseudo second order kinetics fitted best. The adsorption process was exothermic and spontaneous. Thus, active carbon produced from Pili Nut-Shell can be used to adsorb PNP.

Jun 22, 2017
How to Cite
NWOSU, F. O.; ADEKOLA, F. A.; SALAMI, A. O.. Adsorption of 4-Nitrophenol (PNP) Using Pilli Nut Shell Active Carbon. Pakistan Journal of Analytical & Environmental Chemistry, [S.l.], v. 18, n. 1, p. 69-83, june 2017. ISSN 2221-5255. Available at: <>. Date accessed: 27 jan. 2022. doi: