PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE FROM AQUEOUS SOLUTION USING BASE MODIFIED TERMITE SOIL UNDER UV LIGHT IRRADIATION

Abstract

Photocatalysis is an effective treatment method for removal of toxic pollutants from industrial wastewaters. Sodium hydroxide was used to modified termite mound soil obtained from Ahmadu Bello University Zaria, Kaduna State, Nigeria. The soil was washed with deionized water and placed in an oven set at 60oC for 6 hrs before crushing with an aggregate impact crusher, sieved with 0.075 m mesh pore size. The sieved soil sample was tagged as unmodified-TMS (termite mound soil). The soil sample was modified using sodium hydroxide (NaOH) at different concentrations (5 %, 10 %, 15 %, and 20 % W/V). The modified and unmodified-TMS catalysts were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray fluorescence (XRF), Electron diffractive X-ray (EDX), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), thermogravimetric analyses (TGA), and Selected area electron diffraction (SAED), The photocatalytic activity of the unmodified-TMS, 5 % NaOH, 10 % TMS-NaOH, 15 % TMS-NaOH, and 20 % TMS-NaOH, were assessed by testing the degradation rate of Methylene Blue under ultraviolet light irradiation. The results indicated that the samples exhibited the best photocatalytic activity at optimum parameters of catalyst dosage 2.5 g /L. pH 9 and 125 mg/L concentration of MB this is evidenced by the highest methylene degradation rate of (74 %). The photocatalytic degradation of the Methylene blue dye was found to obey first-order kinetics.