MODIFICATION OF TERMITE MOUND SOIL USING PHOSPHORIC ACID FOR PHOTODEGRADATION OF METHYLENE BLUE DYE UNDER UV LIGHT IRRADIATION

Abstract

Termite mound was mined from the termite nest spotted at Ahmadu Bello University, Zaria Kaduna State, Nigeria. It was washed with deionized water and placed in an oven set at 60oC for 6 hrs before crushing with an aggregate impact crusher and sieved into 0.075 m mesh pore size. The sieved soil sample was tagged as unmodified-TMS (termite mound soil). The soil sample was modified using orthophosphoric acid (H3PO4) at different (5 %, 10 %, 15 %, and 20 %) concentrations. The modified and unmodified-TMS were characterized by the methods of scanning electronic microscope (SEM), transmission electron microscope (TEM), 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 % TMS-H3PO4, 10 % TMS-H3PO4 , 15 % TMS-H3PO4 , and 20 % TMS-H3PO4, were assessed by testing the degradation rate of Methylene Blue under ultraviolet light irradiation using optimum parameters (1.5 g/L, pH 11 & 75 mg/L). The results indicated that the samples exhibited the best photocatalytic activity at optimum parameters of catalyst dosage 1.5 g /L. pH 11 and 75 mg/L concentration of MB as evidenced by the highest methylene degradation rate of (88 %). The photocatalytic degradation of Methylene blue dye was found to obey first-order kinetics.