Utilization of organic by-products for the removal of organophosphorous pesticide from aqueous media

Sorption potential of rice (Oryza sativa) bran and rice husk for the removal of triazophos (TAP), an organophosphate pesticide, has been studied. The specific surface area were found to be 19 ± 0.7 m2 g−1 and 11 ± 0.8 m2 g−1 for rice bran and rice husk, respectively. Rice bran exhibited higher removal efficiency (98 ± 1.3%) than rice husk (94 ± 1.2%) by employing triazophos solution concentration of 3 × 10−5 M onto 0.2 g of each sorbent for 120 min agitation time at pH 6 and 303 K. The concentration range (3.2-32) × 10−5 M was screened and sorption capacities of rice bran and rice husk for triazophos were computed by different sorption isotherms. The energy of sorption for rice bran and rice husk was assessed as 14 ± 0.1 and 11 ± 0.2 kJ mol−1 and kinetics of the sorption is estimated to be 0.016 ± 0.002 and 0.013 ± 0.002 min−1, respectively. Intraparticle diffusion rate was computed to be 4 ± 0.8 and 4 ± 0.9 nmol g−1 min−1/2. Thermodynamic constants ΔH, ΔS and ΔG at varying temperatures (283-323 K) were also calculated.