Synthesis and Technological Application of Agro-Waste Composites for Treatment of Textile Waste Water

The untreated dyes released into the water reservoirs pose a toxic effect on the agricultural land through irrigation. Pakistan’s economy is agro based demanding best quality product yield. However, the large consumption of rice in the country also produces waste (husk). It is either thrown or used as animal fodder. The present investigation is an endeavor to offer technological application of Rice Husk composite for treatment of azodyes (Congo red, Crystal violet, Methyl orange) from industrial effluents. For this purpose rice husk was modified with saturated (stearic) and unsaturated (oleic) fatty acids and applied as adsorbent in batch mode. Adsorption mechanism was accessed on the basis of varying adsorbent dose and adsorbate concentration for optimization of working parameters. The synthesized composite was characterized using FTIR, SEM-EDX, TGA and UV-Vis spectroscopy. FTIR spectrum showed sharp peak of esters (1700cm-1 - 1715cm-1) indicating modification due to fatty acids. It also suggests that binding of rice husk is through this ester linkage. Adsorption experiments analyzes the increased removal efficiency of rice husk composites for dye, showing removal of 81% and 77% on oleic and stearic acid modification, respectively. An instantaneous adsorption-desorption hysteresis loop was attained in 20 minutes and 35 minutes under optimum conditions. Comparison among adsorbent composites for efficiency removal of azodyes showed that congo red dye removed more efficiently from industrial waste water as compared to other dyes. % Removal trend observed for azodyes was: congo red > crystal violet > methyl orange. The present study concludes economical green synthesis of agro based composites and recommends its application for in-situ and ex-situ removal of azodyes from water reservoirs.