SOLAR PHOTOCATALYTIC TREATMENT OF TEXTILE EFFLUENT FOR ITS POTENTIAL REUSE IN IRRIGATION.

Since textile industry is the greatest consumer of water, it generates large quantities of effluents. The advanced methods of water treatment present a great potential in terms of wastewater reuse for irrigation. Heterogeneous photocatalysis is a promising technique to mortify the dye residues from textile effluent. In this study, Fe3+ doped ZnO has been synthesized through microwave assisted sol-gel method. The crystallinity and elemental composition of fabricated material was determined by X-ray diffraction (XRD). Two-dimensional disc shaped morphology of photocatalyst has been examined by scanning electron microscopy (SEM) of Fe+3 doped ZnO. Diffused reflectance spectroscopy confirmed its high photocatalytic activity in solar range on reduction of band gap from 3.2 to 2.8 eV after doping. The characterized Fe+3 doped ZnO samples have been used to degrade RB5 dye on irradiating with artificial sunlight (D65). The reaction parameters i.e. initial dye and oxidant concentration, pH and irradiation time have been optimized by Response surface methodology (RSM). The extant of dye degradation has been evaluated by UV/vis and FTIR spectroscopy. The maximum degradation up to 98.32 % in 3 h was achieved on using ZnO doped with 5 mM of Fe+3 under optimized conditions. The phytotoxicity of treated and untreated effluent on length of root and shoot of spinach in addition to yield was measured. The remarkable increase in vegetative growth of plants was observed on using treated textile effluent. [ABSTRACT FROM AUTHOR]