Abstract

Many industrial wastewaters contain toxic and carcinogenic dyes. Health and environmental problems will occur by discharging such wastewaters into the environment. This study was conducted to evaluate the efficiency of ashes from palm and pistachio wastes in removal of reactive red 120 dye from aqueous solutions. In order to perform this experimental study, initially synthetic wastewater was prepared at a concentration of 20 mg L-1. Then the effects of variables of ashes obtained from palm and pistachio wastes were assessed at 30, 60, 90, 120, 150 and 180 min and pH of 3, 5, 7, 9 and 11 on the removal efficiency of dye by adsorption method. The dye concentration in various samples was measured using a spectrophotometer at a wavelength of 525 nm. The levels of dye removal at pH 3-11 for the dye concentration of 20 and 0.05 g L-1 palm ash absorbent in mentioned time were respectively 75.5, 79.4, 84.4, 89.3, 91.3 and 92.8 as well as for pistachio ash absorbent in mentioned time were respectively 84, 88.2, 91.6, 92.2, 93.7 and 94.6 adsorption isotherm for the both absorbents was compatible with Langmuir Model (R2 0.876 for pistachio ash and R2 0.980 for palm ash). The dye removal value enhanced with increasing reaction time. The highest efficiency for the palm ash and pistachio ash was at acidic and neutral pH, respectively. The use of palm ash in removal of reactive red 120 dye is efficient and cost-effective. © Medwell Journals, 2016.