Background & Aim: Dyes are one of the most important pollutants in textile wastewater that are toxic, carcinogenic, teratogenic and non-biodegradable. Entering of dyes into water resources reducing the penetration of sunlight and eutrophication is occurred. Melia azedarach core and fruit is one of the inexpensive natural absorbent that has an important place in the treatment of textile wastewater.

Methods: In this study solid structure of absorbent was analyzed using Fourier transform infrared spectroscopy and Scanning electron microscope, also effect of various parameters such as initial dye concentrations (10-100 mg/l), adsorbent dosage (0.1-1.1 g/l), contact time (0-60 min) and solution pH (4-10) on the removal of dye were investigated and at the end, kinetics and adsorption isotherm were also noted by the adsorbent. The remaining of dye was analyzed by UV/VIS spectrophotometer at a wavelength of 665 nm.

Results: Maximum removal of color, which is 85%, was in color concentration 32.5 mg/l , adsorbent dose 0.85 g/l, detention time 45 min and pH=8.5.initial concentration had the greatest impact on color removal (P=0.0001). The results showed data were explained acceptably by pseudo second-order model (R²=0.95_0.99) and Langmuir isotherm model (R² = 0.98).

Conclusion: Core and Melia azedarach fruit has the ability to remove methylene blue. The optimum pH to remove the color by absorbing was in alkaline range and most textile wastewater has an alkaline pH therefore, it is an appropriate and cost-effective adsorbent to take away color from the wastewater of textile industry.