The ability of Date palm Leaves powder (DPLP) to remove methylene blue (MB) from aqueous solutions by the
biosorption process has been studied. Biosorption studies were carried out at different initial dye concentration,
contact time, initial solution pH, biosorbent dosage, the particle size of (DPLP) and temperature. Biosorption data
were modeled using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich adsorption isotherms. The results
showed that equilibrium was reached within 160 min. The used biosorbent gave the highest adsorption capacity at
pH 6.5 . Equilibrium data of the biosorption process fitted very well to the Temkin model (R2=0.994). The maximum
adsorption capacity, Langmuir’s qmax, improved from 43.103 to 58.14 mg/g as the temperature increased from 30 to
60°C. The enthalpy