Abstract: Modified adsorbent prepared by local agricultural and forestry waste banana peel in Hainan was used to study the efficacy of its absorbing heavy metal Pb²⁺ in wastewater. Based on the effects of single factor such as absorber dosage,adsorption time,the initial concentrations of Pb²⁺,and pH value on the adsorption rate,Box-Behnken response surface methodology was conducted to optimize the design and experiment. The results showed that the optimized condition of modified banana peel absorbing Pb²⁺ in wastewater by the response surface analysis was such：adsorption time 48min,absorber dosage 3 mg/L,the initial concentrations of Pb²⁺ 5.5 mg/L and pH 6,under which the adsorption rate reached 96.90%,and this was consistent with the predicted value 96.97%. Adsorption time,the initial concentrations of Pb²⁺ and the interaction between adsorption time and initial concentrations of Pb²⁺ affected extremely significant on the adsorption rate（P<0.001）;pH had significant effects on the adsorption rate（P<0.05）. The variance analysis of the model revealed that the P value was < 0.000 1.The regression equation of the model was very significant,it could be used to analyze the adsorption of Pb²⁺ by modified banana peel.

Key words: banana peel, Pb²⁺, adsorption, response surface methodology