To valorize organic waste in order to get a potential environmental application, the characteristics of Banana peel biochar (BPB) were studied to assess the effect of temperature on the physicochemical characteristics. In this study, various biochar was synthesized from the pyrolysis of two particle sizes of banana wastes (1 and 3 mm) at eight different temperatures varying between 200 and 600 ºC. The experimental results showed that biochar yield production decreased with the increase in temperature and the decrease in banana peel particle size. Indeed, for particle size of 1 mm, these yields decreased from 45.79% at a temperature of 200º C to less than 15.24% at 600 ºC. The physicochemical characteristics of the produced biochar by using various analyses including X-Ray fluorescence (XRF), X-Ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning electron microscopy (SEM) showed that the XRD analysis indicates that pyrolysis of banana peel at 500˚C is incomplete, resulting in the presence of amorphous carbon, Fullerene, and Chaolite. The FT-IR spectrum shows no difference in BPB of different sizes and pyrolysis temperatures. The BET surface areas of BPB are generally low, and the SEM investigation shows an irregular porous external surface. The XRF analysis reveals high carbon, potassium, and chlorine percentages in BPB. Moreover, this biochar could promote the adsorption of various pollutants. The test of BPB for the adsorption of copper from synthetic aqueous solutions showed that, it could be considered as a promising adsorbent with a maximum adsorption capacity of 54.9 mg/g for copper (Cu2+) removal. Increasing Cu2+ concentrations from 50 to 550 mg/L resulted in an increase in BPB's adsorption capacity by approximately 52 mg/g and an increase in metal removal efficiency by about 40%. The optimal Cu2+ concentrations for adsorption were found to be 450 and 550 mg/L.