The study aims to produce renewable and green activated carbon (AC) from palm biomass through pyrolysis and the activation process. The study also aims to evaluate the application of AC as adsorbent in palm oil mill effluent treatment (POME). This is in order to reduce the pollutant levels in its final discharge. The AC was prepared from empty fruit bunch (EFB), by pyrolysis (to produce bio-char), followed by physical activation. The bio-chars with higher carbon content were selected for the preparation of the AC. The physical activation process was carried out by purging with carbon dioxide (100 cm3 min-1) at 10°C min-1 heating rate for 30 min until the AC reaches the desired activation temperature. The activation temperatures studied ranged from 500°C to 900°C in quartz tube furnace. The optimum activation temperature i.e. 800°C gave the maximum specific surface area, (SBET) of 937 m2 g-1. Batch adsorption experiments applying the prepared adsorbent to synthetic dye yielded adsorption data well fitted to the Langmuir isotherm model. The AC produced from EFB performed better in dye removal achieving a maximum adsorption capacity of 333.3 mg g-1. The EFB-based AC was able to reduce the biochemical oxygen demand of POME. These studies suggested that the EFB AC could be useful as a low cost alternative adsorbent in wastewater treatment.