In the present study, high surface area boehmite nanopowder was recovered from aluminum cans waste. The sodium aluminate solution was first prepared by dissolving aluminum cans in NaOH solution and then, H2O2 solution was added to precipitate boehmite. The prepared boehmite was characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption–desorption techniques. The thermal stability of the boehmite sample was investigated using thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. The feasibility of using the prepared boehmite powder as a new low-cost adsorbent for the treatment of oilfield produced water was investigated. For comparison, commercial activated carbon was used for the treatment of the produced water under the same conditions. The efficiency of both of boehmite and activated carbon in the treatment of produced water was determined by monitoring the values of a number of pollution indicators [i.e. turbidity, sulfides, sulfates, total organic carbon (TOC), total petroleum hydrocarbon (TPH), and chemical oxygen demand (COD)] before and after the treatment. The boehmite powder showed very good efficiency in the treatment of the produced water, which is very close to that of commercial activated carbon under the same conditions. The effect of adsorbent dose, treatment time, and pH of the media on the adsorption efficiency of both of boehmite and activated carbon was examined at room temperature using chemical oxygen demand as a pollution indicator. The maximum capacity for COD reduction was 69.6% for boehmite and 83.5% for activated carbon at 40 g/l adsorbent dosage, pH7, and 24-h contact time. Graphic abstract