Ca-bentonite sample from Boane region, Maputo Province, Mozambique exhibiting a white colour was organo-modified and subsequently evaluated for uses as an adsorbent for the treatment of produced water from a natural gas production platform. The clay was subjected to organo-modification through ion-exchange reaction by cationic surfactants namely benzalkonium chloride and cetrimonium bromide. The organophilization process altered the natural hydrophilic character to hydrophobic. The effectiveness of the ion-exchange procedure was revealed by XRD patterns, wherein the main Ca-MMT d001 peak changed from 1.520 nm to 1.960 nm when the concentration of cetrimonium bromide used for organo-modification varied from 50 to 100 meq and from 1.520 to 1.830 nm when a fixed concentration of benzalkonium chloride was used. Wastewater treatment performance evaluation of synthesized products showed that the physico-chemical and bacteriological properties improved significantly, showing clearly that Boane bentonite has enormous potential to be applied as an adsorbent material for produced water treatment.