In this study, a two-stage process was conducted. The first stage was carrying out for the activationrnprocess of Peanut shell powder at different temperatures and concentrations to select the optimumrnparameters. The second stage was bleaching of Niger seed oil using the chosen activated peanutrnshell powder adsorbent. The peanut shell collected from Sululta, Ethiopia was activated byrnphosphoric acid, and further bleaching experiments were conducted to assess the activatedrnpowders effect on the bleaching capacity of Niger seed oil. The Two key parameters of the acidrnactivation process were acid concentration and activation temperature. The highest bleachingrncapacity was obtained around 3M acid concentration and at 350rnornC of activation temperature as rnoptimal activation. The PSP and PAAPSP at optimal condition were characterized by XRD, FTIRrnand SEM with EDS. The results of the XRD showed that the PSP is composed of cellulose,rnhemicellulose and lignin polysaccharide. The XRD analysis of PAAPSP illustrated the presencernof crystalline carbonaceous structure and different alumino silicate minerals. X-ray and FTIR datarnconfirmed that acid activation degrades cellulose. The results of the analysis by Energy DispersivernSpectroscopy (EDS) showed that, presence of carbon, oxygen, silica, alumina and phosphorous.rnFull factorial Box Behnken design (BBD) experimental design was employed to correlate thernbleaching parameters (temperature, time and dosage of PAAPSP) to the percentage colorrnreduction for Niger seed. The result showed that the optimum condition for the bleaching processrnwas a temperature of 110rnornC, a period of 20 minutes and 3% PAAPSP dosage which resulted in rn88.02% bleaching performance of the Niger seed oil. The experimental result was in agreementrnwith the model prediction. Generally, the study has shown that the phosphoric acid activatedrnpeanut shell powder is a good adsorbent for the bleaching of the Niger seed oil. This research hasrnfurther established that acid activated peanut shell powder has the capacity to remove not onlyrnpigments but also reduce the free fatty acid and peroxide value of unbleached oil.