Heavy metal contamination by chemical processing industries is detrimental to aquatic life. In this study, a factorial experimental design technique was used to optimize the chromium removal through biosorption from synthetic solution using Sapindus trifoliatus fruit powder (soapnut) as adsorbent. The process was analyzed and modeled using factorial design 24. The four process parameters considered were pH, metal concentration, soapnut concentration and soapnut particle size at two different levels of pH (4.0 and 8.0), metal concentration (100 and 500 mg/L), Soapnut concentration (5 and 10 g) and soapnut particle size (3 and 12 mm). Experiments were carried out in a bubble column system with working volume of 2L. The efficiency of chromium removal during an exposition time of 72 h was studied. The results were statistically analyzed using the Student’s t-test and analysis of variance to define the most important process variables affecting the chromium removal efficiency. It was observed that the most significant factor affecting Cr(VI) was ascribed to metal concentration.