Human daily activities increase water consumption, which increases the quantities of wastewater. The produced wastewater must be treated thoroughly before discharging to protect the environment. Adsorption technique is one of the most common methods of treating water and wastewater. Graywater is resulting from human uses, as it is a mixture of bathroom and kitchen drainage. The main pollutants in greywater are oils&greases, total suspended solids (TSS), chemical and biological oxygen demand (COD and BOD5), nitrogenous compounds, and phosphorus pollutants. This study aimed to verify the effectiveness of bio-adsorbents and the granular activated carbon produced from corncob as an agricultural waste. The corncob was converted into granular activated carbon. The removal efficiency of adsorbents depends on several factors such as contact time, the doses of adsorbents, pH of a solution, and depth of column bed. The maximum percent removal attained at the 120 min, 0.8 g/L of adsorbent. The results indicated that the second-order kinetic model gave a good fit of the data for adsorption of pollutants onto the GACC. The values of R2 were very well in the pseudo-second-order kinetic model, The R2 was 0.893, 0.986, 0.996, and 0.961 for COD, TSS, TKN, and phosphorus, respectively. Furthermore, the breakthrough study was conducted using GACC. The removal efficiency (R %) of GACC for COD, TSS, TKN, and T.P at 4 h were 88.18, 81.14, 87.11, and 99.57, respectively. The overall results in case study for greywater treatment by using GACC were complying with the Egyptian Environmental Association Affair (EEAA) limits.