Pyrolysis of biomass is the carbonization process where biomass is processed into biochar (BC) and the characteristics of BC like surface area, hydrophilicity, carbon content etc., are determined by the carbonization process. Trichloroethylene (TCE) and tetrachloroethylene (PCE) are chlorinated hydrocarbons that are used for metal degreasing and found in groundwater. In this study, six lignocellulosic feedstocks were gathered to produce BCs through pyrolysis in an argon atmosphere at temperatures between 300 °C and 900 °C. TCE and PCE batch adsorption tests were conducted for 72 h to generate Freundlich and Langmuir isotherm profiles. The results showed that as the pyrolysis temperature increased, hydrophilicity, surface area, and carbon content of all the BCs increased. Among the six examined feedstocks, the BC produced from walnut shells showed better results than other feedstocks with a microporous area of 37.91 m2/g, Qmax of 194 mg/g for TCE, and KF of 133 mg/g for PCE.