In this research, novel PANI/BN-based absorbent was prepared by bonding polyaniline and bentonite for water remediation and their structures were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The effect of pH, concentration of metal, and dosage amount on synthesized novel PANI/BN-based absorbent was investigated in detail. The result indicated that the PANI/BN-based absorbent has an excellent adsorption performance towards Cu, Pb, and Ni, and the highest binding capacity of 130 mg g−1 for Ni was obtained under normal conditions. The adsorption of PANI/BN absorbent was found to depend on pH when pH < 7.0, but the adsorption has been found independent from the ionic bond effect. The adsorption at optimum pH for Cu (pH 6) and Pb (pH 5) was observed as 85 mg g−1 and 105 mg g−1, respectively. The best results collected at those conditions of isotherm data and adsorption kinetics are represented by the Langmuir model and pseudo-second order equation, respectively. Thermodynamic results (ΔH > 0, ΔS > 0, ΔG < 0) showed that the adsorption process of Cu, Ni, and Pb is significantly increased by the synthesized novel PANI/BN-based absorbent.