An efficient liquid-liquid extraction method was developed for the removal of Cd2+, Ni2+,
Pb2+, and Zn2+ from environmental waste using n-benzoyl-n-phenyl hydroxylamine (BPA). The effects
of solvents, pH, stripping agents, extraction time, and interference of other ions on the recoveries were
investigated. Study shows chloroform is the most efficient solvent for BPA and maximum extraction
percentage of metals can be achieved by it. These metals can be quantitatively extracted between the pH 6.5-10. 1M
HNO3, 4M HNO3, 1M HCl, and 5M HNO3 can be used as stripping agents to achieve the maximum percentage recovery
of Cd2+, Ni2+, Pb2+, and Zn2+, respectively.