Metal adsorption by agricultural biosorbents: Adsorption isotherm, kinetic and biosorbents chemical structures.
Biosorption of Cu(II), Co(II) and Fe(III) ions from aqueous solutions by rice husk, palm leaf and water hyacinth was investigated as a function of initial pH, initial heavy metal ions concentration and treatment time. The adsorption process was examined by two adsorption isotherms: Langmuir and Freundlich isotherms. The experimental data of biosorption process were analyzed using pseudo-first order, pseudo-second order kinetic models. The equilibrium biosorption isotherms showed that the three studied biosorbents possess high affinity and sorption capacity for Cu(II), Co(II) and Fe(III) ions. Rice husk showed more efficiency than palm leaf and water hyacinth. Adsorption of Cu(II) and Co(II) was more efficient in alkaline medium (pH 9) than neutral medium due to the high solubility of metal ion complexes. The metal removal efficiency of each biosorbent was correlated to its chemical structure. DTA studies showed formation of metal complex between the biosorbents and the metal ions. The obtained results showed that the tested biosorbents are efficient and alternate low-cost biosorbent for removal of heavy metal ions from aqueous media.
Faculty of Science, Zagazig University, Zagazig, Egypt.
Sadeek A
SA
Sadeek
Petrochemicals Department, Egyptian Petroleum Research Institute, Cairo, Egypt. Electronic address: nabelnegm@hotmail.com.
Nabel A
NA
Negm
Petrochemicals Department, Egyptian Petroleum Research Institute, Cairo, Egypt.
Hassan H H
HH
Hefni
Petrochemicals Department, Egyptian Petroleum Research Institute, Cairo, Egypt.
Mostafa M Abdel
MM
Wahab
D000327:Adsorption; D000383:Agriculture; D002482:Cellulose / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D008031:Lignin / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D015394:Molecular Structure; D013696:Temperature; D062065:Wastewater / Q000737:chemistry; D018508:Water Purification / Q000379:methods
D002482:Cellulose; D007477:Ions; D008031:Lignin; D019216:Metals, Heavy; D062065:Wastewater
Adsorption isotherm; Agricultural wastes; Heavy metal ions; Kinetics; Wastewater treatment