title: Adsorption and removal kinetics of phosphonate from water using natural adsorbents.
abstract: The removal of phosphonate from water was studied using some natural adsorbents. Potassium phosphonate is a fungicide used for the control of Phytophthora capsici, which is prevalent in black pepper (Piper nigrum L.). Batch adsorption kinetic experiments were conducted on the adsorption of phosphonate onto the adsorbents. The concentration of phosphonate was measured on a high-performance liquid chromatograph fitted with a conductivity detector. The percentage removal of phosphonate by powdered laterite stone (PLS) from water was 40.4%, within a residence time of 15 minutes. The mechanisms of the rate of adsorption were analyzed and compared using the pseudo-second-order, Elovich, and intraparticle diffusion models. The experimental data was found to correlate well with the pseudo-second-order kinetic model, indicating adsorption as a chemisorption process. A possible reaction in the phosphonate-PLS system also has been proposed. The PLS can be used as a low-cost natural adsorbent for phosphonate removal from water.
authors.affiliation: Department of Science and Humanities, National Institute of Technology-Calicut, Kozhikode, Kerala, India. anilmuktharam@yahoo.co.in
authors.forename: R Anil
authors.initials: RA
authors.lastname: Kumar
authors.forename: K T
authors.initials: KT
authors.lastname: Velayudhan
authors.forename: V
authors.initials: V
authors.lastname: Ramachandran
authors.forename: R Susheela
authors.initials: RS
authors.lastname: Bhai
authors.forename: G
authors.initials: G
authors.lastname: Unnikrishnan
authors.forename: K
authors.initials: K
authors.lastname: Vasu
mesh_terms: D000327:Adsorption; D005659:Fungicides, Industrial / Q000737:chemistry; D007700:Kinetics; D016014:Linear Models; D008956:Models, Chemical; D063065:Organophosphonates / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D005659:Fungicides, Industrial; D063065:Organophosphonates; D014874:Water Pollutants, Chemical; D014867:Water