title: Developing Polycation-Clay Sorbents for Efficient Filtration of Diclofenac: Effect of Dissolved Organic Matter and Comparison to Activated Carbon.
abstract: The presence of nanoconcentrations of persistent pharmaceuticals in treated wastewater effluent and in surface water has been frequently reported. A novel organic-inorganic hybrid sorbent based on adsorbing quarternized poly vinylpyridinium-co-styrene (QPVPcS) to montmorillonite (MMT) was designed for the removal of the anionic micropollutants. QPVPcS-clay composites were characterized by X-ray diffraction, FTIR, thermal gravimetric analysis, Zeta potential and element analysis. Based on these measurements polymer-clay micro- and nanostructures, as a function of polymer loading, were suggested. The affinity of the anionic pharmaceutical, diclofenac (DCF), to the composite was high and did not decrease dramatically with an increase of ionic strength, indicating that the interactions are not only electrostatic. The presence of humic acid (HA) did not hinder DCF removal by the composite; whereas, its filtration by granulated activated carbon (GAC) was compromised in the presence of HA. The kinetics and adsorption at equilibrium of DCF to the composite and to GAC were measured and modeled by the time dependent Langmuir equation. The adsorption of DCF to the composite was significantly faster than to GAC. Accordingly, the filtration of micro- and nanoconcentrations of DCF by composite columns, in the presence of HA, was more efficient than by GAC columns.
authors.affiliation: Department of Soil and Water Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Hagay
authors.initials: H
authors.lastname: Kohay
authors.affiliation: Department of Soil and Water Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Avital
authors.initials: A
authors.lastname: Izbitski
authors.affiliation: Department of Soil and Water Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Yael G
authors.initials: YG
authors.lastname: Mishael
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D001546:Bentonite / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D000077215:Clay; D004008:Diclofenac / Q000302:isolation & purification*; D005374:Filtration; D006812:Humic Substances / Q000032:analysis; D007700:Kinetics; D009930:Organic Chemicals / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D000071228:Polyelectrolytes; D011726:Pyridinium Compounds / Q000737:chemistry; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D020058:Styrene / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry; D018508:Water Purification
chemical_list: D000538:Aluminum Silicates; D001546:Bentonite; D002606:Charcoal; D000077215:Clay; D004008:Diclofenac; D006812:Humic Substances; D009930:Organic Chemicals; D011073:Polyamines; D000071228:Polyelectrolytes; D011726:Pyridinium Compounds; D020058:Styrene; D014753:Vinyl Compounds; C518451:N-vinylpyridinium