title: Atrazine removal from water by polycation-clay composites: effect of dissolved organic matter and comparison to activated carbon.
abstract: Atrazine removal from water by two polycations pre-adsorbed on montmorillonite was studied. Batch experiments demonstrated that the most suitable composite poly (4-vinylpyridine-co-styrene)-montmorillonite (PVP-co-S90%-mont.) removed 90-99% of atrazine (0.5-28 ppm) within 20-40 min at 0.367% w/w. Calculations employing Langmuir's equation could simulate and predict the kinetics and final extents of atrazine adsorption. Column filter experiments (columns 20x1.6 cm) which included 2g of the PVP-co-S90%-mont. composite mixed with excess sand removed 93-96% of atrazine (800 ppb) for the first 800 pore volumes, whereas the same amount of granular activated carbon (GAC) removed 83-75%. In the presence of dissolved organic matter (DOM; 3.7 ppm) the efficiency of the GAC filter to remove atrazine decreased significantly (68-52% removal), whereas the corresponding efficiency of the PVP-co-S90%-mont. filter was only slightly influenced by DOM. At lower atrazine concentration (7 ppb) the PVP-co-S90%-mont. filter reduced even after 3000 pore volumes the emerging atrazine concentration below 3 ppb (USEPA standard). In the case of the GAC filter the emerging atrazine concentration was between 2.4 and 5.3 microg/L even for the first 100 pore volumes. Thus, the PVP-co-S90%-mont. composite is a new efficient material for the removal of atrazine from water.
authors.affiliation: Department of Soil and Water Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Dikla
authors.initials: D
authors.lastname: Zadaka
authors.forename: Shlomo
authors.initials: S
authors.lastname: Nir
authors.forename: Adi
authors.initials: A
authors.lastname: Radian
authors.forename: Yael G
authors.initials: YG
authors.lastname: Mishael
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D001280:Atrazine / Q000737:chemistry / Q000302:isolation & purification*; D002606:Charcoal / Q000737:chemistry*; D000077215:Clay; D005374:Filtration; D007700:Kinetics; D008956:Models, Chemical; D009930:Organic Chemicals / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D000071228:Polyelectrolytes; D012995:Solubility; D013535:Suspensions; D014867:Water / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D001280:Atrazine; D002606:Charcoal; D000077215:Clay; D009930:Organic Chemicals; D011073:Polyamines; D000071228:Polyelectrolytes; D013535:Suspensions; D014867:Water