title: Response surface methodology investigation into the interactions between arsenic and humic acid in water during the coagulation process.
abstract: Interactions between arsenic and natural organic matter (NOM) are key limiting factors during the optimisation of drinking water treatment when significant amounts of both must be removed. This work uses Response Surface Methodology (RSM) to investigate how they interact during their simultaneous removal by iron chloride coagulation, using humic acid (HA) as a model NOM substance. Using a three factor Box-Behnken experimental design, As and HA removals were modelled, as well as a combined removal response. ANOVA results showed the significance of the coagulant dose for all three responses. At high initial arsenic concentrations (200μg/l), As removal was significantly hindered by the presence of HA. In contrast, the HA removal response was found to be largely independent of the initial As concentration, with the optimum coagulant dose increasing at increasing HA concentrations. The combined response was similar to the HA removal response, and the interactions evident are most interesting in terms of optimising treatment processes during the preparation of drinking water, highlighting the importance of utilizing RSM for such investigations. The combined response model was successfully validated with two different groundwaters used for drinking water supply in the Republic of Serbia, showing excellent agreement under similar experimental conditions.
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia. Electronic address: malcolm.watson@dh.uns.ac.rs.
authors.forename: Malcolm Alexander
authors.initials: MA
authors.lastname: Watson
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Tubić
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Agbaba
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Nikić
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia.
authors.forename: Snežana
authors.initials: S
authors.lastname: Maletić
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Molnar Jazić
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemisty and Environmental Protection, Trg Dositeja Obradovića 3, Novi Sad 21000, Serbia.
authors.forename: Božo
authors.initials: B
authors.lastname: Dalmacija
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D060766:Drinking Water / Q000737:chemistry*; D060587:Groundwater / Q000737:chemistry; D006812:Humic Substances / Q000032:analysis*; D055771:Serbia; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification
chemical_list: D060766:Drinking Water; D006812:Humic Substances; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Arsenic; Box-Behnken design; Coagulation; Groundwater; Humic acid