title: Simultaneous Removal of Nitrate and Natural Organic Matter from Drinking Water Using a Hybrid Heterotrophic/Autotrophic/Biological Activated Carbon Bioreactor.
abstract: Simultaneous removal of nitrate ([Formula: see text]) and natural organic matter (NOM) from drinking water using a hybrid heterotrophic/autotrophic/BAC bioreactor (HHABB) was studied in continuous mode. The HHABB consisted of three compartments: ethanol heterotrophic part, sulfur autotrophic part, and biological activated carbon (BAC)-part (including anoxic and aerobic sections). Experiments were performed with [Formula: see text] concentration 30 mg N/L, [Formula: see text] loading rate 0.72 kg N/m(3)/d, C : N ratio 0.53, and three concentrations of NOM (0.6, 2.6, and 5.7 mg C/L). Overall denitrification rate and efficiency of the HHABB were not affected by NOM concentration and were in the suitable ranges of 0.69-0.70 kg N/m(3)/d and 96.0%-97.7%, respectively. NOM removal at concentration 0.6 mg C/L was not efficient because of organic carbon replacement as soluble microbial products. At higher NOM concentrations, total NOM removal efficiencies were 55%-65%, 55%-70%, and 55%-65% for dissolved organic carbon, trihalomethane formation potential, and UV absorbance at 254 nm (UV(254)), respectively. The more efficient compartments of the HHABB for the removal of NOM were the ethanol heterotrophic phase and aerobic BAC-phase. The efficiency of the HHABB in the removal of NOM was considerable, and the effluent dissolved organic carbon and trihalomethane formation potential concentrations were relatively low. This study indicated that the HHABB without the anoxic BAC-phase could be a feasible alternative for simultaneous removal of [Formula: see text] and NOM from drinking water at full scale.
authors.affiliation: Department of Environmental Health Engineering, School of Public Health and Center for Environmental Research,  Tehran University of Medical Sciences , Tehran,  Iran .
authors.forename: Reza
authors.initials: R
authors.lastname: Saeedi
authors.forename: Kazem
authors.initials: K
authors.lastname: Naddafi
authors.forename: Ramin
authors.initials: R
authors.lastname: Nabizadeh
authors.forename: Alireza
authors.initials: A
authors.lastname: Mesdaghinia
authors.forename: Simin
authors.initials: S
authors.lastname: Nasseri
authors.forename: Mahmood
authors.initials: M
authors.lastname: Alimohammadi
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Nazmara