title: NH4+-NH3 removal from simulated wastewater using UV-TiO2 photocatalysis: effect of co-pollutants and pH.
abstract: The main objective of the present study was to investigate the efficiency of titanium dioxide (TiO2) assisted photocatalytic degradation (PCD) process for the removal of ammonium-ammonia (NH4(+)-NH3) from the aqueous phase and in the presence of co-pollutants thiosulfate (S2O3(2-)) and p-cresol (C6H4CH3OH) under varying mixed conditions. For the NH4(+)-NH3 only PCD experiments, results showed higher NH4 -NH3 removal at pH 12 compared to pH 7 and 10. For the binary NH4(+)-NH3/S2O3(2-) studies the respective results indicated a significant lowering in NH4(+)-NH3 PCD in the presence of S2O32- at pH 7/12 whereas at pH 10 a marked increase in NH4(+)-NH3 removal transpired. A similar trend was noted for the p-cresol/NH4(+)-NH3 binary system. Comparing findings from the binary (NH4(+)-NH3/S2O3(2-) and p-cresol/NH4(+)-NH3) and tertiary (NH4(+)-NH3/S2O3(2-)/p-cresol) systems, at pH 10, showed fastest NH4(+)-NH3 removal transpiring for the tertiary system as compared to the binary systems, whereas both the binary systems indicated comparable NH4(+)-NH3 removal trends. The respective details have been discussed.
authors.affiliation: Civil Engineering Department, King Fahd University of Petroleum and Minerals (KFUPM) Dhahran, Kingdom of Saudi Arabia 31261. vohra@kfupm.edu.sa
authors.forename: M S
authors.initials: MS
authors.lastname: Vohra
authors.forename: S M
authors.initials: SM
authors.lastname: Selimuzzaman
authors.forename: M S
authors.initials: MS
authors.lastname: Al-Suwaiyan
mesh_terms: D000641:Ammonia / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D002384:Catalysis; D045424:Complex Mixtures / Q000737:chemistry / Q000528:radiation effects; D003198:Computer Simulation; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D010777:Photochemistry / Q000379:methods*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D045424:Complex Mixtures; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D000641:Ammonia; D014025:Titanium