title: Gamma radiation-induced degradation of p-nitrophenol (PNP) in the presence of hydrogen peroxide (H2O2) in aqueous solution.
abstract: The synergistic effect of gamma radiation with hydrogen peroxide (H(2)O(2)) for p-nitrophenol (PNP) decomposition in aqueous solution was evaluated. The PNP solution with initial concentration of 50mg/L was irradiated in the presence of extra H(2)O(2) at initial concentration of 0, 20, 40, and 80 mg/L. The experimental results showed that the decomposition of PNP conformed to the pseudo-first-order reaction kinetics under the applied conditions. When initial H(2)O(2) concentration was in the range of 0-80 mg/L, higher concentration of H(2)O(2) was more effective for the decomposition, mineralization and nitrogen release of PNP. However, the removal of total organic carbon (TOC) and total nitrogen (TN) was not as effective as that of PNP. Ammonia and nitrate were detected as the main inorganic nitrogen products of PNP decomposition without extra H(2)O(2), whereas nitrate was considered as a final inorganic nitrogen product with extra H(2)O(2) in the initial concentration range of 0-80 mg/L. Major decomposition products, including organic acids were identified by LC/MS and IC. Possible pathways for PNP decomposition by gamma radiation in aqueous solution were proposed.
authors.affiliation: Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, China.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Yu
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.forename: Jianlong
authors.initials: J
authors.lastname: Wang
mesh_terms: D000641:Ammonia / Q000032:analysis; D005720:Gamma Rays; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007700:Kinetics; D009566:Nitrates / Q000032:analysis; D009596:Nitrophenols / Q000737:chemistry / Q000528:radiation effects*; D009930:Organic Chemicals / Q000032:analysis; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects*; D018508:Water Purification / Q000379:methods
chemical_list: D009566:Nitrates; D009596:Nitrophenols; D009930:Organic Chemicals; D012996:Solutions; D014874:Water Pollutants, Chemical; D000641:Ammonia; D006861:Hydrogen Peroxide; C024836:4-nitrophenol