Kinetics, intermediates and acute toxicity of arsanilic acid photolysis

• Published in: Chemosphere (Oxford) Vol. 107; pp. 274 - 281
• Main Authors: Zhu, Xiang-Dong, Wang, Yu-Jun, Liu, Cun, Qin, Wen-Xiu, Zhou, Dong-Mei
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2014; Elsevier
• Subjects: Aliivibrio fischeri - drug effects; Animals; Applied sciences; Arsanilic acid; Arsanilic Acid - chemistry; Arsanilic Acid - metabolism; Arsanilic Acid - toxicity; Arsenates - metabolism; Biological and physicochemical phenomena; Environmental Pollutants - chemistry; Environmental Pollutants - metabolism; Environmental Pollutants - toxicity; Exact sciences and technology; Hydrogen-Ion Concentration; Kinetics; Mechanism; Natural water pollution; Oxygen - chemistry; Photolysis; Pollution; Toxicity; Water treatment and pollution; Arsanilic acid; Photolysis; Toxicity; Mechanism; Pollutant behavior; Acute; EPR spectrometry; Antiprotozoal agent; Vibrio fischeri; Medium effect; Reaction mechanism; Bacteria; Vibrionaceae; Parasiticide; Kinetics; Aqueous solution; Degradation product; Arsenic Organic compounds
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2013.12.060

[Display omitted] •Inorganic ions such as arsenite, arsenate and NH4+ were found as the main photolysis products of ASA.•The distribution of arsenite and arsenate was highly depended on the dissolved oxygen.•The pathway of ASA photolysis was proposed on the basis of the identified intermediates.•The toxicities of reaction solution and reactive oxygen species were discerned. Arsanilic acid (4-amino phenyl arsenic acid, ASA) is widely used in poultry production as feed additives, while most of ASA in the feed is excreted in the animal manure and released into the environment. However, the environmental behaviors of ASA were not well understood. In the present study, the photolysis behaviors of ASA and the toxicity of its metabolites to luminescent bacterium were studied. The results showed that ASA could be photodegraded and this process was strongly affected by solution pH, humic acid and dissolved oxygen. Upon UV irradiation for 360min, ASA could be completely eliminated, but the reduction of total organic carbon (TOC) was not significant. In addition, NH4+ ions and inorganic arsenic including arsenite and arsenate were identified as the predominant end-products. The conversion of ASA included both direct and indirect photolysis involving radicals, and its possible photolysis pathways were proposed on the basis of the identified intermediates. Unfortunately, higher adverse effects of the conversion products of ASA on bacteria were observed during the photolysis reaction. The results of present study might be helpful for assessing the environmental persistence and risks of ASA.