sodium-nitrite and ferric-chloride

Organophosphate triesters (OPEs) have caused great concern as a class of emerging environmental contaminants due to their widespread use and their toxicity to organisms. However, the phototransformation behavior of OPE is still not fully understood, which is important for understanding their environmental fate. In the present study, the photodegradation of tricresyl phosphate (TCP), one of the most widely detected OPEs in aqueous environments, was investigated including the direct photolysis and in the presence of several natural water factors, NO

Topics: Chlorides; Ferric Compounds; Humic Substances; Hydroxyl Radical; Kinetics; Photolysis; Sodium Nitrite; Tritolyl Phosphates; Water; Water Pollutants, Chemical

Topics: Adsorption; Biomass; Carbon; Chlorides; Cost Savings; Culture Media; Ferric Compounds; Nitrogen; Sodium Nitrite; Spectrophotometry, Ultraviolet; Spirulina; Water

A combination of ferric chloride and sodium nitrite significantly improved the wet oxidation of the azo dye Acid Orange 7 (AO7) in acid aqueous media (pH 2.6) under moderate conditions (T=150 degrees C; oxygen pressure=0.5 MPa). To evaluate the catalytic system, wet oxidation of AO7 was carried out at temperatures between 90 and 150 degrees C and oxygen pressures ranging from 0.1 to 0.5 MPa. The effect of initial solution pH from 2.6 to 11.4 and the amount of catalyst on the degradation of AO7 were also investigated. AO7 initial concentration was kept 200 mg L(-1). The degradation process was monitored by UV-visible spectroscopy, HPLC, IC (ion chromatography), GC-MS and TOC analysis. At 150 degrees C and 0.5 MPa oxygen pressure, 56% TOC was removed after 4h of treatment, while no obvious TOC removal were achieved without catalyst at the same experimental condition. The main degradation products were some small organic acids: formic acid, acetic acid, pyruvic acid, oxalic acid, succinic acid (identified and quantified by IC) and phthalic acid (identified by GC-MS).

Topics: Azo Compounds; Benzenesulfonates; Catalysis; Chlorides; Chromatography, High Pressure Liquid; Ferric Compounds; Hydrogen-Ion Concentration; Molecular Structure; Oxidation-Reduction; Oxygen; Sodium Nitrite; Temperature

Assistance and acceleration of the environment's self-remediation of pollutants represent an important and long-standing goal for environmental chemistry communities. Here, a degradation route using a combination of a nitrite and a ferric salt as the photocatalyst is presented for catalytically removing 17beta-estradiol (E2), estriol (E3), and 17alpha-ethynylestradiol (EE2) in water under mimicked natural environmental conditions, i.e., in the phytotron. After a 1 day reaction, 86.6% of the estrogen E2 was degraded. Extending the incubation time to 30 days, more than 99.9% E2 was removed and a very small quantity of malonic acid observed as the residual organic compound, and estrogenic activity was determined. The results showed that the estrogenic activities of the intermediate products are negligible and that there is no secondary risk associated with increased the estrogenic activity. The degradation system demonstrated that FeCl3/NaN02 is an efficient photocatalyst which is active on natural light irradiation. This work highlights a promising development for in situ treatment of pollutants in natural-environment conditions.

Topics: Catalysis; Chlorides; Estrogens; Ferric Compounds; Gas Chromatography-Mass Spectrometry; Light; Sodium Nitrite; Solutions; Water

Topics: Adult; Ascorbic Acid; Chlorides; Ferric Compounds; Humans; Oxalates; Oxalic Acid; Reagent Kits, Diagnostic; Sodium Nitrite