Remediation of 4-nonylphenol in aqueous solution by using free radicals generated by the oxidative reactions.
BACKGROUND
This study relates to use of zerovalent iron to generate hydroxyl free radicals and undergo subsequent oxidation to destroy 4-nonylphenol (NP) by mild process in aqueous solution and activation of oxygen gas (O2) at room temperature. This technology is based on a novel oxidative mechanism mediated by zerovalent iron rather than commonly used reduction mechanism.


METHODS
A laboratory scale device consisting of a 250 ml pyrex serum vials fixed to a Vortex agitator was used. Different amounts of zerovalent iron powder (ZVI; 1, 10, and 30 g/l) at pH 4 and room temperature with bubbling of oxygen gas were investigated.


CONCLUSIONS
Experiments showed an observed degradation rate k (obs) directly proportional to the amount of iron. 4-Nonylphenol degradation reactions demonstrated first-order kinetics with a half-life of about 10.5  ±  0.5 and 3.5  ±  0.2 min when experiments were conducted at [ZVI] = 1 and 30 g/l respectively. Three analytical techniques were employed to monitor 4-nonylphenol degradation and mineralization: (1) spectrofluorimetry; (2) high-performance liquid chromatography; (3) total organic carbon meter (TOC meter). Results showed a complete disappearance of 4-nonylphenol after 20 min of contact with ZVI. The intermediate by-products of the reaction were not identified but the disappearance of NP was monitored by the three above-mentioned techniques.
Department of Chemistry, Faculty of Sciences II, Lebanese University, Fanar, Lebanon. jrima@ul.edu.lb
Jamil
J
Rima
Karine
K
Assaker
D001391:Azo Compounds; D001557:Benzenesulfonates; D002851:Chromatography, High Pressure Liquid; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005609:Free Radicals / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D014867:Water; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D001391:Azo Compounds; D001557:Benzenesulfonates; D005609:Free Radicals; D010636:Phenols; D014874:Water Pollutants, Chemical; D014867:Water; C542566:lithol rubine BCA; C041594:4-nonylphenol