title: Fate and degradation kinetics of nonylphenol compounds in aerobic batch digesters.
abstract: Nonylphenol (NP) compounds are toxic and persistent chemicals that are not fully degraded either in natural or engineered systems. Current knowledge indicates that these compounds concentrate in sewage sludge. Therefore, investigating the degradation patterns and types of metabolites formed during sludge treatment are important for land application of sewage sludge. Unfortunately, the information on the fate of nonylphenol compounds in sludge treatment is very limited. This study aims to investigate the biodegradation patterns of nonylphenol diethoxylate (NP2EO) in aerobic batch digesters. For this purpose, two NP2EO spiked and two control laboratory aerobic batch digesters were operated. The spiked digester contained 3 mg/L NP2EO in the whole reactor content. The compounds of interest (parent compound and expected metabolites) were extracted with sonication and analyzed by gas chromatography-mass spectrometry (GC-MS) as a function of time. Results showed that, following the day of spike, NP2EO degraded rapidly. The metabolites observed were nonylphenol monoethoxylate (NP1EO), NP and dominantly, nonylphenoxy acetic acid (NP1EC). The mass balance over the reactors indicated that the total mass spiked was highly accounted for by the products analyzed. The time dependent analysis indicated that the parent compound degradation and daughter product formation followed first order kinetics. The digester performance parameters analyzed (VS and COD reduction) indicated that the spike of NP2EO did not affect the digester performance.
authors.affiliation: Department of Environmental Engineering, Middle East Technical University, Ankara 06800, Turkey.
authors.forename: Seçil
authors.initials: S
authors.lastname: Ömeroğlu
authors.affiliation: Department of Environmental Engineering, Middle East Technical University, Ankara 06800, Turkey. Electronic address: dsanin@metu.edu.tr.
authors.forename: F Dilek
authors.initials: FD
authors.lastname: Sanin
mesh_terms: D019149:Bioreactors; D052244:Endocrine Disruptors / Q000737:chemistry* / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D007700:Kinetics; D010636:Phenols / Q000737:chemistry* / Q000378:metabolism; D010647:Phenyl Ethers / Q000737:chemistry* / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism
chemical_list: D052244:Endocrine Disruptors; D010636:Phenols; D010647:Phenyl Ethers; D012722:Sewage; D014874:Water Pollutants, Chemical; C025256:nonylphenol
keywords: Aerobic digestion; Nonylphenol; Nonylphenol diethoxylate; Nonylphenoxy acetic acid; Sewage sludge