Environmental Fate of Nonylphenol Ethoxylates: Differential Adsorption of Homologs to Components of River Sediment

Abstract

Abstract-Nonylphenol ethoxylate (NPEO x ) homologs present in commercial mixtures were rapidly adsorbed to and desorbed from native river sediment. Adsorption isotherms, established using high-performance liquid chromatography analysis to monitor individual homologs NPEO 3 to NPEO 13 simultaneously, were linear for each component adsorbing to native sediment, organic-free sediment, and kaolinite, usually with small positive intercepts on the isotherms indicating an additional low-capacity, high-affinity binding site. The adsorption partition coefficients (K d ) for the native sediment decreased progressively from 1,460 L/kg for NPEO 3 to 450 L/kg for NPEO 10 , then increased again slightly for higher homologs. In contrast, K d values for organic-free sediment (range 230-590 L/kg) or kaolinite (190-490 L/kg) increased steadily from NPEO 3 to NPEO 13 . Adsorptions to silica and alumina were very weak, but to sewage sludge all components adsorbed strongly (K d values 12,000-33,000, with a maximum at NPEO 7 ). The adsorption to sewage sludge was related to the low-capacity, high-affinity sites observed for native sediment. Dependence of K d values on ethoxylate chain length was analyzed, in terms of both possible adsorption mechanisms, and the environmental fate and impact of NPEO x s as endocrine disruptors.

Occurrence of endocrine-disrupting chemicals in riverine sediments from the Pearl River Delta, China

“…Since the sedimentary organic carbon is an important factor in the sorption of EDCs (John et al, 2000;Ferguson et al, 2001), the influence of the total organic carbon (TOC) on the distribution of APs and other estrogens in our surface sediments was investigated using linear regression analysis conducted by the software of Origin 8. It was found that OP, NP and E2 were significantly correlated with TOC contents and their correlation coefficients (r) were 0.83, 0.82 and 0.90 (Fig.…”

Nonylphenol, an Integrated Vision of a Pollutant

“…Nonylphenoxyethoxy acetic acid was shown to be the most important carboxylate species. John et al [24] found that NPE homologues, commonly present in commercial mixtures, were rapidly adsorbed to and desorbed from native river sediment. The adsorption partition coefficients (Kd) for the native sediment decreased progressively according the chain length of alkyl moiety from 1460 L kg-1 for NPE3 to 450 L kg-1 for NPE10.…”

Degradation of Nonylphenol in Spiked Soils and in Soils Treated With Organic Waste Products

“…Due to their lipophilic properties, these degradation products sorb and concentrate during wastewater treatment to the organic particles or mineral constituent present. Sorption has been shown to be highly dependent on the number of ethoxy groups [3,[10][11][12]. Compounds such as NP may pose a health * To whom correspondence may be addressed (gerda@rh.dk).…”