National inventory of alkylphenol ethoxylate compounds in U.S. sewage sludges and chemical fate in outdoor soil mesocosms

Abstract

We determined the first nationwide inventories of alkylphenol surfactants in U.S. sewage sludges (SS) using samples from the U.S. Environmental Protection Agency's 2001 national SS survey. Additionally, analysis of archived 3-year outdoor mesocosm samples served to determine chemical fates in SS-amended soil. Nonylphenol (NP) was the most abundant analyte (534±192 mg/kg) in SS composites, followed by its mono- and di-ethoxylates (62.1±28 and 59.5±52 mg/kg, respectively). The mean annual load of NP and its ethoxylates in SS was estimated at 2408–7149 metric tonnes, of which 1204–4289 is applied on U.S. land. NP compounds showed observable loss from SS/soil mixtures (1:2), with mean half-lives ranging from 301 to 495 days. Surfactant levels in U.S. SS ten-times in excess of European regulations, substantial releases to U.S. soils, and prolonged half-lives found under field conditions, all argue for the U.S. to follow Europe's move from 20 years ago to regulate these chemicals.

Occurrence and estrogenic potency of eight bisphenol analogs in sewage sludge from the U.S. EPA targeted national sewage sludge survey

“…The total 17β-estradiol equivalents (E 2 EQ) of bisphenols in sludge samples were 7.74 (range: 0.26-90.5) pg/g dw, which were 1000 times lower than the estrogenic activity contributed by natural estrogens (E 1 +E 2 +E 3 ; 27.9-63.8 ng/g dw) present in the sewage sludge samples [53]. Moreover, based on the concentrations of 4-nonylphenol (4-NP) measured in the SS [54], the 17β-estradiol equivalent of 4-NP (E 2 EF was 0.0001 [55]) was 53.4 (range: 40.5-86.1) ng/g, which was three orders of magnitude higher than that calculated for bisphenols. However, BPA can stimulate cellular responses even at low concentrations through non-genomic mechanisms and membrane-associated estrogen receptors [56][57].…”

Isomer-specific biodegradation of nonylphenol in an activated sludge bioreactor and structure–biodegradability relationship

“…After investigating sludge samples from the U.S. Environmental Protection Agency's 2001 national sewage sludge survey, Venkatesan and Halden (2013) reported that the concentration of NP in sludge was 534 ± 192 mg/kg with 100% detection frequency and the estimated mean annual loading of NP into sewage sludge was 2066e5510 metric tons, of which 1033e3306 metric tons were introduced to soil via land applications of biosolids. Hence, control of NP release from WWTPs is crucial to reducing its environmental levels.…”

“…Biodegradation of NPEOs to NP in wastewater treatment plants (WWTPs) is the most important source for NP release into the environment. Therefore, high concentrations of NP have been frequently detected in WWTP effluent-impacted surface water, sediment and aquatic organisms Soares et al, 2008;Venkatesan and Halden, 2013;Vidal-Dorsch et al, 2012;Ying et al, 2002).…”

United States National Sewage Sludge Repository at Arizona State University—a new resource and research tool for environmental scientists, engineers, and epidemiologists

“…EPA 2013a). In 2013, we reported the first nationwide inventories of AP & APEOs surfactants in MSS samples from the 2001 NSSS (Venkatesan and Halden 2013a). NP was the most abundant analyte (534 ± 192 mg/kg dw), followed by its mono- and di-ethoxylate derivatives (62.1 ± 28 and 59.5 ± 52 mg/kg dw, respectively) (Fig.…”