Nonylphenol mass transfer from field-aged sediments and subsequent biodegradation in reactors mimicking different river conditions

Abstract

Purpose Sediments can function as secondary source for water pollution of aerobically biodegradable nonhalogenated organic compounds, which are persistent in anaerobic sediments. The mass transfer of compounds from sediment to bulk water depends on hydraulic conditions. In this study, desorption, mass transfer and biodegradation are investigated under settled and resuspended sediment conditions for branched nonylphenol (NP), which was used as model compound for aerobically biodegradable and anaerobic persistent compounds. Materials and methods Continuous flow through reactor experiments were performed in duplicate with aged NP polluted sediment under sterile and non-sterile conditions to investigate the mass transfer and combined mass transfer and biodegradation. Results and discussion The mass transfer of NP from the sediment bed to the bulk water decreased from 5.1± 0.6 μg d -1 to a stable value of 0.3±0.02 μg d -1 . The desorbed NP in the non-sterile reactors was biodegraded in the first 20 days of the experiment. At the end of the settled sediment conditions, the biodegradation became very limited, and the mass transfer was comparable to the mass transfer under sterile conditions. Upon resuspension, the NP concentration in the bulk water increased instantaneously in all reactors with a factor of 100. This immediate, increased mass transfer of NP from the sediment was larger than the amount that can be biodegraded under optimal conditions. Under non-sterile conditions, a second increase in the mass transfer was observed. However, the amount of desorbing NP during this second increase in mass transfer can be biodegraded under optimal environmental conditions. Conclusions NP desorbs continuously at low concentrations from the sediment bed into the bulk water, which can almost be completely biodegraded. Resuspension of NP-polluted sediment initially led to an increase in the desorbing NP concentrations and can be followed by a subsequent reduction of the concentrations due to biodegradation under environmental conditions where biodegradation of NP can occur.

Storm Event–Driven Occurrence and Transport of Dissolved and Sorbed Organic Micropollutants and Associated Effects in the Ammer River, Southwestern Germany

“…Storm and flood events can cause combined sewer overflows and thereby the release of untreated wastewater, including sewage sludge particles, into surface waters (Phillips et al 2012; Madoux‐Humery et al 2013). Furthermore, remobilization of contaminants from sediments has to be considered (Eggleton and Thomas 2004; de Weert et al 2010; Müller et al 2019).…”

Endocrine disruptors in blue mussels and sediments from the Gulf of Gdańsk (Southern Baltic)

“…4-NPs may persist for decades in anaerobic environments (Diehl et al 2012 ), while those deposited in recent sediments may be subject to resuspension, as well as biotic and abiotic transformations. Thus, they continue to pose a serious threat to marine organisms (de Weert et al 2010 ). 4-NPs can be accumulated by aquatic organisms, especially in tissues with a high lipid content (EPA 2005 ).…”

Isomer-Specific Biodegradation of Nonylphenol in River Sediments and Structure-Biodegradability Relationship

“…Nonylphenol biodegradation in sediments has attracted considerable attention, as it affects the potential for NP secondary pollution and food chain accumulation. ,− For example, Yuan et al reported that the half-lives of NP in four river sediments under oxic conditions varied from 13 to 99 d . However, a few other studies showed that NP was highly persistent in sediments, especially under anoxic or reduced conditions. ,, Shang et al detected NP in marine sediment cores near a Canadian coast which may date back to 1960s, with the estimated half-life longer than 60 years …”