Pollution of NPEOs in four municipal sewage treatment plants in the north of China

Abstract

The concentration and distribution of nonylphenol polyethoxylates (NPEOs represents the mixture, and NPnEO represents the monomer) and its metabolites in the influent and effluent of four municipal sewage treatment plants (STPs) in the north of China were measured. Moreover, the concentration and distribution of the above chemicals in the sludge of two STPs were also determined, and the transfer and fate of NPEOs in the sewage treatment process were discussed primarily by analyzing the distribution of the products in the effluent and the sludge. The results showed that NPEOs and its metabolites existed in all the samples of the influent, effluent, and sludge. NPEOs were degraded in the sewage treatment process with the removal efficiency in the range of 23.38%-77.11%, or an average of 52.86%. However, the large analogs of NPnEO were only degraded to small ones, whose degradation rate was rather slow, and consequently the degradation was not complete. Hence, the concentrations of some small metabolites, such as nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and nonylphenol diethoxylate (NP2EO) were elevated in the effluent. These small metabolites are more toxic than the large NPnEO analogs, and some of them were reported to exhibit environmental endocrine disrupting activity. From this point of view, the process of sewage treatment does not reduce but elevate the risk of NPEOs, which becomes the main source of these small NPnEO in the environment. The sludge exhibited good adsorption ability for NPEOs, especially for the small analogs, which led to the high level of NPEOs in the sludge. Hence, reasonable disposal of the surplus sludge to avoid re-pollution is very important.

Fate of nonylphenol polyethoxylates and their metabolites in four Beijing wastewater treatment plants

“…It is clear that the total concentrations of nonylphenolic compounds (NP-c) in the dry weather is related to industrial and domestic wastewater content in the WWTPs influents, i. e., 0.115 to 0.183 μmol/L of NP-c in the WWTPs receiving both industrial and domestic wastewaters, and 0.347 μmol/L of NP-c in the WWTP receiving only domestic wastewater. The concentrations of nonylphenolic compounds detected in this study fell into the range reported in other literatures (Ma et al, 2002;Planas et al, 2002;Hou and Sun, 2006;Stasinakis et al, 2008), but were at low level compared to those observed in the European countries, such as Switzerland (2.42-4.05 μmol/L) (Ahel et al, 1994) and United States (425-894 μg/L for NP0-16EO) (Loyo-Rosales et al, 2007), indicating that the contamination in Beijing seemed less heavy than abroad, probably due to less consumption of NPnEOs surfactants in Beijing.…”

Application of the GREAT-ER model for environmental risk assessment of nonylphenol and nonylphenol ethoxylates in China

“….095 μmol/L for NP and 0.116~0.365 μmol/L for NPEOs (Hao et al 2007;Hou and Sun 2006;Lian et al 2009). Average concentrations of NP and NPEOs of these four major STPs were used to calculate their PCCs by equation (1) according to an investigation of the influent volume and population served of the STPs in the Wenyu River catchment (shown in the Table S2 in supporting information).…”

Occurrence of Nonylphenol and Nonylphenol Monoethoxylate in Soil and Vegetables from Vegetable Farms in the Pearl River Delta, South China

“…NP, NP 1 EO, and NP 2 EO were frequently detected in water, sediment, and sewage sludge at high concentrations (Hou and Sun 2006;Ghanem et al 2007;González et al 2010). However, the occurrence of NP and NP 1 EO in soil has not been as well documented as has their occurrence in the aquatic environment (Soares et al 2008).…”

“…Many studies have been conducted to investigate the occurrence of NP and NPEOs in different environmental matrices (Ying et al 2002;Hou and Sun 2006;Ghanem et al 2007;Soares et al 2008;González et al 2010). NP is detected frequently in various matrices, such as sewage sludge, effluents from sewage treatment plants, river water and sediments, and groundwater and has a wide range of concentrations of up to several thousand lg L -1 in surface waters and up to several hundred mg kg -1 in sediment samples (Ying et al 2002;Soares et al 2008).…”

“…Partition of NP in the environment has been assessed to be [60% in sediment, [10% in soil, and approximately 25% in the water phase (Düring et al 2002). However, until now, many studies have focused on the occurrence of NP and NPEOs in sediments and sewage sludge (Ying et al 2002;Hou and Sun 2006;Ghanem et al 2007;Soares et al 2008;González et al 2010), but few studies have reported the occurrence of NP and NPEOs in soil (Ying et al 2002;Soares et al 2008).…”