Fate of emerging and priority micropollutants during the sewage sludge treatment: Case study of Paris conurbation. Part 1: Contamination of the different types of sewage sludge

Abstract

This article provides data on the contamination of different kinds of sludge (raw, centrifuged, digested, thermally dried sludge and sludge cake) from Paris conurbation by 71 various pollutants including pharmaceutical products (PHPs), hormones, perfluorinated acids (PFAs), linear alkylbenzene sulfonate (LAS), alkylphenols (APs), phthalates (PAEs), polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs). Very high contents of LAS (0.1-10g/kg dry matter - DM) compared to other compounds were found in all types of sludge followed by DEHP (10-100mg/kg DM) and fluoroquinolones (1-100mg/kg DM). APs were measured at intermediary contents in Parisian sludge, lying in the 2-20mg/kg DM range. Finally, hormones, PAHs, PCBs, PAEs, PFAs and the remaining PHPs were all found at contents lower than 1mg/kg DM. For most compounds (PHPs, PFOS, DEHP, PAHs), no significant differences in the micropollutant contents were found for similar types of sludge from different WWTP in Paris, highlighting the homogeneity of sludge contamination in downstream Paris catchment. The variability of concentration is rather high (coefficient of variation >100%) for several PHPs, PFAs or PCBs while it is moderate (<100%) or low (<50%) for fluoroquinolones, hormones, PAHs, APs or LAS. In addition, digestion seems to have a buffer effect as variabilities are lower in digested sludge for PHPs, PFAs, APs and PCBs. During sludge treatment (centrifugation, digestion, thermal drying, sludge conditioning+press filtration), the hormones, LAS, APs, PAHs, DEHP and PCBs concentrations increased, while those of PHPs and PFAs decreased. In the case of digestion, the increase of content can be explained by no pollutant removal or a lower removal than DM removal (concentration phenomenon) whereas the decrease underlines that the compound is more removed than the DM. In any case, these concentration variations presuppose the mechanisms of dissipation that could be attributed to volatilization, biotic or abiotic transformation (complete or with metabolites production), bound residues formation. In addition, data on sludge liquors - centrifuged (CW) and condensed (TDW) waters - from respectively centrifugation and thermal drying were collected. Several hormones, PHPs, PFAs, LAS, PAEs, APs, PCBs and PAHs were quantified in CW and TDW, displaying a transfer through the water removal. The concentrations observed are rather comparable to those found in wastewater.

Sewage sludge for sustainable agriculture: contaminants’ contents and potential use as fertilizer

“…Some of these studies indicated that concentrations of DEHP change annually as a function of season and runoff, with the highest concentrations of DEHP occurring during the rainy season, the lower concentrations during the dry season, and the lowest concentrations during the transition seasons [16]. Comparing our maximum concentrations with the maximum Kd = K oc × f oc concentrations from other countries, for example, in sewage sludge from France (Paris), 29 times lower values for NP, ten times higher values for NP1EO, 57 times higher values for NP2EO, and 1.4 times higher values for DEHP were observed as those for Italy [17]. Furthermore, if comparing our maximum concentrations (for Italy) with maximum concentrations in sewage sludge samples from Greece (Athens, Patras), 160 times higher values for NP, three times higher values for the sum of NP1EO and NP2EO, and nine times higher values for DEHP were observed in the Greek sewage sludge samples [18].…”

Determination of Polycyclic Aromatic Hydrocarbons and Their Methylated Derivatives in Sewage Sludge from Northeastern China: Occurrence, Profiles and Toxicity Evaluation

“…The mean concentration of PAHs in this study was 2030 dw, much greater than four sludge sites in Taiwan China (750 ng/g dw) [ 11 ], twelves sewage sludge from Beijing, China (1551 ng/g dw) [ 29 ], nineteen sewage sludge from Guangdong Province China (1276 ng/g dw) [ 7 ], but lower than the level in four sewage sludge from Harbin, Northeast China (8200 ng/g) [ 32 ], six sludge from Guangdong, China (3466 ng/g dw) [ 33 ], six Wastewater sludge from Korea (10,400 ng/g dw) [ 30 ], nineteen sludge from Madrid (5118 ng/g dw) [ 34 ], nine sewage sludge from northern and central Tunisia (11,216 ng/g dw) [ 14 ], and eleven sewage sludge from the mainland and Hong Kong, China (30,000 ng/g dw) [ 9 ]. However, the level in this study was very close to three sewage sludge from Paris (2518 ng/g dw) [ 35 ]. The European Union has proposed a limited fixed value of ten PAHs of 6000 for the implementation of sludge to agricultural fertilizer that includes Flua, BaP, IcdP, Ace, BghiP, BkF, Pyr, Phe, Flu, and BbF [ 29 ].…”

National Alliance for Water Innovation (NAWI) Agriculture Sector Technology Roadmap 2021

“…126 Typically, sewage sludge contains recyclable and agronomical valuable macro-and micro-nutrients. 127 However, it also includes several harmful organic and inorganic pollutants such as heavy metals (e.g., cadmium [ 128,129,130,131,132,133,134 The conversion of sewage sludge to energy (e.g., biofuels, methane, and hydrogen) and/or high-value byproducts (e.g., biofertilizers and glycerols) through biological pathways appears to be a promising and eco-friendly alternative compared to the existing physicochemical and thermal methods. 135,136,137,138 However, the major limitation to the biological conversion of sludge to energy and/or high-value byproducts at an industrial scale is the low productivity and the low yields of the conversion processes due to the complex constituents present in sewage sludge.…”