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Guyancourt, France

Mailler R.,University Paris Est Creteil | Gasperi J.,University Paris Est Creteil | Coquet Y.,SAUR | Bulete A.,CNRS Institute of Analytical Sciences | And 11 more authors.
Science of the Total Environment | Year: 2016

Among the solutions to reduce micropollutant discharges into the aquatic environment, activated carbon adsorption is a promising technique and a large scale pilot has been tested at the Seine Centre (240,000m3/d - Paris, France) wastewater treatment plant (WWTP). While most of available works studied fixed bed or contact reactors with a separated separation step, this study assesses a new type of tertiary treatment based on a fluidized bed containing a high mass of activated carbon, continuously renewed. For the first time in the literature, micro-grain activated carbon (μGAC) was studied. The aims were (1) to determine the performances of fluidized bed operating with μCAG on both emerging micropollutants and conventional wastewater quality parameters, and (2) to compare its efficiency and applicability to wastewater to former results obtained with PAC. Thus, conventional wastewater quality parameters (n=11), pharmaceuticals and hormones (PPHs; n=62) and other emerging pollutants (n=57) have been monitored in μGAC configuration during 13 campaigns.A significant correlation has been established between dissolved organic carbon (DOC), PPHs and UV absorbance at 254 nm (UV-254) removals. This confirms that UV-254 could be used as a tertiary treatment performance indicator to monitor the process. This parameter allowed identifying that the removals of UV-254 and DOC reach a plateau from a μGAC retention time (SRT) of 90-100. days.The μGAC configuration substantially improves the overall quality of the WWTP discharges by reducing biological (38-45%) and chemical oxygen demands (21-48%), DOC (13-44%) and UV-254 (22-48%). In addition, total suspended solids (TSS) are retained by the μGAC bed and a biological activity (nitratation) leads to a total elimination of NO2 -.For micropollutants, PPHs have a good affinity for μGAC and high (>. 60%) or very high (>. 80%) removals are observed for most of the quantified compounds (n = 22/32), i.e. atenolol (92-97%), carbamazepine (80-94%), ciprofloxacin (75-95%), diclofenac (71-97%), oxazepam (74-91%) or sulfamethoxazole (56-83%). In addition, alkylphenols, artificial sweeteners, benzotriazole, bisphenol A, personal care products (triclocarban and parabens) and pesticides have removals lying in the 50 ->. 90% range.Overall, the fluidized bed of μGAC allows obtaining performances comparable to PAC at the same activated carbon dose. Indeed, the average removal of the 13 PPHs found at a high occurrence (>75%) in WWTP discharges is similar at 20g/m3 of μGAC (78-89%) and PAC (85-93%). In addition, this recycled μGAC operation leads to several operational advantages (no FeCl3, reactivable, higher SRT, higher treated flow) and has a stronger impact on the overall wastewater quality compared to PAC. © 2015 Elsevier B.V. Source

Mailler R.,University Paris Est Creteil | Gasperi J.,University Paris Est Creteil | Coquet Y.,SAUR | Derome C.,University Paris Est Creteil | And 6 more authors.
Journal of Environmental Chemical Engineering | Year: 2016

Activated carbon processes, initially designed for drinking water production, are tested for wastewater application in order to characterize their efficiency to remove micropollutants from wastewater treatment plants (WWTPs) discharges. In that purpose, a pilot was studied by the Paris sanitation service (SIAAP) and the water environment and urban systems laboratory (LEESU). The in-situ study raised several additional questions related to the structural and morphological properties of activated carbons, in order to select the proper material, the influence of operational parameters such as the activated carbon dose and the contact time, the role of organic matter concentration and composition, the presence of a residual concentration of methanol or the impact of ferric chloride addition. Thus, various complementary experiments were carried out at laboratory scale to improve the understanding of the micropollutants adsorption process on activated carbon, in particular on powdered activated carbon (PAC). The results have highlighted a strong link between the efficiency of PACs and their specific surface (BET), which can be easily estimated by their bulk density. The study of the sorption process has also confirmed the strong influence of the PAC dose and the rapidity of the sorption kinetic. From an operational point of view, the ferric chloride injection seems to slightly improve most of the detected compounds adsorption, probably thanks to the coagulation of the dissolved organic matter colloidal fraction. In contrary, the presence in the water of a residual concentration of methanol seems to have no impact on the micropollutant fate. The influence of the wastewater matrix is strong, with notably lower adsorption in water from primary settling compared to various WWTP discharges. However, the dissolved organic carbon concentration is not always sufficient to explain sorption competitions in wastewater, and the nature of the organic matter should be considered too. In particular, the carbon removal from biological treatments is the step that clearly modifies both the quantity and the composition of the organic matter. It has been observed that discharges from WWTPs operating with different biological processes (activated sludge, membrane bioreactor or biofiltration) have similar organic matter concentrations and compositions, and allows comparable removals of organic matter and micropollutants by adsorption. The lower performances on micropollutants observed in the settled water can be explained by the higher quantity of protein-like molecules (fluorophores Iδ and Iγ), which compose the most competitive organic matter fraction for adsorption on activated carbon, compared to the other waters. © 2016 Elsevier Ltd. All rights reserved. Source

Mailler R.,University Paris Est Creteil | Gasperi J.,University Paris Est Creteil | Coquet Y.,SAUR | Deshayes S.,University Paris Est Creteil | And 10 more authors.
Water Research | Year: 2015

The efficacy of a fluidized powdered activated carbon (PAC) pilot (CarboPlus®) was studied in both nominal (total nitrification+post denitrification) and degraded (partial nitrification+no denitrification) configuration of the Seine Centre WWTP (Colombes, France). In addition to conventional wastewater parameters 54 pharmaceuticals and hormones (PhPHs) and 59 other emerging pollutants were monitored in influents and effluents of the pilot. Thus, the impacts of the WWTP configuration, the process operation and the physico-chemical properties of the studied compounds were assessed in this article. Among the 26 PhPHs quantified in nominal WWTP configuration influents, 8 have high dissolved concentrations (>100ng/L), 11 have an intermediary concentration (10-100ng/L) and 7 are quantified below 10ng/L. Sulfamethoxazole is predominant (about 30% of the sum of the PhPHs). Overall, 6 PhPHs are poorly to moderately removed (<60%), such as ibuprofen, paracetamol or estrone, while 9 are very well removed (>80%), i.e. beta blockers, carbamazepine or trimethoprim, and 11 are well eliminated (60-80%), i.e. diclofenac, naproxen or sulfamethoxazole. In degraded WWTP configuration, higher levels of organic matter and higher concentrations of most pollutants are observed. Consequently, most PhPHs are substantially less removed in percentages but the removed flux is higher. Thus, the PAC dose required to achieve a given removal percentage is higher in degraded WWTP configuration. For the other micropollutants (34 quantified), artificial sweeteners and phthalates are found at particularly high concentrations in degraded WWTP configuration influents, up to μg/L range. Only pesticides, bisphenol A and parabens are largely eliminated (50-95%), while perfluorinated acids, PAHs, triclosan and sweeteners are not or weakly removed (<50%). The remaining compounds exhibit a very variable fate from campaign to campaign. The fresh PAC dose was identified as the most influencing operation parameter and is strongly correlated to performances. Charge and hydrophobicity of compounds have been recognized as crucial for the micropollutant adsorption on PAC, as well as the molecular weight. Finally, a PAC dose of 10mg/L allows an average removal of 72-80% of the sum of the PhPHs in nominal WWTP configuration. The comparaison of the results with those from the scarce other studies tends to indicate that an extrapolation of them to different PAC processes and to other WWTPs could be possible and relevant, taking into account the differences of water quality from WWTP to WWTP. © 2014 Elsevier Ltd. Source

Wang S.,Aix - Marseille University | Wang S.,Huazhong University of Science and Technology | Wyart Y.,Aix - Marseille University | Perot J.,SAUR | And 2 more authors.
Membrane Water Treatment | Year: 2012

In this study, ageing characteristics of an industrial hollow-fiber membrane module were investigated after 50 months of drinking water production. For this purpose, the industrial module was opened to make 18 smaller modules with hollow-fibers taken from different parts of the industrial module. These modules were probed by the use of a magnetic nanoparticle (NP) challenge test based on magnetic susceptibility (K) measurement of permeate. No magnetic susceptibility was detected in permeate when the challenge test was performed on an intact membrane module, indicating the complete retention of nanoparticles by the membrane. The compromised membrane module can be successfully detected by means of magnetic susceptibility measurement in permeate. So, this study clearly demonstrates that ageing of ultrafiltration membranes can be monitored by measuring the magnetic susceptibility of permeate from an ultrafiltration membrane module. These results showed that the hollow fibers in the center zones of the bundle would age faster than those in the outer zones around the bundle. This result is in agreement with numerical simulation (Daurelle et al. 2011). Source

Guo H.,Aix - Marseille University | Wyart Y.,Aix - Marseille University | Perot J.,SAUR | Nauleau F.,SAUR | Moulin P.,Aix - Marseille University
Membrane Water Treatment | Year: 2011

An alternative ultrafiltration membrane integrity test was already developed in laboratory scale. It is based on the use of magnetic nanoparticles (Fe3O4) and measurement of magnetic susceptibility. The mean size of nanoparticles used is around 35 nm and they show a good disparity between 20 and 100 nm. In this paper, validation of this membrane integrity monitoring method was achieved by industrialscale tests. Two holes with 0.6 mm internal diameter in a module containing 10000 fibers (35 m2 surface area) was efficiently detected by injecting 750 mL of 1.7 g.L-1 nanoparticle solution during 2s when the test was operated at low TMP (0.096 bar, corresponding to a flux of 2.2 m3.h-1). In addition, it has been demonstrated that within the detectable range, this membrane integrity test with magnetic nanoparticles has a very rapid response time. The response time depends on the permeate flux and the dead-volume of the pilot. This membrane integrity test, with the advantages of on-line operation, high detection sensitivity, detection specificity and very low influence on membrane fouling, seems to be suitable for large scale drinking water plants. Source

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