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Damia Barcelo - One of the best experts on this subject based on the ideXlab platform.

  • removal of sulfonamide antibiotics upon Conventional Activated Sludge and advanced membrane bioreactor treatment
    Analytical and Bioanalytical Chemistry, 2012
    Co-Authors: Maria Jesus Garcia Galan, Silvia M Diazcruz, Damia Barcelo
    Abstract:

    This work reports the removal efficiencies of nine sulfonamides (SAs) and one of their acetylated metabolites during Conventional Activated Sludge (CAS) and membrane bioreactor (MBR) treatments. Two different types of membranes were studied, hollow-fiber membranes and flat-sheet membranes, in two separate pilot plants operating in parallel to a full-scale CAS treatment. A total of 48 water samples and 16 sewage Sludge samples were analyzed by liquid chromatography–tandem mass spectrometry. We obtained 100 % elimination in the MBR effluents for three SAs (sulfadiazine, sulfadimethoxine, and sulfamethoxypyridazine) and the metabolite. For the rest of the SAs, the removal efficiencies during CAS and MBR treatments were similar and usually below 55 %. Sulfamethizole was the most recalcitrant SA, exhibiting negative removal efficiencies in all the treatments investigated. The concentrations of SAs in the different sewage Sludge types were also calculated and ranged from 0.01 to 11 ng g-1. Furthermore, adsorption and biodegradation of SAs in Activated Sludge were investigated in two sets of batch reactors, which were spiked at high and low concentration (1,000 and 50 ng mL-1, respectively). All SAs followed a similar trend and, with the exception of sulfathiazole, were not fully eliminated after 25 days of treatment.

  • removal of a broad range of surfactants from municipal wastewater comparison between membrane bioreactor and Conventional Activated Sludge treatment
    Chemosphere, 2007
    Co-Authors: Susana Gonzalez, Mira Petrovic, Damia Barcelo
    Abstract:

    Elimination of alkylphenol ethoxylates (APEO) and their degradation products (alkylphenols and alkylphenoxy carboxylates), as well as linear alkylbenzene sulfonates (LAS) and coconut diethanol amides (CDEA), was studied in a pilot plant membrane bioreactor (MBR) working in parallel to a full-scale wastewater treatment plant (WWTP) using Conventional Activated Sludge (CAS). In the CAS system 87% of parent long ethoxy chain NPEOs were eliminated, but their decomposition yielded persistent acidic and neutral metabolites which were poorly removed. The elimination of short ethoxy chain NPEOs (NP1EO and NP2EO) averaged 50%, whereas nonylphenoxy carboxylates (NPECs) showed an increase in concentrations with respect to the ones measured in influent samples. Nonylphenol (NP) was the only nonylphenolic compound efficiently removed (96%) in the CAS treatment. On the other hand, MBR showed good performance in removing nonylphenolic compounds with an overall elimination of 94% for the total pool of NPEO derived compounds (in comparison of 54%-overall elimination in the CAS). The elimination of individual compounds in the MBR was as follows: 97% for parent, long ethoxy chain NPEOs, 90% for short ethoxy chain NPEOs, 73% for NPECs, and 96% for NP. Consequently, the residual concentrations were in the low μg/l level or below it. LAS and CDEA showed similar elimination in the both wastewater treatment systems that were investigated, and no significant differences were observed between the two treatment processes. Nevertheless, for all studied compounds the MBR effluent concentrations were consistently lower and independent of the influent concentrations. Additionally, MBR effluent quality in terms of chemical oxygen demand (COD), NH4+ concentration and total suspended solids (TSS) was always superior to the ones of the CAS and also independent of the influent quality, which demonstrates high potential of MBRs in the treatment of municipal wastewaters.

Mira Petrovic - One of the best experts on this subject based on the ideXlab platform.

  • fate and distribution of pharmaceuticals in wastewater and sewage Sludge of the Conventional Activated Sludge cas and advanced membrane bioreactor mbr treatment
    Water Research, 2009
    Co-Authors: Jelena Radjenovic, Mira Petrovic
    Abstract:

    Abstract In this paper we report on the performances of full-scale Conventional Activated Sludge (CAS) treatment and two pilot-scale membrane bioreactors (MBRs) in eliminating various pharmaceutically active compounds (PhACs) belonging to different therapeutic groups and with diverse physico-chemical properties. Both aqueous and solid phases were analysed for the presence of 31 pharmaceuticals included in the analytical method. The most ubiquitous contaminants in the sewage water were analgesics and anti-inflammatory drugs ibuprofen (14.6–31.3 μg/L) and acetaminophen (7.1–11.4 μg/L), antibiotic ofloxacin (0.89–31.7 μg/L), lipid regulators gemfibrozil (2.0–5.9 μg/L) and bezafibrate (1.9–29.8 μg/L), β-blocker atenolol (0.84–2.8 μg/L), hypoglycaemic agent glibenclamide (0.12–15.9 μg/L) and a diuretic hydrochlorothiazide (2.3–4.8 μg/L). Also, several pharmaceuticals such as ibuprofen, ketoprofen, diclofenac, ofloxacin and azithromycin were detected in sewage Sludge at concentrations up to 741.1, 336.3, 380.7, 454.7 and 299.6 ng/g dry weight. Two pilot-scale MBRs exhibited enhanced elimination of several pharmaceutical residues poorly removed by the CAS treatment (e.g., mefenamic acid, indomethacin, diclofenac, propyphenazone, pravastatin, gemfibrozil), whereas in some cases more stable operation of one of the MBR reactors at prolonged SRT proved to be detrimental for the elimination of some compounds (e.g., β-blockers, ranitidine, famotidine, erythromycin). Moreover, the anti-epileptic drug carbamazepine and diuretic hydrochlorothiazide by-passed all three treatments investigated. Furthermore, sorption to sewage Sludge in the MBRs as well as in the entire treatment line of a full-scale WWTP is discussed for the encountered analytes. Among the pharmaceuticals encountered in sewage Sludge, sorption to Sludge could be a relevant removal pathway only for several compounds (i.e., mefenamic acid, propranolol, and loratidine). Especially in the case of loratidine the experimentally determined sorption coefficients ( K d s) were in the range 2214–3321 L/kg (mean). The results obtained for the solid phase indicated that MBR wastewater treatment yielding higher biodegradation rate could reduce the load of pollutants in the Sludge. Also, the overall output load in the aqueous and solid phase of the investigated WWTP was calculated, indicating that none of the residual pharmaceuticals initially detected in the sewage Sludge were degraded during the anaerobic digestion. Out of the 26 pharmaceutical residues passing through the WWTP, 20 were ultimately detected in the treated Sludge that is further applied on farmland.

  • removal of a broad range of surfactants from municipal wastewater comparison between membrane bioreactor and Conventional Activated Sludge treatment
    Chemosphere, 2007
    Co-Authors: Susana Gonzalez, Mira Petrovic, Damia Barcelo
    Abstract:

    Elimination of alkylphenol ethoxylates (APEO) and their degradation products (alkylphenols and alkylphenoxy carboxylates), as well as linear alkylbenzene sulfonates (LAS) and coconut diethanol amides (CDEA), was studied in a pilot plant membrane bioreactor (MBR) working in parallel to a full-scale wastewater treatment plant (WWTP) using Conventional Activated Sludge (CAS). In the CAS system 87% of parent long ethoxy chain NPEOs were eliminated, but their decomposition yielded persistent acidic and neutral metabolites which were poorly removed. The elimination of short ethoxy chain NPEOs (NP1EO and NP2EO) averaged 50%, whereas nonylphenoxy carboxylates (NPECs) showed an increase in concentrations with respect to the ones measured in influent samples. Nonylphenol (NP) was the only nonylphenolic compound efficiently removed (96%) in the CAS treatment. On the other hand, MBR showed good performance in removing nonylphenolic compounds with an overall elimination of 94% for the total pool of NPEO derived compounds (in comparison of 54%-overall elimination in the CAS). The elimination of individual compounds in the MBR was as follows: 97% for parent, long ethoxy chain NPEOs, 90% for short ethoxy chain NPEOs, 73% for NPECs, and 96% for NP. Consequently, the residual concentrations were in the low μg/l level or below it. LAS and CDEA showed similar elimination in the both wastewater treatment systems that were investigated, and no significant differences were observed between the two treatment processes. Nevertheless, for all studied compounds the MBR effluent concentrations were consistently lower and independent of the influent concentrations. Additionally, MBR effluent quality in terms of chemical oxygen demand (COD), NH4+ concentration and total suspended solids (TSS) was always superior to the ones of the CAS and also independent of the influent quality, which demonstrates high potential of MBRs in the treatment of municipal wastewaters.

  • analysis and removal of emerging contaminants in wastewater and drinking water
    Trends in Analytical Chemistry, 2003
    Co-Authors: Mira Petrovic
    Abstract:

    The occurrence of trace organic contaminants in wastewaters, their behavior during wastewater treatment and production of drinking water are key issues in the re-use of water resources. Elimination of different classes of emerging contaminants, such as surfactant degradates, pharmaceuticals and polar pesticides in wastewater-treatment plants (WWTPs) was found to be rather low, so sewage effluents are one of the main sources of these compounds and their treatment-resistant metabolites. This article reviews the state-of-the-art in the analysis of several groups of emerging contaminants (acidic pharmaceuticals, antibacterial agents, acidic pesticides and surfactant metabolites) in wastewaters. It also discusses the elimination of emerging contaminants in WWTPs applying Conventional Activated Sludge treatment (AST) and advanced treatment processes, such as membrane bioreactors (MBRs) and advanced oxidation processes (AOPs), as well as during production of drinking water.

Peng Wu - One of the best experts on this subject based on the ideXlab platform.

  • start up of the canon process from Activated Sludge under salt stress in a sequencing batch biofilm reactor sbbr
    Bioresource Technology, 2010
    Co-Authors: Zhaoji Zhang, Shaohua Chen, Peng Wu
    Abstract:

    Abstract In this study, a lab-scale sequencing batch biofilm reactor (SBBR) was used to start-up the completely autotrophic nitrogen removal over nitrite (Canon) process from Conventional Activated Sludge under salt stress for 118 days. A persistent, stable partial nitrification was achieved in the SBBR when the salt concentration gradually increased to 6.5 g NaCl L −1 . Anaerobic ammonium oxidation (Anammox) bacteria were successfully enriched from the Conventional Activated Sludge in the SBBR after 68 days of operation. Anammox bacterial strains similar to the order Planctomycetales , genus Candidatus brocardia and genus Candidatus kuenenia were confirmed to exist in the internal layer of the biofilm via Fluorescence in Situ Hybridization (FISH) analysis. A maximal total nitrogen (TN) removal rate of 0.072 kg N m −3  d −1 was achieved for the Canon process when the salinity was maintained at a constant 10.0 g NaCl L −1 in the SBBR. This reactor may have applications for the Canon process treatment of salinity wastewaters containing high concentrations of ammonia.

Long D Nghiem - One of the best experts on this subject based on the ideXlab platform.

  • Sludge cycling between aerobic anoxic and anaerobic regimes to reduce Sludge production during wastewater treatment performance mechanisms and implications
    Bioresource Technology, 2014
    Co-Authors: Galilee Uy Semblante, William E Price, Long D Nghiem
    Abstract:

    Alternate cycling of Sludge in aerobic, anoxic, and anaerobic regimes is a promising strategy that can reduce the Sludge yield of Conventional Activated Sludge (CAS) by up to 50% with potentially lower capital and operating cost than physical- and/or chemical-based Sludge minimisation techniques. The mechanisms responsible for reducing Sludge yield include alterations to cellular metabolism and feeding behaviour (metabolic uncoupling, feasting/fasting, and endogenous decay), biological floc destruction, and predation on bacteria by higher organisms. Though discrepancies across various studies are recognisable, it is apparent that Sludge retention time, oxygen-reduction potential of the anaerobic tank, temperature, Sludge return ratio and loading mode are relevant to Sludge minimisation by Sludge cycling approaches. The impact of Sludge minimisation on CAS operation (e.g., organics and nutrient removal efficiency and Sludge settleability) is highlighted, and key areas requiring further research are also identified.

  • removal of trace organic contaminants by an mbr comprising a mixed culture of bacteria and white rot fungi
    Bioresource Technology, 2013
    Co-Authors: Luong N Nguyen, Faisal I Hai, Jinguo Kang, William E Price, Shufan Yang, Frederic D L Leusch, Felicity A Roddick, Long D Nghiem
    Abstract:

    The degradation of 30 trace organic contaminants (TrOC) by a white-rot fungus-augmented membrane bioreactor (MBR) was investigated. The results show that white-rot fungal enzyme (laccase), coupled with a redox mediator (1-hydroxy benzotriazole, HBT), could degrade TrOC that are resistant to bacterial degradation (e.g. diclofenac, triclosan, naproxen and atrazine) but achieved low removal of compounds (e.g. ibuprofen, gemfibrozil and amitriptyline) that are well removed by Conventional Activated Sludge treatment. Overall, the fungus-augmented MBR showed better TrOC removal compared to a system containing Conventional Activated Sludge. The major role of biodegradation in removal by the MBR was noted. Continuous mediator dosing to MBR may potentially enhance its performance, although not as effectively as for mediator-enhanced batch laccase systems. A ToxScreen3 assay revealed no significant increase in the toxicity of the effluent during MBR treatment of the synthetic wastewater comprising TrOC, confirming that no toxic by-products were produced.

  • coupling powdered Activated carbon pac adsorption with membrane bioreactor mbr treatment for enhanced removal of trace organics
    Procedia Engineering, 2012
    Co-Authors: Luong N Nguyen, Faisal I Hai, Long D Nghiem, Jinguo Kang, William E Price
    Abstract:

    the occurrence of trace organics such as pesticides, pharmaceutically active compounds, natural and synthetic hormones as well as varous industrial compounds in the aquatic environment is of great concern due to their potential adverse effects on human health and those of other biota. Therefore, the removal of these compounds from wastewater is an important consideration to ensure safe drinking water and better protection of the environment. In the literature, several techniques have been explored for trace organics removal, namely, Conventional Activated Sludge, membrane bioreactors (MBRs), and absorptioin. However it has been found that neither MBR nor Activated carbon on its own can adequately remove all trace organics of concern.

Andrea Frattarola - One of the best experts on this subject based on the ideXlab platform.

  • the upgrading of Conventional Activated Sludge processes with thermophilic aerobic membrane reactor alternative solutions for Sludge reduction
    Journal of Environmental Management, 2020
    Co-Authors: Maria Cristina Collivignarelli, Alessandro Abba, Giorgio Bertanza, Andrea Frattarola
    Abstract:

    Abstract Sludge recovery/disposal represents one of the most crucial aspects related to the management of wastewater treatment plants. The most widely diffused technology for the treatment of industrial and municipal wastewaters is the Conventional Activated Sludge (CAS) process, which is characterized by a relatively high excess Sludge production. Different technical solutions are proposed in the literature for Sludge minimization and they can be applied either on wastewater line (WL) or Sludge line (SL). This work is focused on different approaches based on the use of Thermophilic Aerobic Membrane Reactor (TAMR): this can be added to a CAS plant, and integrated to WL or SL, yielding a significant Sludge reduction. The process performance was analysed in terms of volatile solids (VS) reduction and specific Sludge production. The TAMR was tested both at full-scale and pilot-scale with different feeding substrates: industrial wastewater for the full-scale plant; industrial wastewater, Sludge and a mix of these for the pilot-scale plants. The results obtained are: (i) good solids removal (38–90% and 40–50% in terms of VS for Sludge and mix of industrial wastewater and Sludge, respectively), (ii) low specific Sludge production (0.01–0.09 kgVSS produced kgCOD removed−1 for industrial wastewater and 0.014–0.069 kgVSS produced kgCOD removed−1 for mix of industrial wastewater and Sludge) and (iii) a significant reduction of Sludge when CAS is improved with the TAMR technology.