Article

Biodegradation of persistent polar pollutants in wastewater: Comparison of an optimised lab-scale membrane bioreactor and activated sludge treatment

Europa University of Applied Sciences Fresenius, Limburger Strasse 2, D-65510 Idstein, Germany.
Water Research (Impact Factor: 5.53). 11/2006; 40(18):3419-28. DOI: 10.1016/j.watres.2006.07.011
Source: PubMed

ABSTRACT

The biodegradation of selected non-adsorbing persistent polar pollutants (P(3)) during wastewater (WW) treatment was studied by comparing a lab-scale membrane bioreactor (MBR) running in parallel to activated sludge treatment (AST). The investigated P(3) are relevant representatives or metabolites from the compound classes: pesticides, pharmaceuticals, insect repellents, flame retardants and anionic surfactants. Analyses of all these P(3) at low ng L(-1) levels with sufficient standard deviations was performed in WW influents and effluents. Non-degradable micropollutants, such as EDTA and carbamazepine were not eliminated at all during WW treatment by any technique. However, the MBR showed significant better removals compared to AST for the investigated poorly biodegradable P(3), such as diclofenac, mecoprop and sulfophenylcarboxylates. An application of such an in terms of sludge retention time optimised MBR may lead to a reduction of these P(3) in the watercycle.

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    • "In particular two non-DEET repellent active substances were of interest: Icaridine (Bayrepel ® , CAS number 119515-38-7) and EBAAP (IR3535 ® , CAS number 52304-36-6). In Germany, the DEET concentrations in water bodies have decreased constantly since 1999, when DEET was substituted by Icaridine (Knepper, 2004); meanwhile Icaridine has been detected in low mg/L concentrations in European surface waters (Nendza et al., 2013; Bernhard et al., 2006). Although the other non-DEET active repellent EBAAP is as well increasingly used (Buechel et al., 2015), no data on surface water concentrations are available; nevertheless, it is reasonable to assume that, similar to DEET and Icaridine, also EBAAP may enter surface waters. "
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    ABSTRACT: Commercial insect repellents like DEET (N,N-diethyl-m-toluamide), EBAAP (IR3535(®), (3-[N-butyl-N-acetyl]-aminopropionic acid, ethyl ester)) or Icaridine (picaridin, Bayrepel, 1-piperidinecarboxylic acid, 2-(2-hydroxyethyl), 1-methylpropyl ester) are used worldwide to protect against biting insects and ticks. The detection of these repellents in surface waters in concentrations up to several μg/L levels has caused concern that these substances might affect non-target organisms in freshwaters. Daphnia sp., a keystone organism in lakes and ponds, is known for diel vertical migration (DVM) and life-history changes (LHCs) as inducible defenses against predation by fish. Here we test whether (i) environmentally relevant concentrations of DEET, EBAPP or Icaridine have repellent effects on Daphnia magna and (ii) if these repellents are infodisruptors for DVM and LHCs. Using concentrations of up to 44 μg/L, the repellents neither had effects on juvenile somatic growth nor on clutch size. In thermally stratified water columns with a repellent-free hypolimnion, no repellent effects of the test compounds on D. magna were observed. The presence of fish-born infochemicals induced LHCs, which are characterized by a reduced size at first reproduction, and DVM in D. magna. These effects were not affected by the presence of either repellent. Hence no evidences for infodisruption of the chemical communication of fish and Daphnia by DEET, EBAAP or Icaridine were found.
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    • "The high variability in the efficiency of secondary treatment reported by other studies (Bernhard et al., 2006; Nakada et al., 2010) also suggests the attenuation of DEET should be dominated by biological rather than physical processes such as adsorption. Indeed, with a log Kow in the range 2.02–2.40 and a Koc in the range 47– 126 L Kg À1 (Weeks et al., 2012), DEET is most likely to remain in the aqueous phase rather than accumulating in solids like activated sludge. "
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    • "In the presence of NaN 3 the attenuation of TCEP was approximately 25% in both MFCs and MECs (Fig. 3C). TCEP has been reported to be difficult to attenuate in wastewater treatment plants with reports of zero (Meyer and Bester, 2004) to 42% elimination (Bernhard et al., 2006) in activated sludge systems. MFCs and MECs showed higher attenuation of this compound than has been reported for conventional treatment. "
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