Priority Hazardous Substances Research Articles

Removal of selected chlorinated micropollutants by ozonation

AbstractFeasibility of ozone oxidation for the elimination of selected dissolved organic micropollutants from water and wastewaters was studied. Five organochlorine pesticides, i.e. hexachlorobutadiene, pentachlorobenzene, hexachlorobenzene, lindane, and heptachlor, were used as organic contaminants of model water. The first four of them are classified as priority hazardous substances. The oxidation treatment process was performed in a jet loop reactor. Ozone was prepared from pure oxygen. Quantification of the organochlorine pesticides in water was achieved by the gas chromatographic method after liquid-liquid extraction. Significant contribution of stripping to the removal of the investigated compounds during the ozonation treatment was also proven by the results. Effective ozonation time with regard to treatment efficiencies was 30 min, which corresponds to the ozone input of 317 mg per liter of active volume of the ozonation reactor. Single power law kinetic models were used to describe experimental data and kinetic parameters were estimated. The best fit of the experimental degradation data of all studied pollutants was obtained by the second order kinetic model. It can be concluded, based on the results obtained, that the applied ozonation process is a promising procedure for the removal of the investigated pesticides from aquatic environment.

The Prohibition of Mercury Discharges from Coal-Fired Power Stations under European Law

Coal-fired power plants emit mercury trough the air and the water pathway into surface water. Often the occurring depositions from the air and air-soil pathway are higher then the direct depositions through the water pathway. The following article explores the question whether these depositions are in line with the Industry Emission Directive and the Water Framework directive. Whilst the IED does not contain emission limits, there are limitations via the phase-out requirement of the WFD and via the environmental quality standards for mercury contamination of biota in the daughter directive on priority hazardous substances. The phase-out requirement demands the cessation of mercury depositions by 23.12.2006. And based on the biota requirements any new deposition of mercury by coal power plants is inadmissible. These requirements do not only apply to the permission of new power plants, but also to existing plants.

Mercury environmental quality standard for biota in Europe: Opportunities and challenges

The European Union sets Environmental Quality Standards (EQS) for 33 + 8 “priority or priority hazardous substances”; Hg being included in the latter group. Directive 2008/105/EC fixes EQS for total Hg concentration in filtered water (0.45 µm) and allows Member States to opt for an alternative EQS for biota. However, proposal COM 2011/876, currently under discussion, sets to reverse this approach by requiring the application of a biota-based EQS of 20 ng g−1 total Hg wet weight and specifying, at the time of writing, that this EQS is intended for fish. The biota EQS is meant for the protection of piscivorous wildlife against secondary poisoning and should protect the aquatic ecosystems and human health. Adopting a biota-based EQS for Hg reflects current scientific understanding, with most Hg-related environmental issues arising from the biomagnification of methylmercury (meHg) rather than direct Hg (or meHg) toxicity via water exposure. An EQS for biota also automatically accounts for Hg bioavailability issues, thus greatly increasing the possibility to identify situations requiring risk management during routine monitoring programs. Depew et al. (2012) derived a threshold concentration of 40 ng g−1 wet weight for reproductive effects in fish following dietary exposure to meHg. Besides protecting piscivorous organisms, the proposed EQS is therefore amenable to application for the protection of prey fish. However, adoption of the EQS for biota is likely to pose enormous pressure on regulatory agencies. Looking at fish collected from some European lakes and rivers during 2005–2010, Hg concentrations exceed the proposed EQS by 2- to 16-fold (Table 1). Table 1, albeit far from exhaustive, includes representative water bodies and should reflect the range of Hg contamination in fish from European surface waters. How to reconcile the scientific superiority of the EQS for biota with regulatory compliance, therefore, represents a major conundrum. Guilizzoni (2011) Pessina (2010) Pola (2011) Pola (2011) Ortelli et al. (2009) Babut et al. (2011) ICPR (2011) In this respect, proposal COM 2011/876 makes specific provision for substances behaving as ubiquitous persistent bioaccumulative and toxic (UPBT) substances. If there is a robust statistical monitoring baseline, Member States can justify failure in meeting the EQS for an UPBT by presenting separate classification maps showing that the “bad” status is caused by an UPBT for which all possible measures have been taken. The same proposal allows Member States to apply an EQS for different matrices, provided they demonstrate that it achieves the same level of protection as the EQS for biota. Other arguments, not stated in the proposal, include the application of the EQS for biota to invertebrate groups (expected to have lower Hg concentrations) or, in a purely pragmatic way, a revision of the numerical EQS value to make it less stringent. Reverting to a water-based EQS is not advisable because of the scientific superiority of the standard for biota and, similarly, revision of the EQS numerical value is difficult to justify on a scientific basis. As to the other possibilities, application of the EQS to invertebrates will protect forage fish against dietary Hg exposure (Depew et al. 2012), but EQS for piscivorous wildlife and forage fish may not be interchangeable. Finally, the choice of including Hg in the list of UPBT would shift focus from the national to the global scale, thus reducing efforts to target important local issues. For example, lakes Maggiore and Lugano have contiguous catchments, but current Hg concentrations in fish (Table 1) reflect the long history of Hg contamination of Lake Maggiore through the 20th century and require specific basin-scale measures for remediation. Overall, the impact of Hg on European waters may be much more serious than previously thought. The practical problems of such situations are obvious, but most recent scientific evidence confirms rather than questions the solidity of the proposed numerical value. Regulatory agencies must therefore expand Hg monitoring of biota to fully appreciate the gap between the targeted and the current situation. With more information, specific cases possibly allowing for the use of less stringent EQS for the same level of protection may be identified. Further research on global and local Hg biogeochemical cycles along with ecologically meaningful investigation of Hg ecotoxicology, rather than shortcuts to reduce noncompliance, therefore appear as the correct way to reinforce the successful marriage of science and policy exemplified by the Hg EQS for biota.

Degradation of short chain polychlorinated paraffins by a new isolate: tests in pure culture and sewage sludge

AbstractBACKGROUNDShort chain chlorinated paraffins SCCPs are priority hazardous substances classified by the European Water Framework Directive and have been detected in sewage sludge of wastewater treatment plants worldwide. However, studies on the biodegradation of SCCPs presented in sewage sludge are very scarce.RESULTSIn this study, a bacterial strain that can utilize SCCPs as a sole source of carbon and energy was isolated from soil. This strain was identified as Pseudomonas sp. N35. The efficacy of SCCP degradation by strain N35 was tested in pure culture and sewage sludge microcosms containing 66.1 mg kg–1 SCCPs. The results showed that 57.5% of chloride was released into the medium as chloride ions in pure culture within 20 days. Mesophilic temperature and near‐neutral pH were most favorable for SCCP degradation. The addition of low concentrations of glucose, Tween‐80 and acetone (20 mg L–1) enhanced SCCP degradation. Bioaugmentation resulted in 73.4% removal of SCCPs in the sludge microcosm after 30 days of treatment.CONCLUSIONBioaugmentation with specific strains may be of great significance in bioremediation of SCCP‐containing sewage sludge.© 2012 Society of Chemical Industry

An evaluation of bioaccumulation data for hexachlorobenzene to derive water quality standards according to the EU‐WFD methodology

Hexachlorobenzene (HCB) is a priority hazardous substance within the Water Framework Directive (WFD). For aquatic systems, the European Commission has derived quality standards (QS) for HCB in biota. However, in some countries a preference may exist for QS based on water concentrations. The conversion of biota QS into water QS can be done by dividing the quality standard for biota by a reliable bioaccumulation factor (BAF) or by the product of the bioconcentration factor (BCF) and the biomagnification factor (BMF) (BCF × BMF). An extensive literature review of HCB bioaccumulation was performed, and data on bioaccumulation, biomagnification and bioconcentration, both from the field and the laboratory, were assessed for their usefulness to recalculate biota standards into water standards. The evaluation resulted in 10 reliable values for field BAFs, with a geometric mean of 221 000 L/kg (5% lipid-normalized). Bioaccumulation factor measurements show a high variation of more than 1 order of magnitude. At lower trophic levels (algae, small zooplankton), accumulation of HCB already exceeds expected accumulation through equilibrium partitioning by far. This affects BAFs at higher trophic levels as well. Moreover, observed BAF values for HCB in fish cannot be easily explained from the age of the fish, but there is a significant increase with trophic level. Reliable values for laboratory BCFs for fish were retrieved from literature, partly with water-based exposure and partly with dietary exposure. The 5% lipid-normalized BCF of all these data is 12 800 L/kg. Regarding biomagnification, a number of reliable BMF and trophic magnification factor values, mostly determined in the field, were retrieved. From these data, an overall BMF of 3 per trophic level can be deduced. When comparing BCF values for fish multiplied by the BMF (12 800 × 3 = 38 400 L/kg) to the observed BAF values for fish (geometric mean 238 000 L/kg), there appears to be a large gap. Thus, the uncertainties surrounding values for bioaccumulation of HCB are high. Although the confidence in laboratory BCFs is higher, these data seem to be not relevant for small fish in the field. This makes it difficult to obtain a reliable BAF or BCF × BMF value to recalculate biota standards into water standards. On the other hand, biota concentrations in the field show a high variability that also hampers comparison with a fixed limit such as a quality standard. Thus, compliance checking using biota in the field means that a relatively large amount of fish will have to be used to obtain a reliable estimate. The following "tiered approach" is suggested: 1) calculate a water quality standard, using the BAF value that is most relevant for the trophic level to be protected, and 2) if this standard is exceeded in the field, sample representative biota in the field and compare concentrations of HCB in biota and water with their respective standards in a weight of evidence approach for compliance checking. In this way, unnecessary biota sampling can be avoided for reasons of efficiency and animal welfare.

Determination of polycyclic aromatic hydrocarbons in biochar and biochar amended soil

A method for the determination of the 16 USEPA polycyclic aromatic hydrocarbons (PAHs) in biochar and biochar amended soil was developed. Samples were Soxhlet extracted with an acetone/cyclohexane (1:1) solvent mixture, and PAHs were analyzed by GC–MS after silica gel clean-up. In a comparative study based on reflux extraction, the Soxhlet solvent system acetone/cyclohexane exhibited a higher extraction efficiency of low molecular weight PAHs (e.g. naphthalene) than toluene or dichloromethane. Utilizing a reference biochar, this Soxhlet method possessed a 67–88% recovery of spiked deuterated PAHs (acenaphthene, phenenthrene, and chrysene), analytical precision (as assessed by relative standard deviations) between 5 and 18%, and a limit of detection in the 0.01–0.4ngg−1 range. The method was successfully validated through the analysis of a certified soil material, and was capable to quantify total PAHs following biochar addition at 1% (w/w). The concentration of the 16 USEPA-PAHs along with the 15 EU-PAHs (priority hazardous substances in food) was determined in a suite of currently available biochars for agricultural field applications, which were derived from a variety of parent materials and pyrolysis conditions. The total PAH levels ranged between 1.2–19μgg−1 and 0.2–5μgg−1 interval for USEPA and EU PAHs, respectively. Specifically, benzo[a]pyrene ranged between 0.01 and 0.67μgg−1 across these various biochars. Considering an application of 20–60tbiocharha−1, the degree of PAH contamination will be dependent on both the presence of background PAHs in soil and the sorbed concentrations of PAHs on the biochar. Our data, along with PAH levels determined in other studies, suggest that biochars produced by slow pyrolysis from woody biomass possess the lowest level of sorbed PAHs (<10μgg−1).

Treatment of combined sewer overflows by ballasted flocculation: Removal study of a large broad spectrum of pollutants

This study aims at examining the performance of the ballasted flocculation unit (BFU) on treating combined sewer overflows (CSOs) and the evaluation depends on the values obtained of routine wastewater parameters and on the contents of a large broad spectrum of pollutants. Accordingly, the full-scale BFU at the largest wastewater treatment plant in Europe (Seine Aval plant near Paris, France) is investigated during three sampling campaigns. Of the 97 molecules targeted, 57 substances including 18 priority substances and 11 priority hazardous substances were detected in the BFU influents confirming that wet weather flow (WWF) treatment has definitively proven to be necessary. The WWF treatment by ballasted flocculation appears as a promising but not a fully adapted technology for use in densely urbanized areas to considerably mitigate the CSO impacts. On operating at the optimal chemical and sand doses, this process appears to be a suitable technology to remove particles, carbonaceous and phosphorous pollutants, particulate metals and most of hydrophobic organic compounds whilst nitrogenous pollutants and most of hydrophilic compounds are from poorly (<20%) to moderately (<50%) removed. The BFU appeared less sensitive to the influent concentration fluctuations and hydraulic peak load (at the scale of the campaigns considered) than to the adjustments of chemical doses and sand injection. Investigating the performance of such process, could serve to develop management strategies that enable mitigating the impacts of CSOs on receiving water in compliance with the Water Framework Directive objectives.

Multi-component trace analysis of organic xenobiotics in surface water containing suspended particular matter by solid phase extraction/gas chromatography–mass spectrometry

Suspended particulate matter (SPM) often disturbs the analysis of surface water by conventional methods, such as liquid–liquid extraction (LLE) or solid phase extraction (SPE), caused by insufficient extraction or by plugging. Water and SPM are therefore often separately analysed, which is associated with high expenditure of time, work and costs. Hence, SPM is partly ignored, if the fraction of sorptively bound analytes is small compared to the total analyte concentration. However, the European Water Framework Directive (WFD, Directive 2000/60/EC) requires explicitly an investigation of the whole water sample including SPM, because many priority and priority hazardous substances can sorb substantially to SPM. Therefore, an SPE disk based method was developed for the determination of 54 priority and priority hazardous pollutants including polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), polybrominated diphenyl ethers (PBDE), organic chlorinated pesticides (OCP) and other pesticides in surface water containing SPM. The developed SPE disk method allows analysis of 1L surface water containing up to 1000mg SPM without prior separation of SPM in about 2h including gas chromatography–mass (GC–MS) spectrometry analysis. The limits of quantification vary in a range of 0.8 to 38ng/L.

Occurrence of Diuron and Irgarol in seawater, sediments and planktons of Seto Inland Sea, Japan

Copyright © 2012 by The Geochemical Society of Japan. but may have a potential to impact the coastal ocean via surface runoff due to their solubility (Lamoree et al., 2002). Diuron (3-[3,4-dichlorophenyl]-1,1-dimethylurea) is an herbicide derived from urea that is considered to be a priority hazardous substance by the European commission (Malato et al., 2002). Accordingly, countries including the UK, Sweden, Denmark and France have restricted the use of Diuron in antifouling paints (Konstantinou and Albanis, 2004). In Japan, Diuron has long been used in agricultural and other activities, and a large amount of Diuron discharged into river water has been transported into the Seto Inland Sea with little or no degradation (Sakugawa et al., 2010). Furthermore, extensive quantities of Diuron are used as antifouling paints by the shipping industry and the highest concentration occurred in seawater of Japan was 3.05 μg/L (Okamura et al., 2003). In addition urban areas of Okinawa Island, Japan apply a significant amount of Diuron as a weed control (Kitada et al., 2008). Irgarol (2-[tert-butylamino]-4-[cyclopropylamino]-6[methylthio]-1,3,5-triazine) is a protective algaecide widely used in antifouling paints and has a wide range of action against a number of algal organisms. Irgarol belongs to the s-triazine group of compounds, which act as photosystem-II (PSII) inhibitors, with the inhibition of photosynthetic electron capture transport in chloroplasts as their biochemical mode of action (Dahl and Blanck, 1996). Okamura et al. (2003) found the highest concenOccurrence of Diuron and Irgarol in seawater, sediments and planktons of Seto Inland Sea, Japan

Water management in cities of the future using emission control strategies for priority hazardous substances

Cities of the future face challenges with respect to the quantity and quality of water resources, and multiple managerial options need to be considered in order to safeguard urban surface water quality. In a recently completed project on 'Source control options for reducing emissions of Priority Pollutants' (ScorePP), seven emission control strategies (ECSs) were developed and tested within a semi-hypothetical case city (SHCC) to evaluate their potential to reduce the emission of selected European priority hazardous substances (PHSs) to surface waters. The ECSs included (1) business-as-usual, (2) full implementation of relevant European (EU) directives, (3) ECS2 in combination with voluntary options for household, municipalities and industry, (4) ECS2 combined with industrial treatment and best available technologies (BAT), (5) ECS2 in combination with stormwater and combined sewer overflow treatment, (6) ECS2 in combination with advanced wastewater treatment, and (7) combinations of ECS3-6. The SHCC approach was chosen to facilitate transparency, to allow compensating for data gaps and to decrease the level of uncertainty in the results. The selected PHSs: cadmium (Cd), hexachlorobenzene (HCB), nonylphenol (NP) and pentabromodiphenyl ether (PBDE) differ in their uses and environmental fate and therefore accumulate in surface waters to differing extents in response to the application of alternative ECS. To achieve the required reduction in PHS levels in urban waters the full implementation of existing EU regulation is prioritised and feasible combinations of managerial and technological options (source control and treatment) can be highly relevant for mitigating releases.

Priority substances in combined sewer overflows: case study of the Paris sewer network

This study was undertaken to supply data on both priority pollutant (PP) occurrence and concentrations in combined sewer overflows (CSOs). A single rain event was studied on 13 sites within the Paris sewer network. For each sample, a total of 66 substances, including metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, organotins, volatile organic compounds, chlorobenzenes, phthalates and alkylphenols were analyzed. Of the 66 compounds analyzed in all, 40 PPs including 12 priority hazardous substances were detected in CSOs. As expected, most metals were present in all samples, reflecting their ubiquitous nature. Chlorobenzenes and most pesticides were never quantified above the limit of quantification, while the majority of the other organic pollutants, except DEHP (median concentration: 22 μg.l(-1)), were found to lie in the μg.l(-1) range. For the particular rain event studied, the pollutant loads discharged by CSOs were evaluated and then compared to pollutant loads conveyed by the Seine River. Under the hydraulic conditions considered and according to the estimations performed, this comparison suggests that CSOs are potentially significant local source of metals, PAHs and DEHP. Depending on the substance, the ratio between the CSO and Seine River loads varied from 0.5 to 26, underscoring the important local impact of CSOs at the scale of this storm for most pollutants.

Identification of mutagens in freshwater sediments by the Ames‐fluctuation assay using nitroreductase and acetyltransferase overproducing test strains

Extracts of sediments from an area of concern in the Elbe river basins (Spittelwasser creek) were analyzed with the Ames-fluctuation test and in parallel with gas chromatography/mass spectrometry for compound identification. The standard test strains TA 98 and TA 100 showed mutagenicity mainly in medium-polar fractions of the sediment extracts. PAHs contribute to the overall mutagenic potential of the sample. Especially, cyclopenta[c,d]pyrene that was previously not defined as a priority hazardous substance has to be considered as well. The addition of metabolically competent test strains, which overexpress nitroreductase and acetyltransferase (e.g., YG1041 and YG1042) to the test battery, increased significantly the sensitivity of the Ames test for medium polar to polar genotoxins. The increased mutagenicity that was found in these bacterial strains indicates the presence of nitroarenes and/or aromatic amines. In fact, a number of heterocyclic and nitrogen-substituted aromatic compounds were identified in the sediments of the Spittelwasser creek of which methyl parathion, 1-naphthylamine, and N-phenyl-2-naphthylamine are mutagenic.

Estimation of the environmental risk posed by landfills using chemical, microbiological and ecotoxicological testing of leachates

The leachates from 22 municipal solid waste (MSW) landfill sites in Southern Poland were characterized by evaluation of chemical, microbiological and ecotoxicological parameters. Chemical analyses were mainly focused on the identification of the priority hazardous substances according to Directive on Priority Substances, 2008/105/EC (a daughter directive of the WFD) in leachates. As showed, only five substances (Cd, Hg, hexachlorobutadiene, pentachlorobenzene and PAHs) were detected in the leachates. The compounds tested were absent or present at very low concentrations. Among them, only PAHs were found in all samples in the range from 0.057 to 77.2 μg L −1. The leachates were contaminated with bacteria, including aerobic, psychrophilic and mesophilic bacteria, coliform and fecal coliforms, and spore-forming-bacteria, including Clostridium perfringens, and with filamentous fungi. From the analysis of specific microorganism groups (indicators of environmental pollution by pathogenic or opportunistic pathogenic organisms) it can be concluded that the landfill leachates showed sanitary and epidemiological hazard. In the ecotoxicological study, a battery of tests comprised of 5 bioassays, i.e. Microtox®, Spirotox, Rotoxkit F™, Thamnotoxkit F™ and Daphtoxkit F™ magna was applied. The leachate samples were classified as toxic in 13.6%, highly toxic in 54.6% and very highly toxic in 31.8%. The Spirotox test was the most sensitive bioassay used. The percentage of class weight score was very high – above 60%; these samples could definitely be considered seriously hazardous and acutely toxic to the fauna and microflora. No correlations were found between the toxicity values and chemical parameters. The toxicity of leachate samples cannot be explained by low levels of the priority pollutants. It seems that other kinds of xenobiotics present in the samples at subacute levels gave the high aggregate toxic effect. The chemical, ecotoxicological and microbiological parameters of the landfill leachates should be analyzed together to assess the environmental risk posed by landfill emissions.

Advanced treatment of WWTP effluent with filtration leading to a pretreatment technique for membrane filtration

In 2000 the European Union introduced the Water Framework Directive (WFD). The aim of the WFD is having an ecological and chemical balance for all surface waters in Europe in 2015. The European Commission identified 33 priority substances and their maximum allowable concentrations, FHI-values (Fraunhofer Institute), which are specified in the Annex of the WFD. The objective of this research is to achieve the removal of suspended solids, nitrogen and total phosphorus together with priority substances. All these substances will be removed in one filter called a "One Step Total Effluent Polishing filter" i.e. 1-STEP(®) filter. For this purpose a filter pilot plant was tested at the WWTP Horstermeer. The results show that the filter can fulfil the target values in the filtrate water for total nitrogen (2.2 mg Ntotal/L) and total phosphorus (0.15 mg Ptotal/L). The majority of the priority (hazardous) substances in the WWTP effluent are already below the detection limit. Due to the low concentration ranges, the results on the removal of medicine and pesticides are only indicative. A decreasing tendency in the removal efficiency is shown for all measured compounds. The average specific ultrafiltration resistance (SUR) value decrease of the filter is 55% and the final value is always below 5·10(12) m(-2). This indicates that the filtrate water of the filter is very well filterable and can be used as ultrafiltration feedwater.

Partition of pollution between dissolved and particulate phases: What about emerging substances in urban stormwater catchments?

This paper presents results about the occurrence, the concentrations of urban priority substances on both the dissolved and the particulate phases in stormwater. Samples were collected at the outlet of a dense urban catchment in Paris suburb (2.30 km2). 13 chemical groups were investigated including 88 individual substances. Results showed that stormwater discharges contained 45 substances among them some metals, organotins, PAHs, PCBs, alkylphenols, pesticides, phthalates, cholorophenols and one volatile organic compound, i.e. methylene chloride. With respect to the European Water Framework Directive, these substances included 47% of the priority hazardous substances (n = 8), 38% of the priority substances (n = 10). The remaining substances (n = 27) belong to a list of others specific urban substances not included in the Water Framework Directive but monitored during this work. Finally, stormwater quality was evaluated by comparing the substance concentrations to environmental quality standards (EQS) and the particulate content to Canadian sediment quality guidelines. This showed that stormwater was highly contaminated and should be treated before being discharged to receiving waters in order to avoid any adverse impact on the river quality.

Photothermocatalytic Synergetic Effect Leads to High Efficient Detoxification of Benzene on TiO2 and Pt/TiO2 Nanocomposite

Controlling the emission of volatile organic compound (VOCs) has become an important issue because they are not only hazardous to human health but also harmful to the environment. Among various VOCs, the carcinogenic and recalcitrant benzene, which is one of the most abundant aromatic hydrocarbons found in polluted urban atmospheres, has been regarded as a priority hazardous substance for which efficient treatment technologies are needed. Heterogeneous photocatalysis based on nanostructured TiO2 has attracted much research attention in the past decades as an important and promising technology for the detoxification of organic pollutants because of the superior photocatalytic activity, chemical stability, low cost, and nontoxicity of TiO2. However, when TiO2 photocatalysts are applied to the detoxification of benzene in the gas phase, they are prone to deactivation mainly due to the deposition of less reactive byproducts on the TiO2 surface, making the photocatalytic detoxification of benzene very inefficient. 4] Much effort has therefore been devoted to enhancing the efficiency of benzene photocatalytic oxidation. The modification of TiO2 with noble metal (e.g. , Rh and Pt) as co-catalysts has been found to boost the efficiency of benzene photocatalytic oxidation and improve the durability of TiO2 catalysts. Recently, photocatalytic oxidation combined with ozone oxidation on TiO2 has been developed to improve the efficiency of benzene or toluene oxidation. As ozone is also an air pollutant, additional setup was required to remove the its excess. Plasma-driven photocatalysis and catalysis have been reported to enhance VOC decomposition activity on TiO2 and Al2O3. [10] Developing a highly efficient and cost-effective strategy for the detoxification of recalcitrant VOCs, such as benzene, has been a great challenge. Herein, photocatalysis and thermal catalysis have been ideally combined together just by a facile method of coating TiO2 catalyst and Pt/TiO2 nanocomposite on the surfaces of a UV lamp without using any additional heater, by which both UV irradiation and nonradiative thermal energy emitted from the UV lamp are fully used, and the high efficient photothermocatalytic detoxification of benzene has been realized. In this perfect combination of photocatalysis and thermal catalysis, a new photothermocatalytic synergetic effect has been found for the first time. Various high-pressure Hg lamps have been widely used as UV light sources in photocatalytic studies for decades. However, their nonradiative thermal energy emitted has not been fully used. In the closed gas-phase reactor, when the selfrectified high-pressure Hg lamp was turned on, the thermal energy emitted from the lamp made its surface temperature automatically increase to 240 8C, which provided a possibility for photothermocatalytic oxidation to occur without using an additional heater. The TiO2 sample was coated on the surfaces of the lamp, and thus the TiO2 catalyst was co-excited by both UV irradiation and thermal energy. Under the photothermocatalytic condition, benzene was rapidly oxidized with time and

Synthesis of defined endocrine-disrupting nonylphenol isomers for biological and environmental studies

Nonylphenols are very important environmentally relevant substances in the focus of the world-wide endocrine disrupter research for over 25 years. Thus, they are among the 10 priority hazardous substances of the new European Union Water Framework Directive. They consist of a very complex mixture of isomers representing therefore a multi-component problem like dioxins or PCBs. As estrogenic effect and degradation behavior in the environment of individual 4-nonylphenols are heavily dependent on the structure and bulkiness of the side chain, it is absolutely necessary to consider the nonylphenol problem from an isomer-specific viewpoint. Therefore a range of 28 differently branched nonylphenol isomers were synthesized for biological and environmental studies. Nonylphenols with a quaternary α-carbon, like 4-(1,1,3,4-tetramethylpentyl)phenol (4-NP 95 ) and 4-(1-ethyl-1,3,3-trimethylbutyl)phenol (4-NP 170 ), were obtained by Friedel–Crafts alkylation of anisole with tertiary nonyl bromides and demethylation with BI 3. Nonylphenols with a tertiary α-carbon, such as 4-(1,2-dimethylheptyl)phenol (4-NP 10 ) and 4-(1,2,4-trimethylhexyl)phenol (4-NP 41 ), were accessible via coupling of p-methoxyphenylmagnesium bromide with ketones. Nonylphenols bearing a quaternary β-carbon, like 4-(2,2-dimethylheptyl)phenol (4-NP 15 ) and 4-(1,2,2-trimethylhexyl)phenol (4-NP 39 ), were synthesized starting from 4′-methoxyisobutyrophenone. The compounds were characterized by GC–MS and NMR-spectroscopy. The individual isomers were designated according to the Juelich Nomenclature.

Presence and fate of priority substances in domestic greywater treatment and reuse systems

A wide range of household sources may potentially contribute to contaminant loads in domestic greywater. The ability of greywater treatment systems to act as emission control barriers for household micropollutants, thereby providing environmental benefits in addition to potable water savings, have not been fully explored. This paper investigates the sources, presence and potential fate of a selection of xenobiotic micropollutants in on-site greywater treatment systems. All of the investigated compounds are listed under the European Water Framework Directive as either “Priority Substances” (PS) or “Priority Hazardous Substances” (PHS). Significant knowledge gaps are identified. A wide range of potential treatment trains are available for greywater treatment and reuse but treatment efficiency data for priority substances and other micropollutants is very limited. Geochemical modelling indicates that PS/PHS removal during treatment is likely to be predominantly due to sludge/solid phase adsorption, with only minor contributions to the water phase. Many PS/PHS are resistant to biodegradation and as the majority of automated greywater treatment plants periodically discharge sludge to the municipal sewerage system, greywater treatment is unlikely to act as a comprehensive PS/PHS emission barrier. Hence, it is important to ensure that other source control options (e.g. eco-labeling, substance substitution, and regulatory controls) for household items continue to be pursued, in order that PS/PHS emissions from these sources are effectively reduced and/or phased out as required under the demands of the European Water Framework Directive.

Implementation of Directive 2000/60/EC: risk-based monitoring for the control of dangerous and priority substances

The 2000/60/EC Water Framework Directive sets out a new approach for the assessment and management of chemical pollutants (i.e. formerly dangerous substances) in water bodies. The list of main classes of pollutants was revised and a detailed list of priority substances, including priority hazardous substances, has been provided. Moreover, the Directive asks for additional priority substances to be identified at national and river catchment level. The implementation of the Directive requires the monitoring of the main pollutants after the identification of the priority and dangerous substances potentially discharged into each river catchment area, together with the definition of the Environmental Quality Standards. In this paper, an approach based on the integration of the Driving force-Pressure-State-Impact-Response model with the Environmental Risk Assessment as a support methodology for the monitoring management (i.e. choice of priority substances, quantification of Environmental Quality Standards, identification of interventions) is presented. In addition, a case study on the assessment of monitoring data concerning industrial and municipal discharges, and the surface waters of the Venice lagoon catchment area is discussed. Since 1998, very strict environmental quality standards and discharge limits have been enforced in the lagoon of Venice and its catchment area. The experience gained from this monitoring is used to highlight the implementation issues concerning the Water Framework Directive and to identify the priority substances which can pose a significant risk for freshwater ecosystems.

Identification of nonregulated pollutants in north sea‐produced water discharges

Produced water collected from oil and gas platforms on the United Kingdom Continental Shelf was characterized for nonregulated pollutants through an effects-directed analysis procedure. Produced water samples were characterized for the presence of aryl hydrocarbon receptor (AhR) and estrogen receptor (ER) agonists using the dioxin-responsive, chemical-activated luciferase gene expression assay (DR-CALUX) and yeast estrogen screen (YES) bioassays. The AhR and ER agonists were then isolated by normal-phase, high-performance liquid chromatography and identified using gas chromatography coupled to mass spectrometry in a number of formats. The identified compounds were cross-referenced with those compounds routinely analyzed and regarded by the Oslo and Paris (OSPAR) Commission for the North East Atlantic as priority hazardous substances. The occurrence in produced water of a number of nonregulated compounds with demonstrable potential environmental effects is presented, to our knowledge for the first time. These include persistent organic contaminants, such as hexachlorobenzene, decachlorobiphenyl, and octachlorodibenzofuran.