Melis Muz

Assessment of a novel device for onsite integrative large-volume solid phase extraction of water samples to enable a comprehensive chemical and effect-based analysis

The implementation of targeted and nontargeted chemical screening analysis in combination with in vitro and organism-level bioassays is a prerequisite for a more holistic monitoring of water quality in the future. For chemical analysis, little or no sample enrichment is often sufficient, while bioanalysis often requires larger sample volumes at a certain enrichment factor for conducting comprehensive bioassays on different endpoints or further effect-directed analysis (EDA). To avoid logistic and technical issues related to the storage and transport of large volumes of water, sampling would benefit greatly from onsite extraction. This study presents a novel onsite large volume solid phase extraction (LVSPE) device tailored to fulfill the requirements for the successful effect-based and chemical screening of water resources and complies with available international standards for automated sampling devices. Laboratory recovery experiments using 251 organic compounds in the log D range from -3.6 to 9.4 (at pH7.0) spiked into pristine water resulted in acceptable recoveries and from 60 to 123% for 159 out of 251 substances. Within a European-wide demonstration program, the LVSPE was able to enrich compounds in concentration ranges over three orders of magnitude (1ngL-1 to 2400ngL-1). It was possible to discriminate responsive samples from samples with no or only low effects in a set of six different bioassays (i.e. acetylcholinesterase and algal growth inhibition, androgenicity, estrogenicity, fish embryo toxicity, glucocorticoid activity). The LVSPE thus proved applicable for onsite extraction of sufficient amounts of water to investigate water quality thoroughly by means of chemical analysis and effect-based tools without the common limitations due to small sample volumes.

EDA-EMERGE: an FP7 initial training network to equip the next generation of young scientists with the skills to address the complexity of environmental contamination with emerging pollutants

The initial training network consortium novel tools in effect-directed analysis to support the identification and monitoring of emerging toxicants on a European scale (EDA-EMERGE) was formed in response to the seventh EU framework program call to train a new generation of young scientists (13 PhD fellows and 1 postdoctoral fellow) in the interdisciplinary techniques required to meet the major challenges in the monitoring, assessment, and management of toxic pollution in European river basins. This 4-year project is of particular relevance considering the multidisciplinary analytical chemistry and biology skills required to investigate the enormous complexity of contamination, effects, and cause-effect relationships. By integrating innovative mode-of-action-based biodiagnostic tools including in vitro and in vivo tests, transgenic organisms, and ‘omics’ techniques with powerful fractionation and cutting edge, analytical, and computational structure elucidation tools, powerful new EDA approaches are being developed for the identification of toxicants in European surface and drinking waters. Innovative method development by young researchers at major European universities, research centers, and private companies has been closely interlinked with a joint European demonstration program, higher-tier EDA, and specialized training courses and secondments. Using a simplified protocol based on existing EDA tools, EDA-EMERGE fellows are also being trained to organize and run international and interdisciplinary sampling and monitoring campaigns within selected European river basin sites. Strong networking between academia, the private sector, and leading regulators in the field of river basin management and pollution management ensures the relevance of the research for practice and excellent employment opportunities for the fellows. Additionally, an internationally composed advisory board has been tasked to introduce new perspectives on monitoring, assessment, and management of emerging pollutants within and outside of Europe. The combination of cutting edge science with specialized training in complimentary soft skills is being offered with a strong emphasis on commercial exploitation and media competence which further enhances the employability of the fellows in research, academia, and beyond.

Nontargeted detection and identification of (aromatic) amines in environmental samples based on diagnostic derivatization and LC-high resolution mass spectrometry

The presence of aromatic amines in the environment has been in the focus of research, as many of these compounds are known or suspected mutagens and carcinogens. To facilitate the detection of aromatic amines in complex environmental samples by LC-high resolution mass spectrometry, an on-line-post-column and a pre-column derivatization method to label (in an ideal case) all aromatic amines was evaluated by applying different derivatization reagents. 4-Fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) was found to be the most promising labeling reagent due to its high reactivity with both primary and secondary amines and its low signal in positive mode electrospray ionization (ESI+). Post-column on-line derivatization did not result in sufficient signal intensities of derivatives. With pre-column derivatization most of the selected aromatic amines resulted in a derivative that shows common fragments of diagnostic value. The selectivity of NBD-F was studied in depth with a data set of 220 compounds with different functional groups showing that also aliphatic amines and some thiols yield a derivative. The developed method was successfully applied to wastewater effluent samples and several derivatives were confirmed by diagnostic neutral losses.

Mutagenicity in Surface Waters: Synergistic Effects of Carboline Alkaloids and Aromatic Amines

For decades, mutagenicity has been observed in many surface waters with a possible link to the presence of aromatic amines. River Rhine is a well-known example of this phenomenon but responsible compound(s) are still unknown. To identify the mutagenic compounds, we applied effect-directed analysis (EDA) utilizing novel analytical and biological approaches to a water sample extract from the lower Rhine. We could identify 21 environmental contaminants including two weakly mutagenic aromatic amines, and the known alkaloid comutagen norharman along with two related β-carboline alkaloids, carboline, and 5-carboline, which were reported the first time in surface waters. Results of mixture tests showed a strong synergism of the identified aromatic amines not only with norharman, but also with carboline and 5-carboline. Additionally, other nitrogen-containing compounds also contributed to the mutagenicity when aromatic amines were present. Thus, comutagenicity of β-carboline alkaloids with aromatic amines is shown to occur in surface waters. These results strongly suggest that surface water mutagenicity is highly complex and driven by synergistic mechanisms of a complex compound mixture (of which many are yet unidentified) rather than by single compounds. Therefore, mixture effects should be considered not only from mutagens alone, but also including possible comutagens and nonmutagenic compounds.

Removal of endocrine disrupting compounds in a lab-scale anaerobic/aerobic sequencing batch reactor unit

The fate and removal of six selected endocrine disrupting compounds in a lab-scale anaerobic/aerobic (A/O) sequencing batch reactor (SBR), operating at 5 days, solids retention time (SRT) were investigated. A carbamazepine (CBZ), acetaminophen (ATP), diltiazem (DTZ), butyl benzyl phthalate (BBP), estrone and progesterone mix was spiked as model endocrine disrupting compounds (EDC) into domestic wastewater obtained from a nearby sewage treatment plant. The influent, effluent and sludge samples from the SBR unit were analysed by using an LC/MS/MS instrument equipped with electrospray ionization. More than 80% removal was observed for all the EDCs tested. It was found that biodegradation is the most important mechanism for BBP, ATP and progesterone. Biodegradation constants were calculated according to the simplified Monod model for these compounds. The DTZ seemed to have lower rate of biodegradation. The CBZ appeared totally resistant to biodegradation. However, it presented a high rate of sorption onto the sludge and was thereby treated. This contradicts with the literature studies.

Intermittent Ozone Application in Aerobic Sludge Digestion

Excess biological sludge, WAS, produced during activated sludge process is a growing problem for the utilities owing to the stringent regulations now imposed worldwide. One method of handling the excess sludge is to digest it, to reduce its amount and to stabilize it. Aerobic digestion is particularly suitable for nutrient treating plants as sludge should not be exposed to anaerobiosis since this will lead to release of accumulated phosphorus. A novel and patented ozone-assisted aerobic sludge digestion process (PCT/TR2010/000213) is shown to appreciably shorten the 15–30-day aerobic digestion period and the extent of solids destroyed. WAS samples were ozonated for different periods in Erlenmeyer flasks, once a day, on each of four consecutive days. Flasks were continuously aerated between ozone applications. The MLVSS, MLSS, COD and OUR parameters were measured routinely during the course of four days of digestion in order to optimize the process. As a result 22.6%, 40%, 75% and 84% MLVSS reductions were obtained at total ozone applications of 0.42, 0.64, 0.85 and 1.27 mg O3 g−1 MLSS, at the end of the fourth day. Hence, it became possible to save on contact time as well as achieving a bio-solids digestion far exceeding the standard aerobic process, which is 40–50% in 15–30 days, at the expense of a minimum of ozone dose. The developed process is deemed superior over side-stream ozonation where ozone is applied to the return activated sludge, RAS, line; in that it does not cause any reduction in active biomass amount maintained in the aeration tank. Conversely, reduction in active biomass concentration results in reduced treatment efficiency.

Prolonged reuse of domestic wastewater after membrane bioreactor treatment

AbstractIn this study, experience in a nine-year operation of a full-scale 2000 PE vacuum rotating membrane bioreactor having a submerged flat-type membrane module having pore size of 0.038 μm and a total surface area of 540 m2 is discussed. The plant was designed to treat and reuse raw wastewater collected from dormitories and the academic village at METU campus. Throughout the study, 99.99% BOD5 and above 95% COD removals were achieved most of the time. Moreover, turbidity was consistently measured below 1 NTU and around 6–7 log coliform removals were achieved with less than 1 coliform/100 mL in the effluents most of the time, except for the leakage from the bearings. During the study, energy consumption by the plant was also analyzed by routinely measuring energy consumption in different parts of the plant. Consumption was analyzed in two parts. Energy consumed by the blower supplying aeration to the biological treatment tank was monitored separately from the rest of the plant. Except for the periods w...

Identification of Mutagenic Aromatic Amines in River Samples with Industrial Wastewater Impact

Aromatic amines are one of the most important classes of compounds contributing to surface water mutagenicity due to their widespread occurrence as precursors and transformation products of dyes, pharmaceuticals, agrochemicals, and other compound classes. In this study, we implemented a workflow including novel analytical and data evaluation methods aiming to identify aromatic amines in six mutagenic wastewater effluents from a chemical-industrial area in Germany, collected by the passive sampler Blue Rayon. We identified 14 amines including the two potent mutagenic aromatic amines 2,3- and 2,8-phenazinediamine, which were reported for the first time as environmental contaminants. These two isomers accounted between 4.2 and 86% of the mutagenicity of the blue rayon extracts and may be byproducts of dye production at the studied site.