Egemen Aydin

Integration of environmental and human health risk assessment for industries using hazardous materials: A quantitative multi criteria approach for environmental decision makers

Environmental management, for which environmental and human health risk assessment is the first stage, is a requirement for industries both before construction and during operation in order to sustain improved quality of life in the ecosystem. Therefore, the aim of this study is to propose an approach that integrates environmental and human health risk assessment for industries using hazardous materials in order to support environmental decision makers with quantitative and directive results. Analytic hierarchy process and fuzzy logic are used as tools to handle problems caused by complexity of environment and uncertain data. When the proposed approach is implemented to a scenario, it was concluded that it is possible to define risk sources with their risk classes and related membership degrees in that classes which enable the decision maker to decide which risk source has priority. In addition, they can easily point out and rank the factors contributing those risk sources owing to priority weights of them. As a result, environmental decision makers can use this approach while they are developing management alternatives for unfounded and on-going industrial plants using hazardous materials.

Analysis, occurrence and fate of commonly used pharmaceuticals and hormones in the Buyukcekmece Watershed, Turkey

The occurrence of 14 mostly used pharmaceuticals from different classes (antibiotics, β-blockers, non-steroidal anti-inflammatory drugs, and stimulant) and hormones in surface water in Istanbul, Turkey was investigated in this study. An important drinking water source, Buyukcekmece Lake and main rivers flowing into the lake were selected for the monitoring of the compounds. Sampling was conducted five different times in a year in order to observe seasonal changes. A rapid, robust and sensitive method using solid phase extraction and ultra-performance liquid chromatograph coupled with triple quadrupole tandem mass spectrometer was established for quantification of both pharmaceuticals and hormones. Limit of quantifications were between 0.5 and 1.1 ng L(-1). Recoveries were between 72-119% and 61-98% for ultra-pure water and for surface water, respectively. All selected compounds were detected at least once in the samples. Some pharmaceuticals were detected as high as a few of micrograms per liter levels in the rivers. Most frequently detected compounds were caffeine and antibiotics (amoxicillin, ciprofloxacin, erythromycin and sulfamethoxazole). Synthetic hormone (17α-ethynylestradiol) was detected only 4times corresponding least detected compound in whole sampling period. Field data confirms that amoxicillin is more prone to degradation with respect to other antibiotics. Estrone and 17-β estradiol are converted to estriol by natural processes in surface water.

Respirometric evaluation of a mixture of organic chemicals with different biodegradation kinetics

The study evaluated the biodegradation characteristics of a mixture of organics with different biodegradation characteristics in an integrated chemical plant effluent. The wastewater had a total chemical oxygen demand (COD) content of 12,800mg/L, mostly soluble and 93% biodegradable. The evaluation was based on respirometry, and mainly consisted on model calibration and interpretation of the oxygen uptake rate data, which exhibited an original and specific profile with a sequence of two peaks and three plateaus. A specific model was defined for this purpose, which identified four different biodegradable COD components with significantly different process kinetics. The major fraction accounting for 57% of the total biodegradable COD in the wastewater had to be hydrolyzed before biodegradation with a low hydrolysis rate of 1.3day(-1). The analysis of the experimental data showed that the oxygen utilization started with a delayed response after substrate addition. The delayed logarithmic phase could be characterized by a Haldane type of inhibition kinetics.

S2O82−/UV-C and H2O2/UV-C treatment of Bisphenol A: Assessment of toxicity, estrogenic activity, degradation products and results in real water

The performance of S2O8(2-)/UV-C and H2O2/UV-C treatments was investigated for the degradation and detoxification of Bisphenol A (BPA). The acute toxicity of BPA and its degradation products was examined with the Vibrio fischeri bioassay, whereas changes in estrogenic activity were followed with the Yeast Estrogen Screen (YES) assay. LC and LC-MS/MS analyses were conducted to determine degradation products evolving during photochemical treatment. In addition, BPA-spiked real freshwater samples were also subjected to S2O8(2-)/UV-C and H2O2/UV-C treatment to study the effect of a real water matrix on BPA removal and detoxification rates. BPA removal in pure water was very fast (⩽7 min) and complete via both H2O2/UV-C and S2O8(2-)/UV-C treatment, accompanied with rapid and significant mineralization rates ranging between 70% and 85%. V.fischeri bioassay results indicated that degradation products being more toxic than BPA were formed at the initial stages of H2O2/UV-C whereas a rapid and steady reduction in toxicity was observed during S2O8(2-)/UV-C treatment in pure water. UV-C treatment products exhibited a higher estrogenic activity than the original BPA solution while the estrogenicity of BPA was completely removed during H2O2/UV-C and S2O8(2-)/UV-C treatments parallel to its degradation. 3-methylbenzoic and 4-sulfobenzoic acids, as well as the ring opening products fumaric, succinic and oxalic acids could be identified as degradation products. BPA degradation required extended treatment periods (>20 min) and TOC removals were considerably retarded (by 40%) in the raw freshwater matrix most probably due to its natural organic matter content (TOC=5.1 mg L(-1)). H2O2/UV-C and S2O8(2-)/UV-C treatment in raw freshwater did not result in toxic degradation products.

Seasonal variation of diclofenac concentration and its relation with wastewater characteristics at two municipal wastewater treatment plants in Turkey

The pharmaceutically active compound diclofenac has been monitored during one year at separate treatment units of two municipal wastewater treatment plants (WWTPs) to evaluate its seasonal variation and the removal efficiency. Conventional wastewater characterization was also performed to assess the possible relationship between conventional parameters and diclofenac. Diclofenac concentrations in the influent and effluent of both WWTPs were detected in the range of 295-1376 and 119-1012ng/L, respectively. Results indicated that the higher diclofenac removal efficiency was observed in summer season in both WWTPs. Although a consistency in diclofenac removal was observed in WWTP_1, significant fluctuation was observed at WWTP_2 based on seasonal evaluation. The main removal mechanism of diclofenac in the WWTPs was most often biological (55%), followed by UV disinfection (27%). When diclofenac removal was evaluated in terms of the treatment units in WWTPs, a significant increase was achieved at the treatment plant including UV disinfection unit. Based on the statistical analysis, higher correlation was observed between diclofenac and suspended solids concentrations among conventional parameters in the influent whereas the removal of diclofenac was highly correlated with nitrogen removal efficiency.

Occurrence of THM and NDMA precursors in a watershed: Effect of seasons and anthropogenic pollution

In pristine watersheds, natural organic matter is the main source of disinfection by-product (DBP) precursors. However, the presence of point or non-point pollution sources in watersheds may lead to increased levels of DBP precursors which in turn form DBPs in the drinking water treatment plant upon chlorination or chloramination. In this study, water samples were collected from a lake used to obtain drinking water for Istanbul as well as its tributaries to investigate the presence of the precursors of two disinfection by-products, trihalomethanes (THM) and N-nitrosodimethylamine (NDMA). In addition, the effect of seasons and the possible relationships between these precursors and water quality parameters were evaluated. The concentrations of THM and NDMA precursors measured as total THM formation potential (TTHMFP) and NDMA formation potential (NDMAFP) ranged between 126 and 1523μg/L THM and <2 and 1648ng/L NDMA, respectively. Such wide ranges imply that some of the tributaries are affected by anthropogenic pollution sources, which is also supported by high DOC, Cl(-) and NH(3) concentrations. No significant correlation was found between the water quality parameters and DBP formation potential, except for a weak correlation between NDMAFP and DOC concentrations. The effect of the sampling location was more pronounced than the seasonal variation due to anthropogenic pollution in some tributaries and no significant correlation was obtained between the seasons and water quality parameters.

A Holistic Approach for Wind Farm Site Selection by Using FAHP

In recent years an increasing number of countries have implemented policy measures to promote renewable energy. However, the most important problem that the policy makers face with is the conflicting linguistic terms and subjective opinions on energy and environment policy. As the environmental policy and energy policy always go hand in hand, it is quite clear that wind as a renewable resource should be competitive with conventional power generation sources. From technical, environmental, socio-economical and socio-political standpoint, wind power is the most deserving of all of the cleaner energy production options (geothermal, solar, tidal, biomass, hydro) for more widespread deployment. Although wind power is a never ending green resource, assessment of environmental risks and impactswhich comprise the backbone of environmental policyin the context of specific projects or sites often are necessary to explicate and weigh the environmental trade-offs that are involved. In the case of wind farms, a number of turbines (ranging from about 250 kW to 750 kW) are connected together to generate large amounts of power. Apart from the constraints resulting from the number of turbines, any site selection should think over the technical, economic, social, environmental and political aspects. Each aspect uses criteria for its own evaluation. Decision making by using multi criteria decision analysis is an attractive solution for obtaining an integrated decision making result. Although Lee et al. (2009), Kaya and Kahraman (2010) and Tegou et al. (2010) has studied wind farm site selection by using different kinds of Analytic Hierarchy Process (AHP), Cheng’s extent analysis of Fuzzy AHP (FAHP) is used in this study and a holistic hierarchy were developed. The analytic hierarchy process (AHP) is a multi-criteria decision making tool to deal with complex, unstructured and multi-attribute problems. This method is distinguished from other multi-criteria methods in three ways: I. Construction of the hierarchy structure II. Pairwise comparisons of different criteria III. Weighing with respective to the overall objective. In AHP, decision makers quantify the importance of criteria by using Cheng’s 1-9 scale. To overcome the disadvantage of reluctant and inconsistent comparison judgments, fuzzy analytic hierarchy process (FAHP) might be used on each factor to determine the weight of fuzziness of its attributes. Hierarchy structure diagram of wind farm site selection is given in Figure 1. This study aims to apply the FAHP to find priority sequence of alternatives and obtain the key success factors for the selection of appropriate sites of wind farms.

Optimization of diclofenac quantification from wastewater treatment plant sludge by ultrasonication assisted extraction

A rapid quantification method of diclofenac from sludge samples through ultrasonication assisted extraction and solid phase extraction (SPE) was developed and used for the quantification of diclofenac concentrations in sludge samples with liquid chromatography/tandem mass spectrometry (LC-MS/MS). Although the concentration of diclofenac in sludge samples taken from different units of wastewater treatment plants in Istanbul was below the limit of quantification (LOQ; 5ng/g), an optimized method for sludge samples along with the total mass balances in a wastewater treatment plant can be used to determine the phase with which diclofenac is mostly associated. Hence, the results will provide information on fate and transport of diclofenac, as well as on the necessity of alternative removal processes. In addition, since the optimization procedure is provided in detail, it is possible for other researchers to use this procedure as a starting point for the determination of other emerging pollutants in wastewater sludge samples.

Silver nanoparticles: a mechanism of action on moulds

Silver nanoparticles (AgNPs) are widely used in all branches of industry. However, their mechanisms of action towards moulds have not been studied yet. Thus we conducted this study in which we have used laser desorption/ionization time-of-flight mass spectrometry (LDI-ToF-MS) analysis to determine metabolomic changes, and microscopic analysis (transmission electron microscopy, fluorescent microscopy) to observe changes in mould cells. The AgNP treatment caused the downregulation of 162 (15 ppm) and 284 (62 ppm), and 19 (15 ppm) and 29 (62 ppm) metabolites of Aspergillus niger and Penicillium chrysogenum, respectively. All influenced features were below m/z 600 (mass-to-charge ratio). We have observed silver ions and their clusters (Ag, Ag2, and Ag3) accumulated in the mould mycelium. As well as, mono-silver ion adducts with nucleotide derivatives (Coenzyme A), amino acids (phenylglycine), peptides (LeuSerAlaLeuGlu) and lipids (fatty acids, diacylglycerophosphoglycerols, monoglicerides and glycerophospholipids). The ultrastructure analysis revealed many sever alterations due to the action of AgNPs, such us shortening and condensation of hyphae, ultrastructural reorganisation, cell plasmolysis, increased vacuolisation, numerous membranous structures, collapsed cytoplasm, accumulation of lipid material, condensed mitochondria, disintegration of organelles, nuclear deformation, condensation and fragmentation of chromatin, creation of apoptotic bodies, as well as a new inside cell wall in P. chrysogenum.

Acute and chronic responses of denitrifying culture to diclofenac.

Acute and chronic effect as well as biodegradation potential at different sludge retention times (SRTs) of a priority pollutant, diclofenac on denitrification process was assessed. The continuous amendment of the culture for 6months with 1μg/L diclofenac resulted in 30% decrease in gas production. The average diclofenac removal observed in the diclofenac-acclimated culture was less than 15%. Batch tests showed that nitrate was removed in diclofenac free-control reactor at a higher rate compared to diclofenac amended reactor. Although, SRT did not have any progressive effect on diclofenac degradation, the system operated at low SRT was more sensitive to diclofenac and resulted in an increase in N2O emission. Wastewater treatment plants (WWTPs) operated at higher SRTs may tolerate and recover from the adverse effects of such micropollutants. The study can lead to other researchers to understand the fate and effect of other emerging pollutants in the anoxic unit of WWTPs.