Pesticides are natural or artificial molecules aimed to kill, or mitigate any harmful organism. Although their use in agriculture provides us with an increased crop yield, remains of chemicals on the products creates health concerns in society. Organophosphates and carbamates are two groups of insecticides. Although they are far more lethal against insects and small animals, they can also cause poisoning in humans through the inhibition of acetylcholinesterase enzyme (AChE) that plays an important role in human nervous system. Therefore, the detection of these compounds is crucial. The conventional methods for the detection of these compounds are expensive, time-consuming and need expertise. In this study, a fast, disposable, cheap and accurate acetylcholinesterase biosensor was developed to detect organophosphate and carbamate-based pesticide residues. By means of adsorption method, AChE, the chromophore 5,5&#039 / -Dithio-bis(2-nitrobenzoic acid) (DTNB) and artificial substrate acetylthiocholine (ATCh) were immobilized on the supporting material. In optimization studies / from 3 to 15U/mL concentrations were experimented for AChE, 1 to 5mM DTNB and 1 to 5mM ATCh concentration gradients were used. v As a result of the optimization studies 12U/mL ACHE concentration, 5mM DTNB concentration and 5mM ATCh concentration were determined for constructing a pesticide biosensor. Detection limit of malathion, an organophosphate-based insecticide was found as 2.5ppm in 5% methanol solution. The biosensor conserved its integrity between pH 4 and 8, and gave false positive results after pH 10. Stability studies showed that, biosensor retained its activity for at least 60 days at 4&deg / C to discrimnate between positive and negative controls.

In this study, atmospheric levels and sources of VOCs at Aliaga industrial area was investigated. For this, VOC concentrations were measured at two monitoring stations through winter and summer campaigns in 2005 and 2006. Sampling stations were located in downtown Aliaga and downwind of industrial facilities, approximately 500 m to the south east of Horozgedigi village. After the summer sampling, another temporary station was installed in between PETKIM and T&Uuml / PRAS, named as T&Uuml / PRAS Station to generate T&Uuml / PRAS and PETKIM profiles. More than 50 species were measured in all stations. In all stations, toluene has the highest contribution to total VOC concentration. Toluene is followed by m,p-xylene and benzene. While higher concentrations of traffic related VOCs were measured at Aliaga station, VOCs from industrial solvents and industrial processes were higher at Horozgedigi station. The concentration levels in Aliaga and Horozgedigi are found to be comparable to the other industrial regions reported in the literature. Investigation of episodes, diurnal variations of VOCs and meteorological parameters showed that PETKIM and T&Uuml / PRAS emissions affect the concentrations levels at Horozgedigi and Aliaga stations. Source profiles of PETKIM and T&Uuml / PRAS are determined by using the T&Uuml / PRAS station data set. 2-methyl-hexane, benzene and 2,2,3-tri-methyl-butane+2,3-di-methyl-pentane are found to be good markers of PETKIM emissions. Ten different VOC sources were identified in the region. These were gasoline exhaust, diesel exhaust, natural gas use, gasoline evaporation, industrial emissions-1, natural gas construction, non-industrial solvent use, industrial emissions-2, PETKIM emissions, and mixed emissions from PETKIM and shipbreaking facilities.

Lakes can be used for recreational purposes, agricultural irrigation, domestic water supply or industrial use. However, these functions of the lakes can be impaired due to excess nutrient loadings from industrial facilities, agricultural activities, and discharge of wastewaters from sewage systems. Uluabat Lake is one of the important lakes in Turkey faced with water quality problems due to excess nutrient loading from point and non-point sources. In this study, Water Quality Analysis Simulation Program (WASP Version 7.2), supported by the Environmental Protection Agency (EPA), was used to simulate the water quality of the lake. The model was calibrated using a set of data belonging to the time period from January 1st to June 1st, 2000, for dissolved oxygen (DO), chlorophyll-a (Chl-a), ortho-phosphate (PO4-P) and nitrate (NO3-N). An acceptable similarity was obtained between the predicted and observed water quality values in calibration. Then, the model was verified for another data set. Verification period was from 1st of June to 31st of December, 1999. Verification results were also coherent with the observed values. Following the calibration and verification, the model was used as a management tool to predict the future quality conditions for the lake for different management scenarios. According to the results, sediment dredging had a significant impact on the water quality. Additional methods on top of sediment dredging improved the quality of the lake. The best result was obtained when buffer zone was formed, phosphorus loads from the MustafakemalpaSa District sewage system and Emet and Orhaneli Watersheds were decreased by 50% and 50% decrease was considered in the fertilizer usage throughout the agricultural lands, in addition to sediment dredging.

Phenolic compounds are the chemicals which are used by many different industries and as a result of this spread to the environment. These compounds can be absorbed easily through the human and animal skin and through the mucosal membrane, mix in to the blood circulation and thus create a toxic effect on several tissue and organs including, liver, lung and kidneys. For this reason, determination of phenolic compounds emitted to environment is a very important issue. In fact, there are standard methods for the determination of these compounds like HPLC, Spectrophotometric and calorimetric methods however, these are time consuming methods and requires to be expertise. On the other hand, there are also different types of biosensors developed for the phenolic compound detection. In this study, a new, disposable, cheap and convenient tyrosinase biosensor was developed for the phenolic compound detection. By means of absorption method, the enzyme tyrosinase and the chromophore MBTH were immobilized on the support material and as a model substrate L- dopa was used. As a result of optimization studies 1mg/ml tyrosinase concentration and 1.5mM MBTH concentration were determined for using in biosensor construction. Detection limit of l-dopa, model substrate, found as 0,064 mM and for other phenolic compounds, 4-chlorophenol, catechol, m-cresol and p-cresol, detection limit was obtained 0.032 mM, 0.032 mM, 0.128 mM, 0.128 mM, respectively. In addition, we found that the biosensor response was not affected by pH changes ranging from 3 to 11. The stability of biosensor which is one of the important parameter for commercialization was not change through 70 days at room temperature and 4&deg / C when compared to at the beginning response.

The effect of heterogeneity correlation scale (&amp / #61548 / ) of hydraulic conductivity (K), equilibrium distribution coefficient (Kd) and mass transfer rate (&amp / #61537 / ) on the design and cost of the P&amp / T remediation system for different heterogeneity levels (defined by the variance (&amp / #963 / 2lnK)) and parameter distributions under the rate-limited sorption conditions was evaluated in this study. In addition, the impacts of initial amount of contaminant mass and plume configuration on the remediation design and cost were explored. The effects of different K heterogeneity and remediation design conditions on the length of remediation period, the influence of &amp / #61548 / anisotropy of K, correlation between K and Kd, and Kd and &amp / #61537 / , and the fraction of equilibrium sorption sites (f) on the pump-and-treat (P&amp / T) design and cost were the other studied subjects. In this study, simulation-optimization approach, in which a groundwater flow and contaminant transport simulation model was linked with a genetic algorithm (GA) library, was used. Results showed that not only the amount of PCE mass initially present in the aquifer was important in terms of P&amp / T design, cost and remediation time, but also the location and size of the high and low K regions defined by &amp / #955 / lnK as well as the magnitudes of K represented by geometric mean and &amp / #963 / 2lnK were influential. It was also found that P&amp / T designs utilizing higher numbers of wells with lower pumping rates may be more robust predicting the time-to-compliance compared to a single well with higher pumping rate for aquifers heterogeneous in K. Homogenous Kd assumption might cause serious error in both the design and the cost of remediation. The magnitude of this error may change depending on the spatial distribution of K and Kd, &amp / #955 / lnKd, &amp / #963 / 2lnKd and &amp / #963 / 2lnK. The effect of heterogeneity in &amp / #61537 / on the design and cost of remediation may or may not be significant depending on K, Kd and &amp / #61537 / distributions, &amp / #61548 / ln&amp / #61537 / and &amp / #963 / 2ln&amp / #61537 / . Increased amount of kinetically sorbed mass defined by decreased f value resulted in more costly remediation.

In this study, bio-hydrogen generation potential of sugar-beet processing wastes (sugar-beet processing wastewater and beet-pulp) through dark fermentation was investigated. For this purpose, four different experimental set-ups were used. In the first set-up, sugar-beet processing wastewater was used along with four different cultures to investigate the effect of culture type on bio-hydrogen production. In addition, unseeded reactor was prepared to investigate bio-hydrogen production potential of indigenous microorganisms. The highest bio-hydrogen production yield (87.7 mL H2/g COD) was observed in the unseeded reactor. In the second set-up, beet-pulp was compared with sugar-beet processing wastewater in terms of bio-hydrogen generation potentials at an initial COD level of 4.5 g/L. In the third set-up, bio-hydrogen productivities of only beet-pulp and co-digestion of beet-pulp and sugar-beet processing wastewater at high COD values were investigated. The results of third set-up revealed that the reactor fed by 20 g/L COD beet-pulp provided the highest bio-hydrogen production yield (95.6 mL H2 /g COD). Finally, in the fourth set-up, the effects of five different pretreatment methods on solubilization of beet-pulp were investigated. Then, three out of five pretreatment methods were chosen to compare the corresponding bio-hydrogen productivities. Maximum bio-hydrogen production yield (115.6 mL H2/g COD) was observed in reactor which contained alkaline pretreated beet-pulp. Based on the results obtained in this study, it is postulated that, bio-hydrogen production from sugar-beet processing wastes by dark fermentation can not only enable waste minimization but also contribute to sustainability via valuable bio-based product formation from wastes, namely bio-hydrogen.

Polychlorinated biphenyls (PCBs) are persistent organic pollutants which were not produced in Turkey, however both national and international studies illustrate a measurable amount of PCB pollution in receiving environments, aquatic fauna and people. In this study, various information sources such as the national and international scientific literature, official records and reports are investigated to obtain information regarding PCB pollution in Turkey. Furthermore, various PCB pollution analysis techniques for soil/sediment samples are investigated and the selected methods are established in the laboratories of METU. Satisfactory recoveries are obtained for methods for the extraction of PCBs, clean-up of extract and gas chromatographic (GC/ECD) analysis of the sample. Finally, field studies are performed in two locations in Ankara. The first one is a preliminary pollution investigation study around Lake Eymir. Lake Eymir is suspected to be contaminated with PCBs due to a nearby transformer repair facility. The second, more detailed study is performed for a 25 km reach of Ankara Creek, passing through the Industrial Zone, Sincan Dumpsite and Ankara Central Wastewater Treatment Plant. Total- PCB concentrations are in the range of 0.2 and 777 ng/g with the median of 37.1 ng/g. Toxic Equivalent Concentrations (TEQ) are assessed for dioxin-like congeners and Aroclor 1016/1260 basis. A Chemical Mass Balance Model is used to identify and apportion the sources of PCBs for Ankara Creek samples. Typically highly chlorinated Clophen mixtures are identified in sediments as the pollution sources.

In this study, it is aimed to develop a database on Seyhan River Basin / and an environmental pollution index for the middle section of Seyhan Basin by combining different pollution indices such as water, and air. Water and air pollution indices are developed for the selected quality monitoring stations and the selected years. Water pollution index is calculated by using the method suggested by National Sanitation Foundation of United States, and air pollution index is developed according to the modified Environmental Protection Agency&rsquo / s air pollution index. As aggregation method, weighted arithmetic mean function is used for development of indices. After development of separate water and air pollution indices, environmental pollution index is developed for the year 2008 by two aggregation methods, one based on linguistic interpretation and the other again on weighted arithmetic mean function. The water pollution index for the middle section of the basin is determined as &ldquo / good&rdquo / , and air pollution index as &ldquo / low pollution&rdquo / . According to calculated water and air pollution indices, environmental pollution index is calculated with two methods and obtained the index equal to 4, which is classified as &ldquo / good&rdquo / . Although, both of the methods give same result in development of environmental pollution index, the second method based on weighted arithmetic mean function concluded to be more user friendly.

This study examines the application of two receptor models, namely Positive Matrix Factorization (PMF) and Chemical Mass Balance (CMB), on the investigation of sites contaminated with PCBs. Both models are typically used for apportionment of pollution sources in atmospheric pollution studies, however have gained popularity in the last decade on the investigation of PCBs in soil/sediments. The aim of the study is four-fold / (i) to identify the status of PCB pollution in Lake Eymir area via sampling and analysis of PCBs in collected soil/sediment samples, (ii) to modify the CMB model software in terms of efficiency and user-friendliness (iii) to apply the CMB model to Lake Eymir area PCB data for apportionment of the sources as well as to gather preliminary information regarding degradation of PCBs by considering the history of pollution in the area (iv) to explore the use of PMF for both source apportionment and investigation of fate of PCBs in the environment via use of Monte-Carlo simulated artificial data sets. Total PCB concentrations (Aroclor based) were found to be in the range of below detection limit to 76.3 ng/g dw with a median of. 1.7 ng/g dw for samples collected from the channel between Lake Mogan and Lake Eymir. Application of the CMB model yield contribution of highly chlorinated PCB mixtures (Aroclor 1254 and Aroclor 1260 / typically used in transformers) as sources. The modified CMB model software provided user more efficient and user friendly working environment. Two uncertainty equations, developed and existing in literature, were found to be effective for better resolution of sources by the PMF model.

Soil quality standards (SQSs) are one of the most important elements of management system for contaminated sites. In order to manage risks associated with soil contamination, risk based SQSs are used worldwide. However, in Turkey, the Soil Pollution Control Regulation in force was focusing mainly on the use of stabilized sludge on soil and was including standards for a limited number of parameters, mainly metals and some organic chemicals. Thus, existing SQSs were far away from providing common criteria for assessment of the soil quality. In this study, the aim was to develop human health risk based SQSs for Turkey. For derivation of risk based SQSs, the conceptual framework and technical infrastructure were established. SQSs were derived for 151 chemical substances and for three different land use types by incorporating generic site characteristics for Turkey. Since SQSs are highly sensitive to site conditions and chemical-specific data used in calculations, a Microsoft Excel based exposure model was developed as a technical tool. This tool serves for calculation of generic and site-specific SQSs and maintenance of the currency of the standards by allowing periodic update of data used in calculations. Besides, a hydrogeologic database was developed to provide information on the general soil and hydrogeologic characteristics that are used in derivation of SQSs. This database is ultimately, expected to serve for development of conceptual site models, sampling strategies, and derivation of dilution factors during risk assessment studies. As a result, this study presents a general perspective and approach for derivation of human health risk based SQSs. It is believed that the developed conceptual and technical infrastructure will contribute to contaminated site management and risk assessment studies conducted by the regulatory authorities and the other stakeholders in Turkey.