Denim production is one of the leading sub-sectors of textile industry which basically generates highly colored indigo dyeing effluents. In the present study, ozonation was applied to the indigo-dyeing effluent(COD=820 mg/L / color=5500 Pt-Co), and to the whole effluent from a denim-producing plant before(COD=2750 mg/L / color=3950 Pt-Co) and after(COD=800 mg/L,color=3700 Pt-Co) biological treatment for degradation/detoxification purposes. Ozonation was also tried in the wastewater of the plant(COD=3100 mg/L / color=4500 Pt-Co) that would be produced after some foreseen cleaner production measures / caustic recovery and reusing of dyeing process wastewater. When applied to indigo-dyeing wastewater / ozonation provided 95% color and 61% COD removals at 1320 mg/h ozone dose within 60 minutes The optimum pH was evaluated as 4 when indigo-dyeing wastewater exposed to ozonation at different pHs(1.6-12.3). On the other side, ozonation applied as pre-treatment to the plant effluent provided 86% color and 46% COD removals with 3240 mg/h ozone dose in 70 minutes. Less satisfactory results were obtained when ozonation was tried in the wastewater after measures, with 86% color and 31% COD removals at 3960 mg/h ozone dose in 80 minutes. When applied to the biologically-treated effluent / at 420 mg/h ozone dose and within 40 minutes, ozonation removed 47% of influent COD and 96% of influent color indicating better performance of ozonation in postoxidation. In order to assess possible improvements on ozonation with the addition of H2O2, different concentrations were tried, but no significant improvement was obtained. The improvement in BOD5/COD index was also determined for the ozonetreated plant effluent to measure the effects of ozonation on biodegradability and found out that BOD5/COD ratio has improved to 0.39 from 0.22.

Acrylonitrile were copolymerized with 2-ethylhexyl acrylate and hexyl acrylate via one step emulsion polymerization using ammonium persulfate (initiator), 1-dodecanthiol (chain transfer agent) and DOWFAX 8390 (surfactant) in the presence of water at about 68 0C. Poly (acrylonitrile-2ethylhexyl acrylate) and poly (acrylonitrile-hexyl acrylate) copolymers with three different comonomer composition (8, 12 and 16 molar percent) were prepared. FTIR and 1H-NMR were used in order to clarify the chemical structure of copolymers. The comonomer amount incorporated into copolymers was determined by using 1H-NMR spectra. The thermal behavior of copolymers was determined by DSC and TGA. Molecular weights of copolymers were determined by intrinsic viscosity (IV) measurements. IV measurements revealed that both poly (acrylonitrile-2ethylhexyl acrylate) and poly (acrylonitrile-hexyl acrylate) have sufficient molecular weight to form nanoporous filtration membranes. Nanoporous filtration membranes were prepared and tested for chromium (IV) removal. It was observed that chromium (VI) rejections of nanoporous filtration membrane were highly dependent on the concentration and the pH of the solutions. Almost complete removal (99, 9 percent Cr (VI)) rejection was achieved at pHs 2, 5 and 7 for solution containing 50 ppm, chromium (VI) with permeate flux within a range from 177 to 150 L/m2h at 689.5 kPa. Also, chemical structure, swelling ratios, sheet resistivity and fracture morphologies of the nanoporous filtration membrane were studied. It should be noted that the nanoporous filtration membranes were fouling resistant.

ABSTRACT SULPHATE REMOVAL BY NANOFILTRATION FROM WATER Karabacak, Asli M.Sc., Department of Environmental Engineering Supervisor: Prof. Dr. &Uuml / lk&uuml / Yetis Co-advisor: Prof. Dr. Mehmet Kitis December 2010, 152 pages Excess sulphate in drinking water poses a problem due to adverse effects on human health and also due to aesthetic reasons. This study examines the nanofiltration (NF) of sulphate in surface water using a laboratory cross-flow device in total recycle mode. In the study, three NF membranes, namely DK-NF, DL-NF and NF-270, are used. The influence of the main operating conditions (transmembrane pressure, tangential velocity and membrane type) on the steady-state permeates fluxes and the retention of sulphate are evaluated. Kizilirmak River water is used as the raw water sample. During the experimental studies, the performance of NF is assessed in terms of the parameters of UVA254, sulphate, TOC and conductivity of the feed and permeates waters. Results indicated that NF could reduce sulphate levels in the surface water to a level below the guideline values, with a removal efficiency of around 98% with all three membranes. DK-NF and NF-270 membranes showed fouling when the surface water was fed directly to the system without any pre-treatment. MF was found to be an effective pretreatment option for the prevention of the membrane fouling, but no further removal of sulphate was achieved. Parametric study was also conducted. No change in flux values and in the removal of sulphate was observed when the crossflow velocity was lowered. The flux values were decreased as the transmembrane pressure was lowered / however there were not any decrease in the sulphate removal efficiency.

Wastewaters resulted from anthropogenic influence can encompass a wide range of potential contaminants and concentrations. There are numerous procedures that can be used to clear out wastewaters depending on the type and extent of contamination, however / disposal of pollutants from wastewaters in industrial scale is a difficult and costly problem. In this study, the use of ion exchange theory utilizing natural Turkish clinoptilolite zeolite from G&ouml / rdes-Manisa as ion exchange resins in down-flow column mode is investigated. The clinoptilolite with particle size range of 0.25-0.50 mm is used in the removal of lead Pb2+ and ammonium NH4+ ions from aqueous solutions. The aim of the study is to set up the conditions under which clinoptilolite may be used in an economical and efficient approach in the removal process. Experiments were divided into two sets: binary studies, and ternary studies, and the effects of conditioning clinoptilolite with NaCl solution, flow rate, and initial concentration of the solutions on the removal behavior were investigated. In binary studies, results showed that increasing the loading volumetric flow rate resulted in decreasing the breakthrough capacity and the column efficiency, while the total capacity remained constant. The maximum total capacity was determined as 1.16 meq/g of zeolite for NH4+, and 1.1 meq/g of zeolite for Pb2+ and these values were close to each other and to the sodium content of Na-form of pretreated clinoptilolite (1.16 meq/g of zeolite). In addition, by decreasing the initial contaminant concentration, an increase in breakthrough capacity and column efficiency was observed. In ternary studies, the results showed that the removal of Pb2+ and NH4+ ions are dependent on the flow rate, in which at moderately low flow rate, a higher ion exchange capacity is yielded. That was explained as at higher flow rates, the retention time was insufficient for the ion exchange process to take place completely between clinoptilolite and lead and ammonium ions. Thus, a competition between Pb2+ and NH4+ ions for the exchange sites on clinoptilolite was observed and this competition was in favor of lead ions. Consequently, it was observed that the clinoptilolite zeolite has affinity for both Pb2+ and NH4+ ions. However, the affinity of clinoptilolite for lead ions is higher than that for ammonium ions. Therefore, the cations selectivity for clinoptilolite according to their affinity is determined as the following sequence: NH4+ &gt / Pb2+ &gt / Na+.

This study presents an integrated framework for the automatic generation of the photorealistic 3-d building models from satellite and ground-level imagery. First, the 2-d building patches and the corresponding footprints are extracted from a high resolution imagery using an adaptive fuzzy-genetic algorithm approach. Next, the photorealistic facade textures are automatically extracted from the single ground-level building images using a developed approach, which includes facade image extraction, rectification, and occlusion removal. Finally, the textured 3-d building models are generated automatically by mapping the corresponding textures onto the facades of the models. The developed 2-d building extraction and delineation approach was implemented on a selected urban area of the Batikent district of Ankara, Turkey. The building regions were extracted with an approximate detection rate of 93%. Moreover, the overall delineation accuracy was computed to be 3.9 meters. The developed concept for facade image extraction was tested on two distinct datasets. The facade image extraction accuracies were computed to be 82% and 81% for the Batikent and eTrims datasets, respectively. As to rectification results, 60% and 80% of the facade images provided errors under ten pixels for the Batikent and eTrims datasets, respectively. In the evaluation of occlusion removal, the average scores were computed to be 2.58 and 2.28 for the Batikent and eTrims datasets, respectively. The scores are ranked between 1 (Excellent) to 6 (Unusable). The modeling of the total 110 single buildings with the photorealistic textures took about 50 minutes of processor running time and yielded a satisfactory level of accuracy.

Arsenic is found in drinking waters in many countries and since maximum allowable concentration is as low as 10 &micro / g/L, there are many research efforts to separate it from water. Membrane methods are used more and more widely in separation operations in recent years. Arsenic is mainly present in water as arsenite [As(III)] and arsenate [As(V)]. As pH of water changes, molecular formulas of As(III) and As(V) change. In this study, the performance of different ultrafiltration membranes for arsenic removal from water was investigated at different pH values, different feed concentrations and presence of other anions (SO42-, HPO42-, NO3-, Cl-). Donnan exclusion effect on separation was discussed since distribution of arsenite and arsenate anions change in water due to change in pH of the solution. Experiments were conducted via batch and continuous modes. For continuous ultrafiltration experiments, 30 kDa of polysulfone and 20 kDa of polyether sulfone membranes were used. Batch ultrafiltration experiments were performed with the usage of 3 kDa of regenerated cellulose membrane. Higher retention values for As(V) were obtained compared to retention values of As(III). When membranes&rsquo / performances were investigated, it was seen that highest As(V) removal was observed with the usage of polysulfone membrane. Increase in feed concentration and presence of other anions caused decrement in separation. Hydride Generation Atomic Absorption Spectrometry was used to perform analyses. Hydride generator part was designed, constructed and optimized to obtain reliable and accurate absorbance values.

Endocrine disrupters and trace organic contaminants are recently recognized contaminants in wastewaters. Current concept is the multibarier approach where the contaminants are removed from the water cycle both by water and wastewater treatment facilities, as well as natural die-away. In this thesis work LC/MS/MS determination of selected EDC compounds, namely, diltiazem, progesterone, estrone, carbamazepine, benzyl butyl phthalate and acetaminophen, at ultra trace levels, have been carried out by optimizing analytical parameters. In addition, new methods were developed for their analysis in sludge samples at sub ppb levels. Following optimization and method development, occurrence of these contaminants in wastewaters and their removal in two full-scale and two pilot-scale membrane biological reactors (MBRs) was studied. Progesterone, estrone and acetaminophen were completely removed from wastewater by biodegradation. CBZ and diltiazem were not removed at all during the study. There was little effect of flux and sludge retention times on the removal of selected EDCs in these membrane plants. In SBR combined with membrane filtration, 13 different micropollutants, including Fluoxetine (FLX), Ibuprofen (IBP), Naproxen (NPX), Diclofenac (DCF), Carbamazepine (CBZ), Trimethoprim (TMP), Roxithromycin (ROX), Erythromycin (ERY), Sulfamethoxazole (SMX), Diazepam (DZP), Galaxolide (GLX), Tonalide (TON), Celestolide (CEL). CEL, GLX, TON and FLX were removed by adsorption onto the sludge while ROX, ERY, SMX, IBP and NPX were removed by biological degradation. The CBZ, DZP, TMP and DCF were not removed by biodegradation or adsorption. Whereas, following the addition of powdered activated carbon, all these compounds were removed entirely from the wastewater stream by accumulating in sludge.

Three experimental studies were conducted to quantify the effects of system cycling, evaporator airflow, and condenser coil fouling on the performance of residential air conditioners. For all studies, the indoor dry-bulb (db) temperature was 80°F (26.7°C) db. The cycling study consisted of twelve transient tests conducted with an outdoor temperature of 95°F (35°C) db for cycle times of 6, 10, 15, and 24 minutes. Indoor relative humidities of 40%, 50%, and 60% were also considered. The evaporator airflow study consisted of twenty-four steady-state tests conducted with an indoor condition of 67°F (19.4°C) wet-bulb (wb) for evaporator airflows ranging from 50% below to 37.5% above rated airflow. Outdoor temperatures of 85°F (29.4°C) db, 95°F (35°C) db, and 105°F (40.6°C) db were also considered. The coil fouling study used a total of six condensers that were exposed to an outdoor environment for predetermined amounts of time and tested periodically. Three of the condensers were cleaned and retested during the periodic testing cycles. Testing consisted of thirty-three steady-state tests conducted with an indoor condition of 67°F (19.4°C) wb for outdoor exposure times of 0, 2000, 4000, and 8000 hours. Outdoor temperatures of 82°F (27.8°C) db and 95°F (35°C) db were also considered.

The purpose of this report is to present the results of the study and analysis of loss-of-coolant and loss-of-flow simulations performed on the Modular Helium Reactor developed by General Atomics using the thermal-hydraulics code RELAP5-3D/ATHENA. The MHR is a high temperature gas cooled reactor. It is a prismatic core concept for New Generation Nuclear Plant (NGNP). Very few reactors of that kind have been designed in the past. Furthermore, the MHR is supposed to be a highly passively safe concept. So there are high needs for numerical simulations in order to confirm the design. The project is dedicated to the assessment of the passive decay heat capabilities of the reactor under abnormal transient conditions. To comply with the requirements of the NGNP, fuel and structural temperatures must be kept under design safety limits under any circumstances. During the project, the MHR has been investigated: first under steady-state conditions and then under transient settings. The project confirms that satisfying passive decay heat removal by means of natural heat transfer mechanisms (convection, conduction and radiation) occurs.

This study was aimed at the removal of odorous compounds in gases emitted from rubber processing industries. Odorous gas for test was prepared by mixing fresh air and an odorous gas drawn from an oven in which a sample of rubber powder was kept at 160 and 200 oC, respectively. For ozonation tests, the prepared odorous gas was then premixed with a definite amount of ozone-enriched air before entering into a contact system. The contact system consists of two sieve-plate columns connected in series and each column has four 1-L chambers. Depending on with or without introducing a circulating scrubbing water into the columns, the oxidation reaction could be either wet or dry one. For UV/ozonation (UV/O3) tests, batch reactions were performed in a 3.63-L chamber fitted with an UV lamp inserted in a quartz column. A definite volume of the odorous gas generated from the oven was injected into the chamber containing a definite concentration of ozone. Results from the dry-ozonation tests indicate that that 82 and 70% of VOCs and odorous intensity in the influent gas could be removed, respectively, with the operation conditions of an initial ozone concentration of 4.0 ppm, VOC (methane equivalent) concentrations of 6.5-9.0 ppm, an oxidation temperature of 38.5 oC, and a gas empty-bed-retention time (EBRT) of 8.6 s. Both the VOC and odorous intensity removal efficiencies were roughly proportional to the EBRT in the range of 1.4-11.4 s. Wet-ozonation got 97 and over 90% of VOC and odorous intensity removal, respectively, with the operation conditions of initial ozone concentration 4.0 ppm, VOC (methane equivalent) concentrations 6.5-10.3 ppm, oxidation temperature 37.3 oC, gas EBRT 12 s, and liquid/gas rate ratio 0.01 m3/m3. With conditions similar to those cited above, odor concentration (dilutions to the threshold) in the test gas could be removed from 3,090 to 130 with an EBRT of 14.5 s. Tests also indicate that activated carbon is effective for both physical and chemical removals of the residual VOCs, odorous compounds, and ozone in the effluent gas from the ozonation system. Economical analysis indicates that around NT$ 5.4 is required for treating 1,000 m3 of the tested foul gas by the proposed wet-ozonation and activated carbon adsorption process. Odor concentration (dilutions to the threshold) in a test could be reduced from around 4,000 to 70. Results of UV/O3 tests indicate that the introduction of the 185 nm UV irradiation at the intensity of 5W/3.63L did not help in the additional VOC and odor removals with an initial ozone concentration 4.0 ppm, VOC (methane equivalent) concentrations of 12.2-15.0 ppm, oxidation temperature of 31.5 oC, and reaction time 18.2 s. UV irradiation is not necessary for the ozonation odor removal of the test gas samples.