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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

Applying an ecomorphological framework to the study of orangutan positional behaviour and the morphological variation within non-human apes

Myatt, Julia Patricia January 2011 (has links)
Establishing relationships between morphology and behaviour in response to environmental selection pressures are crucial to understand the evolution of diversity within groups such as the hominoids. Muscle architecture (fascicle length and physiological cross-sectional area) from the fore and hindlimbs in the non-human apes were compared, with the result that it did not differ substantially, likely reflecting their characteristic use of orthograde behaviours. At the micro-architecture level, significant differences in the proportions of fast and slow muscle fibres of the triceps surae were found between orangutans and chimpanzees, reflecting subtle differences in locomotion and habitat use. As the largest, predominantly arboreal ape, orangutans were expected to have specific behavioural adaptations to the complex arboreal habitat. A new method was developed, Sutton Movement Writing and was successfully applied to record the subtle variations in positional behaviour and compliant support use in orangutans under field conditions. Finally, postural specialisations used during feeding in the terminal branch niche were identified. Overall, this thesis shows that although the non-human apes appear to share overall behaviours and morphology, more subtle variations in micro-architecture and behaviour are present in orangutans in response to their habitat, and reflects key adaptations since their split from the last common-ape ancestor.
352

Treatment Of Xenobiotics During Anaerobic Digestion And Its Enhancement Upon Post-ozonation Of The Anaerobically Treated Sludge

Ak, Munire Selcen 01 September 2012 (has links) (PDF)
Treatment of waste sludge has become an important issue in recent years around the world. However, the trend of waste sludge treatment has shifted from volume minimization and stabilization to reuse of the sludge and recover the energy potential of it. Therefore, anaerobic treatment of sludge is gaining popularity because of byproduct methane production and high percentage of VSS reduction. Pre-treatment of sludge before anaerobic digestion in order to increase methane production, and ozone pre-treatment in this context, is one such option. Domestic sludge also contains the recently recognized, so called, emerging compounds such as Endocrine Disrupting Compounds (EDCs). Therefore treatment of EDCs in sludge is another challenge in waste sludge treatment since direct discharge of such chemicals may harm the environment by causing gender shifts within the fauna. In this context two hormones (estrone and progesterone), three pharmaceuticals (acetaminophen, carbamazepine and diltiazem) and one plasticizer (benzyl-butyl phthalate) were routinely analyzed in sludge samples which were subjected to treatment during this study. Treatment of EDCs during anaerobic digestion and the effect of ozonation both on the performance of digestion and the treatability of EDCs were investigated in this study. Four 2.5L anaerobic jars were used for anaerobic digestion connected to four 1L plastic graduated cylinders immersed in salt-water to collect the off gas. Anaerobic sludge culture of the reactor and the sludge feed to the reactors were obtained from Ankara Tatlar Wastewater Treatment Plant anaerobic digester and return activated sludge (RAS) line, respectively. One of the anaerobic digesters was used as control (no ozonation) and the others were fed with sludge samples ozonated at three different ozone doses 0.65, 1.33 and 2.65 mg ozone/g biomass. Sludge ages of the reactors were initially set to 25 days and the reactors were fed once every 2 days. The TSS, VSS, total gas volume, COD, pH, CH4 percentage and EDCs were analyzed routinely. In the reactors, operated at 25 days, because of the observation of reduction of TSS, SRT was set to infinity / thus, sludge wastage was terminated. Following the startup it was seen that at 2.65 mg ozone/g biomass dose TSS and VSS did not stay constant in the reactor and dropped sharply in the course of operation, indicating that system was not steady at this SRT. However, upon stoppage of sludge wastage from the reactors, thereby setting SRT to infinity, a steady culture could be maintained in the reactors. Both total gas production and CH4 percentage increased with the increasing doses of ozone with respect to control reactor. For 2.65 mg/g ozonated reactor total gas volume doubled the amount produced in the control reactor. All the EDCs within the scope of this study were analyzed in sludge using ultrasound-aided sequential sludge extraction method twice a week and the results showed that ozonation affected treatment of EDCs for up to 96%. The highest removal rate was obtained with natural hormones. Rates of treatment of pharmaceuticals were the second best.
353

Treatment Of Xenobiotics During Anaerobic Digestion And Its Enhancement Upon Post-ozonation Of The Anaerobically Treated Sludge

Ak, Munire Selcen 01 September 2012 (has links) (PDF)
Treatment of waste sludge has become an important issue in recent years around the world. However, the trend of waste sludge treatment has shifted from volume minimization and stabilization to reuse of the sludge and recover the energy potential of it. Therefore, anaerobic treatment of sludge is gaining popularity because of byproduct methane production and high percentage of VSS reduction. Pre-treatment of sludge before anaerobic digestion in order to increase methane production, and ozone pre-treatment in this context, is one such option. Domestic sludge also contains the recently recognized, so called, emerging compounds such as Endocrine Disrupting Compounds (EDCs). Therefore treatment of EDCs in sludge is another challenge in waste sludge treatment since direct discharge of such chemicals may harm the environment by causing gender shifts within the fauna. In this context two hormones (estrone and progesterone), three pharmaceuticals (acetaminophen, carbamazepine and diltiazem) and one plasticizer (benzyl-butyl phthalate) were routinely analyzed in sludge samples which were subjected to treatment during this study. Treatment of EDCs during anaerobic digestion and the effect of ozonation both on the performance of digestion and the treatability of EDCs were investigated in this study. Four 2.5L anaerobic jars were used for anaerobic digestion connected to four 1L plastic graduated cylinders immersed in salt-water to collect the off gas. Anaerobic sludge culture of the reactor and the sludge feed to the reactors were obtained from Ankara Tatlar Wastewater Treatment Plant anaerobic digester and return activated sludge (RAS) line, respectively. One of the anaerobic digesters was used as control (no ozonation) and the others were fed with sludge samples ozonated at three different ozone doses 0.65, 1.33 and 2.65 mg ozone/g biomass. Sludge ages of the reactors were initially set to 25 days and the reactors were fed once every 2 days. The TSS, VSS, total gas volume, COD, pH, CH4 percentage and EDCs were analyzed routinely. In the reactors, operated at 25 days, because of the observation of reduction of TSS, SRT was set to infinity / thus, sludge wastage was terminated. Following the startup it was seen that at 2.65 mg ozone/g biomass dose TSS and VSS did not stay constant in the reactor and dropped sharply in the course of operation, indicating that system was not steady at this SRT. However, upon stoppage of sludge wastage from the reactors, thereby setting SRT to infinity, a steady culture could be maintained in the reactors. Both total gas production and CH4 percentage increased with the increasing doses of ozone with respect to control reactor. For 2.65 mg/g ozonated reactor total gas volume doubled the amount produced in the control reactor. All the EDCs within the scope of this study were analyzed in sludge using ultrasound-aided sequential sludge extraction method twice a week and the results showed that ozonation affected treatment of EDCs for up to 96%. The highest removal rate was obtained with natural hormones. Rates of treatment of pharmaceuticals were the second best.
354

Removal Of Lead Using Anaerobic Biomass

Tokcaer, Emre 01 September 2003 (has links) (PDF)
Use of anaerobically digested sludge (ADS) in heavy metal removal, was researched. The raw and dewatered ADS samples collected from the effluent of anaerobic digesters and mechanical dewatering units of Ankara City Wastewater Treatment Plant were used. Sorption kinetic and equilibrium tests were conducted using raw ADS at initial pH of 2.0, 4.0 and without adjusting the initial pH. The highest Pb(II) removal capacity was observed as, 8.5 mmol (or 1760 mg) Pb(II) per g of biomass, when the initial pH was not controlled. When dewatered ADS was used Pb(II) removal capacity of ADS was found to drastically decrease to 2.5 mmol (or 518 mg) Pb(II) per g of biomass. Both biomass samples resulted in an increase in the solution pH from an initial value of 4 &ndash / 5 to an equilibrium value of 7 &ndash / 8. Large floc particles settling rapidly were formed after the ADS samples contacted with Pb(II) solution. The high Pb(II) removal capacities, and visual observations during the experiments indicated that precipitation is a dominant mechanism especially at low initial Pb(II) concentrations. FTIR studies showed that carboxyl groups present in the biomass surface of raw ADS were major functional groups in biosorption of Pb(II). The low capacity values attained at initial pH 2.0 indicated that there was a competition between Pb(II) species and hydrogen ions for carboxyl groups. Single and 3-stage fed-batch reactor systems were operated using raw ADS at different initial Pb(II) concentrations. The efficiency of reactor systems increased when 3-stage fed-batch configuration was used and an effluent Pb(II) concentration below 2 mg/L was reached from an initial value of about 200 mg/L.
355

Treatment Of Xenobiotics During Anaerobic Digestion And Its Enhancement Upon Post-ozonation Of The Anaerobically Treated Sludge

Ak, Munire Selcen 01 November 2012 (has links) (PDF)
Treatment of waste sludge has become an important issue in recent years around the world. However, the trend of waste sludge treatment has shifted from volume minimization and stabilization to reuse of the sludge and recover the energy potential of it. Therefore, anaerobic treatment of sludge is gaining popularity because of byproduct methane production and high percentage of VSS reduction. Pre-treatment of sludge before anaerobic digestion in order to increase methane production, and ozone pre-treatment in this context, is one such option. Domestic sludge also contains the recently recognized, so called, emerging compounds such as Endocrine Disrupting Compounds (EDCs). Therefore treatment of EDCs in sludge is another challenge in waste sludge treatment since direct discharge of such chemicals may harm the environment by causing gender shifts within the fauna. In this context two hormones (estrone and progesterone), three pharmaceuticals (acetaminophen, carbamazepine and diltiazem) and one plasticizer (benzyl-butyl phthalate) were routinely analyzed in sludge samples which were subjected to treatment during this study. Treatment of EDCs during anaerobic digestion and the effect of ozonation both on the performance of digestion and the treatability of EDCs were investigated in this study. Four 2.5L anaerobic jars were used for anaerobic digestion connected to four 1L plastic graduated cylinders immersed in salt-water to collect the off gas. Anaerobic sludge culture of the reactor and the sludge feed to the reactors were obtained from Ankara Tatlar Wastewater Treatment Plant anaerobic digester and return activated sludge (RAS) line, respectively. One of the anaerobic digesters was used as control (no ozonation) and the others were fed with sludge samples ozonated at three different ozone doses 0.65, 1.33 and 2.65 mg ozone/g biomass. Sludge ages of the reactors were initially set to 25 days and the reactors were fed once every 2 days. The TSS, VSS, total gas volume, COD, pH, CH4 percentage and EDCs were analyzed routinely. In the reactors, operated at 25 days, because of the observation of reduction of TSS, SRT was set to infinity / thus, sludge wastage was terminated. Following the startup it was seen that at 2.65 mg ozone/g biomass dose TSS and VSS did not stay constant in the reactor and dropped sharply in the course of operation, indicating that system was not steady at this SRT. However, upon stoppage of sludge wastage from the reactors, thereby setting SRT to infinity, a steady culture could be maintained in the reactors. Both total gas production and CH4 percentage increased with the increasing doses of ozone with respect to control reactor. For 2.65 mg/g ozonated reactor total gas volume doubled the amount produced in the control reactor. All the EDCs within the scope of this study were analyzed in sludge using ultrasound-aided sequential sludge extraction method twice a week and the results showed that ozonation affected treatment of EDCs for up to 96%. The highest removal rate was obtained with natural hormones. Rates of treatment of pharmaceuticals were the second best.
356

Performance Assessment Of Compacted Bentonite/sand Mixtures Utilized As Isolation Material In Underground Waste Disposal Repositories

Ada, Mahir 01 July 2007 (has links) (PDF)
The design and development of isolation or backfill materials, which seal the disposal facility, are important for disposing the wastes. The use of compacted bentonite-sand for construction of shaft seals and liners for waste containment structures has been proposed by various studies. Therefore / it is aimed in this study to develop an isolation material to be used in underground waste repositories. For such designs to be effective, their performance need to be assessed and a minimum hydraulic conductivity requirement defined by regulatory agencies should be satisfied (i.e. 1x10-8 m/s in Turkey, 1x10-9 m/s in USA). Therefore / this study assesses the performance of compacted bentonite/sand mixtures in terms of hydrological and mechanical properties. To be able to assess the performance of this material, a variety of laboratory tests were carried out. Engineering geological tests such as compaction, falling head permeability, swelling, unconfined compression and shear strength tests were conducted to select an optimum mixture. Finally, an optimum bentonite-sand mixture possessing 30% bentonite was recommended for the isolation of underground waste disposal facilities.
357

Municipal Sludge Minimization: Evaluation Of Ultrasonic And Acidic Pretreatment Methods And Their Subsequent Effects On Anaerobic Digestion

Apul, Onur Guven 01 February 2009 (has links) (PDF)
Sludge management is one of the most difficult and expensive problems in wastewater treatment plant operation. Consequently, &amp / #8216 / sludge minimization&amp / #8217 / concept arose to solve the excess sludge production by sludge pretreatment. Sludge pretreatment converts the waste sludge into a more bioavailable substrate for anaerobic digestion and leads to an enhanced degradation. The enhanced degradation results in more organic reduction and more biogas production. Therefore, sludge pretreatment is a means of improving sludge management in a treatment plant. Among pretreatment methods, acidic pretreatment has been subject of limited successful studies reported in the literature. On the contrary / ultrasonic pretreatment was reported as an effective pretreatment method. Main objective of this study was to investigate the effects of these two pretreatment methods and their combination in order to achieve a synergistic effect and improve the success of both pretreatment methods. Experimental investigation of pretreatment methods consists of preliminary studies for deciding the most appropriate pretreatment method. Anaerobic batch tests were conducted for optimization of the parameters of selected method. Finally, operation of semi-continuous anaerobic reactors was to investigate the effect of pretreatment on anaerobic digestion in details. Preliminary studies indicated that, more effective pretreatment method in terms of solubilization of organics is ultrasonic pretreatment. Fifteen minutes of sonication enhanced 50 mg/L initial soluble COD concentration up to a value of 2500 mg/L. Biochemical methane potential tests indicated that the increased soluble substrate improved anaerobic biodegradability concurrently. Finally, semi-continuous anaerobic reactors were used to investigate the efficiency of pretreatment under different operating conditions. Results indicate that at SRT 15 days and OLR 0.5 kg/m3d ultrasonic pretreatment improved the daily biogas production of anaerobic digester by 49% and methane percentage by 16% and 24% more volatile solids were removed after pretreatment. Moreover, even after pushing reactors into worse operating conditions such as shorter solids retention time (7.5 days) and low strength influent, pretreatment worked efficiently and improved the anaerobic digestion. Finally cost calculations were performed. Considering the gatherings from enhancement of biogas amount, higher methane percentage and smaller amounts of volatile solid disposal from a treatment plant / installation and operation costs of ultrasound were calculated. The payback period of the installation was found to be 4.7 years.
358

The Role Of Calcium Ion On Activated Sludge Biochemical And Physical Properties In Phosphorus Deficient Growth Medium

Aksu, Ceren 01 September 2010 (has links) (PDF)
Nutrients and cations have significant effect on activated sludge characteristics and therefore effect the efficiency of whole processes. To determine the properties in phosphorus deficient medium and the effect of calcium ions two reactor sets with two different phosphorus concentration (C/N/P=100/5/0.05 and C/N/P=100/5/1), three different concentrations of calcium (0.5, 5, 15 meq/L) were operated with 8 days of sludge residence time and an effective volume of 2 L. Results showed amount and composition of EPS was dependent on calcium and phosphorus concentrations. Except for the highest calcium concentration, increase in phosphorus concentration resulted in increase in total EPS production. Under phosphorus deficient conditions, calcium ions stimulated the production of carbohydrate type polymers and viscous bulking was observed. However, the increase in phosphorus concentration led to increase in protein type polymer production and bulking condition was cured. Addition of calcium ions increased conductivity in both cases, but increase in phosphorus concentration caused decrease in conductivity. Increase in phosphorus concentration had improved settleability, dewaterability and rheology of sludge. Moreover, effluent turbidity was decreased and COD removal efficiency was recorded as greater than 95 % for all calcium concentrations under phosphorus sufficient conditions. Microscopic analyses showed that under phosphorus deficient conditions flocs were weak, dispersed and nonresistant. Increase in phosphorus concentration resulted in improvement of floc structure. Same Enterobacter and Citrobacter species were identified at all calcium concentrations under phosphorus deficient conditions. Yet, under phosphorus sufficient conditions different species were identified in control reactor as compared to 5 meq/L and 15 meq/L concentrations.
359

Sulphate Removal By Nanofiltration From Water

Karabacak, Asli 01 December 2010 (has links) (PDF)
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.
360

Production Of Alginate From Azotobacter Vinelandii And Its Use In Water And Wastewater Treatment

Moral, Cigdem 01 January 2011 (has links) (PDF)
Alginates are copolymers of &beta / -D-mannuronic (M) and &alpha / -L-guluronic acids (G). In this study, Azotobacter vinelandii ATCC&reg / 9046 was used to produce alginate in a fermentor. The effect of parameters such as dissolved oxygen tension (DOT), agitation speed, initial concentrations of sucrose and calcium on the properties of alginate were examined. Changes of DOT in the range of 1 and 10 % affected alginate production. The optimum DOT giving high alginate yield (4.51 g/L) and maximum viscosity was observed as 5 % yielding moderate GG-blocks of 55 %. Both high and low agitation levels reduced alginate production, but these conditions increased GG-block alginates as 76 and 87 % at 200 and 700 rpm, respectively. Moderate sucrose and calcium concentrations, 20 g/L and 50 mg/L, respectively were found better since further increase in their concentrations did not lead to a considerable improvement in alginate production and quality. Sodium alginates produced in this work were investigated for maximum heavy metal uptake with a special focus on copper ion and the highest copper uptake was around 1.9 mM Cu2+/g alginate. Findings showed that the block distribution of alginate was not as important as expected for copper removal. Alginate together with calcium ions was used for the removal of turbidity. The amount of GG-block was found to be important in turbidity removal. Alginate having 55 % GG block and 8.9 cP viscosity resulted in a final turbidity lower than 1 NTU at 2 mg/L of alginate with 60 mg/L of calcium ion.

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