M.S. Theses

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Wastewater treatment by land disposal on sandy grounds
(Thesis (M.S.) - Bogazici University. Institute for Graduate Studies in Science and Engineering, 1984., 1984.) Baysal, Ayşegül.; Curi, Kriton,
Wastewater disposal on land can be considered as "appropriate" wastewater treatment technology for many less developed and developing countries. The main advantages of .this technique are the low initial and maintenance costs involved, the effective reduction of the organic load as well as the removal of bacteriological pollution, reuse of nutrients such as nitrogen and phosphorus present in the was,tewater through retention by soil and the increase of the productivity of the soil. Treatment of wastewater by land application has not been practised so far in Turkey. The present study was conducted to investigate the applicability of this method in our country and to predict the results. For this purpose, a 25 meter long channel was constructed and after it was filled with sand, domestic wastewater was applied. The variation of the wastewater and soil characteristics with time and distance were investigated through out the application period. Removal efficiencies obtained are given below: Chemical oxygen demand (COD) 74-84 % - Nitrogen (N) 65-75 Z - Phosphorus (P) 73-92 % - Turbidity 75-80 Z - Total coliform 77.5-82.5 % These results are in full agreement with the results of similar studies conducted elsewhere. The conclusion of the present study is that land disposal on sandy grounds is a method which can be used effectively in many parts of Turkey.
Scale effect of modelling on biogas generation
(Thesis (M.S.) - Bogazici University. Institute for Graduate Studies in Science and Engineering, 1984., 1984.) Çukurova, Recep.; Curi, Kriton,
Anaerobic decomposition of manure i s an outstanding alternative energy source, appropriate for most developing countries. Several studies related to this subject were conducted so far, however, the effect of the size of the inodel on the efficiency obtained was not investigated. The main purpose of the present study was t o investigate, the scale effect on the perfomance of an anaerobic digestion. To achieve this three digesters , each of different size and voluue, were installed and operated under ambient conditions. The results obtained have shown that: 1. The size of the model has as light effect on the efficiency of anaerobic digestion, better performance being obtained in larger model. 2. Any digester can be operated under ambient conditions if proper insulating precautions are taken. 3. Mixing has a positive effect on biogas generation. 4. The positive effect of yeast on anaerobic decomposition is verified .
Efficiency of wastewater treatment by land disposal and its effects on crop productivity
(Thesis (M.S.) - Bogazici University. Institute for Graduate Studies in Science and Engineering, 1985., 1985.) Üstün, Beyza.; Curi, Kriton,
Land application of wastewater is one of the oldest methods used for treatment and disposal of wastes.The main advantages of this technique are the low initial and maintenance costs involved,high Nutrieht recyle capacity, and the increase of crop growth. Because of these factors it is believed that land disposal is an advantageous thechnique for deyelooing countries and is strongly recommended for the rural areas of Turkey. in 1984, a 25 meters long channel was constructed by A-Bavsal in Boğaziçi University's Garden.These Channels were filled with sand and gravel domestic wastewater was applied. The variation of wastewater characteristics with timerdistance and effective size of media were investijated through out the anplication period in 1985. Removal efficiencies obtained are given below: Chemical Oxvqen Demand(C0D) 76% in the Sand bed for 35days - 60% in the Gravel bed for 35days -- Nitrogen (N) 70% in the Sand bed for 35 days - 57% in the Gravel bed for 35days -- Phosnhorus (P) 77% in the Sand bed for 35 days - 64% in the Gravel bed for 35days. The study of crop productivity has been performed at Faculty of Forest of Istanbul University. Its aim was to examine the crop productivity of the media through which wastewater has been disnosed.The best result was obtain from a mixture containing 80% of the media and 20% of soil.
Heavy metal taxicity on blue-green alga
(Thesis (M.S.)- Bogazici University. Institute of Environmental Sciences, 1986., 1986.) Berk, Hüma.; İnel, Yüksel.
In this study, the growth response of Anabaena flos-aquae, which is a filamentous, heterocystous blue-green alga, towards heavy metals i s described. The experiments were long term, batch type experiments, and algae were incubated in media containing Hg(I1) as mercuric chloride (HgC12) ,Cd(II) as cadmium chloride (CdC12), Se(1V) as sodium seleni te (Na2Se03), Ni (11) as nickel chloride (NiCI2.6H20) ,Cr(VI) as potassium chromate(K2Cr04) and As(V) as sodium arsenate (Na2HAs04). 7H20) in solution. Growth i s measured spectrophotometrical ly and optical density is used in the expression of results. In all cases, metals were found to be inhibitory on the growth, the degree of inhibition depending upon the type of the metal ion and the concentration in the medium. I t was found that in media contaminated with 10,20 ppm selenium and 0.2 ppm nickel, the growth of cells failed complelety.
A numerical model for the Marmara sea
(Thesis (M.S.)- Bogazici University. Institute of Environmental Sciences, 1987., 1987.) Albek, Erdem Ahmet.; İnel, Yüksel.
In this study, a numerical model has been developed to predict currents and water levels prevailing in the Marmara Sea. The model is a depth averaged two-layer transient model to adequately simulate stratified flow conditions in the sea. The nonlinear partial differential equations of the model have been solved by using an explicit finite difference scheme and employing a local integral method to reduce truncation and round-off errors and to improve accuracy. Special emphasis has been laid on the prediction of currents and water levels under strong winds.
The predicted environmental distribution of selected flame retardant chemicals
(Thesis (M.S.) - Bogazici University. Institute for Graduate Studies in Science and Engineering, 1991., 1991.) Baysan, Semra.; İnel, Yüksel.
The aim of this study is to calculate environmental equilibrium distributions for selected Flame Retardant Chemicals and thus to indicate where each of them goes and what relative concentrations they adopt in the enviromental compartments. In this study, Mackay's Level I Fugacity Model, based on fugacity that characterizes the escaping tendency from a phase, is used for calculations. The fugacity calculations are applied to an evaluate environment a "unit world" consisting of compartments of homogeneous air, soil, water, biota, suspended solids and sediment. Each compartment is assigned a reasonable volume and properties and the equilibrium distributions of those chemicals are calculated using fugacity capacities, that are calculated from physical and chemical data partition coefficients. When the results are designed to yield priorities for each compartment, it is found that Halognated Flame Retardant Chemicals for the air compartment, Phosphorus Flame Retardant Chemicals in the Sediment and Soil compartments are priorities.
Evaluation of the Eutrophication process in lake İznik
(Thesis (M.S.)- Bogazici University. Institute for Graduate Studies in Science and Engineering, 1993., 1993.) Zakrı, Fawaz.; Akkoyunlu, Atilla.
Lake Iznik is located in the southern east part of Marmara region within the province of Bursa . Its water is of a big importance to the region with a Mediterranean climate, and an annual rainfall ranging between 500 - 750 rom, falling mainly in the period from October to March . This water is used in dry season for irrigation . In this thesis, a physical study of the region is conducted . The physical , chemical and biological parameters were examined at several sites in order to determine the eutrophication state and a suitable model was applied to represent the lake . Lake Iznik was found to be very near to the eutrophic state and the limiting nutrient in the lake was found to be the phosphorus element .
Investigation of nitrification characteristics of a nitrogenous industrial wastewater
(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 1994., 1994.) Gökçin, Pınar.; Çeçen, Ferhan.
Treatment of wastewaters containing very high amounts of nitrogen is a problem for industries like the fertilizer industry. Up to date methods like air stripping or ion exchange can also be used in removal of nitrogen but they have certain disadvantages. The main purpose of this thesis was to present another known process used in nitrogen removal. The general concern of the study is to determine if nitrification process could tolerate industrial wastewaters containing high concentrations of nitrogen. In the beginning of the experimental part of the study, sludge previously acclimated to nitrification was introduced to increasing concentrations of ammonium nitrogen. In the second part of the study, wastewater from a fertilizer industry was used in order to detect the removal capacity of the system. Throughout the study effects of pH on the system and the system's tolerance was observed. Data obtained during the study proved that nitrification is a process that behaves according to the zero order kinetics. Finally, the results indicated that a nitrification process can surmount very high amounts of nitrogen if the environmental conditions are idealized.
The characteristics and reuse of Golden Horn surface sediments
(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 1994., 1994.) Aydın, Zehra Semra.; Karpuzcu, Mehmet.
In this study the characteristics and reuse of Golden Horn surface sediment were investigated. 40 per cent of the water content of the sediment is free and immobilised water, and the remaining 60 per cent is bound water content. In accordance with these results, the high specific resistance value of the sediment indicates its poor dewaterability characteristics. The leachate of the samples does not contain the toxic heavy metals even if the deposits get into contact with acid rain of pH 4. The sediment has strong Cu and Pb adsorption properties. Considering the metal content of the sediment, it is obvious that the sediment is not saturated with these metals. Another important characteristic of the samples IS their high buffering capacity. The reuse of the dried sediment as a clay mixture III brick manufacturing seems possible.|Keywords: Sediment, dewatering, metal adsorption
A study of shipping industry and assessment of environmental impacts in Turkey
(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 1998., 1998.) Tuzcu, M. Fikret.; Kocasoy, Günay.
In recent years, the importance of the environmental concerns at shipping and the related standards/safety measures have become subject to clear understanding and acceptance of each country at international platforms. The aim of this study was to evaluatelinvestigate the reflections of the international standardization developments at Turkey and the ways for reaching the very strict and internationally requested standards at her shipping industry at once. For this purpose; general evaluation of the prospective Turkish Shipping Industry, its development during the recent years, its current performance in the terms of conforming with the international standards and ways for reaching these standards with a better conformance have been investigated. The necessary steps that Turkey should immediately take during this period have been evaluated by specifically studying the problems of the Turkish Ports that can be defined as evident indicators of the economic power of a country. The results were expressed by analyzing the economic, commercial and technological means of overcoming the sub standardization at Turkish ShippingIPorts. Moreover, 'Pipe-Line' alternative has been suggested instead of 'Straits' alternative with social cost/benefit analysis of marine pollution and other environmental effects that have been studied by evaluating the effects of tanker accidents on environment and human nature.
Trace-level metals and natural organic matter interactions: |oxidative/adsorptive removal pathways
(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 1999., 1999.) Uyguner, Ceyda Senem.; Bekbölet, Miray.
The destructive removal of humic acids in natural waters has gained increased attention, because these substances are known to be major precursors of carcinogenic disinfection byproducts which are produced during chlorination. Since the conventional treatment methods are expensive and complicated, heterogeneous photocatalytic degradation processes using Ti02 have been applied as an alternative treatment for the destruction of humic acid. This study was conducted to investigate the effects of chromium and manganese ions on the photocatalytic degradation of humic acid (10 mg L-1 ) in aqueous medium at neutral pH conditions (pH=6.7). Bench scale experiments were carried out using titanium dioxide (0.25 mg mL-1 ) as the photocatalyst and Black Light Fluorescent Lamp as the irradiation source. For comparison purposes, the photocatalytic degradation of humic acid was performed both in the presence and absence of metal ions. The degradation was followed by pseudo first order and Langmuir-Hinshelwood kinetics in terms ofColor436, Color4oo, UV280 and UV 254. The presence of chromium and manganese ions resulted in decreased removal rates on the photocatalytic degradation of humic acid compared to the baseline rate of humic acid alone. Pseudo first order reaction rate constants for Color436 and UV254 were found to be 3.86x10-2 min-1 and 2.73x10-2 min-1 in the absence of metal ions. Color436 removal rate constant decreased to 3.13x10-2 min-1 in the presence of 0.10 mg L-1 chromium ion and in the presence of 0.05 mg L-I manganese ion, a value of 3.37xlO-2 min-1 was attained. On the other hand, a similar trend was observed for UV254, the removal rate constant in the presence of chromium was calculated to be the lowest with a value of 2.06x10-2 min-1 whereas, in the presence of manganese it was found to be 2.31xlO-2 min-I. The decrease in the photocatalytic oxidation rate might be explained by the formation of a weak complex between humic acid and the metal ion which might have blocked the active sites on the Ti02 surface. Complimentary adsorption experiments were also performed to evaluate the effect of adsorption intensity on the photocatalytic degradation rates. The results indicated that no significant difference was observed with the adsorption capacity (KF) values, but compared to the other two, the humic acid + manganese system exhibited the highest values.
Biodiversity analysis of marine demersal invertebrate fauna in the princess islands region
(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 1999., 1999.) Hüseyinoğlu, Fatih.; Furman, Andrzej.
A study for the inventory of the diversity of invertebrate species habited in the Princess Islands region, istanbul was conducted to cover the gap between alike studies conducted all over the top biodiversity centres. The mentioned area was one of the most diverse areas in temperate waters. The biodiversity due to over population has been decreased in the area, and this study was made in comparison with the past study. Princess Islands region and Bosphorus Strait was studied in detail in 1952 by Muzaffer Demir, which was the starting point for this comparative study in the area after half a century. Between Muzaffer Demir and this study, the studies conducted over invertebrate fauna in the Sea of Marmara are insufficient. The main concepts as the definitions, value and conservation of biodiversity are also given followed by the key notions of the current trends in conservation biology. Descriptions of the new species and keystone species with their pictures are also added. There are two groups of islands: Inhabited and desolate (see Map3.1 and Map 3.2). The inhabited islands are 6km far from the shore and domestic wastes are discharged directly to the sea. The desolate islands are 12km far from the shore and comparably have greater biodiversity than the inhabited islands coasts which are being polluted both by istanbul wastes because they are nearer and domestically. Several dives were done in various sites to observe the species in their habitats. Comparative which-and-where tables of the demersal invertebrate phyla are added with a scale of abundance that will help future studies. 9 new species were recorded that were not recorded before, and many probable extinctions were noted.
The summer populations of cave-dwelling bat species of Çatalca-Kocaeli region and environmental region and environmental factors that influence their distribution
(Thesis (M.S.)- Bogazici University. Institute of Environmental Sciences, 2000., 2000.) Bilgin, İbrahim Raşit.; Furman, Andrzej.
The summer population of cave dwelling-bat species in Catalca-Kocaeli Region was surveyed between May-August 1999. The effects of geographical location, habitat, and temperature were studied as possible factors in determining the distribution patterns of the bat species in these caves. Nine out of the 11 caves were studied for the first time with regard to the assessment of bat populations inside. Three maternity colonies were identified for Rhinolophus ferrumequinum, R euryale and Minioptems schreiberszi in three different caves. The statistical analysis based on geographical coordinates, and species distribution hinted that Bosphorus might be acting as a natural barrier limiting migration and gene flow between Catalca and Kocadi regions. Hence it may be more correct to treat Catalca and Kocaeli regions separately in terms of species occupancy. The critical habitat types influencing species distribution were traditional arable land, pond, heathland, and maquis. River, riparian treeline, pasture, broadleaved woodland md broadleaved woodmd/pasture edge were the common habitat types recorded for all of the bat species. Habitat surveys around the caves indicated that M. schreibersii might be able to utilize a greater number, and Large Myotis a lesser number of different habitat types, compared to the other species studied. Average temperature in the caves was the weakest contributing factor far explaining the distribution patterns of the species.|Keywords: Chiroptera, Cave, Habitat, Temperature, Turkey
Oxidative treatment of antibiotics in pharmaceutical effluents
(Thesis (M.S.) - Bogazici University. Institute of Environmental Sciences, 2002., 2002.) Ötker, Havva Merih.; Balcıoğlu, Işıl.
Antibiotics are intensively used both in veterinary and human medicine and up to 90 per cent they are excreted through urine and feces into municipal sewage after administration. They can also enter to the sewage treatment plants through the wastewater generated from the formulation process in pharmaceutical industry. Since antibiotic containing effluents are inert towards conventional biotreatment, antibiotics may reach to the aquatic environment and thus such effluents require an oxidative pretreatment. Cephalosporine (I) and penicillin (II) group human antibiotics and quinolone group veterinary antibiotic in synthetically prepared pharmaceutical formulation effluents were treated by ozonation in order to improve their biodegradability. The effects of pH, initial antibiotic concentration, dose of H2O2 and applied ozone doses were investigated on treatment performance. Elevating the reaction pH, inlet ozone concentration and H2O2 dose resulted in an enhancement on treatment efficiencies of all antibiotic formulation effluents. While in the veterinary antibiotic effluent BOD5/COD ratio was increased from 0.077 to 0.38 with an applied O3 dose of 2960 mg/L h, at pH=7, for human antibiotic I and human antibiotic II, BOD5/COD ratio was increased from 0 to 0.1 and 0.27 respectively. In order to correlate biodegradability results with a structure of antibiotics, degradation rates of antibiotics were related with energies required for the degradation by H-abstraction. Combination of ozone with UV, accelerated aromaticity removal from 63 to 83 per cent, and oxygen uptake rate from 0.21 to 0.28 mg/L min for veterinary antibiotic (CODi=900 mg/L), however, did not appear to be more effective than applying mere ozonation in terms of COD removal rates.
Health-care waste management of the hospitals in the European side of Istanbul
(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2004., 2004.) Zeren, Binnur Aylin.; Kocasoy, Günay.
The inefficient management and disposal of the health-care wastes generated at the health-care institutions is the significant problems faced in the İstanbul City of Turkey. This study will refer to the development of an integrated health-care waste management plan at the European Side of İstanbul City. In the scope of the study, firstly the existing institutional and legislative framework are reviewed and the health-care institutions generating the wastes are surveyed through the prepared questionnaires, comprehensive field research and personnel interviews. By the obtained data, the inventory about the amounts, types and sources of the health-care wastes is developed. The infectious composition of the health-care wastes is also determined by the conducted microbiological analyses. To analyze the possible cost reductions, the optimum waste prevention and minimization techniques are suggested for the health-care institutions. For the problem of the transportation and disposal of these wastes; the optimum transportation routes are prepared and the appropriate treatment and disposal technologies are determined. The final stage is planning and proposing a health-care waste management center which can be used as a basis for the other cities in Turkey. All the graphs, tables and maps related to the proposed suggestions are illustrated in the study.
Integrated ozone and biotreatment of pulp mill effluent
(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2005., 2005.) Saraç, Canan.; Balcıoğlu, Işıl.
In this study, the effluents from the biggest pulp and paper plant in Turkey that having amultistage chlorine bleaching process were treated by an integrated process consisted ofozonation and activated sludge processes to enhance the biodegradability and increase the quality of effluent.In the first part of the study, ozonation process was applied to CEHDED and CEH stagebleaching effluents. The effects of fibre type, pH, H2O2, and ozone dose were investigated ontreatment performance of ozonation process. Significant COD and color removals wereachieved by increasing ozonation pH of combined bleaching effluents to a value of 12. The highest treatment efficiency was achieved by the O3/H2O2/pH=7 process with 1632 mg/Lozone dose for CEHDED effluent. While 41 per cent COD removal was obtained by applyingO3/pH=7 process to CEHDED effluent, COD removal was increased to 57 per cent by the addition of 15 mM H2O2. Although ozonation of CEHDED effluent at pH=7 resulted in only amoderate alteration in BOD5/COD ratio, O3/H2O2 /pH=7 treatment increased the BOD5/CODratio from 0.2 to 0.4. Almost complete color removal was also achieved by O3/H2O2 /pH=7treatment. In the second part of the study, activated sludge process was applied to pulp milleffluent. While for the raw effluent overall CODs removal efficiency of biological processwas 61 per cent, it was 77 per cent for the pulp mill effluent, which contained the pretreated(O3/H2O2/pH=7) CEHDED effluent. Furthermore, AOX removal rate was increased from 39 to 70 per cent by the pretreatment of combined bleaching effluent.
Application of the characterisitc root index model tothe estimation of physico-chemical and biological properties of selected endocrine disrupting chemicals
(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2005., 2005.) Özkul, Mustafa.; Saçan, Melek Türker.
Quantitative structure-property relationship (QSPR) models based on two differentsets of parameters have been developed for water solubility (S), n-octanol/water partitioncoefficient (KOW), and Henry̕s Law Constant (H) of selected endocrine disrupting chemicals (EDCs). Similarly, QSPR models have also been established for the biologicalproperties including 50% effective inhibition concentration (48h-EC50) to algae andbioconcentration factor (BCF) in fish for substituted benzenes having endocrine disruptingproperties. The parameters used to develop these QSPR models were topology based Characteristic Root Index (CRI) and semi-empirical molecular descriptors, namely =energies of the highest occupied and the lowest unoccupied molecular orbital (EHOMO andELUMO), and dipole moment (u).The best fit equation found by "forward multiple linear regression" showed that the topology based CRI was the most important parameter for the modeling of S, KOW andBCF. For KOW a two-parameter equation including the CRI and EHOMO was obtained with acorrelation coefficient of r = 0.992, whereas a three-parameter equation including the CRI,ELUMO and u was obtained for both solubility and Henry̕s Law Constant with a correlation coefficient of r = 0.986 and r = 0.933, respectively. EHOMO and u didn̕t appear in the samemodel because of the collinearity. The CRI and ELUMO descriptors were used in regressionsof 48h-EC50 with a correlation coefficient of r = 0.926 while only the CRI had appeared asa descriptor for the prediction of BCF with a correlation coefficient of r = 0.850. Since the number of BCF data is limited to 18 for the CRI-based QSPR model (mod el 6), reliabilityof this model was first checked by classical tests, and then it was compared with the otherCRI-based model (model 7) reported in the literature. The results of modified jackknifetests indicated that the five models were statistically robust. Mean deviation of calculatedvalues from experimental data amounted to 0.27, 0.17, 0.28, 0.19 and 0.29 log units for theS, KOW, H, 48h-EC50, and BCF, respectively. The developed models have been used topredict the S, KOW, H, 48h-EC50, and BCF of those compounds where there are noexperimental measurements.
Effect of different rations of treatment plant sludge on the stabilization of solid wastes at anaerobic and aerobic landfill areas
(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2005., 2005.) Güneş, Gıyasettin.; Kocasoy, Günay.
Sanitary landfilling is one of the solid waste disposal methods. Sanitary landfills have created problems related to biogas emissions, generation of leachate, and long times required for the area recovery. Aerobic landfilling is a new solid waste disposal method. The supply of proper air flow and leachate recycle to an aerobic landfill accelerates the decomposition of organic materials. In this study, the reactors were loaded with solid wastes mixed with different types and ratios of sludge in order to find out the stabilization of solid wastes under anaerobic and anaerobic conditions. Moreover, after 55th day of the research, both aerobic and anaerobic decomposition rates were tried to enhance by using yeast as additive. The results of the study suggested that disposal of sludges mixed to the solid wastes was an effective technique for the stabilization of the solid wastes. At the end of the analyses, the highest ratio 1/4 was found as the optimum sludge ratio for the stabilization of the solid wastes in both the aerobic and the anaerobic reactors. Moreover, the yeast solution addition was an effective technique for the enhancement of biodegradation. Among the different reactor types, the aerobic reactors were more effective than the anaerobic ones.
Investigation of protein and carbohydrate components of extracellular polymeric substances in the sludges having pin floc characteristics and their role in dewaterability
(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2005., 2005.) Yıldırımlı, Aslı.; Erdinçler, Ayşen.
In this research, protein and carbohydrate components of extracellular polymeric substances of the non settling sludges having pin floc characteristics and the role of EPS components were investigated. The results of pin floc sludges compared with waste activated sludges. Five different sludge samples were analyzed. The three pin floc sludge samples were obtained from sequencing batch raector, aerobic pond and facultative ponds of Bursa Hamitler Leachate Traetment Plant respectively. One of the samples was grown in the bench-scale batch reactor in laboratory and the other sample was obtained from a raw pharmaceutical industry wastewater treatment plant. Extracellular polymeric substances of sludge samples were extracted by a cation exchange resin at a dosage of 75 g/g VSS (volatile suspended solids). The dewatering characteristics of the sludge samples were determined by measuring the filterability in terms of capillary suction time and specific resistance time to filtration and compactibility in terms of cake solids concentration. The floc structures of sludge samples were also observed microscopically. The result of observations showed sludges having microflocs (pin flocs) have very high EPSp values compared to lab-grown sludge and typical waste activated sludges. Their EPSc/EPSp values were also low leading to very poor settling and dewatering properties. It seems that protein component of EPS may have an effect on the pinfloc (microfloc) formation and it deteriorates the sludge dewaterability and settleability. Compactibility, in terms of cake solids concentration, increased by decreasing concentrations of EPSprotein. Filterability, in terms of specific resistance to filtration, increased considerably by increasing concentrations of EPSprotein. Sludge samples having pin floc characteristics had very high SRF values compared to the samples of typical waste activated sludge. High SRF values indicate the difficulty of the sludge to be filtered. During the SRF experiments, filtration time for pin floc sludges were too long. On the other hand samples of typical WAS were filtered easily.
Heavy metals in sediments of the Black Sea
(Thesis (M.S.)-Bogazici University. Institute of Environmental Sciences, 2005., 2005.) Aktürk, Mine.; Yenigün, Orhan.
The Black Sea is a semi-enclosed marine basin in the north of Turkey. It is almost in astate of isolation, if we exclude the connection to Mediterranean through the Aegean Sea and the Sea of Marmara. Due to its unique properties, it has been the subject of manystudies.This study̕s aim is to investigate the concentrations of metals such as Fe, Mn, Pb, Zn,Cu, Ni, Cr and Co in the sediments of the Black Sea and evaluate the metal contamination with Al normalization. For the study, the Black Sea Unit 1 sediments were collected from 7stations during the 2003 R/V Knorr Black Sea Cruise, Leg 2 and 3, which are conductedbetween April 25-May 10 and May 10-May 15, respectively. Fe, Mn, Pb, Zn, Cu, Ni, Cr,Co and Al concentrations of sediments obtained from these cruises were determined by atomic absorption spectrometry after total digestion. Hg contents of sediments from threestations were determined by flameless atomic absorption spectrometry after digestion.Experimental results were compared by different ways. Firstly, the metal distributionsand metal/Al normalizations along the cores at each station were investigated. Secondly, comparison of three stations which are located different part of Black Sea was made, inorder to see how the metal concentrations of the cores change from western to eastern partsof Black Sea. Finally, the results of these examinations were compared with the previousstudies.Generally, Mn and Fe concentrations are below the average shale Mn and Fe concentrations. Mn and Fe values show a sudden decrease in anoxic conditions, due to thediffusion to oxic layers throughout the cores.The high Pb contents at the top of the cores from stations which are close toBosphorus may most probably suggest a combination of diagenetic and anthropogeniceffects. Pb/Al ratios in all stations have an increase in the beginning of the cores, which isan indication of pollution.v Hg concentrations which obtained from three stations are generally below the averageshale Hg concentration. Hg/Al ratios are higher in the station which is the closest to theBosphorus. That is an indication of the pollution. High Hg/Al ratio is the consequence ofincreased anthropogenic activities in the vicinity of the Bosphorus Black Sea coastal areas that are urbanized and industrialized.Previous data and results obtained from this study show an increase in Pb, Zn, Cu, Niand Cr contents in the eastern surface sediments. This is because of the metal rich rocks incoast areas and associated economic mineral deposits in the catchment areas of rivers. In addition to this, high Hg/Al and Pb/Al ratios in south western surface sediments indicate ananthropogenic input from industrialized and urbanized regions.

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