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Departman Tezleri
Life cycle assesstment of PET bottle
Human being is recently in petroleum period after living the stoneage and mine age with taking place in history. Petroleum and its derivatives are used nearly all in our daily life and becoming indispensable of our lifes day by day. Crude oil, which is formed by plant and animal residues that putrefied over millions of years, pass through many processes from winning to becoming ready to be delivered to the consumer. Because of petroleum and petroleum products? indispensable role in our lifes, technology which cares about environment must be chosen, wastes of production process must be lowered end disposed with appropriate methods. In this study, PET, which is used for placing on the market our life resource;water, will be evaluated together with its LCA (life cycle assessment). Manufacturing chain of PET (polyethylene terepthalate) bottle started quickly and dense after patented in 1973. The chain consists of crude oil winning, taking naphtha by refining crude oil, getting terephthalic acid and ethylene glycol from naphtha, polymerization terephthalic acid and ethylene glycol, all the stages of PET production and the usage and disposal phases. Types of wastes, environmental fate due to manufacturing process and methods of production wastes? dispose have been evaluated and also feedback mechanisms after the usage of productions are examined and the necessity of feedback is investigated in this study. The aim is to evaluate LCA of PET numerically with material-energy-waste- environmental impact circle.
Material recovery from used cables in Turkey
The aim of this study is to define the material recovery capacity from used cables in Turkey, in details. Also, general instructions about cable recovery are given to support the base of the thesis.For this purpose, at first, cable manufacturing process is explained. One of the key components of a wire is its insulation. Its selection is determined by a number of factors. There are major types of materials used in a cable which are; resins, plasticizers, stabilizers, flame retardants, fillers, lubricants, and colorants.Since there are a lot of different types of cables are in use, variety of used cables presence in recycling circle, too. These cables are classified according to their energy value, telecommunication uses, and their special uses.During the experimental part of the study; each type of cable is divided into its components and weight percent of each different material used is determined gravimetrically for unit length of the cable. Then the calculated theoretical material recovery ratio for each type of used cable is found to determine the market capacity in Turkey by using the data obtained from cable manufacturers that shows annual cable production in the county.
Enzymatic treatment effects on aerobic sludge stabilization
Water/wastewater treatment processes have produced sludge in different characteristics and quantities. The sludges should be processed and disposed of in accordance with the environmental health criteria for environmental reasons. For many authorities and engineers, the effective sludge management is still a big challenge since the investment and operational costs of sludge processing have an important part of overall plant?s costs. Sludge dewatering process has a central role in sludge management for many operations like storage, transport. But, the dewaterability characteristics of sludges can vary depending on their sources and the applied processes. The methods for effective processing cover the methods -thickening, stabilization, conditioning, dewatering-, and the final disposal alternatives- incineration, land application.The main purpose of this thesis was to investigate the effects of hydrolytic enzyme additions on dewaterability performance of activated sludge during aerobic digestion process. Activated sludge was fed to the reactors as a feeding material. The parameters ? pH, electrical conductivity (EC), salinity, oxidation reduction potential (ORP), capillary suction time (CST), zeta potential, suspended solids content, dry solid content, organic matter- were analyzed to determine the sludge characteristics. Reactor performances with and without enzyme additions were monitored. Experimental results showed that the enzyme additions provided enhanced sludge disintegration. Enzyme added reactors showed considerably superior better performance in terms of organic matter reduction and EPS degradation when comparing the control reactor.This thesis as part of a project examining the effects of hydrolytic enzymes in biological sludge stabilization gives important research results to determine the floc disintegration mechanisms by enzymes during aerobic sludge digestion.
Treatment of reject water
Sludge from primary clarifiers and final sedimentation (i.e. excess sludge) are stabilized in an anaerobic digester, and dewatered thereafter. The water flows from sludge dewatering processes (i.e. reject water or sludge liquor) on municipal wastewater treatment plants (WWTPs) are a few liters per person per day. Therefore, the hydraulic influence on the plant is not important. In contrast, the ammonium concentration in the sludge liquor can reach 2500 mg/L. Thus, the rejected nitrogen load can account for up to 25% of the nitrogen load in the raw sewage. Due to the considerable nitrogen load, reject water from dewatering of sludge could impose on the wastewater treatment process. Being returned to the inlet of a wastewater treatment plant the influent loading of the plant is significantly increased causing occoasional overloading situations. Thus, separate treatment alternative is recommended as an optional solution to the problem.Various researches works into finding innovative ways that takes advantage of ammonium rich composition of reject water, and has gained prominence in the wastewater industry over the last two decades. Currently new heights have been attained through the nitritation/denitritation step especillay for ammonium removal. In addition, there are a number of methods for treating phosphorus in reject water namely; magnesium-ammonium-phosphorus (MAP) or struvite precipitation, hydroxyapatite (HAP) precipitation and natural aging of phosphorus. However, progress at phosphorus removal has largely remained at the experimental stage, in spite of its considerable composition in reject water. Therefore, the aim of this thesis is to try to identify theoretically all the methods that have evolved over the years at treating reject water from dewatering sludge and investigate the possible strategies to handle the rejection problem, and processes for separate treatment of the sludge liquor. In this framework, characterization of the reject water taken from two different municipal WWTPs is carried out as first. Characterizaion studies were assisted to realize that important parameters such as pH, nitrogen, phosphorus, suspended solids, coliform and heavy metals for treability studies and use of reject water for irrigation purpose. Afterwards, treability studies were made and struvite and hydroxyapatite precipitation methods were carried out for treatment purpose. Treability studies stated that %25-41 of phosphate phosphorus and %28-46 of amonium nitrogen and %76-100 magnesium were treated by struvite precipitation at optimum pH (8-9), mixing time (4 hours), perlit dose (5, 15 and 20 mg/l) and Mg-P ratio (1:1, 1.1:1). On the other hand, higher phosphate phosphorus removals were achived by hydroxyapatite precipitation. In the hydroxyapatite precipitation studies, phosphate phosphorus treatment ratio was around %92 at optimum pH (9), 2 hours mixing time and 20 g gypsium/L were selected as optimal dose.
Applications of environmental management systems in building chemicals industry
Expeditious developments in science and technology, explosive population growth after the industrial revolution and inadequate environmental sensibility of manufacturers have yielded a series of environmental problems: the breakdown of the environmental balance on a global level, ozone layer destruction, global warming, acid rain, deforestation and desert expansion. They are large and urgent subjects that affect the planet. Environmental Management System is a systematic approach to dealing with the environmental aspects of an installation. ISO 14001 Environmental Management System is a guideline for organizations controlling and minimizing the environmental impacts.In this study, the benefits, properties and requirements of ISO 14001 EMS are analyzed. The steps of applications and implementations of an environmental management system on a building chemicals industry are explained. Mass balances of the production flow, waste costs per product are explained in factory.
Investigations of reuse options for fermentation industry wastewaters
The world industrializing with a growing pace has scarcity problems of water at the same time. For this reason, disposal of the wastewaters to rivers, lakes or wetlands is becoming more and more unacceptable, including the uncontrolled use of water supplies. As the result, investigations of the reuse options and the implementation of these options have come into consideration.This study has been accomplished in accordance with the information gained from the pilot brewery which had been chosen for its appropriateness for the research. Firstly, information about the production steps and the wastewater treatment plant of the brewery has been achieved. Then, the samples that were taken from the influent and the effluent of the treatment plant were analysed to required parameters. According to the results of the analyses, the compatibility of the treated wastewater for industrial use, agricultural irrigation and the groundwater recharge was evaluated. Within the context of this evaluation, recommendations were given for the additional treatment units for the pilot brewery.
İzmir iç körfezinde bulunan ağır metallerin biyolojik sızdırma yöntemiyle giderilmesi
In recent years, heavy metals pollution in aquatic sediments has gained great importance through environmental concerns. The presented study aims to point out the current heavy metal pollution in the sediments of Izmir inner Bay followed by the remediation of metal contaminated sediments with bioleaching method.In the first part of the study, sediment samples collected from 7 points in Izmir inner Bay are characterized by means of their bulk selected metals (Cr, Cu, Pb, Zn) concentrations and the chemical distributions of these metals according to their binding fractions are determined. Total metal contents of the sediments are determined by using microwave acid digestion and the BCR Sequential Extraction Scheme is used for determination of metals bound as four fractions: exchangeable, reducible, oxidizable, and residual.In the second part, bioleaching experiments are conducted in flasks by using the sediment samples. Two major Thiobacilli strains (Thiobacillus ferrooxidans & Thiobacillus thiooxidans) are used for bioleaching and the effects of bacteria type, solid/liquid ratio, sulfur addition rate (as substrate), and the sediment particle size are studied. The changes in chemical distribution of the heavy metals after bioleaching are also observed and reported.The characterization studies point out that there is high pollution of heavy metals in the sediments of Izmir inner Bay and the binding forms of metals are different from each other. Bioleaching experiments lasted for 48 days under 300C. The use of T. thiooxidans, optimum solid content, optimum sulfur addition, and fine particles perform satisfactory results for heavy metals removal.
Effects of filter ratio and operation mode on the efficiency of anaerobic filter treating molasses wastewater
In this thesis, treatability studies were realized by using an upflow anaerobic filter model reactor that is accepted as one of the most economical systems in the world. Hydraulic retention time, filter material ratio, organic loading rate, temperature and operation mode, which are design and performance parameters, were evaluated at four upflow anaerobic filter reactors having different filter material ratios in the study.During the study anaerobic filter reactors were fed with the synthetic wastewater containing molasses. Experimental studies were examined at different organic loading rates varied between 0.5 and 2.0 kg COD/m³day for hydraulic retention time (HRT) of 2 days at temperature range of 37 ± 1°C. Four anaerobic filter reactors called as UAF 100, UAF 75, UAF 50 and UAF 25 according to filter material ratio were operated at continuous and semi-continuous operation mode.Chemical oxygen demand (COD), total solid (TS) and total volatile solid (TVS) analyses were done for evaluate the performance of upflow anaerobic filter reactors during the study. When the results of this analysis were compared, COD, TS and TVS removal efficiencies were affected by continuous operation mode and filter material ratio in anaerobic filters. Depending on operation mode, the highest COD, TS and TVS removal efficiencies were achieved at continuous mode than the semi-continuous mode.
Commissioning of wastewater treatment plants and evaluation of different stages of options
In this study commissioning period is examined with the examples. Actions before andduring commissioning are examined with examples to give the view points to theengineers. The solutions for the possible problems are that may happen duringcommissioning are given.Compact plant is analyzed with different treatment options. These are carbon removal,carbon removal with nitrification, carbon removal with nitrification plus denitrification andextended aeration. The oxygen consumptions, sludge productions, necessary adjustmentsover the process and treatment efficiencies of the wastewater treatment plant are examinedaccording to the German rules and standards for activated sludge plants. All the parametersfor each process are calculated and summarized. Different treatment options are comparedto each other and liability of each options for the typical wastewater treatment plant isexamined.
Ethanol Production from cheese whey powder solution by fermentation
Ethanol production from cheese whey powder (CWP) solution was investigated using batch, fed-batch and continuous fermentation systems. In batch experiments ethanol production from cheese whey, CWP and lactose solutions with the same initial sugar contents were compared by using two different Kluyveromyces marxianus strains (NRRL?1109, NRRL?1195) in order to determine the most suitable substrate and the yeast strain.Then, the effects of initial pH, CWP concentration and external nutrient supplementation on ethanol production were investigated using K. marxianus NRRL-1195. The rate and extent of ethanol formation did not increase with external nutrient addition indicating no requirement for external nutrients. Final ethanol and the rate of ethanol formation increased with increasing CWP indicating no substrate or product inhibitions, but substrate limitations.Performances of two different K. marxianus strains (NRRL-1195 and DSMZ-7239) were compared for ethanol fermentation. DSMZ-7239 was found to be the most suitable strain and was used in further experiments.Effects of initial CWP and yeast concentrations were investigated and a kinetic model describing the rate of sugar utilization as function of the initial substrate and the biomass concentrations was developed in batch fermentation.Then, a five- cycle repeated fed- batch operation with different feed CWP concentrations was used for the same purpose. The growth yield coefficient (Yx/s) decreased and product yield coefficient (Yp/s) increased with increasing feed sugar content.A continuous culture at different feed sugar contents and hydraulic residence times (HRT) was tested for ethanol production. Material balances for yeast growth, sugar utilization and ethanol formation with suitable kinetic models were used to predict the system performance and to determine the kinetic constants.Finally, a continuously operated packed column bio-reactor (PCBR) using olive pits as support particles was used at different HRTs and feed sugar cotent. Sugar concentration decreased and ethanol increased with the height of the column operated in up-flow mode. Effluent ethanol increased with increasing HRT and feed sugar content up to certain levels. Ethanol yields closer to the theoretical predictions were obtained