<p>Phytoremediation as a way to control and lessen nutrient concentrations in landfill leachate is a cheap and environmentally sustainable method. Accumulated nutrients in the plants can then be removed by harvesting and anaerobically digesting the biomass. This study presents two aquatic plants (L. minor (L.) and P. stratiotes (L.)) and one microalgae species (C. vulgaris (L.)), their capacities for growth and nutrient removal in leachate from Häradsudden landfill, Sweden, are investigated. The biogas potential of the two plants is determined via anaerobic digestion in a batch run, followed by a lab-scale reactor run for L. minor only. Results show that growth in leachate directly from the landfill is not possible for the selected species, but at a leachate dilution of 50% or more. Nutrients are removed in leachates with plants to a higher extent than in leachates without, yet the actual amounts do not differ notably between plant species. L. minor proves a better choice than P. stratiotes despite this as growth is superior for L. minor under the experimental conditions of this study. Considering biogas production, L. minor gives more methane than P. stratiotes according to the results from the batch run. The former is however not suitable for large-scale anaerobic digestion unless as an additional feedstock due to practical cultivation issues.</p>

China is the second largest emitter of greenhouse gases (GHG) in the world. Since 68% of its primary energy is from coal, China’s average energy intensity is 7.5 times higher than the EU and 4.3 times higher than the US (EU, 2003). Therefore, introducing advanced clean technologies and management to China represents opportunities for Annex I countries to obtain low-cost CERs through CDM projects, and access to one of the largest energy conservation markets in the world. The Chinese government considers that the introduction of CDM projects can bring advanced energy technologies and foreign investment to China, thereby helping China’s sustainable development. As energy efficiency is generally low and carbon intensity is high in both China’s energy supply and demand sectors, numerous options exist for cost-effective energy conservation and GHG mitigation with CDM. This study has focused on the following areas:  Clean development Mechanism (CDM) Policy and Implementation in ChinaClean development Mechanism (CDM) Policy and Implementation in ChinaChina’s energy development strategy and climate change, how to make CDM work for sustainable development in China?  CDM projects in China: policies assessment and recommendations for improvement.  Energy efficiency CDM projects and renewable CDM projects in China: case studies Firstly, this thesis reviewed the current CDM developments in China, attentions were given to the renewable energy, energy efficiency and methane capture project opportunities in China. Secondly, this study introduced China’s current policy on CDM implementation, and reviewed its permission requirements, institutional arrangements and project procedures. Based on the observations, this study analyzed the current problems and pointed out the shortfalls of the existing Chinese CDM policies and institutional settings. Options to remove these barriers were given as recommendations. This thesis also looked at the problem of that CDM was designed to have double dividends, to reduce the compliance cost of the Annex I countries and to contribute to sustainable development in Non Annex I Parties, but in reality, CDM has caused concerns about whether it could really support sustainable development in host countries. This study analyzed the reasons underpin this problem. Thirdly, based on the analysis made on energy efficiency and renewable CDM project development in China, case study was given on China’s landfill gas to energy project. This study analyzed the perspective of GHG mitigation through landfill gas capture and utilization in China, its opportunities and challenges. Moreover, this study demonstrated how CDM can add value to landfill gas-to-energy projects in China.

The legal requirements for wastewater discharge into environment, especially to zones exposed to eutrophication, lately became stricter. Nowadays wastewater treatment plants have to manage with the new rules and assure better biogenic elements’ removal, in comparison with the past. There are some well-known methods of diminishing concentrations of these compounds, but they are ineffective in case of nitrogen-rich streams, as landfill leachate or reject waters from dewatering of digested sludge. This wastewater disturbs conventional processes of nitrification-denitrification and raise necessity of building bigger tanks. The partial nitritation followed by Anaerobic Ammonium Oxidation (Anammox) process appear to be an excellent alternative for traditional nitrification/denitrification. The process was investigated in three different reactors – Membrane Bioreactor (MBR), Moving Bed Biofilm Reactor (MBBR) and Rotating Biological Contactor (RBC). The process was evaluated in two options: as a two-stage process performed in two separate reactors and as a one-stage process. The two-step process, in spite of very low nitrogen removal rates, assured very high nitrogen removal efficiency, exceeding even 90% in case of the MBBR. However, obtained results revealed that the one-step system is a better option than the two-step system, no matter, what kind of nitrogen-rich stream is taken into consideration. Moreover, the one-step process was much less complicated in operation. Performed research confirmed a hypothesis, that the oxygen concentration in the bulk liquid and the nitrite production rate are the limiting factors for the Anammox reaction in a single reactor. In order to make a quick and simple determination of bacteria activity, the Oxygen Uptake Rate (OUR) tests were shown as an excellent tool for evaluation of the current bacteria activity reliably, and without a need of using expensive reagents. It was also shown, that partial nitritation/Anammox process, could be successfully applied at temperatures much lower than the optimum value. Performed Fluorescent in situ Hybridization (FISH) analyses, proved that the Anammox bacteria were mainly responsible for the nitrogen removal process. / QC 20100707

The bioreactor landfill is an emerging concept for solid waste management that has gained significant attention in the last decade. This technology employs specific operational practices to enhance the microbial decomposition processes in landfills. However, the unsupervised management and lack of operational guidelines for the bioreactor landfill, specifically leachate manipulation and recirculation processes, usually results in less than optimal system performance. Therefore, these limitations have led to the development of SMART (Sensor-based Monitoring and Remote-control Technology), an expert control system that utilizes real-time monitoring of key system parameters in the management of bioreactor landfills. SMART replaces conventional open-loop control with a feedback control system that aids the human operator in making decisions and managing complex control issues. The target from this control system is to provide optimum conditions for the biodegradation of the refuse, and also, to enhance the performance of the bioreactor in terms of biogas generation. SMART includes multiple cascading logic controllers and mathematical calculations through which the quantity and quality of the recirculated solution are determined. The expert system computes the required quantities of leachate, buffer, supplemental water, and nutritional amendments in order to provide the bioreactor landfill microbial consortia with their optimum growth requirements. Soft computational methods, particularly fuzzy logic, were incorporated in the logic controllers of SMART so as to accommodate the uncertainty, complexity, and nonlinearity of the bioreactor landfill processes. Fuzzy logic was used to solve complex operational issues in the control program of SMART including: (1) identify the current operational phase of the bioreactor landfill based on quantifiable parameters of the leachate generated and biogas produced, (2) evaluate the toxicological status of the leachate based on certain parameters that directly contribute to or indirectly indicates bacterial inhibition, and (3) predict biogas generation rates based on the operational phase, leachate recirculation, and sludge addition. The later fuzzy logic model was upgraded to a hybrid model that employed the learning algorithm of artificial neural networks to optimize the model parameters. SMART was applied to a pilot-scale bioreactor landfill prototype that incorporated the hardware components (sensors, communication devices, and control elements) and the software components (user interface and control program) of the system. During a one-year monitoring period, the feasibility and effectiveness of the SMART system were evaluated in terms of multiple leachate, biogas, and waste parameters. In addition, leachate heating was evaluated as a potential temperature control tool in bioreactor landfills. The pilot-scale implementation of SMART demonstrated the applicability of the system. SMART led to a significant improvement in the overall performance of the BL in terms of methane production and leachate stabilization. Temperature control via recirculation of heated leachate achieved high degradation rates of organic matter and improved the methanogenic activity.

The bioreactor landfill is an emerging concept for solid waste management that has gained significant attention in the last decade. This technology employs specific operational practices to enhance the microbial decomposition processes in landfills. However, the unsupervised management and lack of operational guidelines for the bioreactor landfill, specifically leachate manipulation and recirculation processes, usually results in less than optimal system performance. Therefore, these limitations have led to the development of SMART (Sensor-based Monitoring and Remote-control Technology), an expert control system that utilizes real-time monitoring of key system parameters in the management of bioreactor landfills. SMART replaces conventional open-loop control with a feedback control system that aids the human operator in making decisions and managing complex control issues. The target from this control system is to provide optimum conditions for the biodegradation of the refuse, and also, to enhance the performance of the bioreactor in terms of biogas generation. SMART includes multiple cascading logic controllers and mathematical calculations through which the quantity and quality of the recirculated solution are determined. The expert system computes the required quantities of leachate, buffer, supplemental water, and nutritional amendments in order to provide the bioreactor landfill microbial consortia with their optimum growth requirements. Soft computational methods, particularly fuzzy logic, were incorporated in the logic controllers of SMART so as to accommodate the uncertainty, complexity, and nonlinearity of the bioreactor landfill processes. Fuzzy logic was used to solve complex operational issues in the control program of SMART including: (1) identify the current operational phase of the bioreactor landfill based on quantifiable parameters of the leachate generated and biogas produced, (2) evaluate the toxicological status of the leachate based on certain parameters that directly contribute to or indirectly indicates bacterial inhibition, and (3) predict biogas generation rates based on the operational phase, leachate recirculation, and sludge addition. The later fuzzy logic model was upgraded to a hybrid model that employed the learning algorithm of artificial neural networks to optimize the model parameters. SMART was applied to a pilot-scale bioreactor landfill prototype that incorporated the hardware components (sensors, communication devices, and control elements) and the software components (user interface and control program) of the system. During a one-year monitoring period, the feasibility and effectiveness of the SMART system were evaluated in terms of multiple leachate, biogas, and waste parameters. In addition, leachate heating was evaluated as a potential temperature control tool in bioreactor landfills. The pilot-scale implementation of SMART demonstrated the applicability of the system. SMART led to a significant improvement in the overall performance of the BL in terms of methane production and leachate stabilization. Temperature control via recirculation of heated leachate achieved high degradation rates of organic matter and improved the methanogenic activity.

The production of ferrochromium alloys at Vargön Alloys AB contributes to formation of unwanted ferrochromium dust, which contains toxic Cr(VI). The dust is since summer 2005 treated with an iron-sulphate solution to reduce Cr(VI) to the non-toxic Cr(III). A year later the treatment technique was improved and disposal occurs in cells on the landfill. The cells can be up to 300 m3 and the edges can be made out of fro example concrete. Tests are conducted on the treated dust when it is disposed. The analyses show low contents of Cr(VI), which indicates that the reduction is successful. Analyses of leakage water from a small scale cell however showed an increasing content of Cr(VI) and pH under the first two months. This thesis has evaluated the new treatment method. An investigation was conducted to determine if the same changes have occurred in the full scale cells. Half of the 18 collected samples from the disposed dust showed high or very high contents of Cr(VI). The other half had a almost no detectable content. pH was over 12. No correlation between Cr(VI)-content and pH, conductivity, age or water content in the disposed dust could be shown. An experiment was also performed in small scale to reduce the number of influencing parameters. The results showed that if the dust has access to oxygen the Cr(VI) content increases during the first days from a few mg/kg dry substance to over 20 mg/kg dry substance, a level which was maintained during the rest of the experiment period. The content of Cr(VI) was almost constant at 4 mg/kg dry substance when oxygen was eliminated during the whole experiment period. When the water content was below 5 %, the content of chromium did not increase more. Since almost all newly created Cr(VI) is reduced to Cr(III) by the addition of ferrous sulphate, recreation of Cr(VI) occurs. Today there is now possibility to follow the changes in the dust from untreated to after disposed. The addition of iron-sulphate is based upon an average Cr(VI) content in the dust and the variation of disposal occasions can be significant. To determine if the increase in Cr(VI) is caused of an incorrect addition of solution a smaller disposal cell can be constructed. The initial content of Cr(VI) can be controlled and the dust can be examined during the time it ages. If the dosage could be improved the addition can be optimized. It is also important to minimize the infiltration and accelerate the drying of the slurry since the Cr(VI) content can increase the as long as the water content is high the Cr(VI) content can increase. / Vid produktionen av ferrolegeringar på Vargön Alloys AB bildas ferrokromstoft som en oönskad biprodukt, vilken innehåller hälsofarligt sexvärt krom. Sedan sommaren 2005 behandlas stoftet med järnsulfatlösning för att reducera Cr(VI) till mindre hälsofarliga Cr(III). Ett år senare förbättrades tekniken och deponering sker sedan dess i iordningställda celler på deponin. Cellerna rymmer cirka 300 m3 och har kanter av bland annat betongstöd. Provtagning sker på det behandlade stoftet i samband med deponeringen. Analyserna visar mycket låga halter av Cr(VI), vilket tyder på att reduktionen lyckas. Analyser av lakvatten från en småskalig provcell visade däremot att Cr(VI)-halter och pH ökade under de två första månaderna. Detta arbete har utvärderat den nya behandlingsmetoden. Undersökning huruvida samma förändring har skett i fullskaliga celler har utförts. Utav de 18 prov som inhämtades från det deponerade stoftet visade hälften på höga eller mycket höga Cr(VI)-halter och resterande hade nästan omätbara halter. I det deponerade stoftet var pH genomgående drygt 12. Inget samband mellan Cr(VI)-halt och pH, konduktivitet, ålder eller vatteninnehåll i deponerat stoft erhölls. Försök utfördes även i liten skala i för att minska antalet påverkande parametrar. Utan tillgång till syre var Cr(VI)-halten cirka 4 mg/kg torrsubstans under hela försöksperioden. Försöken visade att om stoftet har tillgång till syre ökar Cr(VI) från några mg/kg torrsubstans till dryga 20 mg/kg torrsubstans efter bara några dagar. Halten förblev konstant under resten av försökstiden. Ett samband som sågs var att när Cr(VI)- halten har stagnerat är vatteninnehållet i provet under 5 %. Eftersom nästan allt krom reduceras till Cr(III) vid tillsatsen av järnsulfatlösning har det nyreducerade Cr(VI) återbildats. I nuläget går det inte att följa hur stoftet förändras från obehandlat och vad som händer när det åldras efter att det har behandlats och deponerats. Tillsatsen av järnsulfat doseras efter en medelhalt Cr(VI)-innehåll i stoftet och variationen i Cr(VI)-halt mellan deponeringstillfällen kan vara stor. För att avgöra om ökningen av Cr(VI) beror på felaktig tillsatts av järnsulfatlösning kan en mindre deponeringscell anläggas. Ingående Cr(VI)-halter kan kontrolleras och stoftet kan undersökas medan det åldras på deponin. Visar det sig att dosering behöver förbättras kan tillsatsen optimeras. Det är även viktigt att minska infiltrationen samt påskynda torkningen av slurryn eftersom så länge vattenhalten är hög kan Cr(VI)-halterna öka.

Phytoremediation as a way to control and lessen nutrient concentrations in landfill leachate is a cheap and environmentally sustainable method. Accumulated nutrients in the plants can then be removed by harvesting and anaerobically digesting the biomass. This study presents two aquatic plants (L. minor (L.) and P. stratiotes (L.)) and one microalgae species (C. vulgaris (L.)), their capacities for growth and nutrient removal in leachate from Häradsudden landfill, Sweden, are investigated. The biogas potential of the two plants is determined via anaerobic digestion in a batch run, followed by a lab-scale reactor run for L. minor only. Results show that growth in leachate directly from the landfill is not possible for the selected species, but at a leachate dilution of 50% or more. Nutrients are removed in leachates with plants to a higher extent than in leachates without, yet the actual amounts do not differ notably between plant species. L. minor proves a better choice than P. stratiotes despite this as growth is superior for L. minor under the experimental conditions of this study. Considering biogas production, L. minor gives more methane than P. stratiotes according to the results from the batch run. The former is however not suitable for large-scale anaerobic digestion unless as an additional feedstock due to practical cultivation issues.

The landfill leachate is commonly treated for non-biodegradable organic matters, ammonia and colour. Experimental investigations using polyaluminium chlorite (PAC) and UV/O3 have been conducted for the determination of optimal pH value, reaction time and PAC concentration for the removal of chemical oxygen demand (COD) and colour. In pre-treatment coagulation stages, the highest COD and colour removal efficiencies were observed at the concentration of PAC ≥ 3,000 mglG1 and pH values between 7 and 8. However, these experiments also indicated significant removal efficiency for PAC starting with concentrations of 1,500 mglG1. The efficiency of COD and colour removal were approximately 30% and 70%, respectively. Similar efficiencies have been observed also during the second treatment stage where UV/O3 processes were used to treat coagulated leachate. After UV/O3 application, the pH of leachate reached the optimum value of 7.5 whereas the highest COD and colour removal efficiency was 55% and 72%, respectively, and the optimal reaction time was achieved after 80 min. / Nước rỉ rác sinh ra từ bãi chôn lấp chất thải rắn cần được xử lý các thành phần chất hữu cơ khó phân hủy sinh học, xử lí amoni và độ màu. Một số kết quả thử nghiệm về xử lý COD và màu của nước rỉ rác bằng việc sử dụng phương pháp keo tụ với PAC và quá trình UV/O3 đã được thực hiện cùng với việc xác định các giá trị pH tối ưu, thời gian phản ứng và nồng độ PAC tối ưu. Hiệu suất xử lý cao nhất đạt được khi nồng độ của PAC ≥ 3.000 mg/l, pH trong khoảng từ 7 đển 8 trong giai đoạn tiền xử lý. Tuy nhiên, hiệu quả loại bỏ COD và màu bắt đầu tăng rõ khi nồng độ PAC từ 1.500 mg/l trở lên. Hiệu quả loại bỏ COD và màu tương ứng là khoảng 30% và 70%. Các giá trị pH này phù hợp cho quá trình phản ứng UV/O3 được sử dụng sau giai đoạn keo tụ. Sau quá trình xử lý bằng hệ UV/O3, pH của nước rỉ rác tối ưu được xác định là 7,5 (hiệu suất xử lý COD và màu cao nhất tương ứng là 55% và 72%), thời gian phản ứng tối ưu là 80 phút.

In this research, we dealt with the original landfill leachate, and put the flowing water by a traditional second one that has dealt with of sewage factory directly with the constructed wetland systems in lab-scale. The purpose the study is to compare the experimental results after dealing the leachate by different constructed wetland process systems which was judge at if the, can reach the water quality standard. The constructed wetland systems in the study were set up in a greenhouse on campus, which were operated between May 2004 and July 2003. Constructed wetland systematic attitude, include Free Water Surface System (FWS) and Subsurface Flow System (SSF) contact but two type constructed wetland system that become mainly. In the test use different waste water sources to feet the systems, and we planted different species of plants, and add extra carbon source. Thus, we can divide the experiment into two stages: (1) From July of 2003 to December of 2003. (2) From February of 2004 to May of 2004. In each stage, we tested three experiment group P1, P2 and total nitrogen of P3 except that the rate is 37¡Ó20%, 50¡Ó11% respectively and -6.1¡Ó37.8%. The removal efficiencies of ammonia nitrogen were estimated equal to 84¡Ó11%, 94¡Ó4% and 60¡Ó24% respectively. For total phosphorus and phosphate, P1 , P2 and P3 system were measured equal to 37¡Ó14%, 68¡Ó16% and 77¡Ó16%and 44¡Ó16%, 75¡Ó8% and 80¡Ó17% respectively . The ammonia nitrogen temperature correction coefficient (£c value) were calculated to be 0.921, 0.949, 0.926, 1.043 and 0.785 for P1, P2, P3, U1 and U2 system, respectively. The phosphate temperature correction coefficients (£c values ) were measured to be 1.006, 0.981, 1.070, 1.235 and 0.843 respectively for P1, P2, P3, U1 and U2 system. In order to increase the removal efficiencies of total nitrogen, it was always by adding carbon source. The experimental result showed, that it is add carbon source wait by system to SSF , its President nitrogen is it flow water pollution load leave 2g/m2/day nearly to put to have, and has not added water pollution load has flowed in the putting of the carbon source nearly has 6g/m2/day left, And nearly remain under 1g/m2/day in the putting and flowing water pollution load of TON, and not added the putting of the carbon source water pollution load has flowed nearly has 2-3g/m2/day left. This result showed that high total nitrogen removal efficiencies were by adding carbon source.

The main concern of this thesis is to evaluate the land-cut as an alternative urban design tool instead of landfill in the creation of shore in waterfront areas in terms of improving space quality, increasing the shoreline length for the use and benefit of public, decreasing the risks of natural disasters while increasing the marine ecosystem and habitat, and promoting the development of the land economy. The development of the idea dates back to an urban design studio study carried out in 2005 in Eceabat, &Ccedil / anakkale by Middle East Technical University Urban Design Master Program. During the study, it was observed that the interaction of small town of Eceabat with water was partially blocked by a seaside road and a ferry port created by landfill. Therefore, the ways of integrating the town life with water was searched and in the design schemes proposed after the analyses, the possibility to create a new shore by land-cut method in Eceabat was evaluated. Within this framework, the possibility of using land-cut method is evaluated in a more detailed case study of KuSdili Meadow and KuSdili Stream (Kurbagali v Dere) located in Kadik&ouml / y, Istanbul where there is a potential to create urban space with an approach which has not been used so far in Turkey. Prior to the analysis, the life near waterside has been studied in order to clarify how people from different geographies developed settlements near waterside and how those settlements existed with water. The reasons and the problematic of landfill has been evaluated with specific examples in order to put forward from what aspects the use of an alternative method be considered is necessary. Therefore, the legal and administrative aspects which resulted in the creation of landfills as problematic spaces on the waterside have also been discussed. At the end of the study, the potentiality of the site has been studied to find out from various urban design aspects with a specific reference to the applicability of land-cut method. Therefore, the analysis of the site has been carried out. And the thesis has shown that land-cut may possibly be an alternative to landfill in the development of waterside urban spaces from various spatial, social, and economic aspects.