京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第17933号 / 地環博第112号 / 新制||地環||22(附属図書館) / 30753 / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)教授 勝見 武, 教授 高岡 昌輝, 准教授 乾 徹 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21164号 / 農博第2290号 / 新制||農||1060(附属図書館) / 学位論文||H30||N5138(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 舟川 晋也, 教授 縄田 栄治, 教授 北山 兼弘 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

No description available.

There are several incentives for using bottom ash from municipal solid waste incineration (MSWI bottom ash) as a construction material, such as for road construction. These incentives include decreased disposal of material on landfills and a reduced amount of raw material extracted for road building purposes. However, one of the main obstacles to utilising the material is uncertainties regarding its environmental properties. The overall objective of this thesis is to describe the potential environmental impacts of utilising MSWI bottom ash in constructions and to improve the tools for environmental assessments. An environmental systems analysis (ESA) approach based on a life cycle perspective was outlined and used in a case study, with the aim of describing the differences in resource use and emissions that can be expected if crushed rock in the sub-base of a road in the Stockholm region in Sweden were to be substituted by MSWI bottom ash. The whole life cycle of the road was taken into account and the alternative disposal of the bottom ash was included. It was found that the studied alternatives would cause different types of potential environmental impact; whereas the conventional alternative with only crushed rock in the road’s sub-base would lead to larger use of energy and natural resources, the alternative with MSWI bottom ash in the sub-base would lead to larger contaminant leaching. It was concluded that a life cycle approach is needed in order to include both resource use and emissions in the comparison between the two alternative scenarios. The leaching of metals turned out to be the most important environmental aspect for the comparison and in particular the difference in copper (Cu) leaching was shown to be large. However, a large amount of Cu may not pose an environmental threat if the Cu is strongly bound to dissolved organic carbon (DOC). In order to improve the basis for toxicity estimates and environmental risk assessments, and thereby provide better input values for ESAs, the speciation of Cu to DOC in MSWI bottom ash leachate was studied. It was found that Cu to a large extent was bound to DOC, which is consistent with previous research. The results also suggest that the hydrophilic fraction of the MSWI bottom ash DOC is important for Cu complexation and that the pH-dependence for Cu complexation to MSWI bottom ash DOC is smaller than for natural DOC. This implies that models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate. / QC 20101217

No description available.

The global demand for food is increasing. Different nutrients are used to increase growth in agriculture and are thus essential for the world ́s food supply. An important and common nutrient is phosphorus. It can be mined, in the form of phosphate, from phosphate rock. The problem is that mining causes environmental problems and phosphate rock is a non-renewable resource. A risk is that phosphorus will become a scarce commodity in about 100 years.  Sewage sludge from wastewater treatment plants (WWTP) is rich in phosphorus. In Sweden and other European countries, a stricter legislation is expected with consideration of an increased recovery of phosphorus from sewage sludge. A ban on the spread of hazardous substances like drug residues and heavy metals from the sludge is also expected. Incineration of the sludge can be done to eliminate hazardous substances and at the same time recover phosphorus and metals. Development of technologies to recover phosphorus from incinerated sewage sludge is therefore topical.  EasyMining is a company that invents new technologies to close nutrient cycles. One of their present projects is about recycling phosphorus, iron, and aluminium from incinerated sewage sludge. Hydrochloric acid (HCl) is used to leach the ash and in the following steps metals and phosphorus are recovered, and heavy metals are removed. Batch experiments have been performed and EasyMining examines the process in a continuous stirred tank reactor (CSTR).  The aim with this project is to compare the batch and continuous process for the ash leaching step. The study was limited to investigate different residence times and liquid to solid ratios (L/S ratios) for the ash leaching step in the CSTR. To accomplish the aim, mainly experimental studies have been performed. A total of 14 runs have been conducted to investigate the continuous process. The residence times 10, 30 and 60 min and the L/S ratios 2.5, 3 and 3.5 ml/g were evaluated. The lab-set up consisted of a peristaltic pump to pump diluted HCl solution, a conveyor belt to dose the ash and a CSTR. The filtrate was analysed for phosphorus, iron, and aluminium with a spectrophotometer. Interpretation of the result was conducted after each run and the data was then compared to previous batch data from within the company. A paired t-test was used to evaluate if there was a significant difference in the mean values between different residence times and L/S ratios.  The result shows that the leching is very fast and longer residence times or higher L/S ratios do not result in higher yields for phosphorus, iron, or aluminium. There is no significant difference between the examined residence times or L/S ratios in the paired t-test. Data from the batch process shows that the investigated residence times and L/S ratios do not affect the yield. A more even distribution of the yields is obtained in the batch process compared to the continuous process. The less even distribution in the continuous process, probably depends on errors in the method and the equipment used in the process. For example, there were some problems with the ash dosing, which led to an inconstant L/S ratio in the runs. This affected the calculated yields significantly. Overall, the batch process results in slightly higher yields. This is especially the case when excluding high calculated yields in the continuous process, probably obtained because of an overdosing of the ash. / Den globala efterfrågan på mat ökar. Olika näringsämnen används för att få en högre tillväxt i jordbruket och dessa är essentiella för världens livsmedelsproduktion. Ett viktigt och vanligt näringsämne är fosfor och det bryts i form av fosfat från fosfatmineral. Problemet är att brytningen förorenar miljön och dessutom är fosfat-sten en icke förnyelsebar resurs. Det finns en risk att fosfor blir en bristvara om cirka 100 år.  Avloppsslam från vattenreningsverk innehåller höga fosfatkoncentrationer. I Sverige samt i andra europeiska länder förväntas en striktare lagstiftning, som kräver en ökad återvinningsgrad av fosfor från avloppsslam. Även ett förbud mot spridningen av giftiga substanser som läkemedelsrester och tungmetaller förväntas införas. Slammet kan förbrännas för att eliminera farliga substanser samtidigt som fosfor och olika metaller kan återvinnas. Utvecklingen av nya tekniker för återvinning av fosfor från bränt avloppsslam är därför väldigt aktuell.  EasyMining är ett innovationsföretag som utvecklar nya tekniker för att erhålla slutna näringskretslopp. Ett av deras pågående projekt handlar om att återvinna fosfor, aluminium och järn från förbränt avloppsslam. Saltsyra används för att laka askan och i nästkommande steg återvinns fosfor och metaller, samtidigt som tungmetaller separeras. Satsvisa försök har genomförts och EasyMining vill nu undersöka processen i en tankreaktor.  Syftet med projektet är att jämföra resultat från den satsvisa driften med resultat från en kontinuerlig process för ask-lakningssteget. Studien begränsades till att endast undersöka olika uppehållstider och förhållandet mellan vätskan och askan (L/S-förhållande) i lakningssteget. För att uppnå syftet genomfördes huvudsakligen experimentella studier. 14 körningar genomfördes totalt för undersökning av den kontinuerliga processen. Undersökta uppehållstider var 10, 30 och 60 min och undersökta L/S-förhållandena var 2,5, 3 och 3,5 ml/g. Laborationsuppställningen bestod av en peristaltisk pump för tillförsel av utspädd saltsyralösning, ett rullband för dosering av askan samt en tankreaktor. Filtratet analyserades för fosfor, järn och aluminium i en spektrofotometer. Efter varje körning tolkades resultatet och jämfördes därefter med data från de av företaget tidigare utförda satsvisa försöken. Ett parat t-test användes för att utvärdera om det fanns någon signifikant skillnad i medelvärden mellan olika uppehållstider och L/S-förhållanden.  Resultatet visar att lakningen är väldigt snabb och längre uppehållstider eller högre L/S-förhållanden ger inte högre utbyten för fosfor, järn eller aluminium. Ingen signifikant skillnad erhålls mellan undersökta uppehållstider eller L/S-förhållanden i de parade t-testen. Data från de satsvisa försöken visar att de undersökta uppehållstiderna och L/S-förhållandena inte påverkar utbytet. En mindre spridning av utbyten erhålls i den satsvisa driften jämfört med den kontinuerliga. Den större spridningen i den kontinuerliga processen beror förmodligen på felkällor i processens metod/utrustning. Exempelvis var det en del problem med askdoseringen, vilket medförde icke konstanta L/S-förhållanden. Detta påverkade det beräknade utbytet signifikant. Generellt erhålls något högre utbyten i den satsvisa processen. Framförallt då höga beräknade utbyten exkluderas i den kontinuerliga processen på grund av en överdosering av askan.

Increasing human populations are placing greater strain on water resources, prompting the use of treated wastewater effluent for irrigation in some areas, including the desert regions of the Western United States. To determine the potential effects of using secondary effluent for irrigation, we applied wastewater effluent and irrigation waters to natural and artificially constructed calcareous soils in greenhouse and field lysimeters, and in soil columns. The leachate from one field lysimeter contained increased fecal coliform counts than the effluent. Leachate coliform counts were decreased or not significantly changed in two field lysimeters. Electrical conductivity (EC), sodium adsorption ratio (SAR), chloride and nitrate concentrations also increased significantly in the leachate of the three field lysimeters however. Samples collected from the greenhouse lysimeters showed a significant decrease in all categories except EC, was not significantly changed. Soil column drainage samples showed a decrease in coliform counts, and increase in EC and chloride levels while SAR and nitrate levels varied with clay content. Preferential flow of coliform bacteria and high EC and SAR values could indicate long term effects that may affect the sustainability of the practice.

The purpose of this study was to investigate the effects of copper on the treatment of an abandoned landfill leachate by a Modified Ludzack Ettinger (MLE) single-sludge, activated sludge treatment system. MLE systems are designed to accomplish nitrification and denitrification, and at least two systems were used: one to which copper was added, and one maintained as a control. The system that did not receive copper additions gave an indication of the treatability of the leachate by an MLE system. Copper was added at concentrations of 1.0, 2.0, 2.5, and 5.0 mgCu/L in the influent and the sludge age was varied from 8 to 30 day. It was determined that copper did inhibit nitrification and denitrification. A strong linear relationship was shown to exist between the specific copper loading on the system, that is the total copper entering the system within a day divided by the total biomass within the system, and the soluble copper concentration within the system. The adsorption of copper by the activated sludge, and the resulting soluble copper concentration in the mixed liquor, could be generally described by the Freundlich Isotherm. Intermittent inhibition of nitrification unrelated to copper addition also occurred during treatment of the landfill leachate which was obtained from the abandoned Dixie Caverns Landfill near Roanoke, Virginia. The inhibiting substance was not identified during this study. It did not significantly inhibit denitrification, but did cause elevated effluent suspended solids concentrations. An additional treatment step would be needed for reliable treatment of the leachate. Copper additions caused inhibition of both nitrification and denitrification. The degree of nitrification and denitrification inhibition was a strong function of the soluble copper to ML VSS ratio in the reactors, i.e., the toxin -to -microorganism (TIM) ratio. Nitrification and denitrification appeared to be equally sensitive to copper. Both were severely inhibited at a soluble copper to ML VSS ratio of 0.001 in aerobic and anoxic reactors, respectively. Nitrosomonas species were more strongly inhibited by copper concentrations than were the Nitrobacter species. The denitrifiers appeared to be as sensitive to copper as the Nitrosomonas species. / Master of Science

Cities have the potential to change the way resources and nutrients are utilized as they are centers of consumption and waste production. Losses of nutrients like nitrogen and phosphorus (P) to water ways, called eutrophication, is a major water quality issue that marine ecosystems face (Bennett et al., 2001; Smith & Schindler, 2009). Urban agriculture (UA) provides a chance for some nutrient reuse within city boundaries, but there exists a gap in knowledge regarding how soil properties influence P movement patterns within UA contexts. To explore the relationships between P leachate and soil characteristics from urban gardens, I created generalized linear mixed models (GLMMs) using data from 8 gardens in Linköping, Sweden, over a period of 2 years. Though leachate data and soil traits varied between gardens, values from the urban gardens generally did not vary extensively compared to those from field studies or rural agriculture. As hypothesized, plant-available P from the ammonium lactate soil P test (P-AL) and degree of P saturation (DPS) were both important, although why they were significant to their respective water quality variables was unclear. Moreover, spatial correlations were also not as influential as expected in P leaching. Additionally, other important soil characteristics (pH, clay, plant-available iron (Fe-AL), and plant-available aluminum (Al-AL)) seemed to relate to P adsorption and release, indicating a need for future research in that direction.

京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第22815号 / 地環博第202号 / 新制||地環||39(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 勝見 武, 教授 木村 亮, 准教授 高井 敦史 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM