Finnish government has set an ambitious goal of reaching 50% share of renewable energies by year 2030. To reach this goal several structural changes and new strategies are required. One possible solution is the initiation of bioeconomy program. This thesis work focuses on the implementation of bioeconomy in the North of Finland by reviewing the challenges and opportunities involved in it. The goal is to perform a preliminary technological and economic assessment of a co-digestion plant located in Sodankylä, thus contributing to its bioeconomy strategy. The RECENT project is introduced in the introduction, as this work is closely connected to it. In the theoretical part, the North of Finland, its natural resources and critical infrastructure are introduced. Issues related to bioeconomy realization, climate change’s effect on water services, and municipality’s challenges in northern conditions, are reviewed. Three different biomass utilization methods that are possible in northern conditions are discussed in depth. It was found out that there is great potential for bioeconomy utilization in Northern Finland. There is a lot of biomass available and organic waste unused. At the same time, there are difficulties on their implementation. Few difficulties to overcome are long distances, lack of employees, diminishing population, and doubts regarded to economic sustainability of bioeconomy. One way to speed up the implementation of a new energy system is to use energy assessment tools. Three different tools were reviewed and it was found out that the best tool to use was RETScreen. It is designed to assess single energy systems and was used also to assess the co-digestion plant in Sodankylä. In the experimental part, the municipality of Sodankylä is introduced and the preliminary assessment for the co-digester is performed. All the data for assessing the co-digestion plant were obtained from the municipality itself and from literature. Upgrading the wastewater treatment plant to biogas plant would be profitable if the biomethane generated sold at a price of 1,22 €/kg. Gate fee for bio-waste should be 50 €/m³. The payback period varied between 8 years to 29 years, depending on method and biomethane price used. The amount of biomethane that could be theoretically produced with 4 different feedstocks was 203 250 m³. Based on its energy content, it is sufficient to replace the petrol consumption of 150 cars. RETScreen assessment gave 15 000 m³ lower result. A dry, mesophilic reactor with a capacity of 500 m³ was regarded as a possible solution. Establishing the separate bio-waste collection in the municipality’s center area and practical issues related to the whole biogas plant were discussed also. According to the results, co-digester in Sodankylä is technologically and economically possible to realize. However, several assumptions had to be made. For example, an investment support of 25% is assumed in every calculation and the investment cost for the digester and biogas refinery is based on literature. Also, it is technically challenging to handle feedstocks that are not available throughout the year. The purpose is to produce biogas at a steady rate, but it is challenging, if the reactor is fed with different kinds of raw materials seasonally. The load and the process conditions should be kept stable as possible to ensure high biogas gain. Although the results are positive, more research is recommended to be done to ensure the profitability of the investment. Special attention should be given to the reactor model. This thesis work demonstrates that it is technologically and economically sustainable to realize the bioeconomy in North of Finland. The biogas plant system introduced in the work could be duplicated to other similar territories. The work was done as a part of RECENT (Renewable Community Empowerment in Northern Territories) project. / Suomen hallitus on asettanut kunnianhimoisen tavoitteen nostaa uusiutuvan energian osuus 50 %:in vuoteen 2030 mennessä. Tämän tavoitteen saavuttamiseksi tarvitaan uusia strategioita ja rakenteellisia uudistuksia. Eräs mahdollinen ratkaisu on käynnissä oleva biotalousohjelma. Tämä diplomityö keskittyy biotalouden toteuttamiseen Pohjois-Suomessa sen haasteita ja mahdollisuuksia arvioiden. Tavoitteena on selvittää Sodankylään suunniteltavan yhteismädätyslaitoksen teknis-taloudellinen potentiaali edistäen siten paikallisen biotalousohjelman toteutumista. RECENT -projekti esitellään johdannossa, sillä tämä työ liittyy vahvasti kyseiseen projektiin. Pohjois-Suomen alue, sen luonnonvarat ja kriittinen infrastruktuuri ovat esitelty teoriaosuudessa. Lisäksi tarkastellaan asioita liittyen biotalouden toteutumiseen, ilmastonmuutoksen vaikutukseen vesihuollossa ja kuntien haasteisiin pohjoisissa olosuhteissa. Työssä on kuvattu tarkemmin kolme eri tapaa hyödyntää biomassoja kyseisellä alueella. Teoriaosuudesta käy ilmi, että Pohjois-Suomessa on suuri potentiaali biotalouden hyödyntämiselle, koska biomassaa ja orgaanista jätettä on saatavilla paljon. Ongelmina ovat kuitenkin pitkät välimatkat, pula työntekijöistä, vähenevä väestömäärä ja epäilyt liittyen biotalouden kannattavuuteen. Energiapotentiaalin arvioimiseen käytetyt työkalut ovat yksi tapa nopeuttaa uusien energiasysteemien käyttöönottoa. Työssä käytiin kolme eri työkalua läpi ja saatiin selville, että tarkastelluista työkaluista RETScreen oli potentiaalisin. Se on kehitetty arvioimaan yksittäisiä energiasysteemejä ja sitä käytetään myös Sodankylän yhteismädättämön arvioinnissa. Kokeellinen osuus käsittelee Sodankylän kuntaa ja yhteismädätyslaitoksen kannattavuutta. Laitoksen arvioimiseen tarvittu data saatiin kunnalta ja kirjallisuudesta. Jätevesilaitoksen päivittäminen yhteismädättämöksi on kannattavaa, mikäli tuotettu biokaasu myytäisiin hintaan 1,22 €/kg. Porttimaksu olisi 50 €/m³ biojätteelle. Takaisinmaksuaika, riippuen laskutavasta ja biokaasun hinnoittelusta, vaihteli 8 ja 29 vuoden välillä. Laskennallisesti, neljästä eri syötemateriaalista voitaisiin saada 203 250 m³ metaanikaasua. Energiasisällöltään se riittäisi korvaamaan noin 150 auton bensiinin kulutuksen. RETScreen arviointi antoi noin 15 000 m³ pienemmän arvion metaanikaasun määrästä. Mahdollinen reaktorityyppi olisi tilavuudeltaan 500 m³ ja prosessina mesofiilinen kuivaprosessi. Myös biojätteen erilliskeräyksen järjestämistä kunnan taajama-alueella ja käytännön asioiden järjestämistä biokaasulaitoksella pohdittiin. Tulosten mukaan yhteismädättämön rakentaminen Sodankylään on teknis-taloudellisesti mahdollista. Kuitenkin useita oletuksia täytyi tehdä, esimerkiksi investointitueksi oletetaan 25 % ja reaktorin sekä biokaasun puhdistuslaitteiston hinnat perustuvat kirjallisuuden keskiarvoihin. On myös teknisesti haastavaa käsitellä jätteitä, jotka ovat kausittaisesti saatavilla. Tarkoituksena olisi tuottaa tasaisesti biokaasua, mutta se on haasteellista, jos reaktoriin syötetään erilaista materiaalia riippuen vuodenajasta. Prosessiolosuhteiden ja kuormituksen pitäisi pysyä tasaisena, jotta biokaasulle saataisiin suuri saanti. Vaikka saadut tulokset ovat positiivisia, enemmän tutkimusta kaivattaisiin investoinnin kannattavuuden varmistamiseksi. Erityistä huomiota tulisi antaa reaktorimallille. Tämä diplomityö osoittaa, että biotalous on teknis-taloudellisesti kestävä toteuttaa Suomen pohjoisissa osissa. Työssä esitelty biokaasulaitoskonsepti olisi monistettavissa samankaltaisille alueille. Työ tehtiin osana RECENT (Renewable Community Empowerment in Northern Territories) -projektia.

<p> Water is becoming increasingly scarce; approximately 2 billion people currently live in annual water scarcity, and 3 to 4 billion people are expected to live in water scarcity by 2050 due to population growth alone. Therefore, there is need to determine suitable alternative drinking water sources. Alternative sources present different advantages in terms of supply, initial contamination, and variability. Different technologies may be most effective or sustainable for treating these alternative source waters depending on scale and application (e.g., toilet flushing, irrigation, or potable reuse). Previous reuse research has focused on biological treatment of greywater, passive treatment of stormwater, and reverse osmosis or advanced oxidation for wastewater effluent. The objectives of this dissertation were to (i) study the effectiveness of conventional drinking water treatment (CDWT) for potable reuse of alternative source waters and blends, (ii) compare the environmental sustainability of novel sorbents for micropollutant removal from wastewater effluent, (iii) develop an improved synthetic bathroom greywater that closes matches the characteristics and treatability of real bathroom greywater, and (iv) compare activated carbon and biochar for dissolved organic carbon (DOC) removal from raw and pretreated greywater. </p><p> Bench-scale experiments simulating CDWT achieved high turbidity removal in alternative source waters. Average maximum TOC removal with CDWT was 19%, 27% and 37% for greywater, wastewater effluent, and stormwater, respectively. However, no wastewater effluents and only one stormwater met drinking water regulations for disinfection byproduct formation control. Environmental sustainability was assessed using life cycle methodology. For micropollutant removal from wastewater effluent, wood-based biochar was more sustainable than activated carbon in most environmental impact categories. Higher adsorption capacity was associated with greater environmental benefits. A new synthetic bathroom greywater (SynGrey) was developed that closely matches the median characteristics of forty-nine real bathroom greywaters, and matched the treatability of real bathroom greywater in chlorination, biodegradation, and sorption. Five biochars were screened for greywater treatment, and activated carbon removed more DOC than the best biochar from raw, coagulated, aerated, and rainwater-blended greywater. This research will contribute to the selection and design of effective, sustainable treatment systems for potable and nonpotable reuse of alternative source waters.</p><p>

abstract: Contaminants of emerging concern (CECs) present in wastewater effluent can threat its safe discharge or reuse. Additional barriers of protection can be provided using advanced or natural treatment processes. This dissertation evaluated ozonation and constructed wetlands to remove CECs from wastewater effluent. Organic CECs can be removed by hydroxyl radical formed during ozonation, however estimating the ozone demand of wastewater effluent is complicated due to the presence of reduced inorganic species. A method was developed to estimate ozone consumption only by dissolved organic compounds and predict trace organic oxidation across multiple wastewater sources. Organic and engineered nanomaterial (ENM) CEC removal in constructed wetlands was investigated using batch experiments and continuous-flow microcosms containing decaying wetland plants. CEC removal varied depending on their physico-chemical properties, hydraulic residence time (HRT) and relative quantities of plant materials in the microcosms. At comparable HRTs, ENM removal improved with higher quantity of plant materials due to enhanced sorption which was verified in batch-scale studies with plant materials. A fate-predictive model was developed to evaluate the role of design loading rates on organic CEC removal. Areal removal rates increased with hydraulic loading rates (HLRs) and carbon loading rates (CLRs) unless photolysis was the dominant removal mechanism (e.g. atrazine). To optimize CEC removal, wetlands with different CLRs can be used in combination without lowering the net HLR. Organic CEC removal in denitrifying conditions of constructed wetlands was investigated and selected CECs (e.g. estradiol) were found to biotransform while denitrification occurred. Although level of denitrification was affected by HRT, similar impact on estradiol was not observed due to a dominant effect from plant biomass quantity. Overall, both modeling and experimental findings suggest considering CLR as an equally important factor with HRT or HLR to design constructed wetlands for CEC removal. This dissertation provided directions to select design parameters for ozonation (ozone dose) and constructed wetlands (design loading rates) to meet organic CEC removal goals. Future research is needed to understand fate of ENMs during ozonation and quantify the contributions from different transformation mechanisms occurring in the wetlands to incorporate in a model and evaluate the effect of wetland design. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2013

abstract: Uranium (U) contamination has been attracting public concern, and many researchers are investigating principles and applications of U remediation. The overall goal of my research is to understand the versatile roles of sulfate-reducing bacteria (SRB) in uranium bioremediation, including direct involvement (reducing U) and indirect involvement (protecting U reoxidation). I pursue this goal by studying Desulfovibro vuglaris, a representative SRB. For direct involvement, I performed experiments on uranium bioreduction and uraninite (UO2) production in batch tests and in a H2-based membrane biofilm reactor (MBfR) inoculated with D. vuglaris. In summary, D. vuglaris was able to immobilize soluble U(VI) by enzymatically reducing it to insoluble U(IV), and the nanocrystallinte UO2 was associated with the biomass. In the MBfR system, although D. vuglaris failed to form a biofilm, other microbial groups capable of U(VI) reduction formed a biofilm, and up to 95% U removal was achieved during a long-term operation. For the indirect involvement, I studied the production and characterization of and biogenic iron sulfide (FeS) in batch tests. In summary, D. vuglaris produced nanocrystalline FeS, a potential redox buffer to protect UO2 from remobilization by O2. My results demonstrate that a variety of controllable environmental parameters, including pH, free sulfide, and types of Fe sources and electron donors, significantly determined the characteristics of both biogenic solids, and those characteristics should affect U-sequestrating performance by SRB. Overall, my results provide a baseline for exploiting effective and sustainable approaches to U bioremediation, including the application of the novel MBfR technology to U sequestration from groundwater and biogenic FeS for protecting remobilization of sequestrated U, as well as the microbe-relevant tools to optimize U sequestration applicable in reality. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2014

abstract: Hydrocarbon spill site cleanup is challenging when contaminants are present in lower permeability layers. These are difficult to remediate and may result in long-term groundwater impacts. The research goal is to investigate strategies for long-term reduction of contaminant emissions from sources in low permeability layers through partial source treatment at higher/lower permeability interfaces. Conceptually, this provides a clean/reduced concentration zone near the interface, and consequently a reduced concentration gradient and flux from the lower permeability layer. Treatment by in-situ chemical oxidation (ISCO) was evaluated using hydrogen peroxide (H2O2) and sodium persulfate (Na2S2O8). H2O2 studies included lab and field-scale distribution studies and lab emission reduction experiments. The reaction rate of H2O2 in soils was so fast it did not travel far (<1 m) from delivery points under typical flow conditions. Oxygen gas generated and partially trapped in soil pores served as a dissolved oxygen (DO) source for >60 days in field and lab studies. During that period, the laboratory studies had reduced hydrocarbon impacts, presumably from aerobic biodegradation, which rebounded once the O2 source depleted. Therefore field monitoring should extend beyond the post-treatment elevated DO. Na2S2O8 use was studied in two-dimensional tanks (122-cm tall, 122-cm wide, and 5-cm thick) containing two contrasting permeability layers (three orders of magnitude difference). The lower permeability layer initially contained a dissolved-sorbed contaminant source throughout this layer, or a 10-cm thick non-aqueous phase liquid (NAPL)-impacted zone below the higher/lower permeability interface. The dissolved-sorbed source tank was actively treated for 14 d. Two hundred days after treatment, the emission reduction of benzene, toluene, ethylbenzene, and p-xylene (BTEX) were 95-99% and methyl tert-butyl ether (MTBE) was 63%. The LNAPL-source tank had three Na2S2O8 and two sodium hydroxide (NaOH) applications for S2O82- base activation. The resulting emission reductions for BTEX, n-propylbenzene, and 1,3,5 trymethylbenzene were 55-73%. While less effective at reducing emissions from LNAPL sources, the 14-d treatment delivered sufficient S2O82- though diffusion to remediate BTEX from the 60 cm dissolved-sorbed source. The overall S2O82- utilization in the dissolved source experiment was calculated by mass balance to be 108-125 g S2O82-/g hydrocarbon treated. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2014

Water flows in the Earth system are complex and difficult to quantify. Using data without recourse to an underlying physical theory has been a hallmark of hydrologic science for many years. Currently the expanding ability to handle large data sets using new methods has led to the development and use of sophisticated data-driven models with the ability to integrate physical theory into model architectures. My dissertation relies on theory-informed data-driven models (DDMs) to answer questions in hydrology. I first explore how theory can be integrated with DDMs. I apply and compare various methods to build DDMs to regionalize measured streamflow information to ungaged catchments where measurements are not available. I expand the work to address questions in sociohydrolgyâan emerging sub-discipline within the hydrologic sciences that seeks to integrate the physical and social aspects of hydrologic systemsâand show how the amount of water used across the U.S. is related to both physical and social variables. Finally, I discuss how DDMs in general, and each of the problems that I address in my dissertation in particular, relate to various forms of logical inference and how the feedback between data analysis and established theory is connate to scientific progress.

For hydropower systems under regulatory requirements, high-fidelity water quality models are useful tools for advance prediction of water quality outcomes subject to operating schemes; however, when considered alongside additional reservoir demands and constraints, an optimization approach becomes necessary for determining compliant operations. Hydropower operations optimization subject to environmental constraints is limited by challenges associated with dimensionality and spatial and temporal resolution. This dissertation describes an advancement for computing hourly power generation schemes for a hydropower reservoir using high-fidelity models, surrogate modeling techniques, and optimization methods. An artificial neural network successfully emulates the predictive power of the high-fidelity hydrodynamic and water quality model CE-QUAL-W2. We applied a genetic algorithm (GA) optimization approach to maximize hydropower generation subject to constraints on dam operations and water quality (as predicted by the surrogate model) to a multipurpose reservoir near Nashville, Tennessee. The surrogate model successfully reproduced high-fidelity reservoir information while enabling increases in hydropower production value relative to actual operations for dissolved oxygen (DO) limits of 5 and 6 mg/L, respectively, while witnessing an expected decrease in power generation at more restrictive DO constraints. Exploration of simultaneous temperature and DO constraints revealed capability to address multiple water quality constraints. The optimizerâs solution quality depends upon surrogate model training data selection, and offline training alone (i.e., prior to optimization) yields poor results. We therefore demonstrated a method for adaptively updating the surrogate model with newly supplied training data, influenced by the convergence path of the GA. A random immigrants replacement approach was also explored. Combining both approaches improved solution fitness values compared to those found by optimizing with neither feature. Looking toward expanding this work to a system of reservoirs, we assessed the sensitivity of release water quality in response to an upstream reservoir's releases. Prediction errors caused by differences in the upstream boundary condition indicate minimal impact on potential solutions to the optimization problem, in which these predictions define water quality constraints. Determining independence between reservoirs could enable efficient expansion of the optimization methodology to reservoir systems.

This research integrates geospatial and social datasets to understand the adaptive strategies employed by individuals, communities, and institutions during periods of drought. I apply dimension reduction techniques to remotely sensed data to identify agricultural communities in which cultivation occurred during an extreme drought. Two dominant adaptive strategies emerged from this research: crop diversification and a complex land reallocation process known locally as bethma. I supplemented this qualitative research with Bayesian analysis of project survey data to identify the multi-scalar factors driving participation in these adaptive behaviors. Results suggest that farmers with more assets (agrowell, land, higher socio-economic status) are more likely to engage in adaptive behaviors. To better understand the role of farmersâ risk perception in influencing adaptive behaviors, I constructed an agent-based model to assess the extent to which farmer decision heuristics affect participation in crop diversification and bethma. Simulation results suggest that though environmental changes may produce sudden disruptions in agricultural outcomes, the variations in these outcomes are strongly influenced by the mental models farmers use to make agricultural decisions. I also collaborated with a data scientist to apply machine learning techniques to large remotely sensed datasets to create an open-source prediction software to forecast vegetation health. This is particularly important in tropical countries where cloud cover significantly reduces data availability. The latest version of the software is global in coverage and performs extremely well across agroecological contexts, time, and levels of data availability. The results of my research in Sri Lanka will increase the capacity of decision makers to monitor agricultural systems, identify and promote successful adaptive strategies, and increase agricultural adaptation to changing climate.

<p> Water treatment requirements are steadily increasing globally, with higher demands on both the quality and quantity of water that systems must be able to deliver. These demands disproportionately impact small and rural water treatment systems, where economy of scale makes treating emerging contaminants and achieving higher water quality metrics significant concerns Systems such as reverse osmosis or traditional drinking water plants, may be inappropriate or impractical for these situations. One technology that may be applicable to these scenarios is membrane distillation (MD) as either a stand-alone treatment option or a polishing step. MD is an attractive technology for these small systems, with relatively simple operation and high documented rejection rates of metals, salts, and other non-volatile contaminants. The performance of MD with volatile and semi-volatile components is not as well understood, and the work discussed here seeks to develop an understanding of the factors that govern transport of these compounds within MD systems. </p><p> A novel, gas-tight direct contact membrane distillation (DCMD) system was developed to test a variety of non-volatile, semi-volatile, and volatile compounds in a closed-loop system. This bench scale system is the first of its kind, and allowed for more precise identification of contaminant transport than has been achieved in previous studies. A series of batch experiments were carried out using an array of salts and metals to test the transport of non-volatile substances that have been reported in the literature to be well rejected by MD. Further experiments were carried out with emerging contaminants of concern such as nitrogenous disinfection byproducts, pharmaceuticals and personal care products, and other volatile and semi-volatile constituents. Concentrations of these compounds in the feed and the distillate tanks were measured at intervals to quantify compound behavior, and the data obtained was then compared against physical and chemical parameters of the compounds in question, providing insight into the phenomena governing their transport in these systems. </p><p> As a result of this work, it was determined that compound rejection in MD systems is governed largely by compound volatility, as defined by Henry&rsquo;s Constant. Furthermore, the interpretation of the results indicates that passage of compounds across the membrane is an equilibrium process, dominated by temperature and compound concentration on either side of the membrane. This confirms, and provides a theoretical basis, for the theoretically perfect rejection of non-volatile compounds by MD systems that has often been documented, and explains the behavior of volatile and semi-volatile compounds in these same systems.</p><p>

<p> Jar testing is one of the most common tools that water treatment facilities use to determine the treatment conditions necessary to meet finished water quality goals. A six-place stirrer is normally used for jar testing to provide identical mixing conditions while coagulant dose and pH vary in each jar to create &ldquo;floc&rdquo; that is removed via sedimentation. There are some utilities that are unable to utilize jar testing, since the current jar testing procedures do not identify optimum treatment conditions for their water supply. This is particularly true for those utilities treating low-turbidity, low-TOC waters because low coagulant doses can produce small floc that does not settle efficiently (even though it is removed efficiently by filters). A modified jar test procedure was developed with the goal of providing consistent and reliable results for all treatment facilities without having to make site-specific changes to the mixing speeds and times to try to match the plant performance. Instead of sedimentation, the modified jar test procedure uses a novel granular media filter along with a standardized mixing protocol and titrations to predict and control the pH of the coagulated water. Contour mapping of jar test data was utilized to provide a detailed visual description of zones of effective treatment. Research found that the application of direct filtration (instead of traditional sedimentation) reduced testing time and showed better correlation to treatment plant performance. A method of optimizing coagulant dose and coagulated pH based on titrations is proposed, which is based on an alternating, single-variable optimization method with experimentally determined starting points. Treatment with coagulant only (i.e., without prior pH adjustment) limits the range of coagulation conditions a water treatment plant can operate at. Coagulants are acidic and their addition during treatment causes both the pH and coagulant dose to change simultaneously. Treating water with coagulant only provides only one diagonal path for treatment to occur across a two-dimensional area of pH and coagulant dose combinations, which sometimes misses optimal treatment conditions entirely.</p><p>