The application of microalgae for biofuel production is a subject of increasing interest as fuel prices continue to fluctuate and the United States aims to secure a reliable, domestic fuel source. Though microalgae have proven to be very efficient at producing oil-rich lipids, the optimum conditions for algae cultivation and methods for harvesting and oil extraction have not been determined. In particular, the harvesting component is especially important to the effectiveness of the overall process because of the large volumes of algae-rich water that must be processed, the strict requirements for downstream lysing, oil extraction and fuel production and the necessity to generate algae biomass with significant post-extraction byproduct value. A number of solid-liquid separation technologies have shown some potential for achieving microalgae/water separation; however, application of these processes to biofuel production requires an evaluation of treatment effectiveness as a function of water quality, algae particle characteristics, and process chemistry. The goal of this research was to identify and evaluate several potentially viable harvesting methods that could be incorporated into end-to-end algae to biofuel production. To achieve this goal, a literature review was conducted to identify the most promising harvesting methods for biofuel applications, and bench scale tests were performed for several harvesting processes. A number of significant findings were identified. Batch algae coagulation experiments with ferric chloride, chitosan, and pH-induced autoflocculation suggest that coagulants can provide effective treatment, but the effectiveness is dependent on water composition and pH. Electrocoagulation experiments indicated that dissolution of the sacrificial electrode led to high metal concentrations in the algae. Pre-oxidation with ozone increased the removal of freshwater Neochloris oleobundans by 20-80% after subsequent flocculation and sedimentation compared with non-ozonated samples. Most notably, this research identified the importance of optimizing water quality and algae particle characteristics for a particular algae harvesting process. Implementing a harvesting process that takes advantage of the natural constituents of a water and the surface characteristics of an algae culture, minimize treatment requirements and enables smoother integration with subsequent processing steps. / text

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Hemicellulose, a plant cell wall polysaccharide composed amongst other 6-carbon sugars of xylose, a 5-carbon fermentable sugar, has various side-chains which hinder breakdown by the hydrolytic enzyme xylanase. We executed a screen of a metagenomic library established from heat treated saw dust to isolate novel genes for plant cell wall esterases and isolated two clones that potentially could be utilised as acetyl xylan esterases: HEL12 and HEL37 from Citrobacter farmeri and Bacillus vallismortis respectively are confirmed short-chain acetyl xylan esterases (C2-C4) with an optimal temperature of 30°C and 35°C and pH 8.0. HEL12 (33kDa) and HEL37 (25kDa) are small, dextrous acetyl xylan esterases with HEL37: Km of 1.621mM for p-nitrophenyl acetate and Km of 3.571mM for the substrate p-nitrophenyl palmitate with a Vmax of 2.462 mMol/min/mg protein and Vmax of 0.4363 mMol/min/mg protein respectively. In addition HEL12 was active on other substrates with a Km of 1.321mM protein for p-nitrophenyl acetate and Km of 1.692mM for the substrate p-nitrophenyl butyrate with a Vmax of 3.812 and Vmax of 1.523 mMol/min/mg protein respectively. Both enzymes were assayed on various acetylated polymers including acetylated xylan to indicate their ability to hydrolyse plant lignocellulosic polymers. / AFRIKAANSE OPSOMMING: Met die herwinde interisering in die energie krisis, is “herwinbare energie” vinnig besig om die nuwe modewoord te raak tussen verskeie industriële bedrywighede. Hemicellulose, ‘n plant sel wand polisakkaride opgemaak uit xilose, ‘n 5-koolstof fermenteerbare suiker, het verskillende sykettings wat ‘n hindernis veroorsaak in die hidrolase van die komponent deur xilanase ensieme. HEL12 en HEL37 van bakterieë Citrobacter farmeri en Bacillus vallismortis afsonderlik, is deel van die hidrolitiese groep van ensieme wat die hidrolisasie van ester sy-bindings op die xilaan suikerstring kataliseer. Die ensieme was primêr geassesseer vir aktiwiteit deur middel van sintetiese substraat 4-nitrofeniel asetaat. HEL12 en HEL37 was gevind om kort-ketting asetiel xilaan esterase (C2-C4) te wees, met ‘n optimale temperatuur van 30°C en 35°C afsonderlik, beide met ‘n optimale pH van 8.0. Met ‘n geskatte gewig van omtrent +- 30kDa is beide die ensieme van die kleiner meer behendige asetiel xilaan esterase, met HEL37: Km = 1.621 op 4-nitrofeniel asetaat en Km = 3.571 op substraat 4-nitrofeniel palmetaat, en Vmax = 2.462 met ‘n Vmax = 0.4363 afsonderlik, en HEL12: Km = 1.321 op 4-nitrofeniel asetaat en Km = 1.692 op sustraat 4-nitrofeniel buteraat met ‘n Vmax = 3.812 en Vmax = 1.523 afsonderlik.

Magister Economicae - MEcon / Against the backdrop of rising fuel prices and increasing transport fuel demand, biofuel production, driven by the potential to contribute to energy security, climate change mitigation and rural development has experience rapid growth in recent years. Apart from a few private initiatives, South Africa has no commercialized biofuel industry to date. The concerns are that economic, environmental and socio economic issues can be a hindrance to the success of the industry. In response to these concerns this research intends to ascertain whether biofuel production could offer a viable economic alternative to fossil fuels in South Africa. For decision makers it is hard to find reliable reference material and solid guidance. Uncertainty over the potential risks and benefits has left potential investors unsure whether biofuel production could be a viable investment opportunity. The aim of this study was to determine if the benefits derived from biofuel production are significant enough to justify the substantial investment required. The findings reveal that in the absence of clear government strategies and the availability of low cost feedstocks the production of biofuel cannot be viewed as viable. The results show that bioethanol from grain sorghum and sugarcane are not economically viable since the results turn out to be negative in terms of both net present values (NPV) and internal rate of return (IRR) calculations, thus rendering a viable payback (PBP) period as unattainable. Similarly, the NPV and IRR for biodiesel from soya beans and sunflower is negative and the PBP also unattainable. Sensitivity analyses indicate that these crops (except for sunflowers) could only become viable if there were to be a substantial reduction in feedstock prices. All other changes in parameters would not render any of the production plant viable.

The production of biofuels in South Africa has evolved very slowly and at present there are only a handful of plants producing some derivative of biofuel. The lack of commitment from government and the utter information distortion under which the current policy framework was developed have largely contributed to the current state of affairs. The manner in which the current policy framework was formulated based on the available information has impacted negatively on the development of the industry and it is hypothesised that had a better and more comprehensive analysis process been followed, the framework would be of such a nature that the industry could be sustainable in the long run. The study examines the policies and policy development process that have taken place in other biofuel producing countries and investigates the various policy instruments that are in use in these industries. The study further explores the interactions of industry role players at both government and producer level while attempting to explain the factors that could have caused their deviation from the rational and expected path of strategies and actions. In both games, each at a different level, the resultant Nash Equilibrium changes and prevailing strategies indicate that it is not in the role player's interest to commit to the industry. The government departments involved in formulating the biofuel policy seem to be uninformed and hence choose a low support route while oil companies consistently choose not to invest in capacity and biofuel refiners find their Nash Equilibrium at high levels of investment. A decision tree is formulated to conduct an in-depth review of the current level of profitability of proposed and current projects with specific reference to current legislation. The decision tree unpacks the current economic environment in the industry and identifies various factors that are crucial to the long-term development and growth of the industry. Based on this comprehensive survey of the industry and a detailed comparison of various production costs, together with the design of the game theoretic framework, a conceptual policy framework is designed and it is proposed that this replaces the current biofuel strategy. The new policy framework establishes its sustainable structure based on facts, detailed figures and existing project information. The framework is based on a more sustainable policy structure that combines elements of rural development with the economics that are required in order for the industry to be sustainable in the long run. Unlike the official government biofuels policy, the Industrial Biofuels Strategy, this proposed policy framework takes the industry's and role players' requirements into account and is designed in such a way that government targets and goals are accomplished. It is hypothesised that the implementation of this comprehensive policy framework will assist in the establishment of a successful and sustainable biofuels industry. Copyright / Thesis (DCom)--University of Pretoria, 2010. / Agricultural Economics, Extension and Rural Development / unrestricted

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Biofuels are being promoted as a global necessity to meet climate change targets through the replacement of fossil fuels. Many countries have identified biofuels as a potential mechanism to meet these challenges, with policy directives driving biofuel production. The South African government has proposed that biofuels form part of the country’s future renewable energy and has proposed a draft biofuel strategy. This study aims to investigate appropriate approaches to determine potential biodiversity impacts from biofuel production. Since biofuels are not currently grown to any large extent in South Africa, impact was modelled using future scenarios of converting available land within the Eastern Cape Province of South Africa. Suitable species were identified using the species distribution modelling programme MaxEnt. Some of the proposed biofuel crops were considered as invasive (i.e. they spread from sites where they are cultivated) or are very likely to be invasive in South Africa. This study also highlighted the considerable overlap between suitable growing areas and areas considered important for future biodiversity conservation. The biodiversity intactness index (BII), a broad based biodiversity indicator, was used to assess the biodiversity implications of transforming available land to biofuels. The BII indicates losses of biodiversity between 17.6% and 42.1% for the land use scenarios identified. An important finding was that excluding important biodiversity areas that occur outside of protected areas can reduce biodiversity losses by as much as 13% and maintain an overall intactness of ~70%. Currently the BII does not account for fragmentation or landscape configuration. This was addressed by developing a revised biodiversity intactness index (R-BII) which included the effect of patch-size and habitat fragmentation on biodiversity intactness. This study found that although the original BII reported on the biodiversity trends of large-scale shifts in land-use across multiple scales it could not detect changes in landscape configuration which was reflected by the R-BII. Land-use change can impact on ecosystem processes that underpin the provisioning of ecosystem services by changing the combinations of species and the plant functional traits within communities. The impacts of cultivating potential biofuel species (Acacia mearnsii, Sorghum halepense and Eucalyptus species) were investigated using a plant functional traits approach. These species were shown to affect the leaf nitrogen content, leaf phosphorous content and leaf dry matter content associated with important ecosystem functions within an ecosystem service hotspot in the Eastern Cape. A decline in functional diversity was reported for all transformed land-uses by as much as ~40%. These shifts may be used to identify potential changes to ecosystem services associated with natural vegetation. The methods used in this thesis highlight the overall relevance of this work and its importance to minimising biodiversity resulting from biofuel production. Some of the key findings address resolving spatial conflict, using biodiversity indicators, assessing impacts of potential invasive species and planning for ecosystem services. New drivers of change to land-use, such as biofuel production, are a major challenge to conservation biologists and planners and the insights derived in from this study can be successfully applied to guide biofuel production. / AFRIKAANSE OPSOMMING: Biobrandstof word internasionaal beskou as 'n noodsaaklike komponent in die bereiking van klimaatsverandering doelwitte deur fossielbrandstowwe daarmee te vervang. Daarom word biobrandstof deur verskeie lande geïmplementeer as 'n potensiële meganisme om aan hierdie uitdaging te voldoen. Die Suid-Afrikaanse regering het voorgestel dat biobrandstof deel vorm van die land se hernubare energie toekoms en het daarom 'n konsep biobrandstofstrategie voorgestel. Die aanvaarding van so 'n strategie sal waarskynlik ‘n aantal verreikende gevolge inhou. Hierdie studie gebruik verskeie benaderings ten einde die impak van biobrandstof produksie op biodiversiteit te bepaal. Aangesien biobrandstof nie tans ‘n beduidende bydra maak tot tradisionele brandstofproduksie in Suid-Afrika nie, word die impak daarvan geskoei op die omskakeling van beskikbare grond. Die Oos-Kaap provinsie van Suid-Afrika speel a sleutelrol in hierdie opsig en vorm daarom die fokus van hierdie analise. Geskikte spesies is geïdentifiseer deur die sagtewareprogram, MaxEnt, waardeur spesiesverspreiding gemodelleer word. Hierdie studie beklemtoon die aansienlike oorvleueling wat daar bestaan tussen geskikte aanplantingsgebiede en belangrike biodiversiteitsareas wat nie tans formeel bewaar word nie. Sommige van die voorgestelde biobrandstofgewasse is tans indringers, of het die potensiaal om indringerplante te word en daarom is daar toenemende kommer oor die kweek van biobrandstof gewasse in Suid-Afrika. Die “Biodiversity Intactness Index” (BII), 'n algemene biodiversiteitsaanwyser, is gebruik om die implikasies van grondomskakeling na biobrandstof op biodiversiteit te evalueer. Die BII dui op verliese van tussen 17,6% en 42,1% vir die grondgebruikscenario's wat geïdentifiseer is. 'n Belangrike bevinding was dat die uitsluiting van belangrike biodiversiteitsareas buite beskermde gebiede die verlies van biodiversiteit met soveel as 13% kan verminder en biodiversiteit eenheid van ~ 70% kan behou. Die BII maak egter nie tans voorsiening vir landskap fragmentasie nie. ‘n “Revised-Biodiversity Intactness Index” (R-BII) is ontwikkel wat die effek van kol-grootte en habitat op biodiversiteit eenheid insluit. Hierdie studie het bevind dat alhoewel die oorspronklike BII grootskaalse verandering in die grondgebruik op verskeie skale aandui, dit egter nie verandering in landskapsamestelling kon opspoor soos die R-BII nie. Ten slotte, die impak van die aanplanting van potensiële biobrandstofspesies (Acacia mearnsii, Sorghum halepense en Eucalyptus spesies) op biodiversiteit is ondersoek deur ‘n plant funksionele eienskappe benadering te gebruik. Daar is bevind dat hierdie spesies die stikstof, fosfor en droë materiaal inhoud van blare verander wat geassosieer word met belangrike ekosisteem funksies binne 'n biodiversiteit brandpunt in die Oos- Kaap. ‘n Vermindering van funksionele diversiteit van soveel as ~ 40% is binne alle omgeskakelde grondgebruike gevind. Hierdie skuiwe kan gebruik word om potensiële veranderinge van ekosisteemdienste te identifiseer en benadruk ook die potensiële impak van uitheemse spesies. Die metodes wat gebruik word in hierdie studie beklemtoon die relevansie van die werk asook die belangrikheid daarvan om die nadelige uitwerking van biobrandstofproduksie op biodiversiteit te minimaliseer. Verskeie benaderings tot die oplossing van ruimtelike konflik, die gebruik van biodiversiteitaanwysers, die beoordeling van die impak van die potensiële indringerspesies en die beplanning vir ekosisteemdienste. Nuwe dryfvere van grondgebruikverandering soos biobrandstof is 'n groot uitdaging en die insigte wat uit hierdie studie verkry is dra by tot die vermindering van die potensiële impak van biobrandstofproduksie op biodiversiteit.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Increased demand of petroleum, declining fossil fuel reserves, geopolitical instability and the environmentally detrimental effects of fossil fuels have stimulated research to search for alternative sources of energy such as plant derived biofuels. The main feedstocks for production of first generation biofuels (bioethanol) are currently sucrose and starch, produced by crops such as sugarcane, sugarbeet, maize, and cassava. The use of food crop carbohydrates to produce biofuels is viewed as competing for limited agronomic resources and jeopardizing food security. Plants are also capable of storing sugars in their cell walls in the form of polysaccharides such as cellulose, hemicelluloses and pectin, however those are usually cross-linked with lignin, making their fermentation problematic, and are consequently referred to as lignocellulosics. Current technologies are not sufficient to degrade these cell wall sugars without large energy inputs, therefore making lignocellulosic biomass commercially unviable as a source of sugars for biofuel production. In the present study genes encoding for enzymes for cellulosic, hemicellulosic and starch-like polysaccharides biosynthesis were heterologously expressed to increase the amount of fermentable sugars in sugarcane. Transgenic lines heterologously expressing CsCesA, encoding a cellulose synthase from the marine invertebrate Ciona savignyi showed significant increases in their total cellulose synthase enzyme activity as well as the total cellulose content in internodal tissues. Elevation in cellulose contents was accompanied by a rise in hemicellulosic glucose content and uronic acid amounts, while total lignin was reduced in internodal tissues. Enzymatic saccharification of untreated lignocellulosic biomass of transgenic sugarcane lines had improved glucose release when exposed to cellulose hydrolyzing enzymes. Calli derived from transgenic sugarcane lines ectopically expressing galactomannan biosynthetic sequences ManS and GMGT from the cluster bean (Cyamopsis tetragonoloba) were observed to be capable of producing a galactomannan polysaccharide. However, after regeneration, transgenic sugarcane plants derived from those calli were unable to produce the polymer although the inserted genes were transcribed at the mRNA level. While the ectopic expression of Deinococcus radiodurans amylosucrase protein in the cytosol had a detrimental effect on the growth of transgenic lines (plants showed stunted growth through the 18 months growth period in greenhouse), contrastingly targeting the amylosucrase protein into the vacuole resulted in 3 months old transgenic lines which were having high maltooligosaccharide and soluble sugar (sucrose, glucose and fructose) levels in leaves. After 18 months growing in the greenhouse, the mature transgenic lines were morphologically similar to the untransformed lines and also contained comparable maltooligosaccharide and soluble sugar and starch amounts. The non-biosynthesis of galactomannan and amylose polysaccharides in the matured transgenic plants may be due to post-transcriptional protein processing and or protein instability, possibly explainable by other epigenetic mechanisms taking place to regulate gene expression in the at least allo-octaploid species of sugarcane under investigation in this study.

Ettsyfte med denna uppsats är jämförelsen mellan två behandlingsalternativ för matavfall, hemkompostering eller biogasproducering sett från klimatperspektivet. Koldioxidekvivalenter har beräknats för de två alternativen. Ett annat syfte har varit att studera den politiska processen för att förstå varför det först under 90-talet uppmuntras till att hushållen ska hemkompostera för att sen under början av 2000-talet förespråka rötning av matavfallet. Mina uträkningar och jämförelser visar att det är mer fördelaktigt för klimatet att röta matavfallet, koldioxidutsläppet blir mindre än vid hemkompostering. Mitt andra syfte visar att det kan finnas en klimatvinst genom att låta politiken fatta besluten men det kan även finnas en risk att det egentliga syftet med hemkompostering glöms bort och att hushållen måste betala för något som de egentligen inte behöver (matkärl) eller som inte kanske finns (tillsynen). / One purpose of this study is to compare two treatment options for food waste. Home composting or biofuel production, seen from the climate perspective. The carbon dioxide equivalent has been calculated for the two options. The second purpose was to study the political process with regard to food waste to understand why Swedish households were encouraged to home compost food waste during the nineties only to early twenties advocate biofuel production. My calculations and comparisons shows that it is more beneficial for the climate to digest the food waste then composting since the carbon dioxide emissions is less. My second analysis indicates that while the political reorientation has led to environmental improvements, the effect has also been that to gain control of the food waste stream, waste management organisations effectively provide customers with no choice and economically punish households that have no food waste to collect since they have effective home composting.

I det här examensarbetet har utvecklingen av den svenska politiken kring biodrivmedel under perioden 1975–2020 undersökts. Detta i syfte att öka förståelsen för de politiska motiv som legat till grund vid utformningen av politiska styrmedel samt hur sambanden mellan styrmedel och biodrivmedelsproduktion utvecklats. I rapporten ingår granskningen av de propositioner och underlagsrapporter som varit grund till svenska styrmedel riktade mot biodrivmedel. Styrmedelsförslagen har beskrivits och vissa skillnader mellan underlagsrapporter och slutgiltigt förslag har diskuterats. De motiveringar och politiska mål som hänvisas till i styrmedelsförslagen har satts i en bredare kontext för att beskriva hur utvecklingen sett ut. Utvecklingen av biodrivmedelsmarknaden har samtidigt undersökts med hjälp av Energimyndighetens årliga rapporter samt årsredovisningar och offentliga uttalanden från de största biodrivmedelsproducenterna. Vad denna genomgång visat är att biodrivmedel använts som ett medel för att minska användningen av fossilbaserad bensin och diesel för att nå målen inom ett flertal olika politikområden. I början av tidsperioden var det främsta målet att öka den svenska energiförsörjningstryggheten, det målet kompletterades sedan med mål om att minska hälso- och miljöskadliga utsläpp. Att minska utsläppen av växthusgaser började sedan bli allt mer prioriterat och har under de senaste 20–30 åren varit det främsta målet. Vilka målsättningar som biodrivmedel kopplats till har skiftat under tidperioden och det har även funnits skillnader mellan olika styrmedel under samma tidsperiod. Forsknings- och utvecklingsstöd har varit fokuserade på att omvandla inhemska råvaror till biodrivmedel. Finansiella- och administrativa styrmedel har i stället främst varit utformade för att öka andelen biodrivmedel i den totala mängden drivmedel och inte för att öka den inhemska produktionen. Efter Sveriges inträde i EU har en stor del av den svenska biodrivmedelspolitiken varit utformad till att uppfylla de EU-direktiv som funnits. De styrmedel som existerat har haft en tydlig koppling till hur den svenska biodrivmedelsmarknaden utvecklats men sambandet är komplext och det har även funnits andra faktorer så som oljepriset som också haft en påverkan på utvecklingen. / In this thesis, the development of Swedish biofuel policy during the period 1975–2020 were investigated. The goal was to increase the understanding of the political motives behind the formulation of policy instruments and how the links between policy instruments and biofuel production have developed. A review of policy instruments targeting biofuels were conducted and presented in the report. The basis for the policy proposals has been summarized and some differences between the suggested policy and the final proposal have been discussed. The justifications and policy objectives referred to in the proposals have been put in a broader context to describe the development. The development of the biofuel market was investigated using the reports compiled annually by the Swedish Energy Agency, as well as previous compilations from several journals. What these reviews have shown is that biofuels have been used as a means of reducing the use of fossil-based petrol and diesel to achieve the targets in several different policy areas. At the beginning of the period, the main goal was to increase Swedish energy security, which was then supplemented by the goal of reducing harmful emissions. Reducing greenhouse gas emissions then became an increasing priority and has over the past 20–30 years been the main goal. The objectives to which biofuels have been linked have both changed during the period, and there have also been d¬ifferences between different policy instruments during the same period. Research and development support have been focused on converting domestic raw materials into biofuels, while financial and administrative instruments have mainly been designed to increase the share of biofuel use within the total use of transportation fuels and not to increase domestic production. Since Sweden's entry into the EU, a large part of the Swedish biofuels policy has been designed to comply with the EU directives that have existed. The policy instruments that have existed have had a clear connection to how the Swedish biofuels market has developed, but the relationship is complex and there have also been other factors that have affected the development, such as the oil price.

Tyrimo tikslas – nustatyti įsitraukimo į biodegalų gamybą veiksnius ir įvertinti šalies įsitraukimą į biodegalų gamybą integralumo nacionalinėje ekonomikoje požiūriu. Darbo praktinė vertė. Biodegalų gamyba yra viena iš šiuolaikinės bioekonomikos sričių, kuria susidomi vis daugiau pasaulio šalių. Pastarasis dešimtmetis gali būti apibūdinamas kaip intensyvios biodegalų gamybos plėtros laikotarpis. Šalys, įsitraukdamos į biodegalų gamybą, siekia prisidėti prie darnios energetikos vystymosi. Darbe analizuojama, kaip šalies įsitraukimo į biodegalų gamybą veiksniai varijuoja priklausomai nuo šalies turtingumo naftos ištekliais. Nustatyta, kokie yra dominuojantys įsitraukimo į biodegalų gamybą veiksniai specifinėse šalių grupėse ir kokiu integralumu nacionalinėje ekonomikoje biodegalų gamyba pasižymi šiose šalyse. Tyrimas patvirtina, kad net ir paskatintas politinių iniciatyvų, biodegalų pramonės steigimasis šalyje paprastai grindžiamas išskirtinai didesniu apsirūpinimu biodegalų gamybos ištekliais arba didesne iškastinių energetinių išteklių stoka. Gautos tyrimo išvados gali pasitarnauti formuojant valstybės energetinės politikos gaires alternatyvios energetikos plėtotei. Mokslinio darbo naujumas. Šalies įsitraukimo į biodegalų gamybą vertinimo rezultatai papildo ekonomikos mokslo žinias apie egzistuojančius ryšius tarp ekonominių veiklų plėtojimo ir joms reikalingų gamybos išteklių šalyje gausos. Šių ryšių egzistavimas darbe atskleidžiamas analizuojant bioetanolio gamybą. Tyrimas... [toliau žr. visą tekstą] / Research aim – to identify factors behind engagement in biofuel production and evaluate engagement by a country in terms of production integration in the national economy. Practical value of the research. The production of biofuels is one of the most modern areas of the bioeconomy, which involves more and more countries around the world. The last decade can be described as an intense period of the development of biofuel production. Engaging in the production of biofuels countries seek to contribute to the sustainable energy development. In this research the analysis of factors of country’s engagement in biofuel production, depending on the oil richness of the country, is performed. It was analysed which factors determine the engagement in biofuel production in different groups of countries and which parameters of biofuel production integration in national economy are satisfied in these counties. The study confirms that biofuel industry establishment in the country, even promoted by political initiatives, is usually based on purely larger self-sufficiency in production resources or higher scarcity of fossil energy resource. The resulting findings can serve in shaping the state's energy policy guidelines for the development of alternative energy sources. Originality of the research work. The obtained results supplement the scientific knowledge in economics about the existence of the relationships between development economic activities and the abundance of necessary production... [to full text]

Rapid urbanization has led to the generation of enormous wastewater after independence. The domestic wastewater generated in municipalities is rich in nutrients such as carbon, nitrogen and phosphorus along with other ions. The generated wastewater due to lack of adequate appropriate infrastructure including low treatment efficiencies are either untreated or partially treated and are let into water bodies. Present sewage treatment plants (STP’s) in the city are either under capacity or malfunctioning and hence are unable to meet the growing demand of burgeoning urban population. Water bodies have the ability to uptake nutrients (remediation by algae, bacteria, macrophytes) provided the wastewater inflow does not exceed the threshold. However, the sustained flow of wastewater beyond the water body’s treatment ability has led to the serious problem of nutrient enrichment in surface water bodies which is evident from algal bloom and profuse growth of invasive exotic macrophytes. This necessitates cost effective environmentally sound treatment options. The current research focuses on the characterisation of domestic wastewater fed ponds/lakes, understanding of nutrient regimes in wastewaters, pond dynamics, nutrient transformation and resource recovery. This has aided in devising an algae based treatment system for Bangalore city. The interplay between various biotic and abiotic factors governs water quality in a water body. Regular monitoring helps in characterisation of the water body and also helps in identifying the sources of external input (if any) to the system. Wastewater generated in urban localities in India, due to lack of adequate appropriate infrastructure including low treatment efficiencies are untreated or partially treated and are let into water bodies. Understanding the nature of the wastewater flow regimes and the turnover of biota with prevalent nutrient conditions is required to design treatment systems. Treatment involves breakdown of complex organism forms into simpler forms and transformations of organic nutrients into inorganic forms that are finally absorbed and assimilated by microbes as algae and bacteria. In wastewater fed urban pond systems, an array of microphytes as well as macrophytes grow and help in nutrient cycling in the system and still manage to remove nutrients to satisfactory levels. However, sustained inflow of wastewater with high nutrients results in the deterioration of the system as nutrient input exceed the supportive and assimilative capability resulting in proliferation of macrophytes, algal blooms, froth formations rendering the system anoxic that results in the loss of functional abilities of the urban pond systems. This biota in the system plays a major role in nutrient removal and recycles. Understanding the nutrient cycling aspects of urban wastewater fed systems is essential to find out the key players in treatment and for devising a sustainable treatment option with resource recovery. The review of wastewater generation, treatment systems highlight shortfall of the treatment systems and need for sustainable treatment for removal and recovery of nutrients such as C, N and P. Characterisation of Varthur water body (spatial extent 220 ha) located in the south of Bangalore city has been done through monthly monitoring for 18 months with the analyses of physico-chemical and biological. The analysis showed BOD removal of 70% (filterable) when the lake functioned as an anaerobic–aerobic lagoon for 6 months at an estimated residence time of 5 days. During this period, the biota of the lake, especially primary producers such as algae, treat the water through remediation of nutrients to nearly standard water quality levels. However, the growth and spread of invasive exotic macrophytes such as water hyacinth rendered the lake anaerobic which reduces its ability (due to absence of low algae) to treat the water. This highlights the role of algae especially Chlorophycean members as Chlorococcum sp., Chlorella sp. and Monoraphidium sp. in treating urban domestic wastewater and the scope for introducing algal ponds/lagoons to treat wastewater treatment and it may be used in a larger number of small towns to enable local reuse of water. The entire pond systems comprises of various components that are deeply affected by the biotic and abiotic factors in the system. Hence, studies on major biotic components were conducted especially on algae and macrophytes and the impact of abiotic factors as wind, light, and precipitation with seasonality’s. The diurnal and spatio-temporal variations in the dissolved oxygen as well other treatment parameters were used for zonation through multivariate analysis. Physico-chemical parameters confirm the nutrient enrichment (high Amm.-N) in the water body due to the sustained inflow of wastewater. High levels of nutrients together with BOD have resulted in the lower DO levels affecting the biological life. Study on biota revealed macrophytes altering the photosynthetic regime in the algae in water bodies thus, creating anoxia and nutrient re-suspension. The multivariate analysis showed three distinct zones (clusters) on the basis of physico-chemical variables and nutrient concentrations in the lake. The sedimentary C and N analysis showed a steady increase in the C: N ratio as a function of residence time. Importance of the various sub-systems in the water body in terms of nutrient uptake and accumulation showed algal systems to be efficient. C budgeting accounted to ~ 7 t/d i.e. ~2574 t/y, indicated that the lake is an accumulator of C. An estimated relatively high gas emission across the water/air interface (17 t/d) to carbon burial into sediments (2.3 t/d) further indicates very high emissions compared to sedimentation showing the dominance of internal C cycles. The overall mass balance, gas exchange and carbon burial balance showed Varthur water body as a major emitter of C due to high primary production, substantive allochthonous carbon inputs and intensive anthropogenic activities in the water body. Gaseous carbon emission accounted for 28 % of the total Influx C. The spatial profile of N in sediment ranged from 2280-3539 mg/kg of sediment dry mass. Very low value of N:P ratio in sediments suggested possible N limitation. The determination of ammonification and nitrification showed lower nitrification rates than the ammonification rates. The potentially mineralisable nitrogen content in Varthur pond sediments varied greatly from 21.65% to 75.54% and was strongly correlated (r2=0.85) to sedimentary TN. N budgeting showed NH4-N as the predominant Nr form for microbial uptake and is the major mechanism for nitrogen removal, followed by the sedimentation process. Bacterial biomass, algal biomass and macrophyte biomass accounted for 14, 4 and 1% N removal, respectively. Ammonium concentration and nitrification accounted for 27% and 2%, respectively. While bacterial uptake remained fairly constant throughout the year, micro-algae was the major player during monsoon and winter and macrophytes dominated Nr capture during summer among autotrophs. From the estimates, it has been observed that nearly 55% Nr was recovered, recycled as cell mass and transferred to a crop system when such N-captured water is used for irrigating fodder crops. About 45% of N input into the system was lost and methods to reduce this loss need to be evolved in the future. The spatial profile of P in sediment ranged from 2111.35-3982.03 mg/kg of sediment dry mass. Inorganic-P (IP) ranging from 1270.27-3505.73 mg/kg was found to be the major fraction (61.16-91.56%) of sedimentary P. High p values in both water columns and sediments showed potential P excess conditions. P concentrations in micro and macro-algae collected during the due course of the study (on dry biomass basis) were 0.347% and 0.939% P respectively. The P fractionation revealed metal oxide bound P (NaOH-P) and constituted major fraction of IP indicating, high concentrations of Fe and Al in sediments. High concentrations of sedimentary N and P indicated possible higher trophic status (bio-productivity/unit volume) signifying its towering nutrient status evidenced from the rank order of P fractions: NaOH-P > HCl-P > NH4Cl-P, which is specific for highly enriched water bodies. P budgeting showed that bulk of the P is trapped in sediment layer with a potential of ~50 % recovery from the sediments indicating, ~70% P retention within the system. The biotic components such as bacteria, algae and macrophytes accumulates a substantial amount of P, immobilising ~139, ~482 and ~131 tonness/yr of P. The sequential P extraction shows that ~70 % of sediment bound P is readily reducible during anoxic conditions which can potentially become bio-available to trigger algal growth. Assessment of treatment efficiency of facultative algal ponds, showed moderate treatment levels with 60 % total COD removal, 50% of filterable COD removal; 82% of total BOD removal and 70% of filterable BOD removal. The N removal efficiency was lower. However, a rapid decrease in the suspended solids after a faster euglenoids growth indicated particulate C removal by algal ingestion. Euglenoides dominated the facultative pond and Chlorophycean members were more abundant in the maturation ponds owing to variable surface BOD loadings. Significant correlations between algal biomass and nutrients indicate the importance of the type and nature of algal communities that can be used as an efficient tool for predicting the dynamics of various phases in wastewater treatment systems. Detailed morphological analysis of dominant algal species i.e. euglenoides was also performed. Euglenophycean members (>14 species) sampled from various locations in the facultative pond based system showed various striae patterns and distinct nano channels on the cell surface that might have possible role in cell secretions. Comparative assessment of treatment systems reveal that algal pond systems performed well under higher organic load with a COD removal efficiency of 70%, TN removal efficiency of 73% and TP removal efficiency of 22%. However, the facultative pond based systems were effective in suspended solid (SS) removal up to 93% and BOD removal up to 82%. The conventional wastewater treatment systems were efficient in terms of SS removal up to 88%, COD removal up to 74% and BOD removal up to 63%, but were highly ineffective in nutrient removal. The evaluation of treatment processes in mechanically aerated systems, facultative ponds and large shallow lake based systems in terms of capital and annual O&M costs, COD removal cost and land requirements reveals that the mechanical systems require 5 times more capital and O&M costs than ponds. The treatment systems were also ranked in terms of the total annual cost (e.g., capital, manpower, chemical, repair, electricity, land). It showed that algal pond systems followed by facultative pond based system are economically better choice than mechanical technologies. Finally, it was found that the large pond based systems could be economically the best option for the developing countries considering all factors, including economic viability and treatment efficiency. The treatment efficiency analysis showed that algal pond systems were the most effective options for treating urban wastewater. Culturing native wastewater species in growth media and wastewaters, assessment of efficient cell disruption and solvent systems, lipid profiles of wastewater algal species were studied. Wastewater grown algal species as Euglena sp., Spirogyra sp., Phormidium sp., Lepocinclis ovum, and Chlorococcum sp. are comparatively rich in lipids. These algae grow mixotrophically and can store substantial amount of wastewater carbon as TAG’s in varied environments. Among the different cell disruption methods used for the study, sonication was the most effective. The combination of maceration and methanol: chloroform: water (2:1:0.8, v/v) (Bligh and Dyer’s, solvent) gave highest lipid extraction yield among other combinations. Further more these wastewater algae as Lepocinclis ovum and Chlorococcum sp. were found to grow better in wastewaters. Increased lipid content was recorded during the cell cultures with accumulation of quality FAME with high saturates predominated by C16-C18 fatty acids. These wastewater algal lipids are suitable for bio-energy generation with potential biomass productivity (6.52 t/ha/yr) of wastewater-grown species as Euglena. The studies on Euglena sp. showed mixotrophic mode that offers an efficient removal of TOC, N and P from domestic wastewater without any pre-treatment. Lipid profiles of the extracted algal oil were similar to the vegetative feedstock oils, indicating a good quality fuel for energy generation. Mixed algal consortia’s bioremediation potential (removal of nutrients) with the scope for biofuel production highlights self flocculating abilities of algal consortia aided in the effective treatment of wastewater with substantial algal harvest. Studies on cultivating wastewater algal consortia in novel cascading algal parcel flow reactor (CAPFR) operating in continuous mode showed 70-80 % nutrient and ~90 % C removal with in a residence time of ~4 days with highest cell densities (0.91 g/l) and productivities (0.26 g/l/d) in the last stages. The lipid contents varied from 26-28 % with highest lipid productivities ~58 mg/l/d in the 2nd phase of the bioreactor. Most of the lipids were associated with the pigments as chlorophyll and carotenoids. Furthermore, the algal rector removed bacteria up to 4 log orders. Essential cations and phosphates were responsible for self clumping of algal biomass in the final stages with a high internal P content within the cell. The algal biomass also showed substantial exothermic peaks and high heat values (~18 MJ/kg). Studies on continuous cultivation of Dictyosphaerium sp. showed that this species could adapt to wastewater conditions and also showed good nutrient removal at lower HRT (2.5 days). The high biomass productivities with high lipid content (~36%) at low HRT in the continuous mode offer potential options for economic and feasible nutrient removal with biofuel production. Investigations on city wastewaters showed low nutrient ratio indicating C limitations and possible scope for algal wastewater treatment. Integration of algal ponds in the present treatment network requires an additional land ranging from ~0.37 to 2.75 ha to treat an MLD of wastewater depending on the nutrient content and influent waters fed to algal systems. The treatment plants require an additional ~1.6 ha of land to treat 1 MLD of wastewater considering an average N and P values of 18 and 5 mg/l. The continuous algal bio-processes implemented at decentralised levels would help in the economical ways for nutrient removal and recycling of the nutrient free waters after treatment. This meets multiple objectives of low cost treatment of wastewater, nutrient recovery and fuel production. Algal nutrient capture and consequent biofuel production would ensure sustainability through i) water purification ii) nutrients capture and iii) biofuel to meet the growing energy demand, and would be an optimal treatment option for urban wastewater. The thesis consists of 10 chapters and basically deals with the development of a sustainable and economically viable bioprocess for wastewater treatment and biomass production. Chapter 1 provides a brief introduction to wastewater; domestic wastewater composition, generation and treatment in developing nations and in the country and review of the various techniques for treatment of domestic wastewaters, advantages of algal processes in nutrient removal (C, N and P) and production of valued by-product such as lipid generation, for its use as biofuel. Chapter 2 is based on primary field investigations in a wastewater fed urban water body/pond systems involving monthly sampling and analysis of various physico-chemical and biological parameters. Assessment of treatment capabilities of the continuous systems through detailed characterisation of treatment parameters is explained in the second chapter. Chapter 3 discusses the role of the major biotic (algae and macrophytes) and abiotic factors in nutrient transformations, the diurnal variations in parameters especially dissolved oxygen, multivariate spatio-temporal analysis of functional abilities for zoning, the activities in the sludge/sediment and transitions in the CN ratio as a function of residence time. Chapter 4 involves studies in C, N and P quantification and budgeting in such pond systems and partitioning of the nutrients and their distribution in various biotic and abiotic subsystems. This chapter also highlights the major nutrient losses from the system and un-utilised nutrient stocks, paving way for beneficial use of nutrients from such man made lagoon wastewater systems. Chapter 5 discusses the mechanisms and efficacies of algal pond based treatment systems through a detailed study and highlight its advantages over the mechanical ASP based systems. This has been done through a comparative assessment of treatment efficiency, economics and environmental externalities. This study also provides necessary insights and potential of wastewater algal species such as Euglena for its abilities in nutrient removal and biomass generation. This provides insights to algal treatment options for optimal resource recovery and utilisation from wastewaters. Chapter 6 focuses on testing the growth, biomass and lipid production of various wastewater algae isolated from treatment ponds. The chapter identifies suitable cell disruption and extraction routes for efficient lipid extraction and assesses the potential of these wastewater grown algae for regional and national biofuel production. Chapter 7 discusses the effectiveness of wastewater grown Euglena sp. and algal consortia in nutrient removal and as a source of lipids for biofuel generation. Chapter 8 involves the design and operation of a continuous algal (uni-algal/algal consortia) bioreactor devised taking insights from earlier field based studies and their potential as efficient urban wastewater treatment systems. Chapter 9 discusses the present nutrient levels in the city wastewaters and also an analysis of the temporal and spatial variation of nutrients in city sewers and elaborates the scope for integration of the algal modules i.e. continuous algal bioreactors (designed in the previous chapter) into existing STP’s. Chapter 10 elaborates significant contributions and outcome of the research.