published_or_final_version / Urban Planning and Design / Master / Master of Housing Management

Boreholes in the vicinity of a nuclear waste repository must be reliably sealed to prevent rapid migration of radionuclide contaminated water from the vicinity of the repository to the accessible environment. Few data currently exist regarding the effectiveness of borehole sealing. The objective of this research was to assess the performance of borehole seals under laboratory conditions, particularly with regard to varying stress fields. The approach used to evaluate borehole seals was to compare flow through a sealed borehole with flow through intact rock. Granite, basalt, and tuff were tested, using either cement or bentonite as the seal material. The main conclusions reached as a result of the experiments is that currently existing materials are capable of forming high quality seals when placed under laboratory conditions. Variation of triaxial stress state about a borehole does not significantly affect seal performance if the rock is stiffer than the seal material. Temperature/moisture variations (drying) degraded the quality of cement seals significantly. Performance partially recovered upon resaturation. A skillfully sealed borehole may reasonably be expected to be as impermeable as a fractured rock mass (subject to site-specific verification). The influence of relative seal-rock permeabilities provides insight into important seal parameters. A plug one order of magnitude greater in permeability than the rock through which it passes resulted in an increase in flow through the borehole and surrounding rock of only 1 1/2 times as compared to the undisturbed rock. Since a sealed borehole and its surrounding rock are only a small part of the total rock mass, the effect is even less pronounced. One of the simplest ways to decrease flow through a seal-rock system is to increase the length of the seal. Significant remaining questions include field emplacement techniques; field vertification of plug quality; plug performance over long time periods, particularly with respect to temperature/moisture variations and chemical stability; and radionuclide sorption capabilities. Scale effects are also important, as shafts and drifts must be sealed as well as larger diameter boreholes.

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Providing water and proper sanitation to poor communities by 2015 is one of the United Nations targets for this millennium. In South Africa many communities aspire to waterborne sanitation. However, there is a technology gap for decentralized and sustainable waterborne sanitation systems capable of treating domestic wastewater (Foxon et al., 2006). Although domestic wastewater is more commonly treated using aerobic processes, anaerobic processes may be more appropriate for decentralized applications since they do not require aeration. Research is currently being undertaken to understand the behavior of a combined ABR-MBR unit for treating domestic wastewater. In this study, the anaerobic baffled reactor (ABR) was investigated by analyzing physico-chemical and biochemical data from experiments on a laboratory-scale ABR. This anaerobic reactor was treating complex particulate wastewater made up of sludge from the ventilated improved pit latrine toilets (known as VIP sludge). The main focus of this study was to establish the relationship between the increasing organic loading rates and the effluent characteristics (such as chemical oxygen demand: COD and extrapolymeric substances: EPS). The present work was structured in two parts; in the first part the reactor was operated at constant hydraulic retention time (HRT) without controlling feed characteristics. In the second part, the ABR was operated with step increases in organic loading rates. It was logistically not possible to provide a feed of real domestic wastewater to the laboratory-scale equipment. Consequently, a pit latrine sludge diluted with tap water was used to feed the ABR. This feed was found to have different biodegradability characteristics compared to domestic wastewater. However, the results still give insight into the performance of the ABR and into the treatability of VIP sludge. COD removal ranged from 52 to 80 % depending on the inlet COD. Some COD removal was due to solids retention in compartments, while it was estimated that only 28% of COD removal was due to biological degradation. Soluble extrapolymeric substances (proteins and carbohydrates) which are usually a by -product of anaerobic degradation were higher in the feed than in the effluent despite the increasing organic loading rates. However, more than 50 % of soluble extrapolymeric substances from the influent remained in the effluent and were found (in a parallel project) to influence membrane fouling in the membrane section of the experimental set-up (ABR-MBR unit). Parameters such as pH, conductivity, alkalinity, total and volatile solids were also investigated in this study. The pH decreased slightly from the inlet to the outlet during all runs even though the loading rates were increased. Conductivity increased significantly from influent to effluent with the increasing organic loading rates. Large amounts of total solids were retained in the reactor during the treatment process. Low alkalinity production was recorded during the operation of the reactor. In most cases, the data recorded in this study showed a low biological activity taking place while the reactor was working at room temperatures. Overall, up to 80% of removal efficiencies in terms of total COD and solids were recorded with increasing organic loading rates at constant hydraulic retention time. While these results do not allow the prediction of ABR-MBR performance during the treatment of real wastewater, it was concluded that: Most solids retention occurred in the feed tank. Most COD removal occurred as a result of solids retention and digestion. Loading characteristics did not strongly influence effluent EPS, pH or alkalinity, but did influence COD and conductivity. The relatively low biodegradability of the feedstock indicates that anaerobic digestion is not the most appropriate treatment for VIP sludge. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.

Indien är ett land som växer ekonomiskt samtidigt som problem med hur avfall ska tas omhand fortfarande är i utvecklingsfasen. Studiens fokus ligger på hur avfallshanteringen sköts i staden Bangalore. Utifrån ett svenskt perspektiv på avfallshantering med insamling och behandling har Bangalore undersökts och brister lokaliserats. Förbättringsförslag presenteras utifrån de brister som framkommit och ett fokus har lagts på om svenska avfallslösningar skulle kunna implementeras i Bangalore. Svensk avfallshantering utgör en bra grund för ett funktionellt avfallshanteringssystem och har därför använts som referens vid jämförelser och förbättringsförslag. I Sverige används källsortering vid sortering av avfall för att få en högre grad av återvinningsbarhet. De behandlingssteg som finns ger energi på olika sätt och ytterst lite avfall läggs på deponier. Ett ständigt arbete utförs utifrån avfallstrappans steg. I Bangalore är situationen omvänd och det avfall som lyckas samlas in hamnar till största delen på deponier eller inofficiella dumpningsplatser runt om i staden. I Sverige sköts avfallshanteringen av den formella sektorn medan den i Bangalore till stor del utförs av en informell sektor där privata personer samlar in skräp. En litteraturstudie har gett insikt i vilka problem utvecklingsländer kan ha gällande avfallshantering och även vilka faktorer som spelar in vid verkställandet av ett fungerande system. I projektet gjordes en observationsstudie på plats i Bangalore under två veckors tid. Utifrån observationsstudien kunde mycket av tidigare information kring hur avfallshanteringen går till granskas mer kritiskt och ett mer verklighetstroget resultat framföras. Det saknas ett fungerande system som är heltäckande för hela Bangalore, vilket gör att mycket avfall hamnar direkt på gator eller på övergivna tomter. Detta i sin tur ger upphov till dålig lukt för invånarna och en ohygienisk miljö. De insamlingssystem som finns att tillgå för allmänheten var i övergripande fall otillräckliga. Tre olika faktorer identifierades som hindrar att avfallshanteringen ska kunna fungera. Dessa var politik, den formella och informella sektorn, samt insamlingssystem av avfall. Ett stort hinder inom Bangalore är det bristande politiska intresset att få till en fungerande avfallshantering. Inga stora aktioner eller krafttag tas mot de växande mängder avfall som produceras. Inte heller sker en bra integration mellan de formella avfallsinsamlarna som utgörs av avfallstransporter och avfallsinsamlare versusinofficiella avfallsinsamlare. Då Bangalore saknar ett formellt insamlingssystem ges inte rätta förutsättningar för befolkningen att kunna gå någonstans med sitt avfall. Detta leder till en ökad okunskap om hur avfall bör sorteras för att kunna behandlas på ett lämpligt sätt där föredragsvis energi kan utvinnas. Ett tydligare insamlingssystem behövs om Bangalore ska kunna nå en hållbar utveckling och bromsa de eskalerande miljöproblem som de ställs inför. Någon form av behandling av avfall krävs för att minska mängden avfall som hamnar direkt på deponering. Genom att minska trycket på deponierna finns en potential för att få en hållbar stad. / India is a country that is growing economically while the problems with the waste andit´s treatment are still in the development phase. The study focuses on how the waste ishandled in the city of Bangalore. From a Swedish point of view the waste collection andtreatment have been investigated Bangalore and shortcomings identified. Suggestionsfor improvements are presented from the lack of the waste management and the focushas been on how Swedish solutions could be implemented in Bangalore. In Sweden the sorting of waste at a household level is managed from different fractionsin containers and therefore the waste has a higher degree of recyclability. Theprocessing steps that are providing energy are sufficient leading to very little wastebeing added to landfills. A constant work is done based on the waste hierarchy. InBangalore, the situation is the reverse and the waste collected mostly ends up inlandfills or unofficial dumping sites around the city. In Sweden, waste is handled by theformal sector, while Bangalore is largely dependent on an informal sector whereindividuals collect waste. A literature study has provided insight into the difficulties developing countries mayhave to face regarding waste management and the factors that come into play in theexecution of a functioning system. Within the project, an observational study was madein Bangalore for two weeks. Based on the observational study a lot of previousinformation on how waste is handled could be examined more critically and morerealistic conclusions drawn. The lack of a functioning system for waste collectionthroughout Bangalore results in a lot of waste ending up directly on the streets or onabandoned plots. This in turn gives rise to odors for residents and an unhygienicenvironment. The collection available to the public was in most cases insufficient. Three factors were identified that prevent the waste management from functioning.These were politics, the formal and informal sector, as well as the practical collectionof waste. A major obstacle in Bangalore is the lack of political interest of functioningwaste management. No major action is taken against the growing amounts of wasteproduced. A good integration between the formal waste collectors consisting of thetransport of waste and waste collectors versus informal waste collectors is missing.Bangalore also lacks formal collection systems and the people are not given the rightconditions to be able to go anywhere to get rid of their waste. This leads to increasedignorance about how waste should be sorted for processing appropriately and whereenergy can be recovered. A clearer collection is needed if Bangalore is to achieve sustainable development and tocurb the escalating environmental problems they face. Some form of waste treatment isneeded to reduce the pressure on the city landfill. By doing this there is a change for thecity to be sustainable and green.

It was the purpose of this investigation to determine (1) what organisms are associated with the formation of this slime layer, (2) if certain chemical factors in the environment either enhance or retard formation of the slime layer, (3) whether or not there are certain chemical factors which are detrimental to slime formation, yet not detrimental to purification, or that perhaps enhance purification, (4) whether or not there are chemical factors which enhance purification of the effluent without preventing slime formation, and (5) what effects the chemical treatments have on the microbial flora of the soil system.

M.Sc. / Large development initiatives are currently being implemented in South Africa. Many small towns such as the town of Roossenekal are affected by large developments, especially in terms of their service delivery capacity and resources. This study attempts to illustrate how effective waste management can be implemented in small rural towns such as Roossenekal by incorporating current legislation and development plans as a driving force. The waste stream generated in this town comprises large enough volumes of recyclable waste to attain the national waste-to-landfill reduction targets. Various measures such as at-source separation and the bulk storage of recyclables for collection by commercial recyclers, as well as domestic composting, are considered to be relevant. This study shows that fairly simple interventions could have overridingly positive effects on the management of waste in the town of Roossenekal and that the vision of attaining national strategic goals and objectives could in fact be realised. Cognisance has been taken of the current policy governing waste management and it is evident that by applying the waste hierarchy approach, simple and custom-made solutions can be identified. This study identifies development and national policy as key drivers in implementing effective waste management strategies. Large projects such as the construction of the De Hoop dam, as well as commercial ventures such as the mines and commercial recyclers that are currently operating in the town and its surrounds, are considered to be major role-players which could make a valuable contribution to waste management.

A project report submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree of Master of Science in Engineering Johannesburg, 1993 / Superfines of less than 200 micron are generated when mining coal. They have not been successfully beneficiated in the past and are not acceptable to the consumer. A processh as been developed whereby the superfines are beneficiated, briquetted without the use of binders and devolatilised to produce a premium smokeless briquette which will attract a premium price in the export market. [Abbreviated abstract. Open document to view full version] / MT2017