Wood wastes are mainly originated from forestry, wood industry and construction and demolition sites activities. Among them, three types of wood waste can be identified: untreated wood waste (raw wood considered as biomass), slightly treated wood wastes (issued from coating or gluing treatments) and highly treated wood wastes (issued from impregnation treatments with CCA and creosote, and considered as hazardous wastes).  According to the regulation, management of wastes in Europe is oriented towards more recycling and less elimination. However, among the French requirements, three main trends can be observed in regards of wood waste recovery: only treated wood wastes can be recovered in combustion units, no extensive technologies are allowed to recover highly treated wood wastes, which must then be eliminated by incineration, and slightly treated wood wastes can be either recovered as particle boards or eliminated.  However, in this context, the amount of wood wastes from construction and demolition sites reach 7 million of tons in France. Among them, 5% correspond to raw wood, and 25% are slightly treated. The high combustion potential of wood wastes is moreover an opportunity to replace conventional fuel used in combustion units.  The four main methods used to treat wood wastes are recycling as particleboards, combustion, incineration and land filling. Due to the various typologies of wood wastes, a conditioning step is needed before recovery. Then, if combustion seems to present advantages because of its neutral carbon impact, life cycle analysis demonstrates that emissions of other pollutants are observed. In addition, it is proved that controlled elimination methods are less impacting than unequipped recovery ones. Recycling is then not always the best practice in regards of the impacts considered in the study.  Competition among the different methods treatment and low prices of wood wastes are specific economical aspects that could influence the development of the field. Moreover, the increasing acceptance of people for recovery and local waste treatment methods, as well as the need for energetically independency are factors that can likely promote wood waste derived fuel. These driving forces are evolving in a very rapid way. Regulation is moving towards implementation of standards to promote the development of slightly treated wood waste derived fuel. Technological and social improvement such as sorting at source, and the development of end of pipe treatment methods are also likely to have positive effects.  An integrated solution to develop wood waste derived fuel would be to implement strong financial incentives in favour of clean technologies for wood wastes recovery methods. This enhancement could then be the mean to answer the double challenge of wood waste treatment and fossil fuel replacement.  Wood wastes are mainly originated from forestry, wood industry and construction and demolition sites activities. Among them, three types of wood waste can be identified: untreated wood waste (raw wood considered as biomass), slightly treated wood wastes (issued from coating or gluing treatments) and highly treated wood wastes (issued from impregnation treatments with CCA and creosote, and considered as hazardous wastes).  According to the regulation, management of wastes in Europe is oriented towards more recycling and less elimination. However, among the French requirements, three main trends can be observed in regards of wood waste recovery: only treated wood wastes can be recovered in combustion units, no extensive technologies are allowed to recover highly treated wood wastes, which must then be eliminated by incineration, and slightly treated wood wastes can be either recovered as particle boards or eliminated.  However, in this context, the amount of wood wastes from construction and demolition sites reach 7 million of tons in France. Among them, 5% correspond to raw wood, and 25% are slightly treated. The high combustion potential of wood wastes is moreover an opportunity to replace conventional fuel used in combustion units.  The four main methods used to treat wood wastes are recycling as particleboards, combustion, incineration and land filling. Due to the various typologies of wood wastes, a conditioning step is needed before recovery. Then, if combustion seems to present advantages because of its neutral carbon impact, life cycle analysis demonstrates that emissions of other pollutants are observed. In addition, it is proved that controlled elimination methods are less impacting than unequipped recovery ones. Recycling is then not always the best practice in regards of the impacts considered in the study.  Competition among the different methods treatment and low prices of wood wastes are specific economical aspects that could influence the development of the field. Moreover, the increasing acceptance of people for recovery and local waste treatment methods, as well as the need for energetically independency are factors that can likely promote wood waste derived fuel. These driving forces are evolving in a very rapid way. Regulation is moving towards implementation of standards to promote the development of slightly treated wood waste derived fuel. Technological and social improvement such as sorting at source, and the development of end of pipe treatment methods are also likely to have positive effects.  An integrated solution to develop wood waste derived fuel would be to implement strong financial incentives in favour of clean technologies for wood wastes recovery methods. This enhancement could then be the mean to answer the double challenge of wood waste treatment and fossil fuel replacement. / Träavfall kommer från skogsbruk, trä‐ och byggbranschen och rivningsplatser. Bland dem kan tre typer av träavfall identifieras: obehandlat träavfall (obehandlat trä betraktas som biomassa), lätt behandlat träavfall (från beläggning eller limning) och högbehandlat träavfall (från impregnering med CCA och kreosot, betraktas som farligt avfall). Enligt avfallsförordningen, är hantering av avfall i Europa inriktad mer mot återvinning och mindre mot eliminering. Bland de franska kraven, kan tre huvudsakliga tendenser iakttas för återvinning av träavfall: endast behandlat avfall kan behandlas i förbränningsanläggningar för energiutvinning, högbehandlat träavfall måste elimineras genom förbränning och lätt behandlat avfall kan antingen återvinnas som spånskivor eller elimineras. I detta sammanhang uppgår mängden träavfall från bygg‐ och rivningsplatser till 7 miljoner ton i Frankrike. Bland dem, motsvarar 5% obehandlat trä, och 25% är lätt behandlat. Den höga förbränningspotentialen för träavfall ger dessutom en möjlighet att ersätta konventionellt bränsle som används i förbränningsanläggningar. De fyra huvudsakliga metoder som används för att behandla träavfall är återvinning i spånskivor, förbränning med energiutvinning, förbränning och deponering. På grund av olika typer av träavfall, krävs ett konditioneringsteg innan återvinning. Även om förbränningen är fördelaktigt på grund av sitt neutrala kol, visar livscykelanalyser utsläpp av andra föroreningar. Dessutom visas att kontrollerade elimineringsmetoder har mindre miljöpåverkar än återvinningsmetoder som ej har rätt utrustning. Återvinning är alltså inte alltid att föredra om man beaktar de effekter som gjorts vid denna undersökningen. Konkurrensen mellan olika behandlingsmetoder och låga priser på träavfall är specifika ekonomiska aspekter som skulle kunna påverka utvecklingen inom området. Dessutom, den ökande acceptansen av människor för återvinning och lokala avfallshanteringsmetoder, liksom behovet av inhemska energikällor är faktorer som sannolikt kan främja bränsle från träavfall. Dessa drivkrafter utvecklas på ett mycket snabbt sätt. Avfallsförordningen är på väg mot införandet av standarder för att främja utvecklingen av lätt behandlat träavfalls bränsle. Tekniska och sociala förbättringar, exempelvis källsortering och utveckling av återvinningsmetoder ger också sannolikt positiva effekter. En integrerad lösning för att utveckla bränsle från träavfall skulle vara att genomföra starka ekonomiska incitament till förmån för ren teknik för återvinning av träavfall. Den här förbättringen kan sedan vara ett medel att anta den dubbla utmaningen av hantering av träavfall och ersättning av fossila bränslen.

Call number: LD2668 .T4 1984 D93 / Master of Science

Call number: LD2668 .T4 1984 G666 / Master of Science

Call number: LD2668 .T4 1984 M37 / Master of Science

Call number: LD2668 .T4 1984 M84 / Master of Science

Submitted in accordance with the requirements for the Doctors Degree of Technology: Business Administration, Durban University of Technology, 2009. / Although there is an abundance of health care waste information in South Africa, not enough studies have been done in public district hospitals particularly in rural areas. Hospitals find it difficult to comply with the minimum requirements of health care waste management guidelines, such as segregation of waste. If hazardous waste gets mixed with non-hazardous waste, waste disposal and treatment become costly. Furthermore, there has been a sharp increase in the amount of waste generated from health facilities. However, there seem to be uncoordinated efforts in each province in dealing with waste problems. The purpose of this study was to evaluate the process of operational and administrative procedures of health care waste management in hospitals. The study was conducted to facilitate the optimisation of waste management. A quantitative approach was chosen for this study because cause and effect relationships can more easily be identified, and the research is more structured and controlled. The project involved an enquiry into the perception of respondents on the procedures used in managing health care waste. Data was collected from 270 respondents out of 27 hospitals in nine provinces of South Africa. The informants were health care waste workers who were either directly or indirectly involved in waste management. A questionnaire was used as a research instrument. Results were analysed statistically using a special package for scientific studies. It has been found that in the midst of financial challenges, hospitals are unable to prioritise and rank absolutely important activities that are necessary to be undertaken to meet minimum requirements of health care waste management as laid out in the health care waste guidelines and directives. Shortages of waste equipment such as trolleys, waste containers, and temporary storage areas were the main challenges facing hospitals. The recommendations set the tone and provide a blueprint that health care managers may consider in facilitating improvement in the management of health care waste.

The UK Landfill Tax was introduced by the Finance Act 1996 as an economic measure to discourage the use of landfill as a waste management option and to encourage a more sustainable approach in which less waste is produced and more waste is reused or recycled. A tax credit scheme was also introduced in order that a proportion of the money raised by the tax could be directed to Environmental Bodies to be used for approved environmental projects. The published papers submitted with this thesis evaluate the effectiveness of the operation of Landfill Tax and Landfill Tax Credit Scheme in a legal context by drawing upon a range of sources including the reviews of the Tax, data for Entrust and surveys conducted by the author. The Landfill Tax and Landfill Tax Credit Scheme is a tax law that is multi dimensional with environmental, social, economic, fiscal and political aspects. Like most law it seeks to change or control the behaviour of individuals and institutions but unlike most laws relating to taxation it had the potential for greater public acquiescence by a ‘double dividend’ by seeking to reduce landfill and encourage a more sustainable approach and also to be neutral in taxation terms by making a commensurate reduction in Employer’s Contributions to National Insurance and so reduce the tax on employment. The research finds that the Tax and Credit Scheme has good intentions in achieving a double dividend and recognises that it laid the foundations for a bottom up approach to improved waste management with public participation projects. However the research identifies and addresses a series of issues. In particular the Tax needed to be set at a substantial level to have an impact and did not itself reduce landfill. The Credit Scheme had the potential to encourage alternatives to landfill. However the Scheme’s range of approved projects and flaws in its operation meant it lacked a sufficiently strong sustainable waste management focus. The research notes that stakeholders support the Tax and Credit Scheme but recognise that it has scope for making a greater contribution to sustainable waste management particularly if additional Tax funds were allocated to strategic projects. In 2002 the Government diverted all the funds that would have been applied to ‘bottom up’ waste management projects under the Credit Scheme to centrally run ‘top down’ strategic projects, bringing to an end a key driver for sustainable waste management. The aim of the critical appraisal accompanying the papers is to outline the operation and highlight the criticisms and suggested reforms published in the papers between 1998 and 2004. In addition it suggests a way forward for the Landfill Tax credit Scheme, now called the Landfill Communities Fund to support once more support bottom up waste management projects. It also refers to key elements of the UK experience as an evidenced based guide to other countries that have already or are considering implementing similar taxes to the Landfill Tax

Thesis (MScIng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Recent years have seen the development of various treatment methods for the purification of industrial waste waters due to the increased demand for reduced pollutant effluents. Aqueous waste streams containing toxic organic compounds are of special interest, since conventional treatment methods such as biological waste treatment can not always be used. Other popular treatment methods are often ineffective. Catalytic oxidation of organic wastes has been investigated since the 1960s with varying degrees of success. A major problem associated with this method is the high temperatures and pressures required to improve the activation energies involved. Electrochemical oxidation has become a popular method in the literature of treating these wastes, since the applied voltage determines the activation energy, and therefore the process can often be performed at ambient conditions. This thesis investigates the capability of a unique reactor system in the treatment of these wastes. The reactor utilises proton-exchange membrane technology to eliminate the requirement of conductivity in treated waste streams; thus the membrane serves as a solid electrolyte. The reactor system has therefore been referred to as a solid-polymer-electrolyte reactor. Novel metal oxide anodes are responsible for the oxidation of the organic molecules. These metal oxide catalysts show promise in the treatment of a wide variety of organic wastes. A SnO2 catalyst doped with ZrO2 is used as anode in this study. Dopants are added to the catalyst to improve properties such as catalytic activity and conductivity. Kinetic data was obtained on a wide range of values for the chosen experimental parameters (current density and flow rate). Phenol, an organic molecule often referred to in the literature as model contaminant due to its resistance to oxidation,was also used as contaminant in this study. The use of the reactor system in the disinfection of water containing selected pathogens, were included in the experimental work. This kinetic data served in the development of a simple model of the process, and provided the basis for a full analysis regarding potential scale-up and economic feasibility. A requirement of the study was the accurate determination of the various oxidation breakdown products of phenol. This led to the refinement of an HPLC analytical method in order to quantitatively determine these products. The full analysis showed that the current reactor system would not be economically viable — mainly due to very long reactor lengths required for the complete removal of all organic material. Both mass transfer and charge transfer at the chosen experimental conditions influenced the electrochemical oxidation of phenol. High pressure drops, causing low flow rates in the reactor, accounted for this because of the narrow flow channels required in the reactor. Some catalyst deactivation was also suspected to affect the overall reaction, but the full extent of the deactivation was not investigated thoroughly. There is still room for improvement in the electrochemical oxidation of organic wastes. The design of the flow channels, a factor that was not investigated, can significantly improve efficiency. Another aspect that was not investigated was the catalyst type. The catalyst has been identified in the literature as the main contributing factor to the success of the oxidation reaction. A wide variety of metal oxide catalysts are currently being researched and may improve the kinetics of the process even further. Further improvement needs to be made on the membrane/electrode assembly to improve current density distribution. Every improvement of the process in terms of the reactor design and catalyst will impact on the economics of the process, thus making the process more competitive with current treatment technologies. / AFRIKAANSE OPSOMMING: In die afgelope paar dekades, is daar ’n wye verskeidenheid metodes ontwikkel wat gebruik kan word om industri¨ele afvoer strome te behandel. Hierdie ontwikkeling het plaasgevind as gevolg van die verhoogde eis aan skoner afvoerstrome. Wateragtige afvoerstrome wat organiese verbindings bevat, is van besonderse belang omdat hierdie tipe strome soms besonders moeilik kan wees om te behandel. Gebruiklike metodes is in die meeste gevalle ongeskik vir behandelings-doeleindes. Katalitiese oksidasie is sedert die 1960’s gebruik, maar hierdie prosesse benodig dikwels ho¨e drukke en temperature om suksesvol te wees. Elektrochemiese oksidasie het intussen ’n populˆere behandelingsmetode geword, aangesien die aktiveringsenergie vir die oksidasieproses hoofsaaklik afhanklik is van die aangewende potensiaal en dus kan die proses by atmosferiese toestande gebruik word. In hierdie tesis word die geskiktheid van ’n unieke reaktorstelsel vir water-suiwering ondersoek. Die reaktor gebruik ’n proton-uitruilings-membraan om die behoefte vir konduktiwiteit in die water uit te skakel. Die membraan dien dus as ’n tipe soliede elektroliet en as gevolg hiervan word na die reaktorstelsel verwys as ’n soliede-polimeer-elektroliet reaktor. Nuwe metaal-oksied anodes word in die reaktor gebruik aangesien hulle belowende resultate toon in die oksidasie van organiese verbindings. In die navorsing, is ’n SnO2 katalis wat klein hoeveelhede ZrO2 bevat gebruik. Oksiede soos ZrO2 word dikwels gebruik om die aktiwiteit en konduktiwiteit van hierdie kataliste te bevorder. Kinetiese data is oor ’n wye bereik van parameter waardes ingesamel. Die hoof parameters in die eksperimentele werk was stroom digtheid en vloeitempo. Fenol, ‘n komponent wat volgens die literatuur in hierdie tipe van werk gebruik word, isas die besoedelende komponent gekies. Die doeltreffendheid van die reaktor in die ontsmetting van water, wat met ’n verskeidenheid skadelike mikro-organismes besmet is, is ook getoets. ‘n Eenvoudinge model is opgestel m.b.v. die kinetiese data, waarna ’n volledige analise met betrekking tot grootskaalse bedryf en ekonomiese uitvoerbaarheid gedoen is. ‘n Vereiste van die studie was om die konsentrasie van die afbreek-produkte van die oksidasie akkuraat vas te stel. As gevolg hiervan is ‘n ho¨e-druk-vloeistofchromatografie analitiese metode verfyn. Die analise het getoon dat die reaktorstelsel nie ekonomies sou wees nie. Een van die hoofredes hiervoor is die onrealistiese reaktorlengtes wat benodig sou word. Resultate het getoon dat die reaksie deur beide massa-oordrag en lading-oordrag be¨ınvloed word. Ho¨e drukvalle in die reaktor wat gelei het tot lae vloeitempo’s was hiervoor verantwoordelik. Die deaktivering van die katalis be¨ınvloed waarskynlik die reaksie, maar die deaktiveringsverskynsel is nie ten volle ondersoek nie. Die reaktorstelsel kan verder verbeter word deur verskeie elemente van die reaktor te ondersoek. Die ontwerp van die vloeikanale in die reaktor is nie ondersoek nie en kan die werksverrigting van die reaktor verhoog. Uit die literatuur is gevind dat die tipe metaaloksied wat as katalis gebruik word, die reaksie direk be¨ınvloed. Dus kan navorsing wat tans op die kataliste gedoen word nuwe kataliste na vore bring wat meer doeltreffend sal wees. Laastens, is die huidige membraan/elektrode samestelling nog oneffektief en kan die reaktor-opstelling dus nog verbeter word. Elke verbetering wat op die bogenoemde faktore van die reaktor ontwerp verkry word, sal die ekomoniese uitvoerbaarheid van die proses be¨ınvloed. So, sal die proses al meer kompeterend met huidige behandelingsmetodes word.

Thesis (MEng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Peach and apricot shells are agricultural waste products. These waste products accumulate around canneries and food-processing plants in South Africa. No effort is being made to utilise these waste products. This study is the first part of the product development from these products i.e. peach shell activated carbon and apricot shell activated carbon. By producing activated carbon from peach and apricot shells the solid waste problem is addressed, but most of all a profit can be made. But why activated carbon? Activated carbons are unique and versatile adsorbent with a vast amount of adsorption applications. It can be produced via a simple oxidation reaction with steam and the nature of peach and apricot shells are such that it is expected that activated carbons with good adsorption properties can be produced from it. The single largest consumer of activated carbon in South Africa is the gold mining industry that uses imported coconut shell activated carbon for gold adsorption in the gold recovery process. Activated carbon is also used as water purification adsorbents. During this study activated carbons were produced in a fluidized bed reactor at various activation conditions: 700 - 900°C, 0.0425 - 0.0629 g steamlg char.min and 30 - 60 min. This was done in order to find the optimum activation conditions within the activation parameter range. The optimal activated carbons were defined as peach and apricot shell activated carbons that showed good microporous as well as mesoporous character. The optimal activated carbons produced are: peach shell activated at 875°C, 0.0533 g stearnlg char. min, 60 min and apricot shell activated carbon at 850°C, 0.0533 g steamlg char.min, 60min. The possible use of these optimal activated carbons and two other activated carbons produced (Peach shell activated carbon 900°C, 0.0425 g steamlg char. min, 60 min and apricot shell activated carbon 900°C, 0.0425 g steamlg char.min, 60min) were tested in gold recovery and water purification. The gold adsorption properties of peach and apricot shell activated carbons were found to be better than two commercial coconut shell activated carbons (Chemquest 650 and GRC 22). No definite conclusions could, however, be drawn about the replacement of coconut shell activated carbon with peach or apricot shell activated carbon, because abrasion test work and thermal regeneration of the experimental carbons still have to be performed. The experimental activated carbons displayed good phenol adsorption characteristic, although further test work is required. / AFRIKAANSE OPSOMMING: Perske- en appelkoospitte is landbouafvalprodukte. Hierdie afvalprodukte versamel rondom inmaakfabrieke en voedselververkingsaanlegte. Tans word daar geen poging in Suid-Afrika aangewend om hierdie afvalprodukte te benut nie. Hierdie studie is die eerste deel van die ontwikkeling van die produkte: Perskepitdop-geaktiveerde koolstof en appelkoospitdop-geaktiveerde koolstof. Deur geaktiveerde koolstof van die perske- en appelkoospitdoppe te maak, word nie net 'n antwoord op die vastestofafvalsprobleem gevind nie, maar daar kan ook geld gemaak word. Hoekom geaktiveerde koolstof? Aktiveerde koolstowwe is veelsydige en unieke adsorbente met 'n groot verskeidenheid adsorpsie toepassings. Dit kan vervaardig word via 'n eenvoudige oksidasie reaksie met stoom en die aard van die perske- en appelkoospitdoppe is sodanig, dat verwag kan word om geaktiveerde koolstowwe met goeie adsorpsie eienskappe daarvan te kry. Die grootste enkelverbruiker van geaktiveerde koolstof in Suid-Afrika is die goudmynbedryf, wat kokosneutdop geaktiveerde koolstof invoer om goud te herwin. Geaktiveerde koolstof word ook gebruik vir watersuiwering. Tydens hierdie studie IS geaktiveerde koolstowwe by verskillende aktiveeringskondisies in 'n gevloeïdiseerde bed vervaardig: 700 - 900oe, 0.0425 - 0.0629g stoornlg gepiroliseerde pitdoppe.min en 30 - 60 mm. Die aktiveringskondisies is gevarieer om sodoende die optimale aktiveringskondisies binne die aktiveringsparameterreeks te kry. 'n Geaktiveerde koolstof is as optimaal geklassifiseer as dit 'n goeie mikro- sowel as mesostruktuur getoon het. Die optimaal geaktiveerde koolstowwe is: geaktiveerde koolstof vervaardig van perskepitdoppe by 875°e, 0.0533 g stoornlg gepiroliseerde pitdoppe.min, 60 mm en geaktiveerde koolstof vervaardig van appelkoospitdoppe by 850oe, 0.0533 g stoornlg gepiroliseerde pitdoppe.min, 60min. Die gebruik van die twee optimale geaktiveerde koolstowwe sowel as twee ander geaktiveerde koolstowwe (perskepitdop-geaktiveerde koolstof, 900oe, 0.0425 g stoornlg gepiroliseerde pitdoppe.min, 60 min en appelkoospitdop-geaktiveerde koolstof, 850°C, 0.0533 g stoom/g gepiroliseerde pitdoppe.min, 60min) is VIr goudadsorpsie en watersuiwering ondersoek. Die goudadsorpsie eienskappe van die perske-en appelkoospitdop-geaktiveerde koolstowwe was beter as die van twee kommersiële kokosneutdop-geaktiveerde koolstowwe (Chemquest 650 and GRC 22). Daar kan egter geen definitiewe gevolgtrekkings gemaak word oor die vervanging van kokosneutdop geaktiveerde koolstowwe met dié van perske of appelkoospitdoppe nie, aangesien daar nog toetsresultate oor die slytweerstand en reaktiverings eienskappe van die eksperimentele geaktiveerde koolstowwe uitstaande is. Die eksperimentele geaktiveerde koolstowwe toon goeie adsorpie ten opsigte van fenol, maar verdere toetswerk is egter nodig.

A gas-diffusion tracer experiment was conducted at the ChemNuclear, Inc., nuclear waste burial site near Barnwell, South Carolina, on June 1-10; 1981, testing a new methodology to measure the in situ gaseous diffusion characteristics of unsaturated porous media for the purpose of estimating the diffusive flux of volatile contaminants from the burial ground. The tracers used were CClBrF₂ and SF₆. They were released in the subsurface from permeation devices that closely approximate an ideal point-diffusion source. The permeation devices contain the tracer in liquid form and allow the tracer to escape at a constant rate by diffusion through a Teflon membrane. The release rates for CClBrF₂ and SF6 during the test were 105 and 3.3 nanograms/second, respectively. These compounds were selected on the basis of their compatabi1ity with the permeation-release device, their absence in the subsurface, and detectability in the part-per-tri11ion range in soil gas. Analyses were made in the field on a Varian 3700 series gas chromatograph equipped with an electron-capture detector. The instrument was modified to introduce soil gas through sampling valves and a Nafion tube desiccant. The diffusion sources were placed in the unsaturated soil at depths of 2 meters and 13 meters below land surface. Diffusive movements of tracer were monitored for a period of 7 days and tracer breakthrough was observed at points up to 3.5 meters away. Diffusion was modeled using a three-dimensional, continuous point source, transient-state, analytical model which allowed estimation of the effective diffusion coefficient of the porous media, and an independent assessment of the media's sorptive effects on the tracer gas. The model was calibrated using least squares and curve matching techniques, the latter of which enables a field technician to quickly interpret observed field data. Field values obtained for effective diffusion coefficient ranged from 0.026 to 0.037 cm²/sec. The average tortuosity factor observed for test site was 0.705.