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Development of Water and Wastewater Biofiltration Technologies for the Developing World using Locally Available Packing Media: Case Studies in Vietnam and HaitiThomson, Ashley Anne January 2014 (has links)
<p>Water and sanitation are two of the world's most urgent current challenges (Elimelech, 2006). With a population racing towards seven billion people, over one sixth of the human population does not have access to adequate water and sanitation. Drinking water is inaccessible for approximately 783 million people living in the developing world (WHO, 2014). This is especially critical for people at risk of exposure to deadly pathogens such as <italic>Vibrio cholerae</italic>, <italic>Shigella</italic>, and <italic>Salmonella</italic>, such as those living in Haiti as <italic>Vibrio cholerae</italic> is now ubiquitous (Enserink, 2010). On the sanitation side, more than 2.5 billion people in the world still lack access to adequate resources (WHO, 2014). Almost half of these people have access to no sanitation facilities at all and practice open defecation (WHO, 2014). Thousands of small children still die every day from preventable diseases caused by inadequate sanitation (WHO, 2014). As global climate change is expected to exacerbate these issues, there is an urgent need for the development of sustainable treatment technologies to ensure a better tomorrow for our world (Ford, 1999). Safe water and sanitation technologies, while often disjointed, should be considered together as pathogens transmitted via drinking water are predominantly of fecal origin (Ashbolt, 2004; Montgomery, 2007). </p><p>In this dissertation project, I explore the use of both drinking water and wastewater treatment technologies which are cost effective and rely on locally available materials in low-income countries. For the drinking water treatment side, I focus on the use of biosand filters in Haiti with a specific interest in understanding their ability to remove the pathogen <italic>Vibrio cholerae</italic>, the causative agent for cholera. The wastewater treatment technology consists of biofilters packed with cocopeat, a waste product generated during coconut husk processing, and I investigate their use for the treatment of septic tank effluent in Vietnam. Both of these projects combine lab and field work. The specific objectives of this dissertation project are to 1) compare the removal efficiency of <italic>V. cholerae</italic> to indicator bacteria in field biosand filters and determine the parameters controlling removal; 2) investigate the correlation between removal efficiency of pathogens in field biosand filters having operated for varying lengths of time to schmutzdecke bacterial composition and influent water characteristics; 3) determine the effect of number of charges, total organic carbon loading, and schmutzdecke composition on <italic>V. cholerae</italic> removal efficacy; 4) isolate the effect of biological removal mechanisms and physical/chemical removal mechanisms on <italic>V. cholerae</italic> removal efficiency and determine the correlation to TOC concentration in water; 5) evaluate cocopeat as a packing medium for biofilters in terms of nitrogen, phosphorus and biological oxygen demand removal from simulated wastewater as compared to other traditional packing media; and 6) conduct an assessment of cocopeat-packed, vertical flow constructed wetlands treating septic tank effluent in the Mekong Delta of Vietnam. </p><p>In the first part of this dissertation, biosand filters in the Artibonite Valley of Haiti, the epicenter of the cholera epidemic, were tested for total coliform and <italic>V. cholerae</italic> removal efficiencies. In addition, schmutzdecke samples were collected in order to measure the amount of EPS in the biofilm, as well as characterize the microbial community. Total coliform and <italic>V. cholerae</italic> concentration were measured using novel membrane filtration technique methods. It was found that total coliform concentration does not indicate <italic>V. cholerae</italic> concentration in water, and total coliform removal efficiency does not indicate <italic>V. cholerae</italic> removal efficiency within biosand filters. Additionally, parameters controlling biosand filter performance include: schmutzdecke composition, time in operation, and idle time.</p><p>In the second part of this dissertation, <italic>V. cholerae</italic> challenge tests were performed on laboratory-operated biosand filters receiving high, medium or low TOC influents in order to determine the effect of number of charges, total organic carbon loading, and schmutzdecke composition on <italic>V. cholerae</italic> removal efficacy, as well as to isolate the effect of biological removal mechanisms and physical/chemical removal mechanisms on <italic>V. cholerae</italic> removal efficiency and determine the correlation to TOC concentration in water. To this end, three biosand filters were operated in the lab. Each received lake water or diluted lake water with high, medium or low concentrations of TOC. After being charged once per day for 6 days, the filters were charged with four consecutive charges of pure cultures of <italic>V. cholerae</italic> suspended in PBS buffer, at concentrations of 10<super>2</super>, 10<super>3</super>, 10<super>5</super>, and 10<super>7</super> cfu/mL. This challenge was repeated each time the filters received an additional 6 charges, up to 66 total charges. This was done to determine how number of charges, TOC loading, and schmutzdecke composition affects removal efficiency. Schmutzdecke was analyzed for amount of EPS and microbial community. It was found that parameters controlling biosand filter performance include: TOC loading, schmutzdecke composition, time in operation, and physical/chemical attachment. Additionally, it was shown that physical/chemical attachment is critical during startup, especially at low TOC concentrations. At steady state, physical/chemical attachment is more important than schmutzdecke effects in filters receiving low TOC, and schmutzdecke effect is more important than physical/chemical attachment in filters receiving high TOC.</p><p>For the third section of this dissertation, columns packed with cocopeat, celite, or sphagnum peat were charged with simulated wastewater and removal efficiencies of nitrogen, phosphorus, and biological oxygen demand were measured. Additionally, different redox zones were tested to determine if cocopeat could successfully accomplish nitrification and denitrification. It was found that cocopeat is comparable to traditional packing media and can successfully accomplish nitrification and denitrification in the treatment of synthetic wastewater.</p><p>In the final section of this dissertation, constructed wetlands were built and packed with cocopeat to determine if cocopeat is a suitable packing media in constructed wetlands treating wastewater in Vietnam. Removal efficiencies of nitrogen, phosphorus, and biological demand were measured. Microbial community samples were collected periodically in order to analyze community shifts between wetlands and over time. This work concluded that cocopeat can be used successfully as a packing media in constructed wetlands treating wastewater for the removal of nitrogen, phosphorus, and total coliform.</p><p>Overall, this dissertation work contributes to the body of knowledge on point-of-use water and wastewater technologies. The biosand filter was studied in both lab and field conditions and it was found that total coliform is not a reliable indicator for <italic>V. cholerae</italic>, and that there are several factors controlling biosand filter performance, including idle time, TOC, filter time in operation, physical/chemical attachment, and schmutzdecke composition. Cocopeat was studied for its ability to promote nitrification and denitrification in lab-scale vertical flow columns treating synthetic wastewater. It was shown that cocopeat achieved similar levels of nitrification and denitrification as traditional packing media. Finally, cocopeat packed vertical flow constructed wetlands were operated in Vietnam for the treatment of septic tank effluent. This setup proved effective for the removal of nitrogen, phosphorus, and total coliform in the treatment of wastewater.</p> / Dissertation
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Community-level analysis of the microbiology in constructed wetlands treating distillery effluentDu Plessis, Keith R. (Keith Roland) 04 1900 (has links)
Dissertation (PhD)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Constructed wetlands have been widely used in the treatment of industrial
and domestic wastewater to reduce biological and chemical oxygen demand
(BOD and COD), to remove nitrate and enteric viruses as well as to generally
improve water quality. Distillery wastewater has a complex character due to high
concentrations of sugars, lignins, hemicellulose, dextrins, resins, polyphenols
and organic acids, leading to a high COD that may exceed 100 000 mg/L. The
potential application for the treatment of distillery wastewater by means of
constructed wetlands is relatively unexplored.
In 1999 a study was initiated at Distell Goudini distillery, Western Cape,
South Africa, to explore the possibility of using constructed wetlands to treat
distillery wastewater. It was found that constructed wetlands do have the ability to
treat distillery wastewater providing that the influent COD does not exceed 15
000 mg/L for extended periods and the correct substrate material is used. The
present study expanded on the above-mentioned study and specifically aimed to
provide information on the microbiological controls in wetland systems in an
applied sense that may contribute to improved treatment efficiency. Furthermore,
this project aimed to contribute to our fundamental understanding of the microbial
ecology of constructed wetlands used for the treatment of distillery wastewater.
This study revealed that a highly dynamic microbial composition exists within
wetlands. Furthermore it was found that wetlands can efficiently remove COD
even though a low degree of similarity exists between microbial communities in
various zones of the same wetland and those between different wetlands, as well
as low similarity between communities sampled from the same zone over time.
This demonstrates that it will be difficult to define the ‘ideal’ degradative
community in terms of microbiological criteria and serves as a reminder that
various indicators should be considered for monitoring system health.
Furthermore the shifts in microbial community composition illustrate the ability of microbial communities to adapt to changes in the environment without
compromising their functional efficacy. When studying the attached microbial
communities within wetland systems it was found that different morphotypes are
detected at certain stages of biofilm development while some organisms are
present at most phases of biofilm formation.
Measurement of CO2 production and dissolved organic carbon (DOC) removal in
laboratory scale columns showed that grazing protists had a notable effect on
overall microbial activity and that organic loading influenced these predator-prey
interactions. Interestingly, increased clogging of pores occurred in the presence
of protists, resulting in reduced flow through the porous matrix. Terminalrestriction
fragment length polymorphism (T-RFLP) analysis of biofilms on gravel
in experimental wetlands indicated that the presence of protists and algae had an
effect on the microbial community composition. Scanning electron microscopy
(SEM) showed that the presence of algae also had an influence on biofilm
structure suggesting that the algae provided labile nutrients that were utilized by
the bacterial and yeast members of the community. Finally, augmentation with a
commercial mixture or microbial populations isolated from distillery effluent
demonstrated that the concentration at which supplements are applied influence
degradative efficiency. / AFRIKAANSE OPSOMMING: Kunsmatige vleilande word wêreldwyd gebruik in die behandeling van
indusriële en huishoudelike afvalwater om biologiese en chemiese suurstof
aanvraag (BSA en CSA) te verminder, om nitrate en ingewandsvirusse te
verwyder asook om waterkwaliteit in die algemeen te verbeter.
Distilleerafvalwater het komplekse eienskappe as gevolg van hoë konsentrasies
suiker, lignien, hemisellulose, dekstrien, harpuis, polifenole en organiese sure,
wat lei tot ‘n hoë CSA wat 100 000 mg/L kan oorskry. Daar is tot op hede relatief
min studies gedoen oor die potensiële gebruik van kunsmatige vleilande vir die
behandeling van distilleerafvalwater.
In 1999 is ‘n studie by Distell Goudini distilleeraanleg in die Wes Kaap van
Suid Afrika onderneem om die moontlikheid van kunsmatige vleilande vir die
behandeling van distilleerafvalwater te bestudeer. Daar was bevind dat
kunsmatige vleilande die vermoë het om distilleerafvalwater te behandel gegewe
dat die invloeiende CSA nie 15 000 mg/L oorskry nie en dat die regte substraat
materiaal gebruik word. Die huidige studie het by die bogenoemde studie
aangesluit met die doel om informasie oor die mikrobiologiese kontroles in
vleilandsisteme op ‘n toegepaste wyse te voorsien, wat tot verbeterde
behandeling doeltreffendheid kan lei. Hierdie studie het verder beoog om by te
dra tot ons fundementele kennis van die mikrobiese ekologie van kunsmatige
vleilande wat gebruik word vir die behandeling van distilleerafvalwater.
Dié studie het bevind dat daar ‘n hoogs dinamiese mikrobiese samestelling
binne vleilande bestaan. Daar was verder bevind dat CSA steeds effektief deur
vleilande verwyder kan word alhoewel daar ‘n lae graad van ooreenstemming is
tussen mikrobiese gemeenskappe in verskeie sones van dieselfde vleiland en
verskillende vleilande, asook ‘n lae graad van ooreenstemming tussen
gemeenskappe wat in dieselfde sone oor tyd gemonster is. Dit demonstreer dat
dit moeilik sal wees om die ‘ideale’ degraderende gemeenskap te vind in terme van mikrobiologiese kriteria en dien as ‘n herinnering dat verkeie indikatore in ag
geneem moet word om die welstand van ‘n ekologiese sisteem te monitor. Die
verskuiwings in mikrobiese gemeenskapsamestelling illustreer verder die vermoë
van natuurlike sisteme om aan te pas by veranderinge in die omgewing sonder
om funksionele doeltreffendheid te verminder. Die studie van aangehegte
mikobiese gemeenskappe het aangedui dat veskillende morfotipes bespeur kan
word tydens sekere fases van biofilm formasie terwyl sekere organismes tydens
meeste van die fases teenwoordig is.
Die bepaling van CO2 produksie en die verwydering van opgeloste organiese
koolstof in laboratoriumskaal kolomme het geïlustreer dat voedende protiste ‘n
waarneembare effek gehad op die algehele mikrobiese aktiwiteit en dat die
organiese lading hierdie predator-prooi interaksie beïnvloed het. Dit was
interessant om te vind dat die teenwoordigheid van protiste die verstopping van
porieë aangehelp het en dus tot verlaagde vloei deur die poreuse matriks gelei
het. Terminale-restriksie fragment lengte polimorfisme (T-RFLP) analiese van
biolfilm op klipgruis in eksperimentele vleilande het aangedui dat die
teenwoordigheid van protiste en alge ‘n effek gehad het op die mikrobiese
gemeenskapsamestelling. Skandeerelektronmikroskopie (SEM) het bewys dat
die teenwoordigheid van alge ook ‘n invloed op biofilm struktuur gehad het wat
daarop dui dat alge maklik afbreekbare voedingstowwe aan die bakterieë en
giste van die mikrobiese gemeenskap beskikbaar gestel het. Laastens was
bewys dat die konsentrasie van toevoeging van ‘n kommersiële mikrobiese
mengsel of mikrobiese populasies wat uit afvoer geïsoleer was, die effektiwiteit
van degradering kan beïnvloed.
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Zhuji wetland city: stormwater recycleChen, Yuxiao., 陳瑜瀟. January 2007 (has links)
published_or_final_version / Architecture / Master / Master of Landscape Architecture
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Cold-climate constructed wetland applications in Canada and Northern China and modeling applications in the Canadian Arctic using SubWet 2.0Chouinard, ANNIE 22 October 2013 (has links)
This comparative study explores the mechanisms of pollutant removal efficiency in cold-climate constructed wetlands (CWs) and investigates the benefits, standing and practicability of using these systems to treat wastewater in Canada and Northern China. Treatment efficiencies defined by the Canadian and Northern China experience vary considerably. Experience in both countries shows that the majority of effluent values are generally better than that required by discharge standards in Canada and China. A review of the available case studies on cold weather treatment in both countries indicates that this technology is feasible in Canada and Northern China, although further monitoring data are needed to optimize CW design and ensure that the effluent quality standards are consistently met.
In both of these countries and around the globe, increasingly strict water quality standards and the growing application of treatment wetlands for wastewater treatment is an important motive for the development of better numerical models as predictive process design tools. An investigation of the SubWet 2.0 model, a horizontal subsurface flow modeling program used to predict the level of treatment that can be expected was conducted. It has been shown that SubWet can consider the influence of several factors at one time, where empirical equations are generally not able to consider more than two factors at one time and usually in isolation of the other influential parameters. Three different data sets, two from natural wetlands from the Canadian Arctic and one from a CW in Africa were used to illustrate how SubWet can be calibrated to specific wetlands. Compared to other models, it is suggested that SubWet provides one of the best modeling options available for natural tundra wetlands. Further calibration of SubWet with twelve municipal treatment wetlands in the Canadian Arctic clearly demonstrated its ability to model treatment performance within natural tundra wetlands and thus provide an additional predictive tool to aid northern stakeholders in the treatment of municipal effluents. It is anticipated that increased monitoring and the generation of additional measured data will help to better identify the level of year to year variability and improve the overall predictive capability of the model. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-10-22 17:14:23.322
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Constructed farm wetlands (CFWs) designed for remediation of farmyard runoff : an evaluation of their water treatment efficiency, ecological value, costs and benefitsGouriveau, Fabrice January 2009 (has links)
Farmyard runoff, i.e. the effluent generated by the rain falling over farmyards, tracks and roofs, is a significant and overlooked source of nutrients and pathogens which degrades aquatic ecosystems through eutrophication, siltation and wildlife poisoning, raises public health concerns, and incurs considerable costs for society. Among other Best Management Practices implemented to address agricultural water pollution and help achieve compliance with the Water Framework Directive, Constructed Farm Wetlands (CFWs), i.e. shallow surface flow wetlands comprising several vegetated cells in series, are being recommended for remediation of farmyard runoff, due to their capacity to remove or store pollutants. Investigation is therefore needed of their long-term water treatment efficiency and ecological value to optimize their design and cost-effectiveness and minimize their negative externalities. The main aims of this study were to: 1) evaluate the treatment performance of CFWs and the link between design, hydrology and efficiency; 2) assess their ecological value and the influence of water quality and design on wetland ecology; 3) identify their costs, benefits and the way they are perceived by farmers; and 4) inform guidelines for the design, construction and aftercare of sustainable CFWs. Research focused on two CFWs in south-east Scotland, one at a dairy farm and one at a mixed beef-arable farm, which receive runoff from yards and roofs, field drainage and septic tank overflow. From February 2006 to June 2008, rainfall, evaporation, water levels and flow at the CFWs were monitored, and their treatment efficiency was assessed from water samples collected manually regularly or with automatic samplers during storm events, and analysed using standard methods. In addition, their ecological value was assessed twice a year from vegetation and aquatic macroinvertebrate surveys. Finally, semi-structured interviews with eight farmers and a farm advisor and discussions with three CFW designers in Scotland and Ireland allowed collection of technical and economic data on farm practices, CFW construction and maintenance, and helped assess CFW cost-effectiveness and acceptance by farmers. Both CFWs reduced pollutant concentrations between inlet and outlet, with efficiencies at CFW1 and CFW2 respectively of 87% and < 0% for five-day biochemical oxygen demand, 86% and 83% for suspended solids, 68% and 26% for nitrate/nitrite, 42% and 34% for ammonium, and 12% and 31% for reactive phosphorus. Nevertheless, the concentration of all pollutants at the outlet of CFW1, and concentration of nitrate/nitrite at the outlet of CFW2 frequently exceeded river water quality standards. Water treatment efficiency varied seasonally, being significantly lower in winter, mainly due to lower temperatures, increased volume of inputs and reduced residence time. The ecological value of the two CFWs differed greatly. At CFW1 and CFW2 respectively, 14 and 22 wetland plant species and 24 and 46 aquatic macroinvertebrate species (belonging to 13 and 27 BMWP scoring families respectively) were recorded, illustrating the greater biodiversity conservation value of CFW2, which was one year older, larger, cleaner, comprised several ponds with a combination of open water and densely vegetated areas, and was subsequently more structurally diverse. The socio-economic study revealed that, despite significant costs associated with their construction (£20 000-£50 000 ha-1) and maintenance (£900-£1500 ha-1 yr-1), CFWs may still represent a more cost-effective alternative than conventional methods. However, their adoption, implementation and sustainable use by farmers were conditioned by land availability and suitability, existing farm infrastructure, detailed information on limitations and maintenance requirements, and adequate financial support for both construction and aftercare. To ensure a long-term, consistent and efficient water treatment, and to enhance biodiversity and landscape, well-maintained, large, vegetated, multi-cell CFWs with shallow overflows are recommended. Their size should be adapted to local precipitation patterns and catchment characteristics. Keywords: agriculture, best management practice (BMP), biodiversity, constructed farm wetland (CFW), costs, farmyard runoff, water pollution, water treatment.
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Removal of organic and inorganic nutrients in a constructed rhizofiltration system using macrophytes and microbial biofilmsMthembu, Mathews Simon January 2016 (has links)
Submitted in complete fulfillment for the degree of Doctor of Philosophy (Biotechnology) in the Department of Biotechnology and Food Technology, Durban University of Technology, Durban, South Africa, 2016. / Many households in developing countries are still without proper sanitation systems. The problems are even more prevalent in rural communities where there are no septic systems in place for the treatment of wastewater. This has resulted in the urgent need for the development and implementation of innovative wastewater treatment systems that are inexpensive, environmental friendly and are able to reduce contaminants to levels that pose no harm to the communities. Constructed rhizofiltration systems have been explored for this purpose. They have been used for many decades in many countries with varying degrees of success at the primary, secondary and tertiary levels of wastewater treatment. Poor optimization of this technology has been due to limited information available about the roles played by the whole system as well as by each component involved in the treatment technology. The current work elucidates the role played by macrophytes and microbial biofilms in the removal of nutrients in the rhizofiltration system. Factors affecting waste removal as well as environmental friendliness of the system were also investigated.
The rhizofiltration system was constructed in Durban and was divided into planted (planted with Phragmites australis and Kyllinga nemoralis) and unplanted (reference) section. Dissolved oxygen (DO), pH, water temperature, total dissolved solids (TDS), electrical conductivity (EC) and salinity were monitored. The removal efficiency of nutrients was measured using spectrophotometric methods by measuring the concentration of ammonia, nitrate, nitrite, phosphate and orthophosphate in the wastewater pre- and post-treatment. The total organic carbon, chemical oxygen demand (COD), total Kehldjahl nitrogen, biological oxygen demand (BOD), ammonia, nitrate and the flow rate of wastewater into the system from the settling tank were used for the estimation of carbon dioxide, methane and nitrous oxide emitted from the rhizofilter using the 2009 EPA formulae.
Both the planted and reference sections of the system removed nutrients with varying efficiencies. The reduction of nutrients in the rhizofilter was found to be seasonal, with most nutrients removed during the warm seasons. The system also retained more nutrients when wastewater containing low levels of nutrients was used. The unpaired t-test was used to determine the differences between nutrient removals between planted and reference sections. Higher reduction efficiencies of nutrients were obtained in the planted section. Up to 65% nitrite and 99% nitrate were removed while up to 86% total phosphorus was removed in a form of orthophosphate (86%). Removal of total nitrogen was shown to increase under high temperature conditions, while the same conditions decreased the total phosphorus removal. High temperatures also increased the performance of the system. The reduction of nutrients in the system corresponded to reduction of the chemical oxygen demand which also positively correlated to the dissolved oxygen concentration. Considering the discharge limits for all nutrients, the discharges in the effluent of the planted section were within the allowable limits as per South Africa’s Department of Water affairs and Forestry in 2012 but not in 2013. The results obtained in 2013 were due to increased nutrient loading introduced into the system.
Diverse microbial communities occurred in the treatment system, with more diversity in the planted section. These organisms were supported by macrophytes in the planted section, and were responsible for nitrogen and phosphorus transformation. This explains why total nitrogen and phosphorus reduction was higher in the planted compared to the reference section.
Both the planted and the reference sections of the rhizofiltration system produced the greenhouse gases. When the two sections were compared, the planted section produced more gases. Gases emitted by both sections were lower when compared to emission from sludge treatment reed beds and other conventional systems of wastewater treatments. These findings indicated that constructed rhizofiltration is a cleaner form of waste treatment, producing significantly less greenhouse gases and affecting less of a climate change. Findings of this work have revealed that rhizofiltration technology can be used as a low-cost alternative technology for the treatment of wastewater, using the combination of macrophytes and microbial biofilms. Macrophytes accumulated nitrogen and phosphorus as well as supported diverse microorganisms that metabolized and reduced nutrients in the rhizofiltration unit. / D
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Mikroplast i dagvatten och spillvatten : Avskiljning i dagvattendammar och anlagda våtmarker / Microplastics in Stormwater and Sewage : Removal in Stormwater Ponds and Constructed WetlandsJönsson, Robert January 2016 (has links)
Mikroplast, här definierat som plastobjekt mindre än 5 mm, befaras kunna göra stor skada på vattenlevande djur. Fram tills idag har studier av mikroplastreduktion främst utförts i kommunala avloppsreningsverk där mycket av plasten avskiljs. De stora spillvattenflödena gör ändå reningsverken till betydande utsläppspunkter av mikroplast till sjöar och hav. Information har hittills till stor del saknats om mikroplastförekomst i dagvatten, vilket ofta släpps ut orenat och i större volymer än spillvatten. Förekomst av mikroplast >20 µm (>0,02 mm) har undersökts för tre tätorters dagvatten samt för två avloppsreningsverks utloppsvatten. Avskiljning av mikroplast har undersökts för två spillvattenvåtmarker och två dagvattendammar. Båda anläggningstyper är relativt billiga och effektiva när det gäller reduktion av tungmetaller och övergödande näringsämnen. Örsundsbro våtmark och våtmark Alhagen tar båda emot behandlat spillvatten från kommunala avloppsreningsverk. I våtmark Alhagen finns även ett inlopp för dagvatten från Nynäshamn. Till dagvattenanläggningen Korsängens vattenpark leds en stor del av Enköpings dagvatten, medan Tibbledammen tar emot det dagvatten som kommer från Kungsängen i Upplands-Bro kommun. Vatten från anläggningarnas inlopp och utlopp, samt från två punkter inuti våtmark Alhagen har pumpats genom 20 µm-filter och 300 µm-filter. Provtagningen har kompletterats med insamling av mindre vattenvolymer som har filtrerats på laboratorium. Kvantifiering av mikroplast har gjorts med hjälp av stereomikroskop och vanligt förekommande objekts material har undersökts genom FTIR-spektroskopi. I våtmark Alhagens inkommande spillvatten var mikroplastkoncentrationen 4 objekt/liter, vilket liknar de koncentrationer andra svenska studier uppmätt i behandlat spillvatten. I inkommande vatten till Örsundsbro våtmark var koncentrationen över 950 objekt/liter, långt över vad andra svenska studier uppmätt i helt obehandlat spillvatten. I dagvatteninloppen var mikroplastinnehållet 5,4–10 objekt/liter, vilket indikerar på att mikroplatsutsläpp via dagvatten kan befaras vara minst lika stora som via spillvatten. I alla anläggningars inkommande vatten, förutom i våtmark Alhagens dagvatteninlopp, uppmättes höga koncentrationer av rödfärgade partiklar. Partiklarna kan vara av plast eller av annat okänt material och är till utseendet relativt lika de som andra studier påträffat i svenska kustvatten. Svarta partiklar påträffades i alla inflöden och ofta i mer än 100 gånger högre halter än de för mikroplast och röda partiklar, förutom i våtmark Alhagens spillvatteninlopp där de röda partiklarna var något fler. Partiklarna tros kunna vara däck- och vägrester eller förbränningspartiklar. Alla anläggningar visade på en tydlig avskiljning, ofta 90-100 %, för mikroplast, svarta och röda partiklar >20 µm. Till följd av resultatet samt anläggningarnas variation i ålder, storlek och utformning bör dagvattendammar och anlagda våtmarker generellt kunna förväntas fungera som effektiva barriärer mot spridning av mikroplast, svarta partiklar och röda partiklar. / Microplastics (MPs), here defined as plastic objects smaller than 5 mm, are suspected to cause great harm to fish when released into lakes and oceans. Studies of MP retention have until recently mainly been done for sewage treatment plants (STPs), where much of the plastics are shown to be retained in the sludge. However, due to large water flows in STPs, they can be seen as significant points for the spreading of MPs to recipient waters. Today there isn’t much information to be found about MP contents in stormwater. Stormwater is often released untreated and depending on climate it can be released in greater volumes than sewage water from urban areas. The occurrence of MPs >20 µm (>0.02 mm) has been studied in two STP effluents, and in stormwater from three urban catchments. The retention of MPs has been studied for two stormwater ponds, and for two free water surface wetlands constructed for tertiary treatment of sewage. Wetland Alhagen and Örsundsbro wetland both receive the effluents of secondary STPs. In wetland Alhagen there is also a stormwater inlet from the town of Nynäshamn. To the stormwater pond Korsängens vattenpark, stormwater is lead from the town of Enköping, while the stormwater pond Tibbledammen receives stormwater from Kungsängen in Upplands-Bro municipality. Influents and effluents from the facilities, as well as water from two points within wetland Alhagen was pumped through 20 µm and 300 µm filters. In addition, water from every sampling point was collected in minor volumes for later filtration carried out in a laboratory. Quantification was done with microscopy and a number of objects were analyzed with FTIR spectroscopy for material determination. In wetland Alhagen, the sewage inlet contained 4 MPs/liter, which is similar to results for STP effluents in other Swedish studies. In Örsundsbro wetland, the incoming water contained more than 950 MPs/liter, far greater than what other studies have shown for untreated sewage. The MP concentrations in the three stormwater inlets were between 5.4-10 MPs/liter. This indicates that untreated stormwater could be seen as a pathway for MPs at least as big as treated sewage. In almost all inlets, characteristic red particles were found in great numbers and in sizes of 20-300 µm. Analysis of some of the red particles indicated that they contained plastic while others were of unknown materials. The particles had a similar appearance to red particles commonly found in Swedish coastal waters. Black particles, a kind of microscopic particles that may originate in tyre wear (i.e. MPs) or combustion, was also found in large quantities. Except for in the main influents of wetland Alhagen, where the number of red particles was slightly higher, the black particles were always found in far greater numbers than both regular MPs and red particles (often >100x greater). The retention of MPs, black particles and red particles >20 µm was high in all the facilities, often around 90-100 percent. Based on these results and the variation of size, design and year of construction, stormwater ponds and constructed free water surface wetlands can be seen as effective barriers against the spreading of MPs.
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Constructions of Masculinity in Salman Rushdie’s Novel The Satanic VersesPettersson, Malin January 2017 (has links)
This literary analysis focuses on gendered constructions of masculinity in The Satanic Verses by Salman Rushdie. The main argument is that masculinity is a construction of gender much like femininity. Masculinity, however, has often been disregarded as an approach within gender studies of literature where the aspects of femininity have taken precedence. The theoretical approach in this analysis is the sociological perspective of gender, not determined solely by the biological sex. I will discuss sociological gender, and the constructions of masculinity, from the following five aspects: the male body, sex, fatherhood, violence and performance. I will address the physical mutations of the protagonists’ bodies, the sexual relationships between the characters as well as the reproductive organ and its contextual meaning. I will also focus on the ideas of, and relations to, fatherhood, violence the characters are subjected to, as well as the performance of acting your identity. All of these five aspects show constructions of masculinities clearly, and there is a need for addressing them more thoroughly in literary analyses.
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A Comparison of Selected Student and Environmental Variables in Open-Area and Traditionally-Constructed Elementary SchoolsPitts, Joe M. 05 1900 (has links)
The problem of this study was to assess and compare selected student and environmental variables in seven open-area elementary schools carefully matched with seven traditionally-constructed elementary schools on eight different criteria. The hypotheses were formulated to carry out the following four purposes of the study: 1. To determine the differences between the achievement test scores in reading, language, and mathematics of students attending open-area elementary schools and scores of similar students attending traditionally-constructed elementary schools, as measured by the California Achievement Test and the Comprehensive Tests of Basic Skills administered in grades one, two, and three. 2. To determine if there was greater individualization of instruction in open-area elementary schools as measured by the Individualization of Instruction Inventory. 3. To determine if students attending open-area elementary schools evidenced a greater number of positive actions toward school, as indicated by attendance, number of acts of vandalism, and number of suspensions from school shown in official records of the school district.
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Fiktivní jazyky v literatuře / Fictional languages in literatureJelínek, Jiří January 2014 (has links)
The purpose of this thesis is to introduce the so far ignored topic of fictional languages in literature. In the first part it focuses mainly on the function of the fictional languages in the literary works, and analyses the basic options of the fictional languages classification, based on whether they can be labeled as an independent work of art, as an autonomous part of a work, or as an instrument of the aesthetic function in the work. Furthermore, it divides the fictional languages in accordance to the way in which they take effect, either through the expression-form, through the expression- substance, through the content-form, or through the content-substance, taking the terminology from the Louis Hjelmslev's sign model. The second part consists of the analysis of the cases of fictional language usage in prose; these usages are grouped into three divisions. Languages, which help to create an invented world (and eventually add up to its authenticity), are represented by J. R. R. Tolkien's fictional languages. The dystopian languages include Newspeak from the novel Nineteen Eighty Four by George Orwell, ptydepe and chorukor from the play The Memorandum by V. Havel, and "Moon Czech" from the prose The True Excursion of Mr. Brouček to the Moon by S. Čech. Fictional languages related to philosophy are...
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