Toitainete voogude reguleerimine põllumajanduslikku hajureostust puhastavas tehismärgalas

Väitekirja elektrooniline versioon ei sisalda publikatsiooneÜhiskonna suurenenud toiduvajadus on suurendanud põllumaade osakaalu ning väetiste kasutamist. Intensiivne või halvasti ajastatud väetamine mõjutab pinnavett ja suurendab veekogude eutrofeerumist. Põllumajandusliku hajukoormuse leevendamiseks ja vee kvaliteedi parandamiseks on tõhus meede tehismärgalade rajamine. Need aitavad parandada vee kvaliteeti looduslike protsesside abil ning pakuvad muidki ökosüsteemi hüvesid (suurendavad bioloogilist mitmekesisust, puhverdavad sademevett ja toimivad veereservuaarina). Doktoritöö uuris vahetult voolusängi rajatud Vända avaveelise tehismärgalargala toimet: toitainete vähenemist ja kasvuhoonegaaside (KHG) heitkoguseid mõjutavaid parameetreid. Varasemast on teada, et tehismärgalades sõltuvad toitainete eemaldamise tõhusus ja KHG heitkogused vee parameetritest ja märgalade kujundusest. Vända märgala vähendas tõhusalt fosforit, millel oli selge hooajaline dünaamika. Tõhusamalt eemaldas fosforit soojal perioodil ja külmal perioodil oli tõhusus väiksem. Fosfori eemaldamise efektiivsus oli suurem väikese vooluhulga korral, sest siis aeglane vool soodustas settimis- ja filtreerimisprotsesse. Lämmastiku eemaldamine oli ootustele vastupidine, kuna märgalas suurenes lämmastiku hulk väljavoolu suunas. Lämmastiku lisandumine toimus tõenäoliselt nitraadirikka põhjavee sissevoolu tõttu. Fosfori puhastusefektiivsus sõltus ka taimkattest – mida rohkem taimi, seda tõhusam. Taimestik levis märalal aastate jooksul ning see soodustas fosfori eemaldamist. Metaani (CH4) ja dilämmastikoksiidi (N2O) puhul ilmnes sesoonne dünaamika – soojal perioodil oli lendumine suurem ja külmal perioodil väiksem. N2O heitkogused sõltusid vee sügavusest, voolukiirusest ja vee temperatuurist. Suvel kui mikroobne aktiivsus on suur, täheldati oluliselt suuremaid N2O emissioone.Water quality has degraded due to increased proportion of agricultural lands in some regions, if more fertilizer is used. Intensive or poorly timed fertilization affects surface waters and increases eutrophication in water bodies. Diffuse agricultural pollution is difficult to locate and control due to its diffuse nature, climate conditions and strong anthropogenic influence. In order to maintain or improve surface water quality, it is important to find and use effective measures. One of the best measures for improving water quality is using constructed wetlands. Constructed wetlands help to improve water quality through natural treatment processes, among several other benefits. They increase biodiversity, buffer storm water and act as a water reservoir. The aim of this thesis was to investigate the efficiency of in-stream free water surface flow Vända constructed wetland and study the parameters affecting nutrient reduction and greenhouse gas (GHG) emissions. Long-term monitoring results show that in in-stream CWs, nutrient removal efficiency and GHG emissions are highly dependent on water parameters and wetland design. Vända CW effectively reduced phosphorus that had clear seasonal dynamics. Higher removal efficiency occurred during the warm period and lower values were seen during the cold period. Higher removal efficiency values for phosphorus were seen when the flow rate was lower. With a lower flow rate, sedimentation and filtration processes are favoured. The results for nitrogen removal were contrary to expectations because CW acted more as a source of nitrogen. The addition of nitrogen was suspected to come from groundwater that was contaminated with nitrate. Phosphorus removal had a strong positive correlation with vegetation coverage. Through years’ vegetation spread over the wetland and that promoted phosphorus removal processes. For methane (CH4) and nitrous oxide (N2O), clear seasonal dynamics were seen, with higher emissions during the warm period and lower emissions during the cold period. N2O emissions were strongly related to water depth, flow rate and water temperature. During summer, with high microbial activity, significantly higher N2O emissions were seen

Development of New Catalysts Through the Synthesis and Characterization of High-valent Metal Complexes

Efforts have been made to develop catalytic materials based on transition metals. These complexes are used in catalysis because the metal center can take on multiple oxidation states.1,2 Traditionally, these metal complexes utilizemetals like gold, platinum, and palladium because of their ability to control the properties of reactivity. To develop a more cost-effective catalyst design, a focus was placed on the synthesis of high-valent, first-row, transition metal complexes. First-row transition metals have the potential to form high-valent metal complexes which are stabilized by coordinating with strong electron-donating ligands. Metal complexes supported by a CNC-pincer ligand, CztBu(ImdtBu)2, were synthesized and characterized

Moraalsed argumendid taimetoitluse ja täistaimetoitluse jaoks

Töö sisuks on tuua moraalseid argumente taimetoitluse ja täistaimetoitluse kasuks. Ma toon erinevaid argumente selle kohta, miks taimetoitlus ja täistaimetoitlus on moraalselt õige loomade, inimeste ning keskkonna jaoks, samuti arutlen ma vastuargumentide üle.https://www.ester.ee/record=b517924

Õpetajatele suunatud vägivald Pärnumaa üldhariduskoolide näitel

http://www.ester.ee/record=b4741446*es

The application of environmental management accounting amongst KwaZulu-Natal's top businesses.

Thesis (MBA)-University of KwaZulu-Natal, Westville, 2011.Sustainable development is often described in three dimensions, namely social, environmental and economic. Environmental Management Accounting (EMA) is a management accounting approach which brings the environmental impact of the process to the attention of the stakeholders whilst also looking at the economic aspect so as to control costs. While EMA’s application has been adopted widely in developed countries, does the same apply in South Africa? Seeking to understand the level of current EMA being conducted at the corporate level will assist government and corporations in South Africa to understand the factors encouraging better accounting sustainability. The focus of this study was confined to leaders of organisations operating in the KwaZulu-Natal (KZN) province of South Africa. Quantitative research was conducted on 40 organisations that operated in KZN. The organisations sampled ranged from small to large enterprises, and operated in a number of different industries. The study centred on analysing the organisation’s attitude towards environmental sustainability, the types of EMA reports generated and reasons for or against using EMA. The research revealed that the attitude by each organisation towards environmental sustainability was vital in encouraging organisations to implement EMA as a method of controlling pollution. The majority of organisations had applied some form of EMA in their KZN organisation. A major finding was that for those who chose to apply EMA, their most important reason was to control costs better. The second reason for applying EMA was legislation. Planned implementation of EMA was analysed and a number of specific industries and sizes of industries were highlighted for their implementation of EMA or lack thereof. This research is useful to the reader as it has analysed the current application of EMA to encourage sustainable development, identify the general obstacles encountered to application of EMA and recommend strategies that can be employed to overcome them. These recommendations include government involvement through education programmes to improve the understanding and attitude towards EMA. Secondly, government should pass legislation making environmental reporting a compulsory disclosure for all organisations. Organisations themselves should use advanced computerised recording systems to develop their application of EMA. Larger businesses should encourage and assist smaller organisations in their supply chains to become more active in their own environmental protection

Avaveelise tehismärgala efektiivsus põllumajandusliku hajukoormuse vähendamiseks

Toitainete ärakanne põllumajandusmaadelt hajukoormuse näol põhjustab veekogudes eutrofeerumist. Taimede poolt omastamata jäänud toitained leostuvad pinnaveekogudesse, mistõttu hajukoormuse vähendamiseks on vajalik rakendada meetmeid. Avaveelised tehismärgalad puhastavad vett efektiivselt, on looduslähedased ning bioloogiliselt mitmekesised. Lõuna-Eestis asuv esimene hajukoormuse vähendamiseks voolusängile rajatud Vända avaveeline tehismärgala koosneb settetiigist ja kahest madalaveelisest märgalast, mis on taimestatud hundinuiadega (Typha latifolia). 2017. aasta märtsist kuni 2018. aasta aprillini kogutud andmete põhjal vähendas Vända tehismärgala fosforit 17,5 kg/ha*a. Aastane puhastusefektiivsus fosfaadi puhul oli 9,4% ja üldfosfori puhul 12,0%, olles soojemal perioodil vastavalt 44,6% ja 32,4%. Fosfaadi ja üldfosfori puhastusefektiivsusel oli tugev logaritmiline seos vooluhulgaga, mis näitab, et väiksem vooluhulk ja pikem vee viibeaeg soodustab fosfori vähendamist märgalas. Orgaanilise süsiniku aastane vähenemine märgalas oli 3300 kg/ha*a, kuid üllatuslikult suurenes üldlämmastiku sisaldus märgalas 1375 kg/ha*a. Üldlämmastiku ja nitraatlämmastiku kontsentratsioonid suurenesid aastas vastavalt 20,8% ja 28,5%. Nende tulemuste põhjal on voolusängile rajatud avaveeliste tehismärgalade käivitumise periood põhjamaades küllaltki pikk ning Vända tehismärgalas on kolm aastat peale rajamist puhastusefektiivsused küllaltki tagasihoidlikud

Muusikakooli õpetaja tööks vajalikud kompetentsid muusikakoolide juhtide nägemusel

http://www.ester.ee/record=b4682969*es

Narkootikume süstivate inimeste esmane profiil Tartu linnas

https://www.ester.ee/record=b5196517*es