Sökning: "total nitrogen"

Visar resultat 11 - 15 av 251 avhandlingar innehållade orden total nitrogen.

1. 11. Nitrogen-cycling tracing methods : Case studies at cold-climate mine sites in northern Sweden

   Författare :Lino Nilsson; Anders Widerlund; Andreas Bryhn; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geochemistry; Tillämpad geokemi;

   Sammanfattning : High nitrogen effluents from mine sites is an environmental issue which has received relatively little attention historically. In recent years a number of studies have showed the environmental effects of high nitrogen discharge to natural water bodies, which include local eutrophication, high risk of acute reducing conditions and changed species composition in the receiving waters. LÄS MER

3. 12. Nitrogen effluents from mine sites in northern Sweden : nitrogen transformations and limiting nutrient in receiving waters

   Författare :Sara Chlot; Anders Lundkvist; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

   Sammanfattning : Process water discharged from mine sites may contain elevated concentrations of nitrogen (N) and phosphorus (P), which both are nutrients for algae and aquatic plants. Thus, discharge of nutrient rich mine water can result in algal blooms, eutrophication, oxygen deficiency and changed species composition in the receiving waters. LÄS MER

4. 13. Factors Related to the Formation of Gas Porosity in Grey Cast Iron: Investigation of Core Gas Evolution and Gas Concentrations in Molten Iron

   Författare :Jessica Orlenius; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; core binders; Gas porosity; hydrogen; grey iron; gas absorption; nitrogen; oxygen; gas evolution rate; green sand; mould filling; gas volume; gas solubility;

   Sammanfattning : Since gas porosity is a major casting problem, it is of greatest importance to increase the knowledge about the foundry process in order to minimise the presence of gas porosity and thereby improving the casting quality. Gas porosity is generally considered to originate from gases precipitated during solidification of iron and from entrained gas picked up by the metal during the mould filling. LÄS MER

5. 14. Microalgae for Phosphorus Removal from Wastewater in a Nordic Climate

   Författare :Karin Larsdotter; Gunnel Dalhammar; Jörgen Hanaeus; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; assimilation; hydroponics; light; microalgae; nitrogen; phosphorus; plants; precipitation; wastewater treatment; Bioengineering; Bioteknik;

   Sammanfattning : As part of a research project aiming to develop and evaluate a hydroponic system for wastewater treatment in Sweden, extended nutrient removal by microalgae was tested. The hydroponic/microalgal wastewater treatment system was built in a greenhouse in order to improve growth conditions for plants and algae. LÄS MER

7. 15. Treatment of domestic wastewater using microbiological processes and hydroponics in Sweden

   Författare :Anna Norström; Gunnel Dalhammar; Jörgen Hanaeus; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Microbiology; biological; hydroponics; microbial composition; nitrogen; organic matter; phosphorus; small scale; theoretical energy requirements; wastewater treatment.; Mikrobiologi; Microbiology; Mikrobiologi;

   Sammanfattning : Conventional end-of-pipe solutions for wastewater treatment have been criticized from a sustainable view-point, in particular regarding recycling of nutrients. The integration of hydroponic cultivation into a wastewater treatment system has been proposed as an ecological alternative, where nutrients can be removed from the wastewater through plant uptake; however, cultivation of plants in a temperate climate, such as Sweden, implies that additional energy is needed during the colder and darker period. LÄS MER