Search for dissertations about: "Ammonium concentration"

Showing result 1 - 5 of 78 swedish dissertations containing the words Ammonium concentration.

  2. 1. Cellulose in quaternary ammonium hydroxide solutions

    Author : Shirin Naserifar; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; quaternary ammonium hydroxides; cellulose; N; N-dimethylmorpholinium hydroxide; Triton B; NaOH; dissolution; TMAH; etherification;

    Abstract : An ever-increasing demand to shift away from fossil-based feedstock towards renewable resources has led to more use of bio-based materials. Cellulose being the most abundant biopolymer on Earth has received a considerable attention with a wide range of applications (in textile fibers, films, membranes, etc. READ MORE

  4. 2. Ammonium Feedback Control in Wastewater Treatment Plants

    Author : Linda Åmand; Bengt Carlsson; Peter Vanrolleghem; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aeration control; ammonium feedback control; biological nitrogen removal; full-scale experiments; gain scheduling control; PI control; process control; repetitive control; wastewater treatment; Elektroteknik med inriktning mot reglerteknik; Electrical Engineering with specialization in Automatic Control;

    Abstract : The aeration process is often the single largest consumer of electricity in a wastewater treatment plant. Aeration in biological reactors provides microorganisms with oxygen which is required to convert ammonium to nitrate. Ammonium is toxic for aqueous ecosystems and contributes to eutrophication. READ MORE

  5. 3. Wastewater treatment in constructed wetlands : Effects of vegetation, hydraulics and data analysis methods

    Author : Hristina Bodin; Karin Tonderski; Jesper Persson; Stefan Weisner; Per Milberg; Hans Brix; Linköpings universitet; []
    Keywords : constructed wetland; free water surface flow; wastewater treatment; Kenya; Sweden; vegetation; harvest; Cyperus papyrus; Echinochloa pyramidalis; mass load; phosphorus; ammonium; suspended solids; pollutant removal; hydraulics; residence time distribution; data analysis methods; Konstgjorda våtmarker; avloppsvatten; vattenrening; fosfor; ammonium; partiklar; Kenya; Sverige; växter; Cyperus papyrus; Echinochloa pyramidalis; skörd; hydraulik; dataanalysmetod;

    Abstract : Degradation of water resources has become one of the most pressing global concerns currently facing mankind. Constructed Wetlands (CWs) represent a concept to combat deterioration of water resources by acting as buffers between wastewater and receiving water bodies. READ MORE

  6. 4. Cellulose in Quaternary Ammonium-based Solvents: Dissolution, Modification and Coagulation

    Author : Shirin Naserifar; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; gelation; etherification; quaternary ammonium hydroxides; cellulose; dissolution;

    Abstract : Processing cellulose through dissolution and regeneration is essential for many applications, yet challenges are posed because it does not readily melt or dissolve in commonly used aqueous and organic solvents. Consequently, extensive efforts have been devoted to developing novel and efficient solvents for cellulose, as well as exploring new functionalization routes. READ MORE

  7. 5. Recovery of Scandium using Antisolvent Crystallization in the Valorization of Scandium-containing Waste Streams

    Author : Edward Peters; Kerstin Forsberg; Michael Svärd; Jens-Petter Andreassen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Antisolvent crystallization; ammonium scandium hexafluoride; ammonium metal fluorides; phase equilibria; solubility; supersaturation; seeding; agitation mechanism; crystal size distribution; morphology; Chemical Engineering; Kemiteknik;

    Abstract : Scandium is widely dispersed in the earth’s crust and is rarely concentrated in ores, and a viable option to guarantee a secure supply of scandium is to recover the metal from waste streams of other mining and metallurgical facilities. The valorization of such streams to recover metals of value is a prerequisite to alleviate the global shortages of scandium and other rare earth elements. READ MORE