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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Treatment of Ammonia in Air Streams by Biotrickling Filters

Wang, Chia-Hsi 17 July 2000 (has links)
Abstract Ammonia is a major odoriferous component in the vent gas of the fermentation process of poultry manure compost. To prevent environmental problems, it is full-scale and a lab-scale biotrickling filters (BTF) were used for treatment of ammonia in air streams. The full-scale BTF was constructed by reinforced concrete (inner size = 6 m square ¡Ñ 5 m height) with PVC plate packings (total volume =6 m square ¡Ñ 3 m height = 108 m3 , specific area = 100 m2/m3). Long-term (357 days) experimental results show that, in the conditions of gas empty-bed-retention time EBRT = 35-77 s, liquid-gas ratio L/G = 5-11 L/m3, and recirculation liquid pH = 6.5-6.8, 6.5-29.8 ppm (average 14.3 ppm) ammonia in the influent gas could be reduced to 0-2.0 ppm (average 0.66 ppm). Daily rates were supplementary water = 0.400 m3, discharge water = 0.360 m3, supplementary H3PO4 (85%) = 0.28 kg. With the average volumetric ammonia loading of 0.66 g NH3-N/m3h, the system could achieve an average nitrification efficiency of 62% without supplementary glucose. Ammonia removal efficiencies of over 90% were obtained with recirculation liquid pH¡Ø6.8, and below 22% with pH¡Ù7.33. The lab-scale BTF consisted of a set of two-stage-in-series biotrickling filters, an influent gas supply system, and a liquid recirculation system. Each stage of the biotrickling filter was constructed from a 20 cm ¡Ñ 200 cm (inside diameter ¡Ñ height) acrylic column packed with cokes (average diameter = 3.0 cm and specific area = 150 m2/m3) of 125 cm height. Experimental results indicate that a time of 30 days was required for development of biofilms for nitrification of the absorbed ammonia from the gas. Long-term (187 days) experimental results show that, in the conditions of EBRT = 7.25 s, L/G=7.7 L/m3, and liquid pH=6.65, 230 ppm ammonia in the influent gas could be reduced to 4.0 ppm. With the volumetric ammonia loading of less than 7.37 g NH3-N/m3h, the system could achieve ammonia removal and nitrification efficiencies of 98 and 94%, respectively, without supplementary glucose. However, with a loading of 13.1 g NH3-N/m3h, both decreased gradually due to a lake of carbon (glucose) source and an accumulation of nitrite and nitrate in the recirculation liquid.
2

Degradation of Ternary Mixture of Trihalomethanes in a Biotrickling Filter in the Presence of Biosurfactant and Fungi

Islam, Sanaiya 09 June 2020 (has links)
No description available.

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