博士 / 國立海洋大學 / 水產養殖學系 / 89 / The main purpose of this study is to explore the feasibility of substituting terrestrial fiber materials with filamentous algae that frequently appear in disused aquacultural ponds in Taiwan. Among these abundant algae, Rhizoclonium sp. was the main subject of our investigation. The first part of the study investigated the fiber morphology of Rhizoclonium sp. and the chemical composition of its cell walls. The results indicate that the alga possesses similar strand-shape, carbohydrate composition and cellulose crystallinity as traditional wood fibers. The tubular cells of the alga connect end-to-end forming filamentous aggregates that resemble wood fibers. Thus the alga has a potential to substitute for wood fibers in pulping and papermaking. In the second part of the study, we noted that Rhizoclonium sp. not only could be adjusted for its ''fiber length’, enabling paper forming alone or blended with long and short wood fibers, but also had exceptionally high yield. Using low chemical dosage, low temperature, short cooking time and a sulfur-free cooking liquor, good quality pulps could be obtained. The alga, after trimming for proper length, could be used directly in papermaking, i.e., it could have a pulp yield close to 100%. As a whole, handsheets made from the alga still lag behind wood pulp in strength properties, but for certain grades needing only medium tensile strengths, it has good potential applications for partial substitution of wood fibers. In the third part of the study, we found that in the central and southern part of Taiwan, Rhizoclonium generated substantial quantity of biomass regardless of seasons. Maximum biomass of 945 to 1540 kg dry weight per hectare pond surface per month could be attained. Factors influencing algal growth include salinity, temperature, strand length and hydrological conditions of the growth environment. The best salinity and temperature were 20 parts per 1000 and 25oC. Strand length and agitation in pond water had negative impacts on the growth of the alga. The photosynthetic rate of the alga showed significant correlation with inorganic carbon sources. When NaHCO3 concentration was 2-4 mM, the alga had higher net photosynthetic rates. The study also showed that the osmotic pressure exerted by the salinity of the culturing water had less marked influence than the concentration of inorganic carbon in the water. We also found that Rhizoclonium sp. not only could utilize carbon dioxide but was also capable of using bicarbonate ions in the water. In the future, it possesses good potential to produce biomass and become a replacement resource for wood fibers. Thus not only alleviating the pressure to harvest forests, but also contributing toward the reduction of atmospheric greenhouse gas indirectly as well.
| Identifer | oai:union.ndltd.org:TW/089NTOU0086001 |
| Date | January 2000 |
| Creators | 趙國評 |
| Contributors | , 陳忠信, 蘇裕昌 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 124 |
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