碩士 / 嘉南藥理大學 / 環境工程與科學系 / 104 / In the water treatment processes, raw water with higher algae content belongs to one of the most difficultly treated cases because the algae have the characteristics of shape changing, low specific gravity and cell density, etc. As a result, in the coagulating sedimentation process, it is hard to remove algae completely, hence blocking the filter unit and increasing times of back-washing and material replacement.
This study evaluated efficacy of poly silicate iron (PSI) used in the coagulation of raw water with higher algae content. Via Jar Test, the optimum PSI dosage was estimated. At the silicon/iron molar ratio of 0.2 : 1, the optimal PSI dosage is 10 ppm. At a higher dosage, the water will exhibit brown color and the turbidity is higher. Moreover, co-settling agents (magnetic iron oxide and bentonite) for enhancing settlement efficiency were added and compared. The result showed that magnetic iron oxide can more effectively speed up the settling velocity.
In conclusion, adding PSI and co-settling agent can effectively improve the removal of algae. Furthermore, addition of iron oxide magnetic particles has no noticeable effect on the pH values and electrical properties of water. Spent iron oxide particles were recycled. By calcining the spent iron oxide at 600℃, about 87 wt.% was recovered whilst the iron oxide still retained the magnetic and settlement-assisting ability.
| Identifer | oai:union.ndltd.org:TW/104CNUP0515014 |
| Date | January 2016 |
| Creators | Hong, Ying-Jie, 洪英傑 |
| Contributors | Lin,Shiow-Shyung, Ken,Chi-Chuan, 林秀雄, 甘其銓 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 66 |
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