| Summary: | 碩士 === 嘉南藥理科技大學 === 環境工程與科學系暨研究所 === 96 === For a modern building, the landscaping pond is an indispensable unit, but its water is often full of the alga which causes the problems of odor and appearance. A filter is setup to solve this problem and needs to be clean from time to time. As a result, the fast way to eliminate the mentioned problem is to replace the polluted water with tape water. It results in wasting a large of water resources. The main purpose of the present study is to assess the feasibility of mini-subsurface constructed wetland (SSF) on purifying the water quality of landscaping ponds. The field studies were conducted in two apartment buildings in Tainan city. The system A was composed by tow ponds, the upper pond (UP) and the down pond (DP), which was connected with a ditch. The total water volume was 6.456 m3. The ditch was reformed to a SSF system whose volume of water is 0.341 m3. The aquatic plants, canna (Canna indica L.), ginger (Hedychium coronarium Koening), houseleek (Cyperus alternifolius subsp. flabelliformis), marsh pennywort (Hydrocotyle verticillata) were planted in SSF for system A. System B belonged to the other building with 10 floors was composed of a landscaping pond and cascade. The latter was modified to SSF and planted with pennywort (Hydrocotyle verticillata). The total water volume of pond was 13.12 m3. During the operation period, the water quality parameters, biochemical oxygen demand (BOD), ammonium nitrogen (NH3-N), total phosphorus (TP), were employed to assess treatment efficiency of system. The operation periods were 28 months for system A and 12 months for system B.
From the results of the experiments, the averages of water temperature of both systems, 24.5℃ ~ 23℃, was found to be similar to each other. The pH for both systems were quite stable, 7.58 ~ 7.77. The oxidize reduction potential (ORP) ranged between 173.1 mv and 198.3 mv. This characteristic was different to the traditional system of SSF which was always negative. The dissolved oxygen (DO) for both systems reached 2.9 mg/L ~ 4.9 mg/L because to the aeration induced by water fall for both system. There was no such mechanism to increase DO for traditional SSF where always exited a anaerobic environment. The conductivity for system A increased from 350 (μs/cm) to 634 (μs/cm) whereas, it was increased from 400 (μs/cm) to 638 (μs/cm) for system B. the increase in conductivity was caused by no replace of water and only recharged with tape water to compensate the loss of evaportransperation. During the operation period, the average ranges of BOD, NH3-N and TP were 1.77 mg/L ~ 3.09 mg/L, 0.48 mg/L ~ 1.31 mg/L, and 1.23 mg/L ~ 2.49 mg/L for systems A and B. The water quality in ponds was quite uniformed and maintained a good clarity. It proved the feasibility of SSF to purify the water quality of landscaping pond. And, a lot of water resources were also saved.
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