Integrating constructed wetlands and fish ponds into a recirculating aquaculture system

• Main Authors: Hsuan-Yu Su, 蘇璿煜
• Other Authors: Ying-Feng Lin
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/57802481330758160571

碩士 === 嘉南藥理科技大學 === 環境工程與科學系暨研究所 === 94 === This study is to integrate constructed wetland, or treatment wetland, technology into the recirculating aquaculture, in which constructed wetland is used as a facility for aquaculture water treatment so as to control the water quality in fishpond and reduce pollutant level in the fishpond discharge. The constructed wetland (105m2) was built using part of an existing fishpond, and included a free water surface flow unit followed by a subsurface flow unit. A fishpond (1125m2) was connected with the treatment wetland to constitute a recirculating aquaculture system. Another fishpond (1138m2) without connection of treatment wetland was used as a control fishpond, in which traditional static aquaculture was carried out. This study investigated the performance of the constructed wetland in removing the major pollutants from the recirculating aquaculture water, and examined the effect of wetland treatment on water quality of the fishpond in the recirculating aquaculture system. Two aquaculture trials stocked with larvas of Pacific white shrimp was conducted. One trial was carried out from the middle July to the late September, 2004; Two trial was started from the first January, 2005 to the late May, 2005; Three trial was started from the first may, 2006 to the late July, 2006. Results of water monitoring of influent-effluent showed that constructed wetland effectively reduced TSS (54~78%), turbidity (52~65%), chlorophyll a (54~68%), BOD5 (27~46%) and COD （26~65%） from the recirculating aquaculture water. Water quality of recirculating fishpond were maintained at 21±14, 23±12 and 37±10 mg/L for TSS, 15.5±5.1, 16.5±6.1 and 18.3±12.4 NTU for turbidity, 34.9±31.1, 18.9±11.2 and 37.6±24.1μg/L for chlorophyll a , 5.6±1.6, 6.2±3.0 and 6.6±2.2 mg/L for BOD5, and 42.8±13.5, 76.6±24.1 and 37.6±24.1 for COD in trials 1 , 2 and 3, respectively. These levels of pollutants were significantly lower (p<0.05) than those in the control fishpond. Constructed wetland was demonstrated to be an efficient and low-cost ecological approach to management water quality and control pollution discharge in a fish farm.