Study on Treatment of Livestock Wastewater by Aquatic Plants

• Main Authors: Chiu-Hua Li, 李秋華
• Other Authors: Shu-Chu Tung
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/83586725548664227395

碩士 === 崑山科技大學 === 環境工程研究所 === 98 === Sources of domestic livestock wastewater in Taiwan generate mostly from pig farms and cattle farms. Since most pig houses and cattle houses in Taiwan have concrete floors, in order to maintain the sanitation of livestock farms and the health of pigs and cattle, the farm management often use a large amount of water to wash the animal houses, and thus generate a considerable amount of wastewater. With assistance from the Council of Agriculture over the years, 98% of the pig farms with 200 or more breeding have set up wastewater treatment facilities, and a large proportion of them use the three-stage wastewater treatment system developed by the Livestock Research Institute of the Council of Agriculture. However, the treated livestock wastewater still contains a large amount of nutrients. The waste water is very likely to cause the eutrophication of water bodies if it is discharged directly into the rivers or gutters. The main purpose of this study is to lower potential of eutrophication by using aquatic plants to purify treated waste water and to remove the excessive nitrogen and phosphorus nutrients. Ornamental aquatic plants with strong stain endurance, great reproductive ability and strong purifying ability were chosen as the object plants to purify the waste water with development of added values such as recycling and greening. In this study, three aquatic plants were watered with effluent waste water of livestock in the laboratory. Ceratophyllum demersum has the best performance in all aspects, followed by water hyacinth and water lettuce in that order. Ceratophyllum demersum adapts the environment the best and also has the highest effectiveness of water purification.Due to the high conductivity, the survival time of water hyacinth is not long (about 7 to 10 days) , however, it still has good effectiveness of water purification.The decontamination capability of water lettuce is reduced because its leaves decompose easily in the water. The nitrogen removal rates of ceratophyllum demersum, water hyacinth and water lettuce are 99%, 42% and 4% respectively.The phosphate removal rates of ceratophyllum demersum, water lettuce and water hyacinth are 86%, 81% and 22%. Water hyacinth was planted in the sedimentation tank of the livestock wastewater treatment site. The removal rate of the effluent water in the sedimentation tank from the aeration tank is 30% for phosphate ,while there is only a small cut of nitrogen nutrients.