| As one of the water-shortage-city in north, Tianjin which is locate in the downstream of Haihe River, has been serious polluted, especially in the Tianjin Economic-Technological Development Area (TEDA). Therefore, it is important to carry out water resources projects, using the reclaimed water in the region as the only river water sources. These will not only improve the water environment and urban water reuse, but also benefit to the construction of environmental landscape. It not only helps to the restoration of ecological environment and improve water quality in this region, but also greatly alleviates the situation of fresh water shortage, which will greatly promote the sustainable development in TEDA and even in Tianjin.In this dissertation, a comprehensive and systematic research on the reclaimed water from coastal saline areas reuse to the landscape of the river water environment and ecological reconstruction, eco-purification technology integration was carried out, based on the key point of the river landscape reconstruction of aquatic ecosystems and water quality improvement technology. It developed technology and system solutions to the wetland ecosystem reconstruction by using renewable water as the main source, which fit for the serious water shortage in the north and coastal areas of high saline-alkali soil. Research achievements can be applied to renewable water purification and landscape reuse project in similar areas. The major achievements obtained in this dissertation were as follows:For the first time on reclaimed water reuse for urban landscape water in China. Through four years of research, it built a 220,000 square meters (including river and lake scenery) projects. It screened some keystone species, including terrestrial salt plants such as Suaeda salsa, Siberian Pall and Pteris orchids, and emergent aquatic such as Typha angustifolia, Scirpus validus, Scripus planiculmis, and submerged aquatic such as Ruppia maritima and Potamogetonaceae pectinatus. Compared with conventional green building, one-time investment and operation and maintenance costs were reduced 80.4% and 92%, respectively. While compared with conventional wastewater purification technology, they were reduced 79% and 94.6%, respectively.It developed and researched the multi-level ecological reconstruction & purifying technology system for the salt landscape river in saline coastal areas, which included the following core technologies: the recycling technology for salt water, salt-control technology for saline-alkali soil, pioneer salt-tolerant plant selection & optimal distribution, and the ecological reconstruction technology for riverside buffer zone. These technologies succeed in its first application in TEDA. After 3 years of construction and rehabilitation, a river water ecosystem adapted to local environmental characteristics has been formed, with vegetation coverage rate of 15%. The basic ecological function formed, and self-adjusting ability increased gradually.The multi-media mixed-flow wetland purification technology, pebble-bed bio-film biological purification technology, complex ecological revetment technology, plant belt filtration technology, and biological algae-control grid technology were optimal designed and distributed to develop the intensified bio-ecological surface flow wetland purifying technology system. Its project achieved desired results in application to TEDA.It developed and researched the ecological reconstruction & intensified ecological purifying technology system for the landscape waters of reclaimed water high in salt. Its development creates a new use model for reclaimed water in China. Its application in TEDA artificial rivers and lakes showed an obvious nutrients-purifying effect, with the effluent water quality meeting the demanded standards (Landscape water quality and surface water quality V).
|
PDF Full Text Request