Bio-remediation Technology Used On Remediating The Urban River

Urban rivers are thought to be the symbol of one city. They are known not only for their ecological functions such as supplying water, providing green spaces, protecting environment and conducting tourism, but also they are the spaces where people can take entertainment and be close with nature. However, accompanying with the growth of the population and the economic development, the urban river was polluted more and more seriously. The remediation on the polluted urban river is very important but difficult to construct civil ecological system and improve the environmental quality. According to the remediation experiences from home and abroad, remediation on the urban river should be based on the laws of the ecology system in the river and emphasize the restoration and protection of the ecology. Furthermore, remediation of the urban river should be consistent with the development of the economic, where safe and high-speed remediation is needed.In this study, the water self-purification ability was discussed, and the role of sediment in the self-purification process was studied. When water could not complete the self-purification process, aeration technology and perturbation technology were introduced. It was shown that aeration technology was effective in improving the removal efficiency of organic substance, ammonia-nitrogen and total nitrogen when the sediment existed in the reactor. Comparing with the aeration technology, the perturbation technology was bad, although it was also effective in improving the removal efficiency no matter the sediment exists or not. Because of the intensification by aeration technology and perturbation technology, the organic substance and total nitrogen in the sediment were removed, among which the aeration technology was more effective. In the sediment where the aeration technology was used, the number of typical microorganisms and the species of bacterium increased. Moreover, the enzyme activity was improved. It was shown that sediment was irreplaceable in the purification process.The Bio-energizer technology was conducted, showing that the bio-energizer was helpful to improve the bioactive of the microorganism in the sediment. A lot of the microorganism was grown, thus, the biochemical reaction and the degradation of the contaminant were speeded up. However, a lot of bubbles were generated because of the florescence of the microorganism. Combined with the organic substance and nitrogen contaminant that were released in the water from the sediment, the values of CODCr、TN、NH3-N in the water increased. Although the contamination could be cleared finally by the microorganism, a long time was needed to reach the water standard.The Bio-agent technology was also conducted, showing that water quality can be improved when yeast cells were added into the field river, and the added yeast can absorb the sediment particles where they can exist for a long time. According to the detection after one year, the number of typical microorganisms and the species of bacterium increased, therefore, the enzyme activity was improved. It was believed that the yeast can behave as a leader to improve the bio-environment in the sediment.To make up for the shortage ability of Bio-energizer technology, the Bio-agent technology was added. The result showed that this combination technology was effective on the degradation of water contamination to moderate the inadequate of the Bio-energizer technology.