Study On Xi'an Moat Renovation And Remediation Of Polluted Water

Xi'an moat flows around the city wall with 14.6km long, decorating the ancient city with beauty. Through repair was made in city wall and moat historically every 200 years. However, Xi'an moat is in the difficulty that repeated polluted water is followed by repeated pollution control, silt cleaning of has been carried out for 3 times in just about 20 year, from 1983 to 2004. To this point, this paper gave a suggestion that was helpful in ecological remediation and reconstruction of Xi'an moat pollution control.This paper mainly studied the following two parts. Firstly, feasibility of bioremediation of moat water included instu remediation of moat water by landscaping canna floating bed, purification of moat water by adding predominant isolates into the water body, helping to create an aerobic ecosystem. By doing this, this paper got a new direction in pollution control of moat water. Secondly, aeration capability of overflow dam in moat water was investigated to transfer more oxygen from atmosphere into water when water flows through the dam causing the rapidly varied flow to achieve aeration. DO was determined, showing that increased oxygen resulted from the overflow dam was of great importance to the improvement of DO in moat water.Moat pollution control is a system engineering, at first pollution-cutting was carried out to stop the new pollution source into the moat water; then silt-cleaning was adopted to eliminate the threat of inner pollution of moat water; lastly clean water source was introduced to ensure the water quality of moat water from the water source. Methods such as pollution-cutting, silt-cleaning, introduction of clean water source, watercourse hardening and so on was used to control the water pollution in moat water. And these methods caused a high cost and poor effects. The main points were that ecosystem of the moat water was not recovered causing the purification of the moat water not to act effectively. Therefore, water quality of moat water was not solved actually. Bioremediation technology is a better method that uses bio-floating bed and inoculation of predominant isolates to treat the pollutions in moat water. Furthermore, great emphasis should be placed on the construction of ecological riverbank, and recovering of the moat eco-environment to improve the self-purification ability of moatwater, preserving the water quality of moat water.