Author(s): Y. S. Pei; C. J. Lin; Z. H. Tian
Linked Author(s):
Keywords: Media screen technique; Biogeochemical reaction; Zeolite; Dissolvedoxygen
Abstract: An eco-hydraulic technique was applied to enhance purification functions of the riverbank, particularly nitrogen removal, in river restoration. The technique named media screen technique has combined soil bioengineering technique with porous media embankment. An inner zeolite layer was set up in the inner layer of the riverbank, which could absorb ammonium and further remove nitrogen by microbe effects. Tests in situ showed that average ratios of ammonium removal and nitrogen removal were, respectively, 95% and 81%. An oxygen-deficient condition with dissolved oxygen of 0.87-1.06 mg/L had been observed in the inner zeolite layer. Micro-mechanism of nitrogen removal could consist of both new autotrophic process and traditional heterotrophic process. A self-driving biogeochemical reaction happened could be considered as macro-mechanism for nitrogen removal. The process coupled with water exchange between river and groundwater, owing to fluctuations of water level on both sides of the riverbank. Alteration of oxidative and reductive conditions in the media promoted nitrogen biodegradation without extra energy consumption, which ascribed to new eco-hydraulic technique.
Year: 2009