Li J.-Z.,Nankai University |
Li J.-Z.,Tianjin Institution of Water science |
Li X.-J.,Tianjin Institution of Water science |
Liu X.-G.,Tianjin Institution of Water science |
Huang S.-L.,Nankai University
Huanjing Kexue/Environmental Science | Year: 2011
A kind of modularized and air adjustable constructed submerged plant bed (CSPB) was used to restore the eutrophic water. This CSPB helps hydrophytes to grow up under poor conditions, like frequently changed water depth, blurred water transparency, algae bloom and duckweed rampant in summer, which are not suitable for growing water plants naturally. The experiments in Waihuan River of Tianjin show that total phosphor (TP) reduces 30%-40% in growing season and 7%-20% in winter when the detention time is 5.48 days. The variation between the concentration of TP and the detention time follows the first-order kinetic equation, the correlation coefficients (R 2) is above 0.9.The attenuation coefficients k of the kinetic equation changes with the water temperature. When the water temperature is quite low or quite high, the value of k is not significantly changed with the temperature of water. While when the temperature is in a moderate range, an increase of water temperature leads to a rapid increase of k value.
Li J.,Nankai University |
Li J.,Tianjin institution of water science |
Li X.,Tianjin institution of water science |
Sun S.,Shandong Agricultural University |
And 2 more authors.
Frontiers of Environmental Science and Engineering in China | Year: 2011
A modularized and air adjustable constructed submerged plant bed (CSPB) which can be used to restore the eutrophic water is introduced in this paper. This plant bed helps hydrophyte grow under poor conditions such as frequently changed water depth, impaired water transparency, algae bloom and substantial duckweed in summer, which are not naturally suitable for growing hydrophyte. This pilot study in Waihuan River of Tianjin, China, revealed that reduction of Chemical Oxygen Demand (COD), Total Nitrogen (TN) and Total Phosphorus (TP) by the use of CSPB could be reached 30%-35%, 35%-40%, 30%-40% respectively in the growing season (from March to October) and 5%-10%, 5%-15%, 7%-20% respectively in the winter (from November to February) when the detention time was 6 d. The relationships between the concentration of COD, TN, TP and the detention time fit the first-order kinetic equation well and the coefficients of determination (R2) were all above 0. 9. The attenuation coefficients k of the kinetic equation were a function of the water temperature. When the water temperature was quite low or quite high, k was not significantly changed with increasing or decreasing water temperature. While when the temperature was in a moderate range, an increase or decrease of water temperature would lead to a rapid increase or decrease in k. © 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg.