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 fre...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(R^(2))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.展开更多
基金This work was supported by NSF of Tianjin(Nos.043115111-3,09ZCGYSF00400,200801100)National Key-Projects of Water Pollution Control and Prevention(Nos.2009ZX07209-001 and 2008ZX07314-005-011)the National Natural Science Foundation of China(Grant No.5107906).
文摘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(R^(2))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.
