The bio-rack is a new approach for treating low-concentration polluted river water in wetland systems.A comparative study of the efficiency of contaminant removal between four plant species in bio-rack wetlands and be...The bio-rack is a new approach for treating low-concentration polluted river water in wetland systems.A comparative study of the efficiency of contaminant removal between four plant species in bio-rack wetlands and between a bio-rack system and control system was conducted on a small-scale (500 mm length × 400 mm width × 400 mm height) to evaluate the decontamination effects of four different wetland plants.There was generally a significant difference in the removal of total nitrogen (TN),ammonia nitrogen (NH 3-N) and total phosphorus (TP),but no significant difference in the removal of permanganate index (COD Mn) between the bio-rack wetland and control system.Bio-rack wetland planted with Thalia dealbata had higher nutrient removal rates than wetlands planted with other species.Plant fine-root (root diameter 3 mm) biomass rather than total plant biomass was related to nutrient removal efficiency.The study suggested that the nutrient removal rates are influenced by plant species,and high fine-root biomass is an important factor in selecting highly effective wetland plants for a bio-rack system.According to the mass balance,the TN and TP removal were in the range of 61.03-73.27 g/m2 and 4.14-5.20 g/m2 in four bio-rack wetlands during the whole operational period.The N and P removal by plant uptake constituted 34.9%-43.81% of the mass N removal and 62.05%-74.81% of the mass P removal.The study showed that the nitrification/denitrification process and plant uptake process are major removal pathways for TN,while plant uptake is an effective removal pathway for TP.展开更多
基金the financial support of the National water pollution control and management technology major project (No. 2008ZX07101)
文摘The bio-rack is a new approach for treating low-concentration polluted river water in wetland systems.A comparative study of the efficiency of contaminant removal between four plant species in bio-rack wetlands and between a bio-rack system and control system was conducted on a small-scale (500 mm length × 400 mm width × 400 mm height) to evaluate the decontamination effects of four different wetland plants.There was generally a significant difference in the removal of total nitrogen (TN),ammonia nitrogen (NH 3-N) and total phosphorus (TP),but no significant difference in the removal of permanganate index (COD Mn) between the bio-rack wetland and control system.Bio-rack wetland planted with Thalia dealbata had higher nutrient removal rates than wetlands planted with other species.Plant fine-root (root diameter 3 mm) biomass rather than total plant biomass was related to nutrient removal efficiency.The study suggested that the nutrient removal rates are influenced by plant species,and high fine-root biomass is an important factor in selecting highly effective wetland plants for a bio-rack system.According to the mass balance,the TN and TP removal were in the range of 61.03-73.27 g/m2 and 4.14-5.20 g/m2 in four bio-rack wetlands during the whole operational period.The N and P removal by plant uptake constituted 34.9%-43.81% of the mass N removal and 62.05%-74.81% of the mass P removal.The study showed that the nitrification/denitrification process and plant uptake process are major removal pathways for TN,while plant uptake is an effective removal pathway for TP.
