Degradation of diesel pollutants in Huangpu-Yangtze River estuary wetland using plant-microbe systems

The diesel contaminants in the sediments of Huangpu-Yangtze River estuary (HYRE) affect the ecosystem seriously. The effects of four species of indigenous plants, Scirpus triqueter (Scirpus tripueter L.; STL), reed (Phragmites australis; PA), Herba caricis phacotae (Carex phacota Spr.; CPS) and Sagittaria sagittifolia (S. sagittifolia L.; SSL), with oil-degrading bacteria (M) isolated from the oily HYRE wetland on the degradation ratio of diesel were evaluated by simulation experiments. The results showed that oil-degrading bacteria enhanced the degradation ratio of diesel. Besides, the indigenous plants combine with oil-degrading bacteria further improved the degradation ration. The diesel amount decreased about 76-80% (at 15,000 mg kg−1 diesel level) in the presence of PA & M, STL & M, SSL & M and CPS & M during the 60 d of experimental period. STL & M, SSL & M exhibited preferable degradation ratio at various diesel concentration throughout the whole experiment. The wetland plants with the oil-degrading bacteria showed a marked capability to degrade diesel contaminants.