The influencing factors of BAP exchange flux at the sediment-water interface in Dalian Bay
大连湾沉积物-水界面BAP交换通量的影响因素

The influencing factors of BAP (bio-available phosphorus) exchange flux at the sediment-water interface in Dalian Bay were studied by laboratory incubation experiment, and the BAP fluxes between sediment and water in the dredged area and in the area near the sediment dredging location were analyzed with the methods of laboratory incubation experiment and nutrient concentration gradients in the pore water. The results showed that the fluxes of BAP from sediment to water increased with the increase of pH and temperature in overlying water, and it also increased by the condition of applying sterilized sediment and aerating in overlying water during the incubation experiment. The fluxes from sediment to water decreased when the concentrations of phosphorus increased in the overlying water, and the flux direction reversed with the continuous increase of the concentrations. Both results of the two methods showed that the annual average exchange flux of BAP between sediment and water in the area near the sediment dredging location was higher than that in dredged area affected by dredging works. The exchange fluxes of BAP between sediment and water in Dalian Bay were different in four seasons, which was highest in summer and lowest in winter. However, it was at a high level in the area near the sediment dredging location in winter due to the impact of dredging.