Nitrogen (N) and phosphorus (P) released from the sediment to the surface water is a major source of water quality impairment. Therefore, inhibiting sediment nutrient release seems necessary. In this study, red soil (RS) was employed to control the nutrients released from a black-odorous river sediment under flow conditions. The N and P that were released were effectively controlled by RS capping. Continuous-flow incubations showed that the reduction efficiencies of total N (TN), ammonium (NH4+-N), total P (TP) and soluble reactive P (SRP) of the overlying water by RS capping were 77%, 63%, 77% and 92%, respectively, and nitrification and denitrification occurred concurrently in the RS system. An increase in the water velocity coincided with a decrease in the nutrient release rate as a result of intensive water aeration.
Three active barrier materials (zeolite, ceramicite and light porous media) were applied for preventing nitrogen (N) release from
eutrophic lake sediments. Long term experiment of two di erent lake sediments were carried out and the e ect of zeolite dose was
evaluated. The results indicated that about 90%–100% of total N in overlying water was eliminated by using zeolite. While the N
removal e ciency by ceramic was lower than that by zeolite, and light porous media present the lowest e ciency of 59%. Long term
sediment incubation experiments indicated that two eutrophic sediments were both e ective in preventing N release in spite of di erent
release characteristics. Bio-zeolite capping technology was able to e ectively inhibit the release of N from the sediment, and the zeolite
dose was independently from N removal. 相似文献
Since 1977, the US Army Corps of Engineers Disposal Area Monitoring System (DAMOS) has monitored New England's offshore dredged material disposal sites. DAMOS has shown that by using monitoring information to make management decisions, open water disposal of dredged sediments is possible with minimal environmental impact. Over the past two decades, DAMOS has answered many of the key questions about dredged material impacts. Yet the need for such a programme remains strong from both the technical and public interest perspectives. the programme continues to monitor projects that are extending our knowledge in the areas of deeper water capping, geotechnical behaviour of capping and capped materials, and biological response to contaminants. These investigations, along with the need for specific disposal site surveys, will continue to provide valuable technical information needed by the public, policy makers, and regulators to make critical decisions on dredged sediment management. 相似文献