Project Title: Reduction-release and re-adsorption mechanisms of reducible oxide bound phosphorus and heavy metals in the process of wetland restoration

Project Type: Natural Science Foundation of China--General Project

Project Approval No. 40871244

Project Awardee: Yu Shen

Project Abstract: Under the public pressures of urban environmental protection, wetlands in urban and suburban areas converted to agricultural land and other uses have been restored as urban wetland parks in some of the largest cities in China. Phosphorus and heavy metals cumulated in surface soils from agricultural practices and other uses might impair water quality during the restoration. Especially, the reducible oxides (Fe and Mn oxides) bound phosphorus and heavy metals can be an issue releasing into water from absorbents reduced by anaerobic condition development in urban wetland restoration. This project emphasizes on behaviours of phosphorus and heavy metals binding to reducible (Fe and Mn oxides) and irreducible (Al oxide) oxides and possible mechanisms under anaerobic condition development of wetland restoration; their influences in regulating concentrations of phosphorus and heavy metals in surface water of restored urban wetlands; and their reduction-release dynamics illustrated by statistical models. The project innovates to explore processes of reduction-release and re-adsorption/ transformation of phosphorus and heavy metals between Fe and Mn oxides and Al oxide in soils, and to evaluate capacity of root iron plaques of wetland plants in re-adsorbing phosphorus and heavy metals released from reduction of Fe and Mn oxides in restoring urban wetlands. Results from this project will elaborate fates of phosphorus and heavy metals (oxides-bound) accumulated historically during urban wetland restoration and their impairment to surface water quality, and will benefit to urban wetland restoration and park management.

Period of Project: 2009.1-- 2011.12

Fund of Project: ￥ 460,000