Reducible Oxides Regulate Phosphorus and Heavy Metal Fractions in Sediment of Lake Tai along a Transect.

Reducible oxides play an important role in regulating availability of phosphorus and heavy metals between sediments and water. A transect study was investigated on phosphorus and heavy metal fractionation in sediments of Lake Tai, China. Results indicated that contents of phosphorus and heavy metals (Cu, Zn, and Pb) in sediments increased with distance from Wuliang Bay to the center of Lake Tai. Reducible oxides (mainly Fe)-bound phosphorus and heavy metals were a predominant fraction in the top oxide layer but not in the reduced layer of sediments. Aluminum oxide and organic¨Cbound fractions became more dominant in the reduced layer of sediments. Our results suggested that possible mechanisms of re-distribution/re-sorption of phosphorus and heavy metal ions might occur between reducible oxides and aluminum oxide/organic matter in the sediment when reduced.