Phosphorus fractions and phosphorus sorption characteristics of freshwatersediments and their relationship to sediment composition

Phosphorus was fractionated within a set of sediments operationally divided into acidic, neutral, and alkaline groups. Relationships among fractional distribution of P, concentrations of sediment components important for P-so rption (Fe, Al, organic carbon (OC)), and P-sorption parameters were analyz ed using a redundancy analysis method. The NaOH25-P fraction prevailed with in the group of acidic sediments from forest lakes. NaOH25-P followed by BD -P and HCl-P was the largest fraction in the neutral and alkaline sediment groups. Fe and Al were found to be positively correlated with P in the BD a nd HCl fractions, respectively. A combination of Fe, Al, and OC was positiv ely correlated with P in the NaOH25 fraction. Maximum sediment P-sorption c apacity was the only sorption parameter correlated with P-fractionation; Al and OC in the NaOH25 fraction were the most significant explanatory consti tuents. None of the other sorption parameters (initially adsorbed P, adsorp tion/desorption equilibrium concentration) were correlated with the results of fractionation analysis.