Phosphorus speciation of sediments from lakes of different tropic status in Eastern China

Abstract

Information about the chemical composition of phosphorus (P) in sediment is critical for understanding P dynamics and eutrophication in lake ecosystems. Eutrophication as a result of P pollution still persists so we chose to determine the P characteristics of sediments from ten lakes of different trophic status and the relationships between P fractions and environmental factors. The results show that the Standards, Measurements and Testing (SMT) method combined with 31 P-nuclear magnetic resonance ( 31 P-NMR) can efficiently show the P characteristics of sediment. Phosphorus concentrations in sediments decreased as the trophic status of the lake improved. Inorganic P (Pi) was the dominant form of total P (TP) in most of the lake sediments and was mainly comprised of HCl-Pi, a stable Pi fraction. Results of 31 P-NMR analysis show that the extracts were dominated by ortho-P (36.4-94.8 %) and mono-P (4.0-36.2 %), with smaller amounts of diester-P (.6-23.1 %), pyro-P (.2-4.4 %), and phon-P (.3-.7 %). Analysis of the relationships between the P composition and the trophic status of the lakes indicated that the bioavailability of P forms has an influence on the surface water trophic conditions and the health of aquatic ecosystems.

A paleolimnological investigation of agricultural intensification, water quality and ecosystem change at Lake Nganoke, southern Wairarapa, NZ

“…Primary productivity in lake systems is strongly limited by nutrient availability, with the role of phosphorous (P) in controlling lake water quality and ecosystem growth well established (Giresse et al, 1994;Wetzel & . 2001;Mankin et al, 2007;Zhang et al, 2015;Smith et al, 2016). P loading within lakes can be split into six fractions (NH 4 Cl-P, BD-P, NaOH-rP and NaOH-nrP, HCl-P, Res-P, Total P), all of which have the potential to be mobile during different conditions (Penn et al, 1995).…”