Characteristics, distribution and ecological risk assessment of phosphorus in surface sediments from different ecosystems in Eastern China: A 31P-nuclear magnetic resonance study

Abstract

P-NMR ERI Sediment A B S T R A C TSurface sediments in different ecosystems (lake, river, reservoir, estuary and wetland) in Eastern China were extracted with NaOH-EDTA, and the extracts were analyzed by 31 P-NMR to reveal the phosphorus (P) species distribution. The P release risk was also assessed by sorption experiments. The river sediments accumulated significant amounts of P compared with other sediments. The organic phosphorus (Po) concentration in the estuarine sediment was lower than that in other sediments. Two P compounds classes (phon-P and mono-P) and five P compounds were detected in the sediments. Ortho-P (83.3-97.6%) was the dominant P compounds and mono-P (1.1-18.0%) were the dominant Po compounds classes, while smaller amounts of DNA-P (0-4.1%), pyro-P (0-4.0%) and lipid-P (0-0.8%) were found in the surface sediment. Poly-P and phon-P were detected only in site 11 (wetland), site 10 (wetland) and 11, respectively. The ERI values, as a measure of eutrophication risk, were different in the various sediments, being greater than 25% in sites 1 (river), 3 (estuary) and 4 (estuary), and with values of 26, 59 and 83%, respectively. The Xm and ERI values fitted a power function (R Xm-ERI = 0.89, p < 0.01) and a positive correlation between Xm and OM in the sediment (R Xm-OM = 0.84, p < 0.01) indicated that the chemicalphysical conditions play a vital role in controlling P sorption and desorption.

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

“…The sediment samples were freeze-dried and homogenized, and impurities were removed. Representative samples were obtained for grinding using the quartering method (Zhang et al 2015).…”

Spatial–Temporal Evolution Characteristics of Landscape Ecological Risk in the Agro-Pastoral Region in Western China: A Case Study of Ningxia Hui Autonomous Region

“…The study of landscape pattern change and its evolution pattern can reveal the structural characteristics and change patterns of regional ecosystems, which is widely applied in comprehensive regional ecological evaluations. It is widely used in the comprehensive assessment of regional ecology, providing new ideas and new perspectives for the study of regional ecological risk, and it has become an important method for the assessment of regional landscape ecological risk [20,21]. Compared with other ecological risk assessment methods that focus on the comprehensive overlapping of multiple risks, landscape ecological risk assessment places more emphasis on the impact of landscape pattern on ecological processes or functions.…”

Alteration in the potential of sediment phosphorus release along series of rubber dams in a typical urban landscape river

“…The Standards, Measurements and Testing Program of the European Commission (SMT) method 20 defines a range of sediment P fractions that might be involved in release processes, including exchangeable labile P (ex-P), apatite P (Ca-P, calcium associated forms), non-apatite P (Fe/Al-P, the forms associated with oxides and hydroxides of Al, Fe, Mg and Mn), and organic P (OP); of these, ex-P, Fe/Al-P, and OP are considered as BAP and can easily release or be mineralized to water for maintaining its eutrophic state over a long term 6 . Other physicochemical components of the sediments, including the contents of fine particles 21 , organic matters (OM) 22 and hydratable metals, like Al and Fe 23 , all have negative relationship with sediment P release. On the other hand, P concentration in the water body can also directly influence the state of sediment P release.…”