Data from: Seasonal characteristics of phosphorus sorption by sediments from plain lakes with different trophic statuses

Phosphorus (P) sorption in sediments plays a significant role in trophic
status of a lake. This study investigated the characteristics of P
sorption in sediments from three lakes with different trophic statuses
(moderately eutrophic, lightly eutrophic, and moderately trophic) through
kinetic, batch equilibrium, and thermodynamic experiments. Results show
that pseudo-second-order kinetics best describe P sorption in sediments
from the three lakes. Fitting by modified Langmuir and Freundlich
isotherms indicate that the moderately trophic lake sediments has higher
sorption capacity (maximum of 0.848 mg g-1 at 35 °C) than the sediments of
the other two lakes at different temperatures (5, 15, 25, and 35 °C).
Thermodynamic results indicate that the process of P sorption of the three
sediments are spontaneous, entropy-driven, and endothermic reactions. The
risk of P release in sediments was analyzed according to the calculated
results of isotherms combined with the change in P fraction. Sediments
from the moderately eutrophic lake act as a source in summer. The lightly
eutrophic and moderately trophic lakes act as sources in spring and
winter, and a pool in summer and autumn, respectively. Furthermore, the
amounts of reductant-soluble P (RS-P), calcium bound P (Ca-P), and iron
bound P (Fe-P) are significantly related to the sorption capacity of
sediments from the three lakes (p<0.05). The different sediments
have the different P release risk, and P fraction in sediment is one of
the significant factors of P sorption.