Phosphate Adsorption‐Desorption Characteristics of Soils and Bottom Sediments in the Maumee River Basin of Ohio

Abstract

AbstractLangmuir adsorption isotherms showed that Maumee River Basin sediments had adsorption capacities 10 to 20 times greater than Basin soils. Although the soil clay fractions had adsorption capacities higher than the whole soil, they were considerably less than those of the sediments and the difference is attributed to the higher content of amorphous or low‐range order iron and aluminum components in the bottom sediments. Equilibrium phosphorus concentration (EPC) and phosphorus desorbed was similar for soils and sediments as well as total P, indicating that although the bottom sediments have a high capacity to adsorb P, this capacity has not been realized. Correlations between adsorption‐desorption parameters and soil/sediment properties are presented. Bray P1 “available” P was highly correlated with EPC and P desorbed in the soils but to a lesser extent in the bottom sediments. CDB and oxalate extractable‐P was highly correlated with P adsorption capacity in the bottom sediments but not in the soils.