Phosphorus retention capacity in red ferralitic soil.
In this study the main physical-chemical characteristics of red ferralitic soil to use as substrate in subsurface wetlands was determined. The P-removal was evaluated in a short-term isotherm batch experiment and in a column percolation experiment. The acid characteristic and high content of iron minerals in the red ferralitic soil facilitated the phosphorus removal. Also the sorption isotherms at two different temperatures were obtained. The results showed that the sorption capacity increases with an increase in solution temperature from 25 to 35 °C. The experimental data were fitted to Langmuir and Freundlich models, having a better fit to the Freundlich isotherms. The maximum P-sorption capacities estimated using the Langmuir isotherm were 0.96 and 1.13 g/kg at 25 and 35 °C respectively. Moreover a column experiment was carried out at two different flows. Sequential extractions of the phosphorus-saturated soil indicated that phosphorus is mainly bound with iron or aluminum minerals. The results have demonstrated a good potential for red ferralitic soil for phosphorus removal from urban wastewater.
Study Center of Applied Chemistry, Chemical Pharmacy Faculty, Central University of Las Villas, Cuba E-mail: mairapv@uclv.edu.cu.
M M
MM
Pérez
Department of Applied Analytical and Physical Chemistry, Bioscience Engineering Faculty, Ghent University, Belgium.
J
J
Bossens
Study Center of Applied Chemistry, Chemical Pharmacy Faculty, Central University of Las Villas, Cuba E-mail: mairapv@uclv.edu.cu.
E
E
Rosa
Department of Applied Analytical and Physical Chemistry, Bioscience Engineering Faculty, Ghent University, Belgium.
F M G
FM
Tack
D000327:Adsorption; D008962:Models, Theoretical; D010758:Phosphorus / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D053833:Wetlands
D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D010758:Phosphorus