abstract phosphorus (p) sorption in soils is a key process governing the availability of p to crops. p sorption characteristics and their relationship to soil properties were determined in twenty-one paired surface soil samples (21 cultivated and 21 adjacent virgin soils) belonging to five soil types: typic calcixerepts, typic haploxerepts, typic endoaquepts, vertic endoaquepts, and vertic calc...

In calcareous soils, phosphorus (P) retention and immobilization take place due to precipitation and adsorption. Since soil pH is considered a major soil variable affecting the P sorption, an acidic P fertilizer could result in low P adsorption compared to alkaline one. Therefore, P adsorption from DAP and phosphoric acid (PA) required to produce desired soil solution P concentration was estima...

 This research investigate clayey, lateritic and sandy soils have been selected from agricultural lands in the South-Eastern Nigeria, for their phosphate sorption characteristics using column experiments, in order ascertain the movement of phosphate in the soils. The soil samples were equilibrated in 25ml of 0.01M CaCl2  containing different concentrations of P as KH2PO4 to produce initial conc...

The adsorption behaviour of Methyl violet and Auramine yellow from aqueous solution onto Stishovite clay was investigated as a function of parameters such as initial dye concentration, contact time, p and temperature. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. Adsorption followed pseudo-second order model. The experimental data fitted well ...

Phosphorus (P) sorption dynamics in soils have implications for the environment and soil fertility. Soils clay fractions that were developed from basalt, granite, arkosic sandstone, gneiss Limpopo Province, South Africa analysed their P adsorption characteristics external phosphorus requirements (EPR). The relationship between parameters EPR of also assessed. Langmuir isotherms gave a better fi...

Equilibrium models used for predicting phosphorus (P) loss from a site often use the Langmuir strength of P bonding, KL and the P sorption maximum, Smax, or the Freundlich adsorption coefficient, KF, obtained from traditional isotherms, as model input parameters. The overall objective of the study was to develop a protocol to allow estimation of isotherm parameters for soils using simple extrac...

Nano-hydroxyapatite and its modification, hydroxyapatite with the excess of phosphorus (P-HAP) and hydroxyapatite with the carbon ions built into the structure (C-HAP), were prepared by the wet method. They were studied by means of XRD, accelerated surface area and porosimetry (ASAP), and SEM. The size of crystallites computed using the Scherrer method was nano-hydroxyapatite (HAP) = 20 nm; P-H...

We discuss the thermodynamics of physical adsorption of gases in porous solids. The measurement of the amount of gas adsorbed in a solid requires specialized volumetric and gravimetric techniques based upon the concept of the surface excess. Excess adsorption isotherms provide thermodynamic information about the gas-solid system but are difficult to interpret at high pressure because of peculia...

A commercial multiwall carbon nanotube and its carboxylated derivate (CNTC and COOHC, respectively) was used after purification to study the competitive adsorption of phenol (P) and m-chlorophenol (CP) from 0.1 M aqueous NaCl solutions without external pH control. The adsorption takes place practically exclusively on the external surface of the nanotubes. The uptake of P is suppressed in compar...

The buildup of phosphorus (P) in the soil is a major factor limiting the operating life of a wastewater land treatment system. In this study, we evaluated changes of chemical properties, P profiles, and adsorption isotherms in the soils of a Muskegon wastewater land treatment system, which has received wastewater for approximately 30 years. It was found that the pH in the 15-cm topsoil increase...