Kinetics of Phosphorus Release from Vivianite, Hydroxyapatite, and Bone Char Influenced by Organic and Inorganic Compounds

Abstract

The availability of P is often insufficient and limited by accumulation in soils. This led to the necessity of solutions for the recovery as well as recycling of secondary P resources. Batch experiments were conducted with CaCl2 and citric acid to characterize P release kinetics from vivianite, hydroxyapatite, and bone char. While the P release during the CaCl2 treatment was so low that only vivianite and hydroxyapatite showed a slightly higher release with increasing CaCl2 concentration, the increase of dissolved P was more pronounced for citric acid. The application of citric acid resulted in a 32,190-fold higher P release for bone char. Fourier-transform infrared spectroscopic data suggested higher instability of hydroxyapatite than for bone char. The kinetic data showed that bone char, especially at a lower particle size, had a higher long-term P release than hydroxyapatite or vivianite. The suitability of hydroxyapatite and bone char as a poorly soluble, but sustainable P source is better than that of vivianite. However, the efficiency as a P fertilizer is also dependent on present soil P mobilization processes. The results underline the importance of the accessibility of fertilized or naturally bound P for plant roots to benefit from the excretion of organic acids.

Effect of Interstage Hydrothermal Treatment on Anaerobic Digestion of Sewage Sludge: Speciation Evolution of Phosphorus, Iron, and Sulfur

“…For instance, when biosolids rich in vivianite are land-applied, vivianite can release P in the oxisoils and might be used as a phosphate fertilizer . The organic acids (e.g., critic acid) in soils can also increase the solubility of vivianite . Moreover, S speciation information during AD–HT–AD is important for understanding S bioavailability in HT hydrochars and AD solids serving as soil amendment .…”

“…74 The organic acids (e.g., critic acid) in soils can also increase the solubility of vivianite. 75 Moreover, S speciation information during AD−HT−AD is important for understanding S bioavailability in HT hydrochars and AD solids serving as soil amendment. 76 Changes in S chemistry of biosolids strongly affect the solubility and bioavailability of toxic metals, due to thiols and sulfides for metal complexation.…”

Microbial Volatile Organic Compound (VOC)-Driven Dissolution and Surface Modification of Phosphorus-Containing Soil Minerals for Plant Nutrition: An Indirect Route for VOC-Based Plant–Microbe Communications

“…Acidity of HANP surfaces would be more increased by the attached MVOCs, resulting in the enhanced P release. Indeed, the ability of COOH-containing small organic acids to interact with mineral surfaces is well characterized. − …”

“…Interestingly, these MVOCs are structural parallels to organic molecules capable of engineering mineral surfaces. For example, stearic acid-modified apatite surfaces lead to dispersion in nonpolar matrices, and the interaction of citric acid with the apatite surfaces can modulate the kinetics of apatite dissolution. , Oxalic acid is also capable of modifying mineral surfaces such as gangue, which consequently affects their flotation behavior . These surface modification actions associated with several minerals appear to exploit the ability of oxygen-based functional groups of the organics to facilitate coordination, hydrogen bonding, and dipole–dipole interactions.…”

“…These surface modification actions associated with several minerals appear to exploit the ability of oxygen-based functional groups of the organics to facilitate coordination, hydrogen bonding, and dipole–dipole interactions. It is also important to note that these modifications can coincide with changes in plant growth and physiology because acidity of the mineral surfaces derived from oxygen-based functional groups allows releasing diffusible ions which include plant-available nutrients such as phosphate and metal ions. , This surface engineering-based action can also be prolonged for a long period of time, ,, suggesting that soil quality evolves in terms of plant nutrition. Previous studies have indeed shown that the bioavailability of phosphorus (P) from rock phosphate and P-containing ceramics is higher in the presence of oxygen-containing organic compounds. , …”