Accompanying cations and anions affect the diffusive transport of phosphate in a model calcareous soil system

2009 ◽  
Vol 89 (2) ◽  
pp. 179-188 ◽  
Author(s):  
S O Olatuyi ◽  
O O Akinremi ◽  
D N Flaten ◽  
G H Crow
Keyword(s):  
Cation Exchange ◽  
Calcareous Soil ◽  
Cation Exchange Resin ◽  
Phosphate Fertilizer ◽  
Diffusive Transport ◽  
Sand Column ◽  
Soil System ◽  
Sand Mixture ◽  
Enhanced Solubility ◽  
Phosphate Salts

Mixing non-phosphate salts with phosphate fertilizer modifies the chemical environment of the soil-phosphorus (P) fertilizer reaction zone due to induced changes in soil pH and the interactions of P with soil components and other ions. The objective of this study was to examine the effects of cation and anion interactions on the solubility and diffusive transport of P in columns packed with a mixture of inert quartz sand and Ca2+-saturated cation exchange resin, buffered with CaCO3. The background pH of the resin-sand mixture was 9.4. Three types of cations (K+, NH4+, and Mg2+) were combined with four anions (NO3-, Cl-, SO42-, and CO32-) to produce 12 non-phosphate salts. Each of these salts was mixed with 0.4 g of KH2PO4 to provide 408.9 mg P kg-1 soil. The experiment was carried out in three replicates. Following 2 wk of incubation, columns were sectioned at 3-mm intervals and the pH of each section was measured. The samples were extracted with deionized water and subsequently with 1 mol L-1 HCl. Addition of KH2PO4 alone reduced the pH at the surface (first 3-mm section) of the resin-sand column to 7.1, while pH remained unchanged at 9.1 on addition of K2CO3 and KH2PO4. Addition of MgCl2 and KH2PO4 resulted in the lowest pH in the column and the greatest depth of H+ penetration compared with other treatments. None of the treatments containing NO3- or Cl- salts enhanced the solubility and movement of P. Addition of (NH4)2SO4 or (NH4)2CO3 to KH2PO4 produced the greatest amount of water-extractable P, followed by K2SO4. The lowest solubility of P occurred on addition of K2CO3 (P < 0.05). We attributed the enhanced solubility of P by SO42- and CO32- associated with NH4+ to competition between these anions and HPO42- for precipitation with solution Ca2+. Phosphate ion moved to depths of 5.0, 6.0 and 7.5 cm on addition of K2SO4, (NH4)2SO4, and MgSO4 to the column, respectively. These results suggested that salts such as K2SO4, (NH4)2CO3, (NH4)2SO4 and MgSO4 would enhance the lability of fertilizer P in a calcareous soil system. Key words: Solubility, precipitation, diffusive transport, resin, cation exchange, anion competition, dual banding

Solubility and transport of phosphate and the accompanying ions as influenced by sulphate salts in a model calcareous soil system

2009 ◽  
Vol 89 (5) ◽  
pp. 589-601 ◽  
Author(s):  
S O Olatuyi ◽  
O O Akinremi ◽  
D N Flaten ◽  
G H Crow
Keyword(s):  
Calcareous Soil ◽  
Water Solubility ◽  
Cation Exchange Resin ◽  
Water Soluble ◽  
Diffusive Transport ◽  
Soil System ◽  
Soil P ◽  
Sand Mixture ◽  
Anion Competition ◽  
Sulphate Salts

Plant availability of phosphorus (P) in calcareous soil can be improved by modifying the chemical environment of the soil-P fertilizer reaction zone through the banding of non-phosphate fertilizer with P. We investigated the solubility and diffusive transport of P as influenced by addition of two sulphate salts [(NH4)2SO4 and K2SO4] to NH4H2PO4 and KH2PO4. The salts were applied to a series of wax columns packed with approximately 223 g of Ca2+-saturated cation exchange resin-sand mixture buffered with CaCO3. The background pH of the mixture was 8.8. Each treatment contained approximately 204.5 mg P kg-1 soil, while 632.3 mg SO42- kg-1 soil was added to each P source for treatments containing the dual bands to provide a molar concentration of P and SO42- of 6.6 mmol kg-1 soil. After 2 wk of incubation, column segmentation and extraction showed that H+ moved deeper into the columns on addition of the sulphate salts compared with adding NH4H2PO4 or KH2PO4 alone. The maximum depth of P penetration in the columns containing NH4H2PO4 was 4.2 cm, while P transport in the columns treated with KH2PO4 was restricted to the top 4.0 cm depth. Addition of (NH4)2SO4 or K2SO4 to NH4H2PO4 increased the concentration of water-extractable P by 43 and 21%, respectively, above that in NH4H2PO4 alone. Similarly, addition of (NH4)2SO4 or K2SO4 increased the concentration of water-soluble P by 48 and 41%, respectively, above the amount in KH2PO4 alone. The increased water solubility of P on addition of the sulphate salts was attributed to anion competition between HPO42- and SO42- for precipitation with Ca2+. We also observed ionic competition between NH4+ and K+ when both cations were added together, causing K+ to travel farther into the column and with increased solubility than when applied alone. Our results showed that anion and cation competition can be used to modify the transport and solution concentration of ions through dual banding. These results also suggested that the combination of anion competition by SO42- and pH reduction due to salt effect could have a positive influence on the availability of P in calcareous soils. Key words: Phosphate, sulphate, columns, solubility, diffusive transport, resin

Chemical retardation of phosphate diffusion in simulated acid soil amended with lignosulfonate

2000 ◽  
Vol 80 (2) ◽  
pp. 289-299 ◽  
Author(s):  
X. Hao ◽  
C. M. Cho ◽  
G. J. Racz
Keyword(s):  
Cation Exchange ◽  
Acid Soil ◽  
Cation Exchange Resin ◽  
Fine Sand ◽  
Phosphate Fertilizer ◽  
Solution Concentration ◽  
Exchange Capacity ◽  
P Availability ◽  
Sand Column ◽  
Phosphate Fixation

The availability and movement of inorganic phosphate fertilizer is usually low due to precipitation and adsorption reactions in soil. Lignosulfonate (LS), which is produced from acid sulfite pulping processes, has similar characteristics to soil organic materials. An experiment was designed to study the effects of LS on P movement in a simulated acid soil containing aluminum-saturated cation exchange resin and acid-washed fine sand. The resulting simulated soil had a cation exchange capacity of 22 cmolc kg−1 and either no or 10 g kg−1 gibbsite. Movement of surface-applied monopotassium phosphate was studied in soil columns, either with 20 g kg−1 LS or without LS. Lignosulfonate reduced phosphate fixation and sustained a higher water extractable phosphate concentration near the surface of the columns, but had no effect on downward phosphate movement in the columns with gibbsite. Lignosulfonate reduced the solution concentration of P near the surface and reduced downward phosphate movement in the columns without gibbsite. The resin-sand column with gibbsite closely reflected an acid soil, and this research showed that adding LS would increase fertilizer P availability in a gibbsite-rich acid soil. Adding Ca-LS to Al-rich soil is beneficial for another reason, improving Ca nutrition, which is poor for these soils. Key words: Chemical retardation, phosphate diffusion, lignosulfonate amendment

Synthesis of 3,4-Dihydropyrano[c]chromenes Using Carbon Microsphere Supported Copper Nanoparticles (Cu-NP/C) Prepared from Loaded Cation Exchange Resin as a Catalyst

2019 ◽  
Vol 16 (2) ◽  
pp. 288-293
Author(s):  
Yogesh W. More ◽  
Sunil U. Tekale ◽  
Nitishkumar S. Kaminwar ◽  
László Kótai ◽  
Tibor Pasinszki ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Cation Exchange ◽  
Copper Nanoparticles ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Environmentally Benign ◽  
High Yield ◽  
Carbon Microsphere ◽  
Catalytic Material ◽  
Operational Simplicity

Aim and Objective: The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. Materials and Methods: Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. Results: The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. Conclusion: Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.

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