Katsuya Kaikake

Phosphate recovery from phosphorus-rich solution obtained from chicken manure incineration ash.

The recovery of phosphorus from waste is very important for Japan because Japan has no natural phosphorus resources. In order to recover phosphorus from incineration ash of chicken manure, an acid dissolution-alkali precipitation method was investigated. Phosphorus content in the ash was 8%. The ash was treated with hydrochloric acid to obtain phosphorus-rich solution. Phosphorus could then be recovered as a precipitant by adding sodium hydroxide solution into the phosphorus-rich solution and gradually changing the pH in the solution to 3, 4, and 8. At pH3, a small amount of phosphorus was precipitated to remove iron, which would cause coloring of subsequent precipitants. At pH4, 84% of the phosphorus in the original solution could be recovered as CaHPO4 x 2H2O with a purity of 92%. At pH8, 8% of the phosphorus in the phosphorus-rich solution could be recovered as identified hydroxyapatite. A recovery rate of 92% phosphorus as CaHPO4 x 2H2O and identified as hydroxyapatite was achieved.

EQUILIBRIUM OF PALLADIUM(II) EXTRACTION WITH 1-OCTYLTHEOBROMINE

ABSTRACT 1-Octyltheobromine was synthesized to study extraction equiliburium of palladium(II). To evaluate its efficiency as an extractant, the extraction of palladium(II) from acidic chloride media was studied at 303K using toluene. The extraction of palladium(II) from hydrochloric acid media by 1-octyltheobromine exhibited high selectivity for palladium(II) over the platinum group metals. The stoichiometrics of the extraction of palladium(II) with 1-octyltheobromine was elucidated by examining the effects of hydrochloric acid, chloride ion, hydrogen ion, extractant and metal ion concentrations on its extractability. Palladium(II) was found to be extracted as two molecules of 1-octyltheobromine reacted with PdCl2 as follows: PdCl2 +{2}¯RN ⟺ ¯PdCl2(RN)2. The extraction equilibrium constant was K=2.72 × 108(mol dm−3)−2. The complex of 1-octyltheobromine with PdCl2 was confirmed by mass spectrometric analysis. The stripping of palladium(II) was performed over 60% by a single batchwise treatment with an aqueous solution of thiourea or ammonia.

Synthesis of phenol/furfural polymer nanotubes

The first synthesis of phenol-furfural polymer nanotubes of 2–3nm hollow diameter is demonstrated as well as those with a hexagonal mesostructure. These nanopolymers were obtained by the templating method using a two-step reaction. At the first step, phenol and furfural were moderately reacted into cooligomers in the presence of NaOH. The resulting cooligomeric species were fully anionized and then reacted with additional phenol and alkyl trimetyl ammonium bromide at 40-80°C. The major phase for the 80°C product obtained at low concentration of surfactant was identified as nanotubular polymers of 1.9-3 nm inside and 6 nm outside diameters depending on the chain length of surfactant. In contrast, hexagonal mesostructured polymers characterized by a definite XRD peak occurred preferentially in the reaction using high surfactant-concentrations.