Effects of several harmful anions on the removal of aqueous phosphate by boehmite

Abstract

Boehmite (Al(OH)O) was employed for the removal of aqueous phosphate in the presence of harmful anions such as carbonate, sulphate, nitrate, nitrite, chloride and fluoride at 298 K. Although boehmite was shown to remove a certain simultaneous removal of phosphate together with fluoride, no influence of the presence of carbonate, sulphate, nitrate, nitrite and chloride on the removal of phosphate by boehmite was observed. In the present study, two kinds of boehmite, a commercially available form and boehmite prepared using a sol-gel technique, were employed for the simultaneous removal of phosphate and fluoride, and it was found that the latter form was superior for such removal. Solid-state 31 P MAS NMR analyses revealed that, in the presence of fluoride, phosphate was removed onto boehmite as different types of phosphate species, depending on the solution pH and the source of boehmite.

Recovery of Phosphate From Unused Resources

“…From the sample used in the presence of NH 4 + , NH 4 Cl (JCPDS 7-0007) was also detected together with Al(OH)O (not shown). However, as shown in our previous papers, 2,3 phosphate species was certainly detected from these samples using XPS (TABLE 1). Signals due to P 2p were detected at approximately 134 eV from all samples previously employed to obtain the results shown in FIGURE 1 (A) regardless of argon-ion etching.…”

“…The removal of aqueous phosphate using boehmite was investigated according to the procedure shown in our previous papers. 2,3 Boehmite was prepared from boehmite sol obtained by hydrolyzing aluminum isopropoxide. Boehmite sol thus prepared was evaporated and dried overnight under vacuum, followed by a milling treatment.…”

“…For the former resources, the effect of the coexistence of NH 4 + , NO 2 and NO 3 -, which are contained in a surplus than phosphate in rivers in Tokushima Prefecture, Japan, 1 on the removal of aqueous phosphate using boehmite (Al(OH)O) was examined. 2,3 It had been already reported that boehmite showed a certain simultaneous removal of phosphate together with fluoride while no influence of the presence of carbonate, sulphate and chloride on the removal of phosphate by boehmite was observed. 3 It should be noted that rivers in Tokushima Prefecture contains the greatest amount of phosphates among all prefectures in Japan, due to the delay of the spread of a sewage institution.…”

“…2,3 It had been already reported that boehmite showed a certain simultaneous removal of phosphate together with fluoride while no influence of the presence of carbonate, sulphate and chloride on the removal of phosphate by boehmite was observed. 3 It should be noted that rivers in Tokushima Prefecture contains the greatest amount of phosphates among all prefectures in Japan, due to the delay of the spread of a sewage institution. For the latter resources, the elution behaviors of phosphate from dephosphorization slag using various eluates were examined.…”

Key Factors for the Separation of Silicon and Iron During Phosphorus Recovery From Slag Discharged From the Double-Slag Refining Process

“…Phosphorus recovery is typically intended as a remediation for environmental pollution to insure water quality. [1][2][3][4] Recovering phosphorus from water systems that contain small amounts has improved the environment, [5][6][7] but reuse of the recovered phosphorus has not been considered. Recovery of phosphorus from water systems containing high concentrations, however, such as those contaminated with untreated sewage 8 or phosphorus-containing detergents, 9 has led to the use of the recovered phosphorus as a fertilizer.…”