Reactive Extraction of o-Aminophenol with Tri-n-butyl Phosphate in Different Solvents

Abstract

Tri-n-butyl phosphate (TBP) is used as the extraction agent for the extraction of o-aminophenol (OAP) in active solvents and inactive solvents. The effects of aqueous solution pH, solvents, concentration of TBP, and the initial OAP concentration on distribution coefficient (D) are investigated. Results show that the neutral OAP molecule is hydrogen-bonded to TBP effectively into the organic phase, and D was maximum when the equilibrium pH was between pK a1 and pK a2. The extraction efficiency is TBP–1-octanol > TBP–kerosene > TBP–carbon tetrachloride > TBP–chloroform, when the concentration of TBP is between (0.3632 and 0.7264) mol·L–1, while the result is TBP–kerosene > TBP–1-octanol > TBP–carbon-tetrachloride > TBP–chloroform when the concentration increases [(1.0896 to 1.8159) mol·dm–3]. Fourier transform infrared spectroscopic analysis shows that the extractive behavior is controlled by hydrogen bonding. An expression for equilibrium D is proposed, and the parameters of the apparent extraction equilibrium constants (K) and the complex ratio (n) (TBP vs OAP) were calculated by fitting the experimental data. It was found that the K and n are 5.97, 5.37, 5.47, and 2.99 and 1.56, 1.51, 1.47, and 1.76 in TBP/kerosene, 1-octanol, carbon tetrachloride, and chloroform, respectively.

Experimental Study on Reactive Extraction of Malonic Acid with Validation by Fourier Transform Infrared Spectroscopy

“…(g) The IR spectra of TBP–MA–MIBK have also depicted a major shift from 1155 to 1234 cm –1 because of P=O stretching vibrations, and a =PO 4 group was observed at 991 cm –1 ; both detected groups help in promoting interactions between acid and the phosphoryl group …”

“…63 (g) The IR spectra of TBP−MA−MIBK have also depicted a major shift from 1155 to 1234 cm −1 because of P=O stretching vibrations, and a =PO 4 group was observed at 991 cm −1 ; both detected groups help in promoting interactions between acid and the phosphoryl group. 64 (h) TBP−MA−heptane exhibited major peaks in the range of 3000−2800 cm −1 , which depict asymmetric stretch and the H−C−H symmetric stretch, which indicate the existence of alkane chains in the system. The spectrum of 1320−1140 cm −1 exhibits P=O stretching vibrations, which were shifted from 1265 to 1270 cm −1 , and the =PO 4 group observed at 1012 cm −1 , which gives evidence of interaction occurring between extractant and acid molecules.…”

Investigation of Extraction of Phenol from Wastewater UsingN,N-Didodecyl-1-dodecanamine (Tridodecylamine) in Benzene

“…In the reactive, the equilibrium reactions taking place in the system can be written as by a set of equations of one phenol molecule (HA represents the nondissociated part of the phenol present in the aqueous phase) and n molecules of TDDA to form (1, n) complexes in the organic phase, eq 3. 20 + ↔ n HA TDDA (TDDA) (HA)…”

“…9 Aminophenols are key components in industrial effluent from printing and dyeing mills, which are not biodegradable and have serious toxic and contaminative effects. 10 Phenols are produced in very large quantities for use as solvents and starting materials for chemical synthesis. Phenolic compounds are some of the major hazardous compounds in industrial wastewater because of their poor biodegradability, high toxicity, and ecological aspects.…”

“…p -Nitrophenol aids in converting hemoglobin to methamoglobin, that is, oxidation of iron­(II) to iron­(III) reducing the oxygen transport capacity of hemoglobin in the body . Aminophenols are key components in industrial effluent from printing and dyeing mills, which are not biodegradable and have serious toxic and contaminative effects …”