Extraction of Lactic Acid from Whey of Yoghurt by Solvent Extraction Technique

The aim of this paper is to investigate the possibility to recover lactic acid (LA) from the whey of yoghurt by easy and effective solvent extraction technique using tri-n-octylamine, tri-n-butyl phosphate, and their mixtures as extractant. All parameters affecting the transfer of lactic acid to the organic phase were investigated including: time of stirring, tri-n-butyl phosphate and tri-n- octylamine concentrations, organic to aqueous phase ratio, temperature, NaCl concentration as a salting out agent, and number of contacts. The maximum yield of LA extraction can be obtained by using the following operation conditions: 0.8M TOA+11% TBP, Vorg/Vaq = 4/1, t = 30 oC, [NaCl] = 2M. Complete stripping of LA from loaded organic phase can be done in 2 stages using double distilled water at 60oC and Vaq/Vorg = 20/1.

Application of a cashew-based oxime in extracting Ni, Mn and Co from aqueous solution

Background Cashew nut shell is a by-product of cashew (Anacardium occidentale) production, which is abundant in many developing countries. Cashew nut shell liquor (CNSL) contains a functional chemical, cardanol, which can be converted into a hydroxyoxime. The hydroxyoximes are expensive reagents for metal extraction. Methods CNSL-based oxime was synthesized and used to extract Ni, Co, and Mn from aqueous solutions. The extraction potential was compared against a commercial extractant (LIX 860N). Results All metals were successfully extracted with pH0.5 between 4 and 6. The loaded organic phase was subsequently stripped with an acidic solution. The extraction efficiency and pH0.5 of the CNSL-based extractant were similar to a commercial phenol-oxime extractant. The metals were stripped from the loaded organic phase with a recovery rate of 95% at a pH of 1. Conclusions Cashew-based cardanol can be used to economically produce an oxime in a simple process. The naturally-based oxime has the economic potential to sustainably recover valuable metals from spent lithium-ion batteries. Graphic abstract

Solvent Extraction of Sc(III) by D2EHPA/TBP from the Leaching Solution of Vanadium Slag

The solvent extraction of scandium by the mixture of di-(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP) has been investigated in the acidic leaching solution of vanadium slag. Thermodynamic analysis of the species distribution diagrams on the Sc-S-H2O system showed that scandium mainly exists as Sc3+ and Sc(SO4)+, and sulfur mainly exists as HSO4− in the actual leaching solution of vanadium slag (pH = −0.75). The extraction process was studied to optimize various parameters such as the extractant concentration, dosage of TBP, phase ratio, and stirring speed. The results indicated that 83.64% of scandium and less than 2% of co-extracted elements were extracted under optimal conditions. Then, over 95% of the co-extracted elements and less than 1.1% of scandium were scrubbed from the loaded organic phase by 4.0 mol/L of HCl. Finally, 87.20% of scandium was stripped with 2 mol/L of NaOH and 1 mol/L of NaCl at a stripping O/A of 1:1.

Extraction of rubidium and cesium from brine solutions using a room temperature ionic liquid system containing 18-crown-6

Application of 1-butyl-3-metyhlimidazaolium hexafluorophosphate ([C4mim][PF6]), in the extraction of rubidium and cesium from brine solutions using 1,4,7,10,13,16-hexaoxacyclooctadecane (18C6) as extractant was investigated. Parameters that affect the extraction including pH of aqueous phase, equilibration time, dosage of the ionic liquid, phase ratio, concentration of 18C6 were studied. Under the optimal conditions, the single extraction efficiency of rubidium ions and cesium ions were up 84.11% and 94.99%, respectively. The stripping of alkali metal ions from the loaded organic phase with different stripping agents and concentrations were also investigated. The initial value of the K/Cs and K/Rb ratios were 93.0 and 104.3, respectively, which have dropped 91.21% and 88.01%, respectively, after the extraction and stripping experiments. It was taken a big step in the separation and enrichment of cesium (rubidium) ion and potassium ion. The extraction mechanism was revealed most likely to be a cation exchange mode in this system.