Ultrasonic Assisted Process

Due to the variability of additives and polymer types used in electrical and electronic equipment (EEE), and in accordance with the European Directive 2012/19/EU, an implementation of sound management practices is necessary. This work focuses on assessing the content of tetrabromobisphenol-A (TBBPA) in acrylonitrile-butadiene-styrene (ABS), polypropylene (PP), polycarbonate (PC) and their polymer blends (i.e. PC/ABS). A total of 36 plastic housing samples originating from microwave ovens, electric irons, vacuum cleaners and DVD/CD players were subjected to microwave-assisted-extraction (MAE) and/or ultrasound-assisted-extraction (UAE). Maximum mean concentration values of TBBPA measured in DVD/CD players and vacuum cleaners ranged between 754−1146 μg/kg, and varied per polymer type, as follows: 510−2515 μg/kg in ABS and 55−3109 μg/kg in PP. The results indicated that MAE was more sufficient than UAE in the extraction of TBBPA from ABS. To optimize the UAE procedure, various solvents were tested. Higher amounts of TBBPA were obtained from ABS and PP using a binary mixture of a polar-non-polar solvent, isopropanol:n-hexane (1:1), whereas the sole use of isopropanol exhibited incomplete extraction.

This work demonstrated the optimization and scale up of microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) of bioactive compounds from Orthosiphon stamineus using energy-based parameters such as absorbed power density and absorbed energy density (APD-AED) and response surface methodology (RSM). The intensive optimum conditions of MAE obtained at 80% EtOH, 50 mL/g, APD of 0.35W/mL, AED of 250 J/mL can be used to determine the optimum conditions of the scale-dependent parameters i.e. microwave power and treatment time at various extraction scales (100-300 mL solvent loading). The yields of the up scaled conditions were consistent with less than 8% discrepancy and they were about 91-98% of the Soxhlet extraction yield. By adapting APD-AED method in the case of UAE, the intensive optimum conditions of the extraction, i.e. 70% EtOH, 30 mL/g, APD of 0.22 W/mL, AED of 450 J/mL are able to achieve similar scale up results.

This study focuses on the role of a hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMIM] +[NTf 2] - in the preparation of emulsion liquid membrane (ELM) phase containing kerosene as solvent, Span 80 as surfactant, NaOH as internal phase and TOMAC (tri-n-octylmethylammonium chloride) a second ionic liquid as carrier. The first time used [BMIM] +[NTf 2] - in ELM was found to play the role of a stabilizer. The emulsion prepared using [BMIM] + [NTf 2] - has a long period of stability of about 7h (at 3% (w/w) of [BMIM] +[NTf 2] -) which otherwise has a brief stability up to only 7min. The stability of the emulsion increases with the increase in concentration of [BMIM] +[NTf 2] - up to 3% (w/w). Nevertheless, with further increase in concentration of [BMIM] +[NTf 2] -, a reduction in the stability occurs. The extraction experiments were carried out after holding the ELM for 2h after the preparation and a removal efficiency of approximately 80% was obtained for Cr. The destabilization of the emulsion was studied by observing the change in the interface height. An empirical correlation for the stability of the emulsion has been proposed. © 2011 Elsevier B.V.

http://ac.els-cdn.com/S030438941100327X/1-s2.0-S030438941100327X-main.pdf?_tid=8f80d766-0ca1-11e4-8821-00000aab0f01&acdnat=1405485056_f3aef836306a8c21880bfaca21598a0a 
http://www.ncbi.nlm.nih.gov/pubmed/21962862 
http://www.sciencedirect.com/science/article/pii/S030438941100327X

This work demonstrated the optimization and scale up of microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) of bioactive compounds from Orthosiphon stamineus using energy-based parameters such as absorbed power density and absorbed energy density (APD-AED) and response surface methodology (RSM). The intensive optimum conditions of MAE obtained at 80% EtOH, 50 mL/g, APD of 0.35 W/mL, AED of 250 J/mL can be used to determine the optimum conditions of the scale-dependent parameters i.e. microwave power and treatment time at various extraction scales (100–300 mL solvent loading). The yields of the up scaled conditions were consistent with less than 8% discrepancy and they were about 91–98% of the Soxhlet extraction yield. By adapting APD-AED method in the case of UAE, the intensive optimum conditions of the extraction, i.e. 70% EtOH, 30 mL/g, APD of 0.22 W/mL, AED of 450 J/mL are able to achieve similar scale up results.