scholarly journals Removal of chromium(III) from aqueous waste solution by liquid–liquid extraction in a circular microchannel

2017 ◽  
Vol 76 (9) ◽  
pp. 2313-2320 ◽  
Author(s):  
Jian Hong Luo ◽  
Jun Li ◽  
Lei Guo ◽  
Xin Hua Zhu ◽  
Shuang Dai ◽  
...  
Keyword(s):  
Extraction Efficiency ◽  
Operating Conditions ◽  
Process Conditions ◽  
Waste Solution ◽  
Aqueous Waste ◽  
Initial Ph ◽  
Circular Microchannel ◽  
Inner Diameter ◽  
Optimized Conditions ◽  
Microchannel Device

Abstract A new circular microchannel device has been proposed for the removal of chromium(III) from aqueous waste solution by using kerosene as a diluent and (2-ethylhexyl) 2-ethylhexyl phosphonate as an extractant. The proposed device has several advantages such as a flexible and easily adaptable design, easy maintenance, and cheap setup without the requirement of microfabrication. To study the extraction efficiency and advantages of the circular microchannel device in the removal of chromium(III), the effects of various operating conditions such as the inner diameter of the channel, the total flow velocity, the phase ratio, the initial pH of aqueous waste solution, the reaction temperature and the initial concentration of extractant on the extraction efficiency are investigated and the optimal process conditions are obtained. The results show that chromium(III) in aqueous waste solution can be effectively removed with (2-ethylhexyl) 2-ethylhexyl phosphonate in the circular microchannel. Under optimized conditions, an extraction efficiency of chromium(III) of more than 99% can be attained and the aqueous waste solution can be discharged directly, which can meet the Chinese national emission standards.

scholarly journals Study on Mg2+ removal from ammonium dihydrogen phosphate solution by an emulsion liquid membrane

2014 ◽  
Vol 68 (3) ◽  
pp. 341-346 ◽  
Author(s):  
JianHong Luo ◽  
Jun Li ◽  
Bao Wang
Keyword(s):  
Extraction Efficiency ◽  
Liquid Membrane ◽  
Volume Fraction ◽  
Operating Conditions ◽  
Dihydrogen Phosphate ◽  
Phosphate Solution ◽  
Ammonium Dihydrogen Phosphate ◽  
Emulsion Liquid Membrane ◽  
Internal Phase ◽  
Initial Ph

Mg2+is extracted from ammonium dihydrogen phosphate (NH4H2PO4) solution by an emulsion liquid membrane (ELM) using mono-(2-ethylhexyl) 2-ethylhexyl phosphonate (HEHPEHE)as a carrier, sulfonated liquid polybutadiene (LYF) as a surfactant and kerosene as a solvent. To study the extraction efficiency and advantages of the ELM process in the separation of Mg2+,the effects of various operating conditions on the extraction -HEHPEHE volume fraction, reaction temperature, treat ratio (emulsion phase / external phase), phase ratio (membrane phase / internal phase), agitation speed, extraction time, internal phase concentration, surfactant LYF concentration and initial pH of NH4H2PO4 solution are experimentally investigated and discussed. The results show that Mg2+ in NH4H2PO4 solution can be effectively removed by the ELM process. An extraction efficiency of more than 83.1% is attained at the optimized parameters and superior-grade NH4H2PO4can be obtained by two levels of extraction.

Bio-Treatment of APMP Effluent with Activated Sludge

2014 ◽  
Vol 675-677 ◽  
pp. 505-509
Author(s):  
Ting Zhi Liu ◽  
Hao Yu Wang ◽  
Shuai Li ◽  
Yuan Liu
Keyword(s):  
Activated Sludge ◽  
Ph Value ◽  
Effluent Treatment ◽  
Treated Wastewater ◽  
Process Conditions ◽  
Wood Extractives ◽  
Mechanical Pulp ◽  
Alkaline Peroxide ◽  
Initial Ph ◽  
Optimized Conditions

Aerobic activated sludge was more appropriate for APMP(Alkaline Peroxide Mechanical Pulp) effluent treatment than anaerobic processes because the high content of toxic wood extractives in the effluent. In this article, Eucalyptus APMP effluent was treated with activated sludge and the process conditions was optimized. The optimized conditions were: the initial pH value was 6.0, SV30of activated sludge was 35%, and loading volume of flask was 150ml (250ml flask), cultured shakily for 3 days at 35°Cand 150rpm. The removal of COD was 66.75%, from 4181mg/l to 1390mg/l, and the color of the effluent and treated water were 2541C.U. and 1557C.U. under the optimized conditions, respectively. In most cases, the color of treated wastewater was increased compared with the initial effluent, but the removal of COD was significant.

Preparation of Solar-Grade Polysilicon by Acid Leaching

2010 ◽  
Vol 160-162 ◽  
pp. 1297-1300
Author(s):  
Yu Chang ◽  
Hong Yu Chen ◽  
Qi Wen Luo ◽  
Qi Hui Ye
Keyword(s):  
Grain Size ◽  
Removal Efficiency ◽  
Low Cost ◽  
Acid Leaching ◽  
Operating Conditions ◽  
Process Conditions ◽  
Primary Process ◽  
Optimal Operating ◽  
Orthogonal Experiments ◽  
Optimized Conditions

A low-cost acid leaching process is studied in this paper to prepare solar-grade polysilicon. The effects of process conditions (grain size, acid species and concentration, leaching time and temperature) are discussed. The further optimized conditions by orthogonal experiments are given in this paper. Optimal operating conditions are suggested: 75μm of grain size, 80 min of leaching time, 0.28 mol/l of concentration of HF, 80 C of leaching temperature. The removal efficiency of impurity reaches 98.41%. Analysis by ICP-AES and SEM illustrates acid leaching appears to be a potential primary process for solar-grade Si purification. .

scholarly journals Continuous Integrated Process of Biodiesel Production and Purification—The End of the Conventional Two-Stage Batch Process?

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 403
Author(s):  
Matea Bačić ◽  
Anabela Ljubić ◽  
Martin Gojun ◽  
Anita Šalić ◽  
Ana Jurinjak Tušek ◽  
...  
Keyword(s):  
Extraction Efficiency ◽  
Deep Eutectic Solvent ◽  
International Standards ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Process Conditions ◽  
Integrated Process ◽  
Free Glycerol ◽  
Mass Ratio ◽  
Glycerol Content

In this research, optimization of the integrated biodiesel production process composed of transesterification of edible sunflower oil, catalyzed by commercial lipase, with simultaneous extraction of glycerol from the reaction mixture was performed. Deep eutectic solvents (DESs) were used in this integrated process as the reaction and extraction media. For two systems, choline chloride:glycerol (ChCl:Gly) and choline chloride:ethylene glycol (ChCl:EG), respectively, the optimal water content, mass ratio of the phase containing the mixture of reactants (oil and methanol) with an enzyme and a DES phase (mass ratio of phases), and the molar ratio of deep eutectic solvent constituents were determined using response surface methodology (RSM). Experiments performed with ChCl:Gly resulted in a higher biodiesel yield and higher glycerol extraction efficiency, namely, a mass ratio of phases of 1:1, a mass fraction of water of 6.6%, and a molar ratio of the ChCl:Gly of 1:3.5 were determined to be the optimal process conditions. When the reaction was performed in a batch reactor under the optimal conditions, the process resulted in a 43.54 ± 0.2% yield and 99.54 ± 0.19% glycerol extraction efficiency (t = 2 h). Unfortunately, the free glycerol content was higher than the one defined by international standards (wG > 0.02%); therefore, the process was performed in a microsystem to enhance the mass transfer. Gaining the same yield and free glycerol content below the standards (wG = 0.0019 ± 0.003%), the microsystem proved to be a good direction for future process optimization.

scholarly journals Comparison between Different Keratin-composed Biosorbents for the Removal of Heavy Metal Ions from Aqueous Solutions

2002 ◽  
Vol 20 (4) ◽  
pp. 393-416 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Dheaya‘ Al-Rousan
Keyword(s):  
Aqueous Solutions ◽  
Human Hair ◽  
Metal Ion ◽  
Ph Value ◽  
Freundlich Isotherm ◽  
Operating Conditions ◽  
Ion Uptake ◽  
Chicken Feathers ◽  
Initial Ph ◽  
Metal Ion Uptake

This study examined and compared the ability of chicken feathers, human hair and animal horns, as keratin-composed biosorbents, for the removal of Zn2+ and Cu2+ ions from single metal ion aqueous solutions under different operating conditions. The three biosorbents investigated in this study were all capable of adsorbing Zn2+ and Cu2+ ions from aqueous solutions. The biosorbent showing the highest uptake of Zn2+ and Cu2+ ions was animal horns. Chicken feathers showed a higher Cu2+ ion uptake and a lower Zn2+ ion compared to human hair. Increasing the initial concentration of Zn2+ or Cu2+ ions, or increasing the initial pH value, increased the metal ion uptake. Such uptake decreased when the temperature was raised from 25°C to 50°C for all adsorbent/metal ion combinations except for Zn2+ ion/human hair where the uptake increased with temperature. It was demonstrated that the addition of NaCl salt to the metal ion solution depressed the metal ion uptake. The Freundlich isotherm model was found to be applicable to the adsorption data for Cu2+ and Zn2+ ions.

scholarly journals Tantalum and Niobium Selective Extraction by Alkyl-Acetophenone

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 654 ◽  
Author(s):  
Moussa Toure ◽  
Guilhem Arrachart ◽  
Jean Duhamet ◽  
Stephane Pellet-Rostaing
Keyword(s):  
Extraction Efficiency ◽  
Methyl Isobutyl Ketone ◽  
Selective Extraction ◽  
Extraction Process ◽  
Liquid Extraction ◽  
Methyl Isobutyl ◽  
Isobutyl Ketone ◽  
Waste Solution ◽  
Liquid Liquid Extraction ◽  
D Values

A study has been carried out on Ta and Nb recovery by a liquid-liquid extraction process using 4-methylacetophenone (4-MAcPh) as the organic phase. The 4-MAcPh was compared to methyl isobutyl ketone (MIBK) with respect to extraction efficiencies (D values) at different concentrations of H2SO4 in the aqueous phase. The results showed a similar extraction of Nb for both solvents. However, for Ta, extraction efficiency is increased by a factor of 1.3 for 4-MAcPh. In addition, the MIBK solubilized completely after 6 mol∙L−1 of H2SO4 against only a loss of 0.14–4% for 4-MAcPh between 6 and 9 mol∙L−1 of H2SO4. The potential of 4-MAcPh has also been studied to selectively recover Ta from a model capacitor waste solution. The results showed a selectivity for Ta in the presence of impurities such as Ag, Fe, Ni and Mn. The 4-MAcPh also presents the advantage of having physicochemical properties adapted to its use in liquid-liquid extraction technologies such as mixer-settlers.

Property of Cu2O-CuO/ZSM-5 nanocomposite and degradation process of azo dye AO7 without sacrificial agent (H2O2)

2016 ◽  
Vol 73 (11) ◽  
pp. 2747-2753 ◽  
Author(s):  
Wusong Kong ◽  
Hongxia Qu ◽  
Peng Chen ◽  
Weihua Ma ◽  
Huifang Xie
Keyword(s):  
Catalytic Activity ◽  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Surface Element ◽  
Impregnation Method ◽  
X Ray ◽  
Initial Ph ◽  
Sacrificial Agent

In this study, Cu2O-CuO/ZSM-5 nanocomposite was synthesized by the impregnation method, and its catalytic performance for the destruction of AO7 in aqueous solutions was investigated. The morphology, structure and surface element valence state of Cu2O-CuO/ZSM-5 were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The operating conditions on the degradation of AO7 by Cu2O-CuO/ZSM-5, such as initial pH values, concentration of AO7 and catalyst dosage were investigated and optimized. The results showed that the sample had good catalytic activity for destruction of AO7 in the absence of a sacrificial agent (e.g. H2O2): it could degrade 91% AO7 in 140 min at 25 °C and was not restricted by the initial pH of the AO7 aqueous solutions. Cu2O-CuO/ZSM-5 exhibited stable catalytic activity with little loss after three successive runs. The total organic carbon and chemical oxygen demand removal efficiencies increased rapidly to 69.36% and 67.3% after 120 min of treatment by Cu2O-CuO/ZSM-5, respectively.

Linking Microbial Community Dynamics in BIOX® Leaching Tanks to Process Conditions: Integrating Lab and Commercial Experience

2017 ◽  
Vol 262 ◽  
pp. 38-42 ◽  
Author(s):  
Mariette Smart ◽  
Robert J. Huddy ◽  
Catherine J. Edward ◽  
Charl Fourie ◽  
Trust Shumba ◽  
...  
Keyword(s):  
South Africa ◽  
Community Structure ◽  
Microbial Community ◽  
Research University ◽  
Community Dynamics ◽  
Operating Conditions ◽  
Process Conditions ◽  
Significant Shift ◽  
Engineering Research ◽  
Microbial Community Dynamics

In the commercial BIOX® process, an acidophilic mixed bacterial and archaeal community dominated by iron and sulphur oxidising microorganisms is used to facilitate the recovery of precious metals from refractory gold-bearing sulphidic mineral concentrates. Characterisation of the microbial communities associated with commercial BIOX® reactors from four continents revealed a significant shift in the microbial community structure compared to that of the seed culture, maintained at SGS (South Africa). This has motivated more detailed study of the microbial community dynamics in the process. Microbial speciation of a subset of the BIOX® reactors at Fairview mines (Barberton, South Africa) and two laboratory maintained reactors housed at Centre for Bioprocess Engineering Research, University of Cape Town, has been performed tri-annually for three years by quantitative real-time polymerase chain reaction. The laboratory BIOX® culture maintained on Fairview concentrate was dominated by the desired iron oxidiser, Leptospirillum ferriphilum, and sulphur oxidiser, Acidithiobacillus caldus, when operated under standard BIOX® conditions. Shifts in the microbial community as a result of altered operating conditions were transient and did not result in a loss of the microbial diversity of the BIOX® culture. The community structure of the Fairview mines BIOX® reactor tanks showed archaeal dominance of these communities by organisms such as the iron oxidiser Ferroplasma acidiphilum and a Thermoplasma sp. for the period monitored. Shifts in the microbial community were observed across the monitoring period and mapped to changes in performance of the commercial process plant. Understanding the effect of changes in the plant operating conditions on the BIOX® community structure may assist in providing conditions that support the desired microbial consortium for optimal biooxidation to maximize gold recovery.

scholarly journals Liquid Membrane Formulation for Removal of Kraft Lignin from Simulated Liquid Waste Solution

2014 ◽  
Vol 9 (1) ◽  
Author(s):  
Norasikin Othman ◽  
Ooi Zing Yi ◽  
Norlisa Harruddin
Keyword(s):  
Sodium Bicarbonate ◽  
Liquid Membrane ◽  
Liquid Waste ◽  
Kraft Lignin ◽  
Water Bodies ◽  
Aliquat 336 ◽  
Waste Solution ◽  
Lignin Removal ◽  
Aqueous Waste ◽  
Brownish Black

Extraction of lignin from pulping wastewater as an external biofuel and in specialty chemicals will additionally benefit the chemical and automobile industries. Though lignin is nontoxic, it imparts brownish black colouration to the water bodies can cause environmental problems. Emulsion liquid membrane (ELM) technology is proposed to extract and recover the kraft lignin (KL) compound from the aqueous waste solution. This study investigated on development of a liquid membrane formulation for lignin removal from aqueous waste solution. Several parameters such as types and concentration of carrier, types of diluents and types of stripping agentswere studied. The results showed that the most favorable liquid membrane formulation is using Aliquat 336 as extractant, kerosene as diluents and sodium bicarbonate (NaHCO3) as stripping agent which is almost 93% of lignin was extracted.

scholarly journals Ionic Liquid-modified NiTi Composite Nanosheets Coating for Efficient Solid Phase Microextraction of Octadecylamine in Brine

2019 ◽  
pp. 1-8
Author(s):  
Huiju Wang
Keyword(s):  
Ionic Liquid ◽  
Solid Phase Microextraction ◽  
Extraction Efficiency ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Fiber Coating ◽  
Relative Standard ◽  
Optimized Conditions ◽  
As Solid Phase

Ionic     liquid (IL), 1-dodecyl-3-methylimidazolium-3-hydroxy-2-naphthoate (C12mimHNC) was synthesized and coated on the surface of NiTi as solid phase microextractiom fiber coating for determination the octadecylamine in brine. Prior to modification with IL, the NiTi was hydrothermally treated for in-situ growth of titanium and nickel oxide composite nanosheets (TiO2/NiOCNSs). The TiO2/NiOCNSs fibers coating was oriented  around the NiTi  substrate and  presented  double-faced  open  access  sites,  which provided a desired support framework for the further modification with IL. The extraction performance of C12mimHNC-TiO2/NiOCNSs fiber coating was evaluated for       detection of octadecylamine (ODA) coupled to HPLC with UV detection. As a result, the C12mimHNC-TiO2/NiOCNSs fiber coating illustrated excellent adsorption and extraction capability for ODA. The main factors affected extraction efficiency were optimized. Under the optimized  conditions,  good  linearity was  obtained  in  the  range of  1-150  µg/L with correlation  coefficients  (r2)  above  0.985.  Limits of detection (LODs) for  the  developed method was 0.280 µg/L. The proposed method was first applied to extract the ODA in brine samples. Relative recoveries varied from 78.3% to 96.5% at spiking level of 15µg/L and 30 µg/L with the relative standard deviations (RSDs) less than 8.7%.

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