Optimization of an Oil Extraction Process for Algae from the Treatment of Manure Effluent

Increasing interest in the coupling of biological wastewater treatment processes with the generation of value-added products (such as oil containing ω-3 fatty acids (FA)) has stimulated efforts in adapting extraction methods for treatment byproducts. This study’s objective was to compare a high temperature/pressure extraction method (accelerated solvent extraction) (ASE) and a manual extraction method (modified Folch extraction) with regard to their ability to extract total oil from three algae samples from the treatment of dairy manure effluent. The efficiency of total oil and FA extraction with three solvents (chloroform/methanol, isopropanol/hexane, and hexane) was also evaluated using the ASE method. Results showed that the ASE method yielded higher values for total oil content compared to the Folch method but similar values for FA content and composition after four extraction cycles with chloroform/methanol. However, the ASE method yielded much higher amounts of FA in the first cycle (85–95% of total extracted) compared to the Folch method (44–55% of total extracted in the first cycle). As expected, the extraction efficiency of the ASE method for FA was dependent on the extraction solvent. FA content values using ASE with chloroform/methanol > isopropanol/hexane > hexane. FA content values using the Folch method or ASE with chloroform/methanol were not significantly influenced by sample particle size within the size range of 0.1–1 mm.     

氧乐果可溶性液剂的研究

在氧乐果可溶性液剂的制备中,我们对溶剂、助溶剂、乳化剂、稳定剂进行了研究。筛选出了两个最佳配方：氧乐果50％(质量浓度),苯乙基酚聚氧乙烯聚氧丙烯醚2．5％,烷基酚甲醛树脂聚氧乙烯醚0．7％,无水十二烷基苯磺酸钙(500^#)1.8％,稳定剂0．2％,助溶剂5％,溶剂补加到100％;氧乐果80％(质量浓度),苯乙基酚聚氧乙烯聚氧丙烯醚3％,烷基酚甲醛树脂聚氧乙烯醚0．9％,无水十二烷基苯磺酸钙(500^#)2．2％,稳定剂0．5％,助溶剂6％,溶剂补加到100％。用两种配方生产的产品性能优良。田间试验结果表明,防效优于乳油。     

Isopropyl Alcohol Extraction of De‐hulled Yellow Mustard Flour

Vegetable oils are typically extracted with hexane; however, health and environmental concerns over its use have prompted the search for alternative solvents. Mustard oil was extracted with isopropyl alcohol (IPA) to produce an IPA‐oil miscella suitable for industrial applications. Single‐stage extraction resulted in 87.6 % oil yield at a 10:1 (v/w) IPA/flour ratio. Multiple‐stage extraction resulted in higher extraction efficiency with lower IPA use. Four‐stage cross‐current extraction at an IPA/flour ratio of 2:1 (v/w) per stage resulted in 93.7 % oil yield. At 45 °C, a 91.5 % oil yield was achieved with three‐stage extraction using a 2:1 (v/w) IPA/flour ratio. Any changes to the pH of the mixture resulted in reduced oil yield. Water also reduced the extraction efficiency. The azeotropic IPA solution containing 13 % water extracted ~40 % less oil than did dry IPA in both single and multiple‐stage extractions. Some polar compounds were also extracted, including sugars; however, protein extraction was negligible. The protein left in the extracted meal was not degraded or lost during the extraction. The results suggest that IPA is an excellent solvent for mustard oil, but water content exceeding 5 % in the solvent adversely affects the oil extraction and reuse of the IPA.     

Comparison of the bligh and dyer and folch methods for total lipid determination in a broad range of marine tissue

For many studies, it is important to measure the total lipid content of biological samples accurately. The Bligh and Dyer method of extraction was developed as a rapid but effective method for determining total lipid content in fish muscle. However, it is also widely used in studies measuring total lipid content of whole fish and other tissues. Although some investigators may have used modified Bligh and Dyer procedures, rarely have modifications been specified nor has their effectiveness been quantitatively evaluated. Thus, we compared this method with that of the classic Folch extraction in determining total lipid content of fish samples ranging from 0.5 to 26.6% lipid. We performed both methods as originally specified, i.e., using the chloroform/methanol/water ratios of 1:2:0.8 and 2:2:1.8 (before and after dilution, respectively) for Bligh and Dyer and of 8:4:3 for Folch, and with the initial solvent/sample ratios of (3+1):1 (Bligh and Dyer) and 20:1 (Folch). We also compared these with several other solvent/sample ratios. In samples containing <2% lipid, the results of the two methods did not differ. However, for samples containing >2% lipid, the Bligh and Dyer method produced significantly lower estimates of lipid content, and this underestimation increased significantly with increasing lipid content of the sample. In the highest lipid samples, lipid content was underestimated by up to 50% using the Bligh and Dyer method. However, we found a highly significant linear relationship between the two methods, which will permit the correction of reported lipid levels in samples previously analyzed using an unmodified Bligh and Dyer extraction. In the future, modifications to procedures and solvent/sample ratios should be described.     

Purification of bioxylitol by liquid–liquid extraction from enzymatic reaction mixture

Xylitol purification is the most difficult step of the whole manufacturing process, and its purification being of commercial importance. This study aimed to purify bioxylitol by liquid–liquid extraction (LLE) from enzymatic reaction mixture. Bioxylitol extraction was conducted under various conditions of extraction time (45–105 min), sample to solvent ratio (SSR) (1:1–1:9 v/v), and number of extraction stages (NES) (1–9 n), and the response surface method was followed to optimize the variables. Xylitol separation was markedly affected by SSR and NES. Optimum time, SSR, and NES determined were 60 min, 1:4.5 (v/v), and 5 (n), respectively. Xylitol extraction yield attained was 78.14% (w/w) at these conditions. This research reveals the feasibility of clarifying bioxylitol produced via enzymatic reduction of xylose by LLE using ethyl acetate.     

Solvent extraction of rosmarinic acid from lemon balm and concentration of extracts by nanofiltration: Effect of plant pre-treatment by supercritical carbon dioxide

The present work investigates a complex scheme of valuable components extraction from herbs and extracts concentration by nanofiltration. Two ethanol–water mixtures (50:50 and 80:20 (v/v)) have been used for solvent extraction of rosmarinic acid (RA) from dry lemon balm aerial parts and high recovery (up to 94%) has been obtained in three steps scheme. A positive impact of a preliminary treatment by supercritical CO₂ (in order to utilize the plant essential oil) on the successive RA extraction has been observed. The cross-linked polyimide membrane Duramem™ 200 has performed RA rejection of over 99% and reasonable flux at dead end nanofiltration pressure of 30 bar. This high rejection being independent of ethanol content in the solvent, supercritical pretreatment and RA concentration of the extracts has allowed to obtain nearly saturated retentate solutions (up to 19 g/L RA) and to reuse the permeates for lemon balm extraction in place of pure solvent. A RA content in the extracts dried total solid mass of 28 ± 2 % has been achieved.The additional resistance due to osmotic pressure difference and concentration polarization has been determined as a power function of retentate concentration with power value near to unity and approximately similar for the extracts and a model solution of RA.The study has confirmed the potential benefits of nanofiltration implementation in herbal extracts processing.     

Pressurized Liquid Extraction as a Promising and Economically Feasible Technique for Obtaining Beta-Ecdysone-Rich Extracts from Brazilian Ginseng (Pfaffia glomerata) Roots

Pressurized liquid extraction was used to obtain beta-ecdysone-rich extracts from Brazilian ginseng (Pfaffia glomerata) roots. The effects of temperature, pressure, and solvent on extraction yield, beta-ecdysone content, and antioxidant activity were determined. Extraction yield increased with temperature up to 25% (dry basis) while the selectivity decreased. The use of Ethanol:Water (80:20 v/v) as solvent produced extracts with the highest antioxidant activity. Beta-ecdysone recovery was maximized using pure ethanol. In the first hour of extraction, approximately 70% of the total yield and 74% of the total beta-ecdysone mass is obtained. The cost of manufacturing significantly decrease as the extractor capacity increased.     

加压提取枳实总黄酮的研究

采用加压提取法提取枳实中黄酮类成分,并与乙醇回流法比较提取效果。采用单因素试验,考察提取压力、提取温度和溶剂用量等对黄酮提取的影响,并采用正交设计法优化工艺。结果表明最适宜条件为:乙醇体积分数为40%,温度130℃,压力500 kPa,粒径60目,固液质量比1∶20,时间20 min,在此条件下,提取率为4.16%,提取速率为2.08 mg/(g·min)。乙醇回流提取法在相同药材粒径和料液比情况下,提取率为3.44%,提取速率为0.19 mg/(g·min)。加压提取法具有省时和高效的优点。     

Optimization of microwave-assisted extraction of bioactive compounds from pistachio (Pistacia vera L.) hull

ABSTRACT

Phenolic compounds were extracted from pistachio hull using microwave-assisted solvent extraction (MASE). The effects of four parameters, microwave power, extraction time, solvent to sample ratio, and ethanol concentration were evaluated. The extraction conditions were optimized by response surface methodology to enhance the total phenolic content (TPC). Optimal conditions were found as 140 W microwave power, 4.5 min extraction time, 19:1 (v/w) solvent to sample ratio, and 56% ethanol concentration to get maximum TPC (62.24 mg GAE/g dry hull). Also, MASE was compared with conventional solvent extraction (CSE) and MASE gave higher TPC, yield, and antioxidant activity.     

Rates of acetate extraction from simulated waste streams in chloromycetin production

The kinetics for extraction recovery of acetate ions from simulated waste streams in chloromycetin production by Aliquat 336 (a quaternary amine) and tri‐n‐butylphosphate (TBP) in xylene were examined using a microporous membrane‐based stirred cell. The waste stream typically contained 15.4% acetic acid, 8.8% sodium acetate, and 4.7% (w/w) NaCl. The stirred cell could give intrinsic rates for formation of the complex occurring at or near the organic–aqueous interface. It was shown that the extraction rate with TBP was higher than that with Aliquat 336. The effect of temperature (288–318 K) on the reaction rate with TBP was also examined and the activation energy (54.5 kJ mol⁻¹) was obtained. © 1999 Society of Chemical Industry     

Separation and recovery of vanadium from leached solution of spent residuehydrodesulfurization (RHDS) catalyst using solvent extraction

Leached solution, generated by oxalic acid washing of spent residue hydrodesulfurization (RHDS) catalyst, was used for separation and recovery of vanadium. First of all, solvent extraction, using mixture of 20% (v/v) Alamine-336 and 5% (v/v) tri-butyl phosphate (TBP) as a phase modifier, was conducted to extract molybdenum completely at pH 0.50. Then molybdenum-free solution was used for vanadium extraction at pH 1.25 with 20% Alamine-336 and 5% TBP. Stripping of vanadium from loaded organic solution was performed with 1.5 M H₂SO₄ at O/A phase ratio of 5:1 where more than 99% of vanadium was stripped in two stages. The stripped vanadium solution was further processed by precipitating with ammonium hydroxide to recover ammonium-meta-vanadate which was calcined to obtain vanadium pentoxide. Finally a conceptual process was established for recovery of high purity vanadium pentoxide from oxalic acid leached solution of spent residue hydrodesulfurization (RHDS) catalyst.     

Recovery of vinyl chloride from by-streams of polyvinyl chloride production by TPSA in a multitubular adsorber

This work aims at developing an efficient and feasible adsorption-based separation process for the separation of vinyl chloride and nitrogen, on activated carbon, by employing a multitubular packed bed geometry, with adsorbent material inside the tubes. Using this geometry, a 2-dimensional mathematical model of a temperature pressure swing adsorption process was used to developed a 6-step three multitubular adsorbers system capable of separating and purifying an industrial scale gas stream of a 40:60% (v/v) vinyl chloride/nitrogen mixture into a 95% (v/v) vinyl chloride stream and a nitrogen stream with a vinyl chloride limit concentration of 8 ppm (w/w). The process reported energy consumption of 4.88 × 10⁶ J/kg_VCM and recovery capacity of 24.35 kg_VCM/(m³_unit h). The multitubular geometry enabled the use of lower adsorbent loads, shorter cycle times, and lower regeneration temperatures. An equivalent 1-dimensional model has also shown to satisfactorily estimate the performance of the current equipment.     

高分子螯合剂处理含镉废水的试验研究

探讨了投药量、pH值、沉淀时间、体系温度对高分子螯合剂捕集Cd2+离子的影响.确定了该药剂处理20 mg/L含镉模拟废水最佳工艺参数为:投药量为浓度1％(m/V)的螯合剂0.7 ml,pH值为6～9,沉淀时间30 rain,比较合适的温度为30℃.     

Recovery of metals from complexed solutions by electrodeposition

Electrolytic recovery of metals from aqueous solutions containing complexing chelating agents such as EDTA, NTA, and citrate was studied in a two-chamber cell separating with a commercial cation-exchange membrane (CEM). Equimolar solutions of metal and a chelating agent as a catholyte and NaNO₃ as an anolyte were used; the effect of current densities, initial catholyte and anolyte pH, metal concentration and the type of the CEM, chelating agent and metal on the recovery of metals was determined. The recovery of metal increased with higher initial anolyte pH, concentration and current density, whereas it decreased with lower initial catholyte pH. The results show that electrodeposition seems to be an applicable method for the recovery of metals under appropriate conditions.     

Free fatty acid content of human milk: Physiologic significance and artifactual determinants

Analysis of human milk was conducted to determine if free fatty acids occur naturally or as a consequence of artifactual lipolysis after milk expression. Five mothers provided triplicate early morning milk samples on day 43 of lactation. Following extraction, lipid classes were separated by preparative thin layer chromatography and quantified by capillary gas liquid chromatography. Fresh milk samples collected with 20 volumes chloroform-methanol (1∶1, v/v) were analogous in total free fatty acid level and profile of fatty acids to a duplicate sample collected with 0.4M EDTA and immediately frozen at −10 C. Low milk levels of free fatty acids appear to exist naturally. During days 4–37 of lactation, four serial milk samples from 15 mothers were collected and frozen with 0.4M EDTA. The concentration of free fatty acids in colostrum (0.03–0.5%, w/w) was lower than for subsequent days (0.3–2.5%, w/w). Additional samples were collected with and without a lipase inhibitor (0.4M EDTA) and subjected to routine collection and storage procedures. Significantly different fatty acid profile and higher levels of free fatty acids in milk collected without a lipase inhibitor added indicate that domestic freezing and/or thawing ruptures the fat globule membrane, allowing sn-1-stereospecific serum stimulated lipoprotein lipase contact with its triglyceride substrate. Standard procedures for collection of human milk for gavage fed infants appear to stimulate artifactual lipolysis of milk triglyceride and subsequent release of free fatty acids. The proposed relationship between dietary free fatty acids and prolonged, unconjugated hyperbilirubinemia in the newborn is discussed with regard to the significance of preintestinal lipolysis.     

Dicyclohexano-18-crown-6 as active material in PVC matrix membrane for the fabrication of cadmium selective potentiometric sensor

PVC based membrane containing dicyclohexano-18-crown-6 (I) as active material along with sodium tetraphenyl borate (NaTPB) as an anion excluder and dibutyl phthalate as solvent mediator in the ratio 20:4:150:150 (w/w) (I-NaTPB-DBP-PVC) exhibits good properties with a Nernstian response of 29.0±1.0 mV per decade of activity and a working concentration range of 2.1×10⁻⁵-1.0×10⁻¹ M. The working pH range of the sensor is 1.9-7.0. It exhibits a fast response time as fast as 17 s and has a lifetime of about 6 months. The proposed sensor has good selectivity for cadmium over alkali, alkaline earth, some transition and heavy metal ions. The sensor works satisfactorily in mixtures having 10% (v/v) non-aqueous content without showing any considerable change in working concentration range or slope. It has been successfully used as an indicator electrode for the potentiometric titration of Cd²⁺ against EDTA as well as for its determination in wastewaters.     

Influence of chemical speciation on the separation of metal ions from chelating agents by nanofiltration membranes

The simultaneous separation of various metal ions (nickel, copper, calcium, and iron) from chelating agents (EDTA and citric acid) in water streams using Nanofiltration membranes is analyzed. Assuming that multiply-charged species are highly rejected, chemical speciation computations reproduce the observed patterns of metal and ligand rejection at different pH values and concentrations. The separation of metal ions from citric acid is achieved in acidic conditions, where multiply-charged free metal ions and neutral or singly charged free chelating species are abundant. Overall, speciation studies help to evaluate the applicability of Nanofiltration for recycling chelating agents used for metal extraction.     

不同亚临界溶剂从微拟球藻湿藻泥中提取油脂

以微拟球藻(Nannochlorsis sp.)湿藻泥为原料,研究了亚临界乙醇、亚临界乙醇-正己烷共溶剂及硫酸辅助亚临界乙醇-正己烷共溶剂3种萃取体系对微藻油脂提取的影响. 结果表明,亚临界乙醇-正己烷比亚临界乙醇对湿藻细胞有更高的油脂萃取率和低的溶剂用量,加入少量硫酸可进一步提高油脂的提取率、降低溶剂用量. 微拟球藻湿藻泥(含水约70%)优化提取条件为,正己烷/乙醇体积比3:1,液固比(溶剂/藻细胞干重)7 mL/g,加入藻细胞干重6%的硫酸,1.5 MPa下90℃萃取30 min,在此条件下油脂提取率可达90%以上. 3种萃取体系获得的微藻油脂均以甘油三酯为主,甘油三酯的脂肪酸主要为C16:0, C18:1和C16:1,其中硫酸辅助亚临界共溶剂萃取的微藻油脂中甘油三酯含量最高,约占总脂的86%以上.     

Three phase partitioning coupled with ultrasound for the extraction of ursolic acid and oleanolic acid from Ocimum sanctum

In this study, three phase partitioning (TPP) is coupled with ultrasound for the extraction of ursolic acid (UA) and oleanolic acid (OA) from Ocimum sanctum leaves and process has been optimized to obtain maximum recovery. TPP is a relatively novel bioseparation technique used for the extraction, concentration and purification of enzymes and natural products. The technique of TPP was explored for the extraction of ursolic acid (UA) and oleanolic acid (OA) from O. sanctum leaves. The influence of various process parameters (pH, ammonium sulfate saturation, crude extract to t-butanol ratio, time and feed loading) on the extraction efficiency was investigated to get highest yield. The optimized conditions were found to be as follows: time – 120 min, pH – 7, ammonium sulfate saturation – 50% w/v, crude extract to t-butanol ratio – 1:1 and feed loading – 7.5% w/v. The highest yield obtained for UA and OA was 79.48% and 80.67% respectively under optimized conditions of TPP. Compared with TPP higher yield (83.36% and 85.58%) was obtained by ultrasound assisted TPP (UATPP) at 40 kHz and 180 W power and the time required was only 14 min as compared to 120 min of TPP. The extraction yield obtained was also compared with conventional solvent extraction and TPP-ultrasound was found to be an attractive technique for the extraction of UA and OA from O. sanctum leaves.     

Optimization of the Extraction of Anthocyanins from the Fruit Skin of Rhodomyrtus tomentosa (Ait.) Hassk and Identification of Anthocyanins in the Extract Using High-Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (HPLC-ESI-MS)

Anthocyanins are naturally occurring polyphenols that impart bright color to fruits, vegetables and plants. In this study, the extraction of anthocyanins from freeze-dried fruit skin of downy rose-myrtle (Rhodomyrtus tomentosa (Ait.) Hassk var. Gangren) was optimized using response surface methodology (RSM). Using 60% ethanol containing 0.1% (v/v) hydrochloric acid as extraction solvent, the optimal conditions for maximum yields of anthocyanin (4.358 ± 0.045 mg/g) were 15.7:1 (v/w) liquid to solid ratio, 64.38 °C with a 116.88 min extraction time. The results showed good fits with the proposed model for the anthocyanin extraction (R(2) = 0.9944). Furthermore, the results of high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) analysis of the anthocyanins extracted from the fruit skin of downy rose-myrtle revealed the presence of five anthocyanin components, which were tentatively identified as delphinidin-3-glucoside, cyanidin-3-glucoside, peonidin-3-glucoside, petunidin-3-glucoside and malvidin-3-glucoside.