Removal of Copper in Aqueous Solution by Apple Wastes

Abstract

Removal of copper from a solution was investigated to evaluate the cation-exchange capacities of apple residues from agricultural wastes. The effects of solution pH, ionic strength, co-ion, ligands, initial metal concentrations, and particle size of apple residues were studied. The optimal pH range for copper removal by apple residues was shown to be from pH 5.5 to 7.0, and the maximum percentage of copper removal was 91.2%. Increasing ionic strength, up to 0.1 N, has little effect on metal uptake. The presence of co-ions such as lead decreases the removal capacity of copper as expected. The presence of ligands, such as EDTA and ammonia, also reduces metal removal efficiency due to the formation of a metal-ligand complexation in solution. Equilibrium of copper sorption was established very rapidly initially and decreased markedly after 1 hour. Equilibrium isotherms of copper fit the Langmuir equation adequately. Column experiments showed that the dynamic capacity of chemically modified apple residues was four to five times higher than that of raw residues which contained acidic groups such as carboxylic and phenolic functional groups. The adsorbed copper ions were completely recovered with three bed volumes of 0.5 N HCl. Thus, modified apple residues could be applied successfully for metal removal from wastewater.     

Production of Citric Acid from Apple Pomace Enzymolyzed by Cellulase

Cellulase can evidently increase the content of glucose and has a significant effect on the production of citric acid from apple pomace by Aspergillus niger. Based on experiments, a cellulolytic enzyme named cellulase A6 was found able to produce about 170 g glucose from 1 kg dried apple pomace after 12 h reaction, with cellulase concentration of 20 U/g in the medium at 50℃, natural pH without pretreatment of alkali. Using the treated apple pomace as a liquid state substrate, Aspergillus niger-C selected out was able to produce about 256 g citric acid from 1 kg dried apple pomace at 35℃ in 3 d or 30℃ in 5 d with flask rotation speed of 210 r/min, and the conversion of citric acid could reach 80% based on the amount of sugar consumed.     

Sulphide inhibition of methanogenic activity at various pH levels at 55°C

The purpose of this study was to evaluate the toxic effect of sulphide on thermophilic methanogenic bacteria, pre-cultivated in UASB-reactors fed with and without sulphate, at 55°C and different pH levels. For granular sludge, precultivated in the presence of sulphate, the inhibition caused by hydrogen sulphide was dependent on the pH imposed. At alkaline pH the inhibitory effect of hydrogen sulphide was higher than at neutral or acidic pH. The effect of sulphide could not be described in terms of free hydrogen sulphide level only. For dispersed sludge, pre-cultivated in the absence of sulphate, the inhibition caused by free hydrogen sulphide was independent of the pH, and the toxic effect of sulphide could be described in terms of free hydrogen sulphide.     

Usefulness of solute elution from frozen matrix for freeze-concentration technique

A novel freeze-concentration method was proposed to use solute elution from a frozen matrix as a concentrating operation. A batch crystallizer was made up to freeze solution with a jacket cooler, and a rod heater was set at the centre of the crystallizer in order to make the solution contact with the frozen zone. Commercial apple juice was employed as a model liquid food, and the concentration behavior was investigated with the present apparatus. It was found that the concentration clearly increased with time, and the concentrate was recovered at desirable level if the temperature of the jacket and the heater were properly selected. In fact almost all the solute could be recovered from the original apple juice. The present method would mainly be governed by the solute elution from a frozen phase to a liquid phase, therefore, would not require complicated operation.     

橘黄酮的提取及其抑菌特性

采用乙醇浸提法从橘子皮中提取黄酮,通过正交试验确定提取的最佳条件为：70%乙醇为提取剂,固液比为1︰20(g/mL),提取温度是70℃,提取时间2h,在510nm处测定橘黄酮质量浓度为0.205g/L,从橘子皮中提取的黄酮干重得率为2.938mg/g。本实验探究橘黄酮的抑菌活性,采用牛津杯法测抑菌作用,结果表明,橘黄酮对金黄色葡萄球菌、大肠杆菌、黑曲霉、灰葡萄孢菌和黄枝孢菌均有抑制作用,铜和镁离子可分别增强橘黄酮对细菌和真菌的抑菌作用,低pH和低温可提高抑菌效果,且优化pH和温度的橘黄酮剂型降低了最小抑菌浓度（MIC）20%,对金黄色葡萄球菌、大肠杆菌、黑曲霉、灰葡萄孢菌和黄枝孢菌的抑菌作用分别提高了17%、27%、25%、28%、19%,高于对氯间二甲苯酚和甲基托布津的抑菌作用,特别是高于对细菌的抑菌作用。     

PORE FORMATION IN SELECTED FOODS AS A FUNCTION OF SHELF TEMPERATURE DURING FREEZE DRYING

Porosity and density of abalone, potato, apple, and two varieties of dates were investigated as a function of shelf temperature during freeze-drying. The pore formation in food materials showed two distinct trends when shelf temperatures were maintained at constant level between -45 to 15°C. The materials in a group I (i.e., abalone, potato, and brown date) showed a decreasing trend, whereas in the group II (i.e., apple and yellow date) showed an increasing trend in pore formation. The results found in this study could not be explained alone by the glass transition concept.     

Quality of Infrared Dried Apple Slices

The aim of this work was to compare quality of apple slices dried by near infrared heating and convection in such parameters in which final material temperature in both methods was similar. The infrared drying was done at the distance between the emitters (with total power of 7.875 kW/m²) and heated surface equal to 10, 20, and 30 cm. Flow of ambient air was set at 0.5, 1.0, and 1.5 m/s. Convective drying was done in the same dryer using hot air at 65 and 75°C flowing with velocity 1.5 m/s. Quality attributes measured in this work included: color, kinetics of water adsorption, mechanical properties, and microstructure. It was stated that the changes in chromaticity coefficients are not dependent on the mode of heat supply, but are related to the final temperature of the dried material. Luminance of dried apple slices was affected by temperature as well. Final material temperature, not the way heat is supplied, could be responsible for the differences in the ability of dry apple slices to adsorb water. The similar correlation was stated for mechanical properties: slope of initial part of the deformation curve (crispness), breaking force (hardness or crispness), and work of breaking were all related to the final material temperature. Microstructure of convective and infrared dried apple were different but it seems that the drying rate can be responsible for observed differences.     

三元铁基离子液体-乙醇-水体系的湿法烟气脱硫性能研究(英文)

Fe-based ionic liquid(Fe-IL) was synthesized by mixing FeCl3?6H2O and 1-butyl-3-methylimidazolium chloride [Bmim]Cl in this paper.The phase diagram of a ternary Fe-IL,ethanol and water system was investigated to construct a ternary desulfurization solution for wet flue gas desulfurization.The effects of flow rate and concen-tration of SO2,reaction temperature,pH and Fe-IL fraction in aqueous desulfurization solution on the desulfuriza-tion efficiency were investigated.The results shows that the best composition of ternary desulfurization solution of Fe-IL,ethanol and water is 1︰1.5︰3 by volume ratio,and pH should be controlled at 2.0.Under such conditions,a desulfurization rate greater than 90% could be obtained.The product of sulfuric acid had inhibition effect on the wet desulfurization process.With applying this new ternary desulfurization solution,not only the catalyst Fe-IL can be recycled and reused,but also the product sulfuric acid can be separated directly from the ternary desulfurization system.     

Uptake of organic acids byClostridium acetobutylicum B18 under controlled pH and reduced butanol inhibition

Uptake of organic acids byClostridium acetobutylicum B18 was studied at controlled pH and under reduced butanol inhibition conditions. A pervaporative membrane module was placed in the fermentor to remove butanol from the fermentation broth. Uptake of added butyric acid followed zero order kinetics at pH 4.75 and first order kinetics at pH 5.75. At pH 5.25 the kinetic order shifted from zero to first order as the butyric acid was taken up. At the point of order shift undissociated butyric acid (UBA) concentration was approximately 0.5 g/L. Unlike butyric acid, uptake of acetic acid followed first order kinetics regardless of pH. The difference in acid uptake kinetics could be explained by the combined effect of acid diffusion across the cell membrane and intracellular enzymatic reaction. The acid concentration for kinetic order shift seemed to be dependent upon pH and the kind of the acid used. Glucose was consumed simultaneously with added acids. Both butyric and acetic acids were taken up simultaneously but the rate was faster for butyric acid. Added butyric acid was completely assimilated whereas acetic acid uptake was incomplete.     

PORE FORMATION IN SELECTED FOODS AS A FUNCTION OF SHELF TEMPERATURE DURING FREEZE DRYING

ABSTRACT

Porosity and density of abalone, potato, apple, and two varieties of dates were investigated as a function of shelf temperature during freeze-drying. The pore formation in food materials showed two distinct trends when shelf temperatures were maintained at constant level between ?45 to 15°C. The materials in a group I (i.e., abalone, potato, and brown date) showed a decreasing trend, whereas in the group II (i.e., apple and yellow date) showed an increasing trend in pore formation. The results found in this study could not be explained alone by the glass transition concept.     

低pH对高负荷厌氧氨氧化反应器性能的影响

厌氧氨氧化(ANAMMOX)工艺是一种新型生物脱氮工艺,具有良好的应用前景。但ANAMMOX以亚硝酸盐为电子受体,需与短程硝化(SHARON)联合应用。SHARON是一个产酸反应,而ANAMMOX是一个嗜碱反应,后者会受前者的干扰。试验结果表明,低进水pH冲击对高负荷(总氮负荷9.3～27.7kg·(m3·d)-1)ANAMMOX反应器效能具有显著影响。在一定范围内,提高总氮负荷可削弱低进水pH冲击的影响,设置回流也可缓解低进水pH冲击所致的负面效应。低进水pH冲击对厌氧氨氧化反应器效能的影响主要来自低pH与游离亚硝酸毒性的双重抑制,其中低pH的直接作用对反应器效能的影响更大。低进水pH冲击所致的反应器效能恶化可采用停车自然恢复、清水冲洗恢复和外加碱液恢复。     

Genome-Wide Analysis of the Apple CBL Family Reveals That Mdcbl10.1 Functions Positively in Modulating Apple Salt Tolerance

Abiotic stresses are increasingly harmful to crop yield and quality. Calcium and its signaling pathway play an important role in modulating plant stress tolerance. As specific Ca²⁺ sensors, calcineurin B-like (CBL) proteins play vital roles in plant stress response and calcium signaling. The CBL family has been identified in many plant species; however, the characterization of the CBL family and the functional study of apple MdCBL proteins in salt response have yet to be conducted in apple. In this study, 11 MdCBL genes were identified from the apple genome. The coding sequences of these MdCBL genes were cloned, and the gene structure and conserved motifs were analyzed in detail. The phylogenetic analysis indicated that these MdCBL proteins could be divided into four groups. The functional identification in Na⁺-sensitive yeast mutant showed that the overexpression of seven MdCBL genes could confer enhanced salt stress resistance in transgenic yeast. The function of MdCBL10.1 in regulating salt tolerance was also verified in cisgenic apple calli and apple plants. These results provided valuable insights for future research examining the function and mechanism of CBL proteins in regulating apple salt tolerance.     

Multiple forms of the enzyme glycerophosphodiesterase are present in human brain

Brain levels of glycerophosphodiesters, including glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE), are altered in many human central nervous system disorders. Although much information is available on the enzymes responsible for the formation of these phospholipid metabolites, little information is known regarding their catabolism, by glycerophosphodiesterases, in human brain. In both autopsied and biopsied temporal cortex, a phosphocholine-producing lycerophosphodiesterase activity was observed. In the presence of 1 mM EDTA, the enzyme possessed a pH optimum of 9.0, while the addition of 5 mM zinc acetate shifted the pH optimum to 10.5. When assayed at pH 9.0 in the absence of zinc acetate, the K_m and V_max were 104±2 μM and 77±18 nmol/h/mg protein, respectively, while assaying at pH 10.5 in the presence of 5 mM zinc acetate yielded a K_m of 964±56 μM, and a V_max of 534±114 nmol/h/mg protein. Furthermore, whereas submillimolar concentrations of zinc acetate stimulated the activity of the enzyme in a dose-dependent manner when assayed at pH 10.5 (EC₅₀=20.3±3.0 μM), this did not result in a reciprocal inhibition of glycerophosphocholine phosphodiesterase (GPC PD) activity when assayed at a more acidic pH. This may suggest that human brain contains two phosphocholine-producing GPC PD activities, differentiable by their sensitivity to zinc ions. An activity capable of hydrolyzing GPE to form phosphoethanolamine could not be detected in either biopsied or autopsied brain. However, a choline/ethanolamine-producing glycerophosphodiesterase activity could be readily detected in biopsied, but not autopsied brain. This novel enzyme possessed a neutral pH optimum and was dependent upon divalent cations for activity. In conclusion, human brain contains at least two different glycerophosphodiesterases, a phosphocholine, and a choline/ethanolamine-producing activity, only one of which can be detected in autopsied tissue. The results of previous studies measuring brain glycerophosphodiesterase activity in degenerative brain conditions may need to be reevaluated in the light of these observations.     

甲氰菊酯和辛硫磷混合剂在苹果及土壤中的残留分析

报道了甲氰菊酯、辛硫磷及其混合剂在苹果及土壤中快速、简单残留分析方法。农药用溶剂提取,经液－－液分配和柱层析后,分别用气相色谱电子捕获检测器（ＥＣＤ）或火焰光度检测器（ＦＰＤ）检测。两农药在苹果和土壤中三个浓度的添加回收弦均达到农药残留分析的要求。     

富士苹果果皮中花青素含量测定

苹果中花青素的主要成分为矢车菊素-3-半乳糖苷。文章研究了苹果中矢车菊素-3-半乳糖苷提取的条件与测定方法。提取条件为:以1.00%盐酸甲醇溶液为提取溶液,在温度40℃下超声提取60min。在优化的条件下,首次对北京昌平、陕西白水、山东烟台等3个不同地区长富2号苹果果皮的矢车菊素-3-半乳糖苷含量进行测定。在3个地区的9个果园的样品矢车菊素-3-半乳糖含量在4.51～14.7μg/cm2之间,其中陕西白水苹果含量最高,平均含量达14.0μg/cm2。     

Computer vision for bulk volume estimation of apple slices during drying

The accuracy of imaging for bulk volume estimation of apple slices in the process of drying at temperatures from 40 to 80°C was investigated and compared with physical caliper measurements. The initial hypothesis was to estimate bulk volume of cylindrically shaped apple slices from diameter and thickness imaging. Imaging of diameter showed strong agreement with caliper measurements throughout the entire drying process, however imaging of thickness was not accurate due to the irregular shrinkage and bending phenomena. A linear model reflecting the relationship between diameter and bulk volume was developed and validated at temperatures of 40, 60, and 80°C. It showed good correlation between imaging diameter and bulk volume changes in the range of moisture contents from 9.1 to 0.25?g/g. The relative percentage error of the prediction model was approximately 6.45%, which suggests that imaging can be used as a robust tool for bulk volume estimation of apple slices during convective drying.     

Modeling and Predicting the Drying Kinetics of Apple and Pear: Application of the Weibull Model

Drying data of apple and pear at 40, 50, 60, 70, and 80°C were described by the Weibull model and it was observed that the shape parameter of the Weibull model did not depend on temperature. Therefore the reduced Weibull model with fixed shape parameter was proposed as the primary model to describe drying data with a slight loss of goodness-of-fit. Temperature dependence of time-parameter (time necessary to reduce the initial moisture ratio by 90%) could be described by two ad hoc models as the secondary models. Predictions using the integrated models almost perfectly agreed with the experimental drying data of apple at 45 and 65°C and of pear at 55 and 75°C, respectively. Kinetic analyses with published data have shown that the reduced Weibull model can also successfully be used to describe the drying data of certain fruits. Time-parameters tabulated in this study can be useful for food manufacturers.     

Valorization of some lignocellulosic agro‐industrial residues to obtain biopolyols

BACKGROUND: The valorization of renewable and abundant resources (date seed, olive stone, corncob, rapeseed cake and apple pomace) from agro‐industrial activities was performed by mild liquefaction using polyhydric alcohols to obtain biopolyols that constitute an attractive choice for polyurethanes and other industrial sectors. RESULTS: The results indicated that liquefaction yields above 90% were obtained for almost all resources (except for rapeseed cake residue) at a minimum ratio of 0.25 mass/liquefying solvent by using weight ratio polyethylene glycol:glycerol:sulphuric acid of 80:20:3, at quite reasonable reaction temperature and time; 160 °C and 60 min, respectively. The values determined for hydroxyl number and viscosity in polyols from date seeds were found to be in the range of those typical of commercial polyols used in polyurethane foam production. On the other hand, the multifunctional liquids from apple pomace, olive stone, corncob and rapeseed cake could be used not only as precursor in polyurethane production but also for replacement of a certain amount of the polyhydroxy alcohol in polyester synthesis. CONCLUSION: The results obtained demonstrated the viability of using polyhydric alcohol liquefaction to generate bio‐based polyols, thus opening new avenues of exploitation of these by‐products. Copyright © 2011 Society of Chemical Industry     

Selective Transport of Histamine from a Mixture of Histidine and Histamine by the Use of Organic Liquid Membrane Systems

Abstract

The transport behaviors of histidine (His) and its related compounds through organic liquid membranes were examined. The organic liquid membranes system was composed of two aqueous phases (Phases I and II) which were put on both sides of an organic layer containing a carrier. Chloroform and sodium di-2-ethylhcxyl sulfosuccinate (AOT) were used as the organic layer and the carrier, respectively. No transport reaction occurred without the carrier. The amounts of removal into the organic layer increased with an increase in the concentration of AOT up to 5 mM and maintained at higher concentrations. His and carnocine, which possess the carboxyl group, could be removed into the organic layer from Phase I at pH 4–5 but could not be removed at pH values higher than 5. On the other hand, histamine (Hm) and histidinol, which lack the carboxyl group, could be removed into the organic layer from Phase I at pH 7. Also, the compounds in the organic layer could be removed into Phase II at pH 10. On the basis of these results, the separation of Hm from the Hm-His mixture occurred with pH 7 in Phase I and pH 10 in Phase II through the organic layer containing 5 mM of AOT. Hm was effectively transported from Phase I to Phase II through an organic layer using some molar ratios (1, 50, and 100) of mixtures (molar ratio = concentration of His/concentration of Hm).     

端羧基超支化型绿色阻垢剂的制备及阻垢性能

采用熔融聚合法以木糖醇为中心核,成功制备了端羧基超支化型绿色阻垢剂,通过红外光谱仪和核磁共振对其结构进行了表征,采用静态阻垢法探讨了阻垢剂的添加量、水样环境的pH和水样温度对其阻碳酸钙和硫酸钙的能力。结果表明,端羧基超支化型绿色阻垢剂在较宽的温度范围及水体环境的pH=6~9时,对钙垢（CaCO₃和CaSO₄）均具有优异的阻垢性能,且当阻垢剂添加量为24 mg/L时,其对碳酸钙垢的阻垢效率达到了91.6 %;当阻垢剂的添加量为15 mg/L时,其对硫酸钙的阻垢效率达到了94.7 %;端羧基超支化型绿色阻垢剂的使用,均能极大程度地降低了钙垢晶体的规整性,且对于碳酸钙垢而言,端羧基超支化型绿色阻垢剂的使用还可以使碳酸钙垢的晶格发生畸变,从而达到分散阻垢的目的。