电渗析技术在反渗透浓水再利用过程中的研究

东营市港城热力有限公司以自来水为水源采用全膜法水处理技术制备超纯水,过程中反渗透浓水电导率在3500μs/cm左右,约占总进水量的30%。为了实现资源的回收利用,本论文拟采用电渗析系统对反渗透浓水进行脱盐。试验结果表明电渗析技术可以成功的将反渗透浓水中的离子脱除。在试验考察的条件中,均可以在15 min内成功地将浓水中的电导率降低到反渗透进水水质要求。且20 V,15 L/h的试验条件下,膜组件能耗最低为0.1816 w·h·L-1。     

Electrodialysis Application of the Ultrafiltration Permeate of Milk Before and After Reverse Osmosis

Ultrafiltered (UF) milk permeate was concentrated by reverse osmosis (RO). UF and UF + RO samples were then desalted by electrodialysis (ED) to three levels of desalination: 1, 2.5, and 4 % of ash in the dry matter. Ions were analyzed by a new high‐performance liquid chromatography method, which enables simultaneous estimation of cations and anions. ED of UF permeate has some advantages over that of UF + RO samples, including a shorter ED time and a higher average salt flow rate, but RO treatment of UF permeate before ED enables the processing of larger volumes of UF permeate. Therefore, ED of milk permeate, particularly after RO, improves the handling characteristics and may offer advantages for further processing of secondary dairy products.     

真空膜蒸馏浓缩反渗透浓盐水的工艺研究

分别采用聚乙烯、聚丙烯微孔膜对反渗透海水淡化浓盐水进行真空膜蒸馏的研究。考察了膜下游真空度、浓盐水温度、浓度、流速对膜通量及截留率的影响。结果表明,真空度增大,膜通量和截留率呈增长趋势。料液温度升高,膜通量增加,截留率呈减少趋势。料液流速增加会使通量增加,截留率呈减少趋势,但影响相对不大。随着料液浓度的增加,膜的通量下降,截留率基本保持不变。本实验条件下最大截留率可达99．99％,表明利用真空膜蒸馏技术可有效实现反渗透海水淡化浓盐水的浓缩。     

单段式排列和二段式排列反渗透系统在印制线路板废水回用工程的实例及总结

文章介绍了单段式排列和二段式排列反渗透系统在印制线路板废水回用的实例,通过两组系统在同等条件下的对比,结果表明:在进水TDS≤500 mg.L-1,系统回收率介于75%~80%,温度≤30℃的条件下,系统产水水质均能满足电导率≤100μs.cm-1的回用要求。单段式排列在能耗、透盐率方面比二段式高,但由于采用了短流程大循环设计,化学清洗周期长;如果能延长膜元件的更换周期,单段式的设计可能会更为经济;至于何种设计更为经济,应综合分析更换周期差和水质需求等因素。     

Benefits of High Shear Rate Dynamic Nanofiltration and Reverse Osmosis: A Review

Dynamic filtration permits to increase permeate flux and membrane selectivity, as compared to crossflow filtration. It consists in creating the shear rate by a disk rotating near the membrane or by rotating or vibrating the membrane, avoiding the need for large feed flow rates. The benefits of high shear rates are important in microfiltration and ultrafiltration, but they are even larger in nanofiltration (NF) and reverse osmosis (RO). The reduction in concentration polarization by high shear rate can increase the permeate flux by a ratio of 3 to 5 as compared to a spiral wound module and augments also solutes rejection as their diffusive transfer through the membrane is reduced by a factor of 4 to 5. This paper describes available dynamic filtration modules suitable for NF and RO and reviews the treatment of dairy effluents, desalination, oil emulsions, and oligosaccharides recovery using a rotating disk module or a VSEP module with vibrating membranes and compares their performances with those of crossflow filtration. These examples confirm the high potential of dynamic NF and RO when operated at high shear rate and high TMP. The availability of large rotating NF ceramic membrane disks could permit the fabrication of highly efficient modules.     

High-Pressure Reverse Osmosis for Industrial Water Recycling: Permeate-Sided Pressure Drop as Performance-Limiting Factor

In the chemical industry large amounts of saline wastewater occur. Its disposal into rivers is a considerable burden to the ecosystem. To strive for a circular economy and enable a viable raw material recycling, energy-efficient concentration processes are requisite. High-pressure reverse osmosis meets this criterion, but its industrial application demands suitable membrane elements that withstand the exceptional operation conditions and provide sufficient performance. Hence, new requirements regarding the design of spiral-wound elements arise. To identify those, specific performance-limiting effects need a better understanding.     

反渗透处理黄原胶发酵废水的实验研究

在一自制的高压反渗透评价池内,对反渗透法处理黄原胶发酵废水过程进行研究,考察了反渗透的操作压力,温度,膜面流速及废水浓度对水的透过通量及脱盐率的影响,并对膜的清洗作了进一步的研究。     

活性炭、有机物污染的反渗透膜运行的探讨

中盐株洲化工集团公司动力厂反渗透装置的膜受到活性炭和有机物污染后，产水量急剧下降。通过认真分析和试验，查明了原因，采取了应对措施，保证了系统正常运行。     

Inland Treatment of the Brine Generated from Reverse Osmosis Advanced Membrane Wastewater Treatment Plant Using Epuvalisation System

The reverse osmosis (RO) brine generated from the Al-Quds University wastewater treatment plant was treated using an epuvalisation system. The advanced integrated wastewater treatment plant included an activated sludge unit, two consecutive ultrafiltration (UF) membrane filters (20 kD and 100 kD cutoffs) followed by an activated carbon filter and a reverse osmosis membrane. The epuvalisation system consisted of salt tolerant plants grown in hydroponic channels under continuous water flowing in a closed loop system, and placed in a greenhouse at Al-Quds University. Sweet basil (Ocimum basilicum) plants were selected, and underwent two consecutive hydroponic flowing stages using different brine-concentrations: an adaptation stage, in which a 1:1 mixture of brine and fresh water was used; followed by a functioning stage, with 100% brine. A control treatment using fresh water was included as well. The experiment started in April and ended in June (2012). At the end of the experiment, analysis of the effluent brine showed a remarkable decrease of electroconductivity (EC), PO₄³⁻, chemical oxygen demand (COD) and K⁺ with a reduction of 60%, 74%, 70%, and 60%, respectively, as compared to the influent. The effluent of the control treatment showed 50%, 63%, 46%, and 90% reduction for the same parameters as compared to the influent. Plant growth parameters (plant height, fresh and dry weight) showed no significant difference between fresh water and brine treatments. Obtained results suggest that the epuvalisation system is a promising technique for inland brine treatment with added benefits. The increasing of channel number or closed loop time is estimated for enhancing the treatment process and increasing the nutrient uptake. Nevertheless, the epuvalisation technique is considered to be simple, efficient and low cost for inland RO brine treatment.     

反渗透技术在电厂锅炉给水处理中的应用

结合化学水处理工艺设计及运行实例,浅谈了如何正确选择水处理系统,以及反渗透技术在电厂锅炉补给水处理系统的应用和应注意的问题。同时对各类水处理工艺进行了综合经济分析比较,提出了自己观点。     

Spiral Wound Reverse Osmosis Modules Decomposition into Elementary Units by Analyzing Stimulus Response Experiments: Characterization of the Solute Transfer across the Membrane

A model for spiral wound reverse osmosis modules FT30‐4040 has been developed by analyzing stimulus response experiments. Perfect mixing cells represent edthe flow and dispersed plug flow represented the membrane. The model was based on phenomenological equations describing the permeation. The identification of the Peclet number and the space‐time characterizing each dispersed plug flow led to the estimation of the tracer dispersion coefficient in the membrane. Ones new and two used composite reverse osmosis modules were tested. The decrease of the rejection properties of the used membranes was linked to the apparition of new plug flows with high dispersion coefficients within the membrane.     

Parameters of the Mass-Transfer Through the Reverse Osmosis Polysulphonamid Membrane of the Binary Aquatic Solutions of Salts

Abstract

Experimental data of mass transfer through the reverse osmosis polysulfonmide membrane of binary aqueous solutions of salts are compared with the predictions of phenomenological equations of mass transfer.     

Evaluation of Selective Sorbents for the Extraction of Valuable Metal Ions (Cs,Rb, Li,U) from Reverse Osmosis Rejected Brine

Abstract

Three commercially available sorbents/exchangers (namely CsTreat, ZrP, and S910) were evaluated under column conditions for the extraction of four metals (Cs(I), Rb(I), Li(I), and U(VI)) from a brine rejected by a Seawater Reverse Osmosis plant. From the obtained breakthrough curves and periodic analysis of the influent and effluent, the uptake capacities of the materials were quantified. The fixation of the target metal onto the sorbents was investigated also by SEM-EDX and FTIR-ATR analysis. The results showed that CsTreat displayed a high sorption capacity of Rb(I) and a fairly high sorption capacity of Cs(I), as the resin S910 showed of U(VI), while ZrP proved to be ineffective for the retention of Li(I).     

Effect of Cross-flow Velocity on the Critical Flux of Ceramic Membrane Filtration as a Pre-treatment for Seawater Desalination

Pre-treatment, which supplies a stable, high-quality feed for reverse osmosis (RO) membranes, is a critical step for successful operation in a seawater reverse osmosis plant. In this study, ceramic membrane systems were employed as pre-treatment for seawater desalination. A laboratory experiment was performed to investigate the effect of the cross-flow velocity on the critical flux and consequently to optimize the permeate flux. Then a pilot test was performed to investigate the long-term performance. The result shows that there is no significant effect of the cross-flow velocity on the critical flux when the cross-flow velocity varies in laminar flow region only or in turbulent flow region only, but the effect is distinct when the cross-flow velocity varies in the transition region. The membrane fouling is slight at the permeate flux of 150 L穖^-2穐^-1 and the system is stable, producing a high-quality feed (the turbidity and silt density index are less than 0.1 NTU and 3.0, respectively) for RO to run for 2922.4 h without chemical cleaning. Thus the ceramic membranes are suitable to filtrate seawater as the pre-treatment for RO.     

Reverse osmosis for the production of aromatic concentrates from mussel cooking juices: a technical assessment

An industrial mussel cooking juice was concentrated by reverse osmosis (11-fold) after a desalination step by electrodialysis in order to produce a natural aroma concentrate and a clean water stream. The concentrate quality was evaluated by a trained sensory panel (triangular tests, sensory profiles) and by gas chromatography coupled with mass spectrometry (GC-MS). About 34% of the aroma compounds were lost, inducing a slight modification of the sensory profile of the concentrate compared to the unprocessed mussel cooking juice one. This modification was not obstructing because this concentrate can be used in industrial recipe with a routine rate (10–15%) for natural aroma concentrates. In addition, as a result of this process the polluting load of the permeate was strongly reduced. The chemical oxygen demand was below the discharge standards.     

Whole-Cell Biocatalysis in Seawater: New Halotolerant Yeast Strains for the Regio- and Stereoselectivity Reduction of 1-Phenylpropane-1,2-Dione in Saline-Rich Media

The application of green chemistry concepts in catalysis has considerably increased in recent years, and the interest in using sustainable solvents in the chemical industry is growing. One of the recent proposals to fall in line with this is to employ seawater as a solvent in biocatalytic processes. This involves selecting halotolerant strains capable of carrying out chemical conversions in the presence of the salt concentrations found in this solution. Recent studies by our group have revealed the interest in using strains belonging to Debaryomyces and Schwanniomyces for catalytic processes run in this medium. In the present work, we select other yeasts based on their halotolerance to widen the scope of this strategy. We consider them for the monoreduction of 1-phenylpropane-1,2-dione, a well-characterized reaction that produces acyloin intermediates of pharmaceutical interest. The results obtained herein indicate that using seawater as a solvent for this reaction is possible. The best ones were obtained for Saccharomyces cerevisiae FY86 and Kluyveromyces marxianus, for which acyloins with different stereochemistry were obtained with good to excellent enantiomeric excess.     

Bone Marrow Microenvironment as a Source of New Drug Targets for the Treatment of Acute Myeloid Leukaemia

Acute myeloid leukaemia (AML) is a heterogeneous disease with one of the worst survival rates of all cancers. The bone marrow microenvironment is increasingly being recognised as an important mediator of AML chemoresistance and relapse, supporting leukaemia stem cell survival through interactions among stromal, haematopoietic progenitor and leukaemic cells. Traditional therapies targeting leukaemic cells have failed to improve long term survival rates, and as such, the bone marrow niche has become a promising new source of potential therapeutic targets, particularly for relapsed and refractory AML. This review briefly discusses the role of the bone marrow microenvironment in AML development and progression, and as a source of novel therapeutic targets for AML. The main focus of this review is on drugs that modulate/target this bone marrow microenvironment and have been examined in in vivo models or clinically.     

A New Strategy for the Preparation of Terephthalic Acid by the Aerobic Oxidation of p‐Xylene using N‐Hydroxyphthalimide as a Catalyst

A new methodology for the production of terephthalic acid ( 3 ) by the aerobic oxidation of p‐xylene ( 1 ) using a combined catalytic system of N‐hydroxyphthalimide (NHPI)/Co(OAc) ₂/Mn(OAc) ₂was developed. The oxidation of 1 under a dioxygen atmosphere in the presence of a catalytic amount of NHPI/NHPI(OAc) ₂/Mn(OAc) ₂at 100 °C for 14 h afforded terephthalic acid in 82% yield. Removal of Mn(OAc) ₂ from the catalytic system resulted in considerable reduction in the yield of 3 . When the oxidation of 1 was carried out under a pressure of air (30 atm) at 150 °C, the reaction was completed within 3 h to give 3 in 84% yield. The oxidation of p‐toluic acid ( 2 ), which can be prepared by the oxidation of 1 using the NHPI/NHPI(OAc) ₂ system at room temperature, by the NHPI/NHPI(OAc) ₂/Mn(OAc) ₂system under pressure of air (30 atm) at 150 °C gave 3 in 95% yield. N‐Acetoxyphthalimide (NAPI) was found to require a lower catalyst loading than NHPI, but oxidation with NAPI was slower. Thus, the oxidation of 1 catalyzed by NAPI (5 mol %)/Co(OAc) ₂ (0.5 mol %)/Mn(OAc) ₂ (0.5 mol %) under a dioxygen atmosphere (1 atm) in acetic acid at 100 °C gave 3 in 80% yield.     

Porcine Small Intestinal Submucosa (SIS) as a Suitable Scaffold for the Creation of a Tissue-Engineered Urinary Conduit: Decellularization,Biomechanical and Biocompatibility Characterization Using New Approaches

Bladder cancer (BC) is among the most common malignancies in the world and a relevant cause of cancer mortality. BC is one of the most frequent causes for bladder removal through radical cystectomy, the gold-standard treatment for localized muscle-invasive and some cases of high-risk, non-muscle-invasive bladder cancer. In order to restore urinary functionality, an autologous intestinal segment has to be used to create a urinary diversion. However, several complications are associated with bowel-tract removal, affecting patients’ quality of life. The present study project aims to develop a bio-engineered material to simplify this surgical procedure, avoiding related surgical complications and improving patients’ quality of life. The main novelty of such a therapeutic approach is the decellularization of a porcine small intestinal submucosa (SIS) conduit to replace the autologous intestinal segment currently used as urinary diversion after radical cystectomy, while avoiding an immune rejection. Here, we performed a preliminary evaluation of this acellular product by developing a novel decellularization process based on an environmentally friendly, mild detergent, i.e., Tergitol, to replace the recently declared toxic Triton X-100. Treatment efficacy was evaluated through histology, DNA, hydroxyproline and elastin quantification, mechanical and insufflation tests, two-photon microscopy, FTIR analysis, and cytocompatibility tests. The optimized decellularization protocol is effective in removing cells, including DNA content, from the porcine SIS, while preserving the integrity of the extracellular matrix despite an increase in stiffness. An effective sterilization protocol was found, and cytocompatibility of treated SIS was demonstrated from day 1 to day 7, during which human fibroblasts were able to increase in number and strongly organize along tissue fibres. Taken together, this in vitro study suggests that SIS is a suitable candidate for use in urinary diversions in place of autologous intestinal segments, considering the optimal results of decellularization and cell proliferation. Further efforts should be undertaken in order to improve SIS conduit patency and impermeability to realize a future viable substitute.