Enhanced Water Recovery from Membrane RO Concentrate PDF Download

Author: Yoram Cohen
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :

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Author:
Publisher:
ISBN:
Category : Reverse osmosis
Languages : en
Pages : 16

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Author: Tae Lee
Publisher:
ISBN:
Category :
Languages : en
Pages : 210

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Book Description
Improvements in system and process design has enabled reverse osmosis (RO) membrane technology to gain foothold in various water treatment and desalination applications. However, energy consumption and mineral scaling on membrane surfaces remain impediments to high recovery operation of RO desalination. Accordingly, research efforts have been devoted to process optimization to improve permeate water productivity, reduce energy cost, and mitigate membrane mineral scaling. In this regard, RO concentrate recycling is an effective approach for enhancing product water recovery, reducing system footprint, and lowering installation as well as operating costs of RO desalination systems and plants. Energy consumption and membrane mineral scaling propensity in RO processes are impacted primarily by the osmotic pressure magnitude and the level of supersaturation of mineral scalants at the membrane surface, respectively, which are, in turn, governed by the operational strategy. Optimization of RO processes with concentrate recycle require fundamental models of RO processes with concentrate recycle under both steady and unsteady-state operation, To date, only simple models have been proposed which are of limited applicability to practical systems given the use of various simplifying assumptions of complete energy recovery, neglect of the efficacy of concentrate flushing in unsteady-state semi-batch RO (SBRO), and omission of concentration polarization. Previous studies have not provided experimental data to corroborate conclusions regarding system performance based on oversimplifications. Moreover, SBRO operation was not assessed relative to steady state RO (SSRO) with partial recycle (SSRO-PR) which is also suitable for high recovery operation with a small footprint. Accordingly, in the present work a fundamental quantitative modeling framework was developed and implemented for the design and operation of SSRO-PR and SBRO. Modeling RO desalting, including at the limit of the thermodynamic restriction, was undertaken to evaluate the minimum energy consumption as a function of product water recovery. SBRO process analysis revealed a significant increase in the salinity range during the RO filtration period and a progressive rise in the initial filtration period salinity until the stable cycle-to-cycle operation is reached. SBRO performance is highly dependent on the efficacy of concentrate discharge and flushing during the SBRO flushing period. For the condition of concentrate flushing under ideal plug flow, energy consumption in SBRO was assessed to be lower than for single-pass RO (SPRO) operation at the same level of overall product water recovery. However, for the practical range of expected concentrate flushing efficacy energy consumption in SBRO could be significantly above that which would be attained in SPRO. Using the direct real-time membrane surface optical imaging mineral scaling was experimentally evaluated in both SBRO and SSRO-PR pilot systems, with respect to the efficacy of concentrate flushing with the undersaturated raw feed water, at given levels of supersaturation or product water recovery. The predicted RO element feed stream osmotic pressure and solution supersaturation levels (for the target mineral scalant) at the membrane surface, for a given product water recovery, were higher on average in SBRO relative to SSRO-PR as corroborated by experimental data. The experimental data revealed mineral scaling propensity, which was significantly higher in multi-cycle SBRO operation, relative to SSRO-PR at the same water recovery. However, the rates of crystal nucleation and growth were similar at when both systems are compared at the same level of average supersaturation, although the product water recovery was lower in SBRO compared to SSRO-PR. The present theoretical modeling framework, validated by experimental data, provide a fundamental approach to assessing the performance of SBRO and SSRO-PR desalting systems with respect to energy consumption and mineral scaling propensity. The presented approach provides the means necessary for optimizing these low footprint technologies for high recovery RO desalination.

Author: Gautam Patwardhan
Publisher:
ISBN:
Category : Nanofiltration
Languages : en
Pages :

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Author: Despo Fatta-Kassinos
Publisher: Springer
ISBN: 3319238868
Category : Technology & Engineering
Languages : en
Pages : 313

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This volume offers a detailed overview of currently applied and tested wastewater treatment technologies and the integration of advanced processes to remove trace organic contaminants and microorganisms. It discusses the potential of enhanced biological treatment to produce effluent suitable for reuse, new processes for urban wastewater disinfection and the reduction of antibiotic resistant bacteria, as well as the effect of advanced oxidation processes on wastewater microbiome and chemical contaminants. It also presents membrane bioreactors, moving bed bioreactors, light and solar driven technologies, ozonation and immobilised heterogeneous photocatalysis and provides an evaluation of the potential of constructed wetlands integrated with advanced oxidation technologies to produce wastewater safe for reuse. Furthermore, the volume discusses water reuse issues and standards, the status of membrane bioreactors applications, and the treatment of reverse osmosis concentrate for enhanced water recovery during wastewater treatment. Finally, it presents recent developments in potable water reuse and addresses various important issues in this framework, like the proper protection of public health, reliability and monitoring. This volume is of interest to experts, scientists and practitioners from various fields of research, including analytical and environmental chemistry, toxicology and environmental and sanitary engineering, as well as treatment plant operators and policymakers.

Author: Rajindar Singh
Publisher: Elsevier
ISBN: 0444633162
Category : Technology & Engineering
Languages : en
Pages : 492

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Emerging Membrane Technology for Sustainable Water Treatment provides the latest information on the impending crisis posed by water stress and poor sanitation, a timely issue that is one of the greatest human challenges of the 21st century. The book also discusses the use of membrane technology, a serious contender that can be used to confront the crisis on a global scale, along with its specific uses as a solution to this escalating problem. - Provides a unique source on membrane technology and its application for water treatment - Focuses on technologies designed for the treatment of seawater and brackish water - Highlights the most economically and environmentally friendly membrane technologies - Lists various technologies and emphasizes their link to renewable energy, energy efficiency, nanotechnology, reuse, and recycle

Author: Anil K. Pabby
Publisher: CRC Press
ISBN: 1003811574
Category : Science
Languages : en
Pages : 601

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The third edition of the Handbook of Membrane Separations: Chemical, Pharmaceutical, Food, and Biotechnological Applications provides a comprehensive discussion of membrane applications. Fully updated to include the latest advancements in membrane science and technology, it is a one-of-its-kind overview of the existing literature. This fully illustrated handbook is written by experts and professionals in membrane applications from around the world. Key Features: Includes entirely new chapters on organic solvent-resistant nanofiltration, membrane condensers, membrane-reactors in hydrogen production, membrane materials for haemodialysis, and integrated membrane distillation Covers the full spectrum of membrane technology and its advancements Explores membrane applications in a range of fields, from biotechnological and food processing to industrial waste management and environmental engineering This book will appeal to both newcomers to membrane science as well as engineers and scientists looking to expand their knowledge on upcoming advancements in the field.

Author: Jack Lei
Publisher:
ISBN:
Category :
Languages : en
Pages : 73

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Reverse osmosis (RO) desalination of inland brackish water can replenish dwindling water supplies in various regions around the world. However, successful implementation of RO technology requires high product water recovery (>85%) in order to minimize the volume of generated concentrate brine. Therefore, brine management is a critical aspect of inland water desalination. At high water recovery, dissolved mineral salts (e.g. CaSO4, CaCO3) may concentrate above their solubility limits and may crystallize, potentially blocking or damaging RO membrane surfaces, reduce water permeate flux, and shorten membrane life. Therefore, it is essential to reduce the propensity for mineral scaling in order to increase the potential for high product water recovery. Attaining high recovery for inland water desalination, while avoiding membrane mineral scaling, can be achieved via an intermediate concentrate demineralization (ICD) method that utilizes two-step chemically-enhanced seeded precipitation (CESP) process. In the CESP approach, primary RO concentrate is first treated via partial lime softening in which residual antiscalant in the PRO concentrate is scavenged by precipitating calcium carbonate (CaCO3). The filtered lime treated PRO concentrate is then treated in a seeded gypsum (CaSO4[TM]2H2O) precipitation step whereby, gypsum crystal seeds promote rapid crystal growth. As a consequence, the treated PRO stream is desupersaturated with respect to gypsum and upon filtration step; a secondary RO desalting step is carried out to increase the overall product water recovery. Development of the ICD approach as a continuous process suitable for deployment in RO desalting is the focus of the present study. Accordingly, a novel system for continuous chemically enhanced seeded precipitation (CCESP) pilot was developed and constructed consisting of an alkaline chemical softening flocculation tank followed by a vertical static mixing bed reactor for seeded precipitation. The overall feasible feed slow rate for the pilot CCESP system was 0.026 - 0.25 gpm. Evaluation of the continuous ICD process performance was undertaken with a range of solutions that mimic PRO concentrate produced from desalination of San Joaquin Valley brackish water at a recovery of 63%. The major salts in the PRO concentrate feed to the CCESP included CaCl2 (30.7 mM), Na2SO4 (145.4 mM), MgSO4 (31.2 mM), NaHCO3 (11.4 mM), and NaCl (20.3 mM). Antiscalant (Flocon 260, 5 mg/L) was introduced to the PRO concentrate in order to assess the feasibility for residual antiscalant (typically present in PRO concentrate) removal so as to avoid retardation of the subsequent gypsum desupersaturation step. The CCESP system enabled continuous gypsum desupersaturation by purging spent gypsum seeds and recycling a portion of the seeds or introducing fresh seeds to the fluidized bed. Various gypsum seeds were tested, with a focus on industrial sources for gypsum (e.g. mining, drywall, food, agriculture) due to their availability and low cost. The purity of the gypsum seeds was found to be a key factor, where gypsum seeds with >98% purity were found to be most effective. Using the synthetic PRO concentrate, each of the two steps of the process were first evaluated individually to determine the optimal operating conditions and subsequently combined to evaluate the complete continuous operation. In the CCESP, lime softening occurs in a flocculation tank with recirculation, solids removal from the lime treated stream is via an inline centrifugal separator, and the gypsum seeded precipitation takes place in a fluidized bed. It was found that CCESP treatment of the PRO concentrate with 5.75 mM lime enabled up to 68% removal of the residual antiscalant. Subsequent gypsum seeded precipitation (initial seed loading of 240 g/L gypsum) reduced the PRO concentrate gypsum supersaturation index (SIg) level from 2.36 to nearly unity. The above level of gypsum desupersaturation was assessed to be sufficient for carrying out a secondary RO desalting that would enable increased recovery from 63% at the PRO step to an overall recovery of about 85% and possibly higher. The present study successfully developed a continuous ICD process and demonstrated its technical feasibility. The present results are encouraging and support the merit of evaluating the process under field conditions. Overall, it is expected that deployment of the CCESP process will enable high recovery desalting of challenging inland water of high mineral scaling propensity.

Author: Luigi Gurreri
Publisher: MDPI
ISBN: 3036515305
Category : Technology & Engineering
Languages : en
Pages : 236

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Electromembrane processes offer a multitude of applications, allowing for the recovery of water, other products, and energy. This book is a collection of contributions on recent advancements in electromembrane processes attained via experiments and/or models. The first paper is a comprehensive review article on the applications of electrodialysis for wastewater treatment, highlighting current status, technical challenges, and key points for future perspectives. The second paper focuses on ZSM-5 zeolite/PVA mixed matrix CEMs with high monovalent permselectivity for recovering either acid or Li+. The third paper regards direct numerical simulations of electroconvection in an electrodialysis dilute channel with forced flow under potentiodynamic and galvanodynamic regimes. The fourth paper investigates the reasons for the formation and properties of soliton-like charge waves in overlimiting conditions. The fifth paper focuses on the characterization of AEMs functionalized by surface modification via poly(acrylic) acid yielding monovalent permselectivity for reverse electrodialysis. In the sixth paper, CFD simulations of reverse electrodialysis systems are performed. The seventh paper proposes an integrated membrane process, including electrochemical intercalation–deintercalation, for the preparation of Li2CO3 from brine with a high Mg2+/Li+ mass ratio. Finally, the eighth paper is a perspective article devoted to the acid–base flow battery with monopolar and bipolar membranes.

Author: Zhien Zhang
Publisher: Springer Nature
ISBN: 3030412954
Category : Technology & Engineering
Languages : en
Pages : 195

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This book presents a detailed discussion of the fundamentals and practical applications of membrane technology enhancement in a range of industrial processes, energy recovery, and resource recycling. To date, most books on the applications of membrane technology have mainly focused on gas pollution removal or industrial wastewater treatment. In contrast, the enhancement of various membrane processes in the areas of energy and the environment has remained largely overlooked. This book highlights recent works and industrial products using membrane technology, while also discussing experiments and modeling studies on the membrane enhancement process.