Download or read book Water Recovery from Silica saturated RO Concentrate by the Concentrate Enhanced Reverse Osmosis Process CERRO written by Gautam Patwardhan and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Continuous Process for RO Concentrate Desupersaturation written by Jack Lei and published by . This book was released on 2016 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Enhancement of Operational Flexibility in Reverse Osmosis Membrane Processes by Concentrate Recycling written by Tae Lee and published by . This book was released on 2019 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Enhancing Recovery of Reverse Osmosis Desalination written by Lauren Fay Greenlee and published by . This book was released on 2009 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Brackish waters are now considered valuable alternative water resources. Reverse osmosis (RO) membranes are the most promising candidate for drinking water production through desalination. Low recovery (the fraction of influent water that becomes product water) prevents widespread application of RO inland because of the high cost of waste disposal. The recovery of a brackish RO system is limited by sparingly soluble salts that become supersaturated and precipitate on the membrane surface. Precipitation is controlled through pH adjustment and antiscalant addition; however, at high salt supersaturation, antiscalant control is overcome and precipitation occurs. To further increase RO recovery and avoid precipitation, a three-stage process treated the waste stream (concentrate) of a brackish water RO system through antiscalant degradation, salt precipitation, and solid/liquid separation. Ozone (O3) and hydrogen peroxide (H2O2) were used to degrade antiscalants, pH elevation and base (NaOH/NaHCO3) addition were used to precipitate sparingly soluble salts, and microfiltration (0.1 [mu]m) was used to separate precipitated solids from the water. Optimal parameters (pH, ozone dose, H2O2/O3 ratio, antiscalant type and concentration, water composition) for antiscalant oxidation were determined. The influence of antiscalant type and concentration and pH was investigated for the precipitation and filtration stages. Results were obtained for particle size distribution, extent of precipitation, particle morphology, and particle composition. The effect of ozonation on precipitation and filtration was evaluated, with a comparison to two-stage treatment consisting of precipitation and filtration. Antiscalant oxidation is controlled by bivalent cation coordination, while pH and ozone dose significantly affect the extent of oxidation. The addition of antiscalant prior to precipitation caused changes to particle size and morphology, and results varied with water composition and antiscalant type and concentration. Ozonation, even for small times such as one minute, prior to precipitation and filtration increased calcium precipitation and decomposed the antiscalant enough to remove the effect of the antiscalant on particle characteristics. During ozonation, antiscalants were not completely oxidized, but the partial oxidation products did not seem to affect precipitation. Ozonation also reduced the fouling of microfiltration membranes used for solid/liquid separation. Results indicated concentrate treatment can significantly increase the overall recovery of an RO system.

Download or read book Improved Concentrate Recovery for Brackish Water Reverse Osmosis written by Scott Henry Hekman and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reverse Osmosis Process written by and published by . This book was released on 1996 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lifecycle Cost Analysis of a New Reverse Osmosis Concentrate Management System Using Brackish Diatoms for Enhanced Freshwater Recovery written by Emon Roy and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: World population increase and climate change call for an urgent need for an alternative water source. Brackish and recycled water (also known as reclaimed water) are considered possible alternative sources. Brackish groundwater desalination and potable reuse of recycled water often require reverse osmosis (RO) to remove undesirable impurities and produce freshwater. However, the challenges of the treatment process are high capital expenditure (CAPEX) and operation and maintenance expenditures (OPEX), along with the availability of brine disposal methods, especially for inland communities. To increase the freshwater recovery and reduce concentrate volume, incorporating an additional stage of RO (secondary RO) after the existing stages (primary RO) is desirable. However, a high concentration of silica, calcium and other inorganic scalants in the primary RO concentrate (ROC) may cause frequent scaling in the secondary RO. A novel diatom-based photobiological treatment of ROC can be introduced after the primary RO to treat the concentrate and solve the scaling problem for the secondary RO. Comprehensive bench-scale research works have been conducted in our laboratory to determine the conditions necessary to operate and maintain a photobioreactor (PBR). Although the technical feasibility of the photobiological treatment has been demonstrated along with bench-scale experiments, no research has been performed to propose this method for an industry-scale implementation. The goal of this research was to construct a detailed life cycle cost analysis (LCCA) model by exploring several parts, including designing a hypothetical industry-scale PBR and secondary RO, estimating the quantities of additional freshwater recovery, energy and chemical use, by-products production, and disposal cost reduction. In this research, a hypothetical one million gallons per day (MGD) industry-scale PBR-secondary RO facility was proposed and designed to enhance freshwater recovery and reduce concentrate disposal costs.

Download or read book Enhanced Water Recovery from Membrane RO Concentrate written by Yoram Cohen and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wastewater Treatment by Reverse Osmosis Process written by Mudhar Al-Obaidi and published by CRC Press. This book was released on 2020-02-25 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wastewater Treatment by Reverse Osmosis Process provides a one-stop-shop for reverse osmosis (RO), outlining its scope and limitations for the removal of organic compounds from wastewater. This book covers the state-of-the-art on RO processes and describes ten RO process models of different features and complexities. It also covers the advanced model-based techniques for RO process operations, including various rigorous methods for process modelling, simulation, and optimization at the lowest energy cost, as well as advanced tools such as genetic algorithms for achieving the same. • Highlights different types of physico–chemical and biological wastewater treatment methods including hybrid systems • Provides an overview of membrane processes, focuses on different types of membrane processes for water treatment and explains characteristics of membrane modules • Introduces the importance and challenges of process modelling for simulation, design, and optimization and offers examples across various industries •Describes the concept of different types of genetic algorithms for process optimisation and provides the state-of-the art of the GA method in terms of its application in water desalination and wastewater treatment •Emphasizes economic aspects of RO processes for wastewater treatment With its focus on the challenges posed by an increasing demand for fresh water and the urgent need to recycle wastewater at minimum cost, this work is an invaluable resource for engineers and scientists working within the field of wastewater treatment.

Download or read book Cost effective Volume Reduction of Silica saturated RO Concentrates written by Anthony J. Tarquin and published by . This book was released on 2008 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Concentrate Chemical Softening to Improve the Recovery of Brackish Water Reverse Osmosis Desalination written by Michael Brian Cobb and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhanced Reverse Osmosis Systems written by and published by American Water Works Association. This book was released on 2011 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book MAXIMIZING WATER RECOVERY DURING REVERSE OSMOSIS RO TREATMENT OF CENTRAL ARIZONA PROJECT CAP WATER written by Umur Yenal and published by . This book was released on 2009 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Central Arizona Project water was treated using slow sand filtration (SSF) and reverse osmosis (RO) in series. Additional desalination water was recovered from RO brine using the vibratory shear-enhanced processing (VSEP®; New Logic, Inc.). SSF removed 90% of the turbidity in raw CAP water. SSF decreased total organic carbon by almost 20%. After a little more than a year of continuous operation, performance of the RO system declined noticeably, as indicated by a rapid decrease in membrane permeation coefficient and an increase in salt flux. Foulant scrapings contained both clay material and large amounts of unidentified organics. Alternative hypotheses regarding major sources of membrane foulants are discussed in this study. Water lost as brine was reduced from 20% to 2-4% via post-RO VSEP treatment. Estimated costs were compared to those of a no-VSEP option in which disposal of the entire RO brine flow was required. The total annualized cost of brine treatment was fairly insensitive to recovery during VSEP treatment in the range 80-90%, and the period of VSEP operation between cleanings in the range 25-40 hrs. These values define a fairly broad window for near optimal VSEP operation under the conditions of the study. The cost of VSEP treatment to minimize brine loss was estimated at 3 94- 4 30 per acre foot (1 .21 - 1 .32 per 1000 gal) of 15 MGD CAP water treated. For a hypothetical 3 MGD RO brine flow, the use of VSEP to recover water and reduce the volume of brine for disposal results in a savings of more than.

Download or read book Forward Osmosis for the Treatment of Reverse Osmosis Concentrate from Water Reclamation written by Shahzad Jamil and published by . This book was released on 2013 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Overcoming the Limitations of Mineral Scaling and Feed Pressure in Reverse Osmosis Desalination written by Yeunha Kim and published by . This book was released on 2020 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reverse osmosis (RO) membrane desalination is increasingly used for production of potable water from seawater and brackish water and in municipal and industrial water reuse applications. However, RO processes at high recovery are impacted by membrane mineral scaling and the upper pressure barrier of RO elements, pumps and the associated energy expenditure. Membrane surface scaling decreases membrane water permeability and may reduce membrane lifetime. Membrane mineral scaling can be partially mitigated via antiscalant dosing of the RO feed, but this is at an added cost. An alternate approach to scale mitigation can be achieved via RO Feed flow reversal (FFR) which is a chemical-free method. By periodically reversing the direction of the raw RO feed, mineral scale that develops at the membrane stage exit can be removed via dissolution, thereby restoring the membrane permeability. Accordingly, an evaluation of the FFR process in a spiral-wound RO pilot system was carried out, without antiscalant dosing, with gypsum as a model scalant whereby the efficacy of the process was monitored via real time membrane surface monitoring. The recovery of RO process depends on both the ability to mitigate scaling and overcoming the pressure barrier, particularly for highly saline source water. However, the upper pressure limit constraint on membrane elements and the added energy cost often place a practical limit on the achievable recovery. In order to overcome the pressure limitation, the present work explored the deployment of a hybrid RO-NF configuration. In this arrangement the RO membrane enable balancing the rejection of the target mineral salts while the NF membranes allow for further concentration of the RO concentrate, which is particularly beneficial for source water high in concentration of divalent ions. The NF membrane permeate is then recycled and directed to the RO membranes. The attained recovery range and energy utilization for the above process were explored demonstrating that a higher recovery can be attained at a lower applied pressure relative to conventional RO system configuration.

Download or read book Comparing Conventional and Pelletized Lime Softening Concentrate Chemical Stabilization written by Charlie He and published by American Water Works Association. This book was released on 2011 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The objectives of this project include: (1) Demonstrate at pilot scale that both conventional and pellet softening Intermediate Concentrate Chemical Stabilization (ICCS) technologies can effectively remove inorganic membrane scale forming constituents (silica, barium, calcium, etc.) and enhance the overall RO [reverse osmosis] system recovery to about 92.5 to 95.5 percent. (2) Compare the pellet vs. conventional ICCS reactors in performance, chemical and power consumption, process footprint, residual quantity, capital, O & M and life cycle costs, environmental impacts and application potentials."--Exec. summ.

Download or read book Water Recovery And Concentrate Processing Of Aquaculture Wastewater Treatment By A Wind Powered Reverse Osmosis System written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: