scholarly journals Impacts of Feedwater Quality Change on the Oldest Continuously Operated Brackish-Water Reverse Osmosis Desalination Plant in the United States

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2654
Author(s):  
Jeffrey L. Pearson ◽  
Michael Hegy ◽  
Thomas M. Missimer
Keyword(s):  
Solute Transport ◽  
Reverse Osmosis ◽  
Process Design ◽  
Brackish Water ◽  
The United States ◽  
Transport Models ◽  
Design Modification ◽  
Solute Transport Modeling ◽  
The World ◽  
Tds Concentration

Brackish groundwater is abundant in many coastal zones of the world. The water can be economically treated with low-pressure reverse osmosis. A key issue is the stability of the feedwater pumped from groundwater systems. Commonly, groundwater solute-transport models are used to evaluate the long-term changes in salinity with time that impact brackish-water reverse osmosis (BWRO) desalination system process design. These models are run to assess changes over a 20- to 40-year period. The City of Cape Coral, Florida operates two regional BWRO facilities with the South Plant being the oldest continuously operated system in the world. This facility has a capacity of 68,182 m3/d and can treat raw water with a total dissolved solids (TDS) concentration up to 4000 mg/L. Two solute transport models were constructed to evaluate future salinity change in the groundwater source. The first model conducted in 1991 produced a range of probable changes with a high, most probable (mid), and low range. Actual data confirm the low range of the model produced an accurate result (within 15%) and that the 4000 mg/L threshold would not be exceeded until beyond 2031. The second modeling effort conducted in 2014 suggested that the 4000 mg/L TDS threshold would be reached in 2018, which did not happen. The use of real data and regression analyses for all wells suggests that the 4000 mg/L TDS concentration will not be exceeded until after 2060. Once the TDS threshold is reached, the plant would require a process change to allow treatment of higher TDS water. The current analysis shows that plant process design modification would not be required for up to 40 years into the future. The standard conceptual model assuming predominantly upward recharge during pumping was accurate with the addition of an enhanced zone of leakage caused by a fracture zone or a fault. A key issue that contributed to the success of the facility was the use of groundwater solute transport modeling prior to the final design of the membrane process during plant expansions.

scholarly journals Changes in Pumping-Induced Groundwater Quality Used to Supply a Large-Capacity Brackish-Water Desalination Facility, Collier County, Florida: A New Aquifer Conceptual Model

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1951
Author(s):  
Quillan L. Arico ◽  
Zoie R. Kassis ◽  
Robert G. Maliva ◽  
Weixing Guo ◽  
W. Scott Manahan ◽  
...  
Keyword(s):  
Solute Transport ◽  
Conceptual Model ◽  
Brackish Water ◽  
Transport Model ◽  
The United States ◽  
Lateral Migration ◽  
Aquifer System ◽  
Collier County ◽  
Groundwater Assessment ◽  
Solute Transport Modeling

Brackish-water reverse osmosis (BWRO) desalination facilities are designed to treat feedwater within a fixed range in salinity. If the salinity and ion concentrations of the feedwater rises above the maximum design concentrations, then the plant may ultimately fail. BWRO plants typically use groundwater as a feedwater source. Prior to the process design, a detailed groundwater assessment is made to characterize the source aquifer system and to develop a solute-transport model that is used to project the changes in water quality over the expected useful life of the facility. Solute transport-modeling performed for the Collier County (Florida) South BWRO facility, which was designed to produce 30,303 m3/d with an expansion to 75,758 m3/d, used an aquifer system conceptual model that assumed upwards migration over time of brackish waters with higher salinities into the production zones. This conceptual model is typical of how most BWRO systems developed in the United States operate. The original solute transport model predicted a range of increases in dissolved chloride concentrations over a 20-year period from a low of 5 mg/L/yr, a mid-range of 35 mg/L/yr, and a high range of 85 mg/L/yr. Actual data collected over a 11- to 13.5-year period showed that the dissolved chloride concentration average of the feed water decreased by 16 mg/L/yr. The original conceptual model was found to be inaccurate in that it suggested an upwards recharging system, whereas downward leakage (or perhaps lateral migration) of fresher water appears to be occurring in the system. This is an example of a long-term solute-transport model audit, which is rarely performed, in which a new conceptual model was found to be applicable to an aquifer system used to feed a BWRO facility.

scholarly journals A novel photobiological process for reverse osmosis concentrate treatment using brackish water diatoms

2017 ◽  
Vol 18 (2) ◽  
pp. 594-602 ◽  
Author(s):  
Keisuke Ikehata ◽  
Yuanyuan Zhao ◽  
Jingshu Ma ◽  
Andrew T. Komor ◽  
Nima Maleky ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Brackish Water ◽  
Water Reuse ◽  
The United States ◽  
Treated Wastewater ◽  
Dissolved Organics ◽  
Concentrate Treatment ◽  
Calcium Iron ◽  
Ro Concentrate ◽  
Aqueous Silica

Abstract A unique aqueous silica removal process using naturally occurring diatoms for water reuse and desalination is described. Several strains of brackish water diatoms have been isolated and tested. Among them Pseudostaurosira and Nitzschia species showed promise. Reverse osmosis (RO) concentrate samples from two full-scale advanced water purification facilities and one brackish groundwater RO plant in Southern California have been successfully treated by this process. This new photobiological process could remove aqueous silica, as well as phosphate, ammonia, nitrate, calcium, iron and manganese very effectively. Under non-optimized conditions, 95% of 78 mg·L−1 reactive silica in an RO concentrate sample could be removed within 72 hours. In most cases, addition of nutrients was not necessary because the RO concentrate typically contains sufficient concentrations of macronutrients derived from the source water (i.e., treated wastewater and brackish groundwater). Preliminary characterization of organics indicated that there was no major generation of dissolved organics, which could potentially foul membranes in the subsequent RO process. This new algal process has a strong potential for its application in desalination and water reuse in the United States and around the world.

A Case Study of Decentralized Off-Grid Water Treatment Using Reverse Osmosis

2017 ◽  
Author(s):  
Reza Baghaei Lakeh ◽  
Daniel Andrade ◽  
Kyle J. Miller ◽  
Bowen Du ◽  
Joshua Pham ◽  
...  
Keyword(s):  
Water Treatment ◽  
Reverse Osmosis ◽  
Brackish Water ◽  
Energy Demand ◽  
The United States ◽  
High Energy ◽  
Water Desalination ◽  
United States Geological Survey ◽  
High Pressure Pump

Decentralized water treatment consists of a variety of water treatment techniques for dwellings, industrial facilities, homes, and businesses independent of the power grid. According to the United States Geological Survey, brackish groundwater is abundant in the southwestern states including California; hence it can potentially be considered a new source for California’s water portfolio. Most of membrane-based desalination technologies (e.g. reverse osmosis) have high energy demand and cost. Using renewable energy (mostly solar photovoltaics) in concert with membrane-based water desalination can be utilized to develop decentralized and off-grid brackish water desalination systems especially for remote and rural regions. In this paper, the results of a case study on decentralized off-grid brackish water system have been presented and discussed. The system utilizes a high pressure pump that can provide a feed flow rate of 2.2 gpm of at 140 psi. The system is run by solar photovoltaic panels through a battery bank. The results of the study show that the system is capable of treating brackish water at a salt rejection rate of more than 97.5% and a recovery rate up to 80%.

scholarly journals From Sea to Sink

2004 ◽  
Vol 126 (10) ◽  
pp. 38-43 ◽  
Author(s):  
Gayle Ehrenman
Keyword(s):  
United States ◽  
Reverse Osmosis ◽  
Fresh Water ◽  
Brackish Water ◽  
The United States ◽  
Deep Wells

This article reviews supplies of water under stress; the prospect of rendering saltwater drinkable is growing more appealing and more affordable. A combination of need and cost is making desalination of saltwater more attractive in the United States, and reverse osmosis is the overwhelming choice when it comes to desalination methods. Desalination, the removal of salt from either brackish or seawater to render it potable, is nothing new. Desalination processes are generally divided into two methods: thermal and membrane. Either process can be used for seawater or brackish water. Brackish water is saltier than fresh water, but typically not as salty as seawater. It may result from the mixing of sea and fresh water, as in estuaries, or it may occur naturally, as in underground aquifers. Brackish water concentrate disposal poses more of a problem, largely because those facilities are typically located inland, so there's no nearby ocean to send the brine back into. Instead, these facilities pump the concentrate into deep wells.

scholarly journals Economics and Energy Consumption of Brackish Water Reverse Osmosis Desalination: Innovations and Impacts of Feedwater Quality

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 616
Author(s):  
Jeffrey L. Pearson ◽  
Peter R. Michael ◽  
Noreddine Ghaffour ◽  
Thomas M. Missimer
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Brackish Water ◽  
Energy Use ◽  
Operating Cost ◽  
Electrical Energy ◽  
The United States ◽  
Water Desalination ◽  
Feed Water ◽  
Plant Capacity

Brackish water desalination, using the reverse osmosis (BWRO) process, has become common in global regions, where vast reserves of brackish groundwater are found (e.g., the United States, North Africa). A literature survey and detailed analyses of several BWRO facilities in Florida have revealed some interesting and valuable information on the costs and energy use. Depending on the capacity, water quality, and additional scope items, the capital cost (CAPEX) ranges from USD 500 to USD 2947/m3 of the capacity (USD 690–USD 4067/m3 corrected for inflation to 2020). The highest number was associated with the City of Cape Coral North Plant, Florida, which had an expanded project scope. The general range of the operating cost (OPEX) is USD 0.39 to USD 0.66/m3 (cannot be corrected for inflation), for a range of capacities from 10,000 to 70,000 m3/d. The feed-water quality, in the range of 2000 to 6000 mg/L of the total dissolved solids, does not significantly impact the OPEX. There is a significant scaling trend, with OPEX cost reducing as plant capacity increases, but there is considerable scatter based on the pre- and post-treatment complexity. Many BWRO facilities operate with long-term increases in the salinity of the feedwater (groundwater), caused by pumping-induced vertical and horizontal migration of the higher salinity water. Any cost and energy increase that is caused by the higher feed water salinity, can be significantly mitigated by using energy recovery, which is not commonly used in BWRO operations. OPEX in BWRO systems is likely to remain relatively constant, based on the limitation on the plant capacity, caused by the brackish water availability at a given site. Seawater reverse osmosis facilities, with a very large capacity, have a lower OPEX compared to the upper range of BWRO, because of capacity scaling, special electrical energy deals, and process design certainty.

International Telesupervision: The Clinical Fellowship Experience

2017 ◽  
Vol 2 (11) ◽  
pp. 73-78
Author(s):  
David W. Rule ◽  
Lisa N. Kelchner
Keyword(s):  
Graduate Students ◽  
Clinical Supervision ◽  
Rural Areas ◽  
The United States ◽  
Speech Language Pathology ◽  
Access To Services ◽  
East African ◽  
The World ◽  
Language Pathology ◽  
National Certification

Telepractice technology allows greater access to speech-language pathology services around the world. These technologies extend beyond evaluation and treatment and are shown to be used effectively in clinical supervision including graduate students and clinical fellows. In fact, a clinical fellow from the United States completed the entire supervised clinical fellowship (CF) year internationally at a rural East African hospital, meeting all requirements for state and national certification by employing telesupervision technology. Thus, telesupervision has the potential to be successfully implemented to address a range of needs including supervisory shortages, health disparities worldwide, and access to services in rural areas where speech-language pathology services are not readily available. The telesupervision experience, potential advantages, implications, and possible limitations are discussed. A brief guide for clinical fellows pursuing telesupervision is also provided.

Sex Differences in Mass Media Preferences Across Four Asian Countries

2011 ◽  
Vol 23 (4) ◽  
pp. 186-191 ◽  
Author(s):  
Malini Ratnasingam ◽  
Lee Ellis
Keyword(s):  
United States ◽  
Sex Differences ◽  
Mass Media ◽  
The United States ◽  
Female Students ◽  
The Internet ◽  
Evolutionary Explanation ◽  
Asian Countries ◽  
The World ◽  
Media Preferences

Background. Nearly all of the research on sex differences in mass media utilization has been based on samples from the United States and a few other Western countries. Aim. The present study examines sex differences in mass media utilization in four Asian countries (Japan, Malaysia, South Korea, and Singapore). Methods. College students self-reported the frequency with which they accessed the following five mass media outlets: television dramas, televised news and documentaries, music, newspapers and magazines, and the Internet. Results. Two significant sex differences were found when participants from the four countries were considered as a whole: Women watched television dramas more than did men; and in Japan, female students listened to music more than did their male counterparts. Limitations. A wider array of mass media outlets could have been explored. Conclusions. Findings were largely consistent with results from studies conducted elsewhere in the world, particularly regarding sex differences in television drama viewing. A neurohormonal evolutionary explanation is offered for the basic findings.

Sandra Ramos Revisited

2020 ◽  
Vol 2 (4) ◽  
pp. 32-54
Author(s):  
Silvia Spitta
Keyword(s):  
United States ◽  
The United States ◽  
Ancient Greek ◽  
Graphic Arts ◽  
Left Behind ◽  
The World ◽  
The Usa ◽  
Political Choices ◽  
The Rich

Sandra Ramos (b. 1969) is one of the few artists to reflect critically on both sides of the Cuban di-lemma, fully embodying the etymological origins of the word in ancient Greek: di-, meaning twice, and lemma, denoting a form of argument involving a choice between equally unfavorable alternatives. Throughout her works she shines a light on the dilemmas faced by Cubans whether in Cuba or the United States, underlining the bad personal and political choices people face in both countries. During the hard 1990s, while still in Havana, the artist focused on the traumatic one-way journey into exile by thousands, as well as the experience of profound abandonment experienced by those who were left behind on the island. Today she lives in Miami and operates a studio there as well as one in Havana. Her initial disorientation in the USA has morphed into an acerbic representation and critique of the current administration and a deep concern with the environmental collapse we face. A buffoonlike Trumpito has joined el Bobo de Abela and Liborio in her gallery of comic characters derived from the rich Cuban graphic arts tradition where she was formed. While Cuba is now represented as a rotten cake with menacing flies hovering over it ready to pounce, a bombastic Trumpito marches across the world stage, trampling everything underfoot, a dollar sign for a face.

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