Desalination of brackish water for agriculture: challenges and future perspectives for seawater intrusion areas in Vietnam

2018 ◽  
Vol 67 (3) ◽  
pp. 211-217 ◽  
Author(s):  
Vo Huu Cong

Abstract This research aims to provide an overview of the seawater encroachment threat on agriculture in lowland areas and potential solutions for better practices. It was found that the Mekong river delta experiences severe impacts from climate change with more than 75% of provinces affected by seawater intrusion, of which Kien Giang, Ca Mau and Ben Tre provinces are the most influenced with 70% affected areas. The salinity of river water was observed in the range of 15–30 g/L in 2015; meanwhile, the strongest tolerated rice species reached ceiling values of 3–4 g/L. Emerging challenges were identified due to the uncertain upstream hydrological regime coupled with high levels of tide, field evaporation and water withdrawal. The development strategies of affected provinces are given on the modification of rice tolerant capacity, and modification to aquaculture in areas with high salinity, in which water purification is in urgent demand. Desalination technologies have been proposed with various innovations which are still not practical on a large scale. The desalination of seawater and brackish water by reverse osmosis, nano-filtration, electro-dialysis, ion-exchange resins, electrochemical processes and thermal distillation has been applied to agriculture. The advance reverse osmosis shows most potential because of its advances in treating performance, cost effectiveness and effective rejection of brine.

2013 ◽  
Vol 821-822 ◽  
pp. 1098-1101
Author(s):  
Wei Xing Li ◽  
Jing Huan Ma ◽  
Ying Liu ◽  
Qing Tong Ren ◽  
Zhan Sheng Ma

Reverse Osmosis (RO) is an effective method to get fresh water from seawater or brackish water. The uncontrolled discharge of RO concentrated brine can contaminate water aquifers and damage marine ecosystems. The techniques to treat or utilize the rejected brine are the research focus in recent years. This paper tried to give an overview of latest development in this filed in order to provide references for its actual application in large-scale engineering.


Desalination ◽  
1986 ◽  
Vol 58 (1) ◽  
pp. 55-67 ◽  
Author(s):  
P. Glueckstern ◽  
Y. Kantor ◽  
S. Kremen ◽  
M. Wilf

2019 ◽  
Author(s):  
Chem Int

The objective of this work is to study the ageing state of a used reverse osmosis (RO) membrane taken in Algeria from the Benisaf Water Company seawater desalination unit. The study consists of an autopsy procedure used to perform a chain of analyses on a membrane sheet. Wear of the membrane is characterized by a degradation of its performance due to a significant increase in hydraulic permeability (25%) and pressure drop as well as a decrease in salt retention (10% to 30%). In most cases the effects of ageing are little or poorly known at the local level and global measurements such as (flux, transmembrane pressure, permeate flow, retention rate, etc.) do not allow characterization. Therefore, a used RO (reverse osmosis) membrane was selected at the site to perform the membrane autopsy tests. These tests make it possible to analyze and identify the cause as well as to understand the links between performance degradation observed at the macroscopic scale and at the scale at which ageing takes place. External and internal visual observations allow seeing the state of degradation. Microscopic analysis of the used membranes surface shows the importance of fouling. In addition, quantification and identification analyses determine a high fouling rate in the used membrane whose foulants is of inorganic and organic nature. Moreover, the analyses proved the presence of a biofilm composed of protein.


2016 ◽  
pp. 377-380
Author(s):  
Marc André Théoleyre ◽  
Anne Gonin ◽  
Dominique Paillat

Regeneration of resins used for decolorization of sugar solutions is done with concentrated salt solutions. Nanofiltration membranes have been proven effective, in terms of industrial efficiency in decreasing salt consumption. More than 90% of the salt that is necessary for regeneration can be recycled through a combination of direct recycling of intermediate eluates, the separation of colored compounds by use of very selective nanofiltration membranes and a system to concentrate salty permeates. According to specific local conditions on energy supply and cost, the concentration of salty permeates can be either a multiple effect evaporator or a combination of electrodialysis and reverse osmosis. The desalted color compound solution is sent to the molasses, limiting considerably the effluent to be treated. Starting from a liquor of 800 IU, the water requirement is limited to less than 100 L/t of sugar and the amount of wastewater can be reduced to less than 40 L/t of sugar.


Water Policy ◽  
2003 ◽  
Vol 5 (3) ◽  
pp. 203-212
Author(s):  
J. Lisa Jorgensona

This paper discusses a series of discusses how web sites now report international water project information, and maps the combined donor investment in more than 6000 water projects, active since 1995. The maps show donor investment:  • has addressed water scarcity,  • has improved access to improvised water resources,  • correlates with growth in GDP,  • appears to show a correlation with growth in net private capital flow,  • does NOT appear to correlate with growth in GNI. Evaluation indicates problems in the combined water project portfolios for major donor organizations: •difficulties in grouping projects over differing Sector classifications, food security, or agriculture/irrigation is the most difficult.  • inability to map donor projects at the country or river basin level because 60% of the donor projects include no location data (town, province, watershed) in the title or abstracts available on the web sites.  • no means to identify donor projects with utilization of water resources from training or technical assistance.  • no information of the source of water (river, aquifer, rainwater catchment).  • an identifiable quantity of water (withdrawal amounts, or increased water efficiency) is not provided.  • differentiation between large scale verses small scale projects. Recommendation: Major donors need to look at how the web harvests and combines their information, and look at ways to agree on a standard template for project titles to include more essential information. The Japanese (JICA) and the Asian Development Bank provide good models.


2021 ◽  
Vol 698 (1) ◽  
pp. 012044
Author(s):  
Sutopo Purwono Fitri ◽  
Alam Baheramsyah ◽  
Agoes Santoso ◽  
Yudhi Satrio Santoso

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2772
Author(s):  
Vishwas Powar ◽  
Rajendra Singh

Plummeting reserves and increasing demand of freshwater resources have culminated into a global water crisis. Desalination is a potential solution to mitigate the freshwater shortage. However, the process of desalination is expensive and energy-intensive. Due to the water-energy-climate nexus, there is an urgent need to provide sustainable low-cost electrical power for desalination that has the lowest impact on climate and related ecosystem challenges. For a large-scale reverse osmosis desalination plant, we have proposed the design and analysis of a photovoltaics and battery-based stand-alone direct current power network. The design methodology focusses on appropriate sizing, optimum tilt and temperature compensation techniques based on 10 years of irradiation data for the Carlsbad Desalination Plant in California, USA. A decision-tree approach is employed for ensuring hourly load-generation balance. The power flow analysis evaluates self-sufficient generation even during cloud cover contingencies. The primary goal of the proposed system is to maximize the utilization of generated photovoltaic power and battery energy storage with minimal conversions and transmission losses. The direct current based topology includes high-voltage transmission, on-the-spot local inversion, situational awareness and cyber security features. Lastly, economic feasibility of the proposed system is carried out for a plant lifetime of 30 years. The variable effect of utility-scale battery storage costs for 16–18 h of operation is studied. Our results show that the proposed design will provide low electricity costs ranging from 3.79 to 6.43 ¢/kWh depending on the debt rate. Without employing the concept of baseload electric power, photovoltaics and battery-based direct current power networks for large-scale desalination plants can achieve tremendous energy savings and cost reduction with negligible carbon footprint, thereby providing affordable water for all.


Desalination ◽  
1977 ◽  
Vol 24 (1-3) ◽  
pp. 341-364 ◽  
Author(s):  
G. Boari ◽  
C. Carrieri ◽  
P. Mappelli ◽  
M. Santori

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