Figure 9 - uploaded by David Antia
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Expected plant layout associated with a 650 train reactor, processing 550 m 3 d −1 (200,750 m 3 a −1 ) and designed to handle the reject brine associated with a reverse osmosis desalination plant.
Source publication
More than 1 billion ha of land is adversely affected by salinization, including about 54 million ha of irrigated cropland. This study trials a batch flow, bubble column, static bed, catalytic, pressure swing adsorption−desorption, zero valent iron, and diffusion reactor train, which is designed to partially desalinate water, for use as either lives...
Contexts in source publication
Context 1
... reject brine volume is typically 80% of the feed volume to the conventional desalination reactor. Processing this reject brine in a ZVI desalination reactor may allow all or part of this reject brine to be recycled to the conventional desalination reactor or may allow it to be discharged into the environment, without increasing the salinity of the surrounding groundwater, riparian water, or seawater ( Figure 9). ...
Context 2
... conventional reverse osmosis plant producing 140 m 3 d −1 of potable water may have a feed water consumption of 690 m 3 d −1 of brackish or saline water and produce 550 m 3 d −1 of reject brine (Figure 9). The ZVI desalination process has the potential to reduce the salinity of the reject brine to below that of the feed water ( Figure 10). ...
Context 3
... integrated plant configuration shown in Figure 9 was not trialed at this time. Therefore, it is not known whether the modelled results (for the process configuration in Figure 9), shown in Figure 10, will occur. ...
Context 4
... integrated plant configuration shown in Figure 9 was not trialed at this time. Therefore, it is not known whether the modelled results (for the process configuration in Figure 9), shown in Figure 10, will occur. Additional treatment of the recycled water (Fig- ure 9) leaving the product water storage tank may be required. ...
Context 5
... it is not known whether the modelled results (for the process configuration in Figure 9), shown in Figure 10, will occur. Additional treatment of the recycled water (Fig- ure 9) leaving the product water storage tank may be required. Additional trials will be required to prove the conceptual process flow shown in Figure 9. ...
Citations
... The quality of unbalanced desalinated water is related to both the type of desalination technology adopted (thermal techniques, electrodialysis (ED), or reverse osmosis (RO)) and the design of the desalination process [3]. Hence, produced water from desalination plants (osmosis water) is characterized by low pH, alkalinity (TAC), hardness, and mineral content [4][5][6]. For this and a variety of reasons (such as corrosiveness, hardness, etc …) this water could not be considered a source of potable water for either domestic consumers or irrigation applications [7][8][9][10]. ...
... • pH: desalinated water usually has an acid value, but after the posttreatment, pH values attained (between 6 and 8), that maintain a high chlorine-based disinfection efficiency, and maintain buffering capacity in produced water. However, a pH value between 5) decreases lead corrosion [18,45]. • Ca 2+ concentration: for human health, calcium concentration is required at least 60-80 mg/L as CaCO 3 , in general, has a high calcium content and is favorable to obtain a positive index LSI >0 and pH close to 8. As a combination of these two criteria, the required Ca 2+ content needs to be between 80 and 120 mg/L as CaCO 3 or (32 mg/L < [ Ca 2+ ] < 50 mg/L) [14]. ...
In a desalination station, the remineralization step of osmosis water (OW) is essential to return to produced water its calco-carbonic equilibrium. For this, the use of calcite CaCO3 or lime Ca(OH)2 for water equilibrium in post-treatment processes needs the utilization of both CO2 and/or H2SO4 in osmosis water. For this reason, we describe here in detail, the effect of H2SO4 and CO2 on the remineralization process in a post-treatment desalination plant, especially with using hydrated lime Ca(OH)2 and calcite contactor (CaCO3)·In this paper, the different cases were discussed and investigated, by monitoring several indicator parameters such as pH, Ca2+ content, alkalinity, Langelier Index, etc. After the remineralization stage, we have shown that the efficiency of the remineralization process by CaCO3 or Ca(OH)2 depends on CO2 or H2SO4 content. Remineralization by CaCO3 (limestone) coupled with CO2 acidification is easy and more operator-friendly compared to the process using Ca(OH)2 (lime); it provides a clean environment for people working in the plant. In addition, the H2SO4 injection in the pretreatment stage followed by CaCO3 contact could lead to great results and correct calco-carbonic equilibrium. In the end, a comparative study of the investment cost in each process shows that the acidification of raw water with sulfuric acid (pretreatment) is the cheapest one, according to many studies. But on the other hand, the direct injection of CO2 is the easiest one to use for water balancing.
... Another key feature from Whitney (1903Whitney ( , 1947 is that, depending on the salinity of natural waters, for pH > 4.5, Fe 0 corrosion produces low-solubility hydroxides/oxides and more soluble salts (Antia 2020, 2022, Tao et al. 2023. The generation of iron hydroxides/oxides is certain as far as Fe 0 is reactive. ...
Permeable reactive barriers (PRBs) containing metallic iron (Fe0) as reactive materials are currently considered as an established technology for groundwater remediation. Fe0 PRBs have been introduced by a field demonstration based on the fortuitous observation that aqueous trichloroethylenes are eliminated in Fe0-based sampling vessels. Since then, Fe0 has been tested and used for treating various biological (e.g., bacteria, viruses) and chemical (organic and inorganic) contaminants from polluted waters. There is a broad consensus on the view that "reactivity loss" and "permeability loss" are the two main problems hampering the design of sustainable systems. However, the view that Fe0 is a reducing agent (electron donor) under environmental conditions should be regarded as a distortion of Corrosion Science. This is because it has been long established that aqueous iron corrosion is a spontaneous process and results in the Fe0 surface being shielded by an oxide scale. The multi-layered oxide scale acts as a conduction barrier for electrons from Fe0. Accordingly, "reactivity loss", defined as reduced electron transfer to contaminants must be revisited. On the other hand, because "stoichiometric" ratios were considered while designing the first generation of Fe0 PRBs (Fe0 as reductant), "permeability loss" should also be revisited. The aim of this communication is to clarify this issue and reconcile a proven efficient technology with its scientific roots (i.e., corrosion science).
... Other remediation reactors use supported Fe 0 :Fe(a,b,c) [102] or SiO 2 @Fe(a,b,c) polymers [103] to catalyse the formation of entrained n-Fe(a,b,c) polymers. These polymers are used to remove pollutants (e.g., Na + and Cl − ions) by reaction and adsorption. ...
... These polymers are used to remove pollutants (e.g., Na + and Cl − ions) by reaction and adsorption. For these reactions, P R can exceed 3,000,000 m 3 t −1 of Fe 0 [103]. ...
... The use of surfactants to recover S oir is well established in the hydrocarbon industry (US7581594B2; US8146666B2; US20150233223A1), and has been used in the subsurface to help remove contaminant plumes [108][109][110][111][112]. It has been demonstrated that lowering the salinity of the aquifer porewaters can reduce S oir and increase S o (US8550163B2). The ZVI reactor (Figures 3 and 4), may, when remediating an immiscible oil, be used to both degrade the oil [101] and desalinate the water [102,103]; this is prior to the injection/infiltration of the product water into the hydrodynamic stationary plume. ...
Polluted aquifers can be decontaminated using either ZVI (zero valent iron) permeable reactive barriers (PRB) or injected ZVI. The placement of ZVI within the aquifer may take several decades to remediate the contaminant plume. Remediation is further complicated by ZVI acting as an adsorbent to remove some pollutants, while for other pollutants, it acts as a remediation catalyst. This study investigates an alternative aquifer decontamination approach to PRB construction or n-Fe 0 injection. The alternative approach reconstructs the potentiometric surface of the aquifer containing the contaminant. This reconstruction confines the contaminant plume to a stationary, doughnut shaped hydrodynamic mound. Contaminated water from the mound is abstracted, decontaminated, and then reinjected, until all the water confined within the mound is decontaminated. At this point, the decontaminated mound is allowed to dissipate into the surrounding aquifer. This approach is evaluated for potential use in treating the following: (i) immiscible liquid plumes; (ii) miscible contaminant and ionic solute plumes; (iii) naturally contaminated aquifers and soils; and (iv) contaminated or salinized soils. The results indicate that this approach, when compared with the PRB or injection approach, may accelerate the decontamination, while reducing the overall amount of ZVI required.
... The bulk of the water required to meet the increased irrigation requirement is likely to be obtained from saline groundwater. Saline irrigation (water EC = 0.6 to 15.7 dSm −1 ) reduces crop yields when compared with freshwater irrigation [5][6][7]. ...
... Crop irrigation currently provides a low return on investment. While replacing saline irrigation water with desalinated water increases crop yields and the total crop sale value, the total return on investment decreases as the cost of the desalinated water increases [4,6,7]. ...
... Since 2008, the patent and academic literature ( Figure 1) has identified that passive (chemical) approaches (termed ZVI (zero valent iron) desalination) based on the use of Fe 0 , Fe n+ , or FexOyHz polymers (e.g., akageneite, green rust), Fe(a) polymers, Fe(b) polymers, Fe(c) polymers, or Fe-organic polymers could be used to partially desalinate water [4,6,7]. These studies have indicated that it may be possible to create solutions where the provision of partially desalinated water could cost between USD 0.1 and 3 m −3 . ...
Globally, more than 50 million ha of arable land is irrigated with saline water. The majority of this saline irrigation water is derived from saline groundwater. Global irrigation requirements may increase from 270 million ha in 2014 to about 750 million ha by 2050 as the global population increases to 9.1 billion people. The majority of this additional irrigation water is likely to come from saline groundwater sources. Desalination of irrigation water increases crop yield. A combination of high water volume requirements and low crop yields requires that, for widespread usage, the desalinated irrigation water product will require a delivery price of 200 m3 of desalinated water.
... A single polymer charge located on 400 g Fe 0 was demonstrated to process 70 batches of water (17 m 3 ) without loss of activity [18]. • Using Fe n+ ions to manufacture SiO 2 supported polymers of the form SiO 2 @Fe(a,b,c) and SiO 2 @Fe(a,b,c)@urea, where the pH increase is effected by bubbling air through the water [19]. Cyclic pressure fluctuations in the water are used to promote adsorption and desorption from the polymer. ...
... Catalyst regeneration is achieved by replacing the partially desalinated water with a fresh saline water charge. A single polymer charge containing 10 g Fe was demonstrated to process 50 batches of water (43 m 3 ) without loss of activity [19]. It was proposed that the polymer catalyses the formation of entrained polymer particles in the water using metal cations present in the feed water [19]. ...
... A single polymer charge containing 10 g Fe was demonstrated to process 50 batches of water (43 m 3 ) without loss of activity [19]. It was proposed that the polymer catalyses the formation of entrained polymer particles in the water using metal cations present in the feed water [19]. The water contained Fe, Ca, Mg and Al ions. ...
Rain-fed and irrigated agriculture associated with salinized soil and saline water supplies is characterized by low crop yields. Partial desalination of this saline water will increase crop yields. Recent studies have established that supported metal polymers can be used to produce partially desalinated irrigation water without producing a waste reject brine. This study assesses the ability of more than 90 different unsupported metal polymer formulations (containing one or more of Al, Ca, Fe, K, Mg, Mn, and Zn) to remove Na+ ions and Cl− ions from saline water (seawater, brine, brackish water, and flowback water). The polymers were constructed using a simple sol-gel approach at ambient temperatures. The overall ion removal followed a first-order reaction. Removal selectivity between Na+ and Cl− ions was a function of polymer formulation. Mg@Al polymers preferentially remove Cl− ions, while Fe@Ca polymers tend to remove Cl− and Na+ ions in more equal proportions. Ion removal can be rapid, with >50% removed within 1 h. These results were used to develop a process methodology, which will allow most seawater, brackish water, and saline flowback water to be desalinated to form usable irrigation water.
Metallic iron (Fe0) is a reactive material for treating polluted water. The effect of water salinity on the efficiency of Fe0-based remediation systems is not yet established. This work aims to clar-ify the reasons why Cl– ions are often reported to improve the efficiency of Fe0/H2O remediation systems. Quiescent batch experiments were carried out to characterize the effect of chloride (Cl–) ions on the efficiency of methylene blue (MB) discoloration in the presence of Fe0. Cl– was used in the form of NaCl at concentrations ranging from 0 to 40 g L–1. The MB concentration was 10 mg L–1, the Fe0 loading was 5 g L–1, and the duration of the experiment varied from 2 to 46 days. Four different Fe0 materials were tested in parallel experiments. Tests with different NaCl levels were performed in parallel with three other organic dyes: Methyl orange (MO), orange II (OII), and reactive red 120 (RR 120). The results clearly show that the presence of Cl– reduces the extent of dye discoloration in all systems investigated. The efficiency of the dyes increased in the order MB < MO < RR 120 < OII. In systems with varying NaCl concentrations, dye discoloration ini-tially decreases with increasing NaCl and slightly increases for [NaCl] > 30 g L–1. However, the extent of dye discoloration for [NaCl] = 40 g L–1 remains much lower than for the system with [NaCl] = 0 g L–1. The results clearly demonstrate that the presence of Cl– fundamentally delays the process of contaminant removal in Fe0/H2O systems, thus improving the understanding of the contaminant interactions in Fe0-based remediation systems. These results also suggest that the effects of other inorganic anions on the efficiency of Fe0/H2O systems should be revisited for the design of field applications.
Saline irrigation water accounts for 15% to 30% of global, anthropogenic, water usage,
and around 10% to 15% of global arable food production. Decreasing the salinity of this irrigation
water has the potential to substantially increase the yields associated with these crops. In this
paper, 87 sol–gel hydrophobic and supra-hydrophobic, hollow, metal, hydroxyoxide and polymer
formulations (constructed using inexpensive, agricultural chemicals) were demonstrated to remove
Na+
ions and Cl− ions from saline water. The process operates without producing a waste brine or
requiring an external energy source and is designed to desalinate water within existing tanks and
impoundments. The desalination results of the polymer were combined with the salinity reduction
profiles of 70 crops suitable for cultivation, including arable, orchard, horticultural, and livestock
forage crops. The analysis established that use of the desalinated water may result in both substantial
increases in crop yield, and an increase in the variety of crops that can be grown. Analysis of the ion
removal process established a novel methodology for assessing the salinity of the product water. This
methodology allows the salinity of the product water to be determined from a combination of EC
(electrical conductivity) and pH measurements
