Incipient membrane scaling by calcium sulfate during desalination in narrow spacer-filled channels

Karabelas, A.J.; Karanasiou, Anthoula; Mitrouli, S.T.

doi:10.1016/j.desal.2014.04.020

Cited by 51 publications

(24 citation statements)

References 30 publications

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“…Figure 9a,b show the effect of citric acid on the morphology of gypsum crystals. In the samples taken by means of an optical microscope, it can be seen that in the presence of citric acid (Figure 9b), the morphology of gypsum had changed from the typical long needles (Figure 9a) [32] to smaller platelets. This effect of citric acid on gypsum morphology confirms what already found in literature in another field of study, namely the positive outcomes of citric acid that, beside from being a retardant for gypsum nucleation, it is known to increase the compressive strength of the calcium sulphoaluminate cements by changing the shape of crystals with an improved densification of the microstructure [33].…”

Section: Resultsmentioning

confidence: 99%

Reduction of Fouling and Scaling by Calcium Ions on an UF Membrane Surface for an Enhanced Water Pre-Treatment

Prisciandaro

Innocenzi

Tortora

et al. 2019

Water

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The control of fouling and scaling on heat and mass transfer surfaces is of major importance in processes as superficial water treatments, since it also improves the efficiency of the whole process from an energy saving point of view. The aim of the paper is to present the experimental results obtained in the inhibition of the fouling and scaling by calcium ions on an ultrafiltration membrane surface, by using citric acid as an additive. The last is an environmentally friendly additive−a so-called “green additive”, which may represent a reliable alternative to phosphorous and nitrogen based compounds typically used as inhibitors, since it has the characteristics of being non-toxic, non-bio accumulating, and biodegradable. The experimental plant is made of a tangential flow system on a lab scale equipped with a flat sheet ultrafiltration polymeric membrane, whose cut-off is 650 nm. In the first series of experiments, the effect of water hardness and its fouling effect due to calcium ions on membrane permeability has been measured in the range of potable waters. Then, the scaling effect of high calcium concentration in solution (supersaturated conditions) has been quantified by measuring the increase in weight of the membrane, with and without the addition of citric acid as an additive; moreover, the retarding effect of citric acid has been evaluated through the measurement of the induction times for the nucleation of calcium sulfate dihydrate (used as model scalant for fouling). Experiments have been carried out at two different supersaturation ratios (S = 2.25–2.60), at room temperature, in the absence of any additive, and with a citric acid concentration varying in the range 0.01 to 0.50 g/L. Experimental results have shown that the addition of citric acid in solution delays the induction times for gypsum crystals nucleation; moreover, it mitigates the phenomenon of membrane fouling and reduces the pressure drops by allowing an acceptable permeate flow for a longer duration.

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Section: Resultsmentioning

confidence: 99%

Reduction of Fouling and Scaling by Calcium Ions on an UF Membrane Surface for an Enhanced Water Pre-Treatment

Prisciandaro

Innocenzi

Tortora

et al. 2019

Water

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“…Thus, inorganic foulants had negligible or no influence on the membrane. However, to suit the permeate for recycling in the textile hosiery dyeing process, caustic soda was dosed to maintain the pH between 6.0 to 7.0 (Guo et al, 2012;Karabelas et al, 2014), and hydrochloric acid was dosed at concentrate to meet the feed pH requirement of the tertiary RO process. The membrane type and other operating parameters, particularly the feed-side pressure, were selected to simultaneously eliminate the maximum amount of TDS contaminants and achieve the optimum sustained permeate water flux.…”

Section: Resultsmentioning

confidence: 99%

“…Parameters (in avg and %) I II III IV V VI 2012; Karabelas et al, 2014), and the concentrate was handled in MEE to produce salt. The combined average permeate characteristics of each system were equivalent to a 92.2% recovery of usable water with pH 6.5, 160 mg/l TDS, silica below the detectable limit and the absence of other foulants.…”

Section: Treatment Of Secondary Ro Reject By Uf and Tertiary Romentioning

confidence: 99%

High Permeate Recovery for Concentrate Reduction by Integrated Membrane Process in Textile Effluent

Sudhakar

Vijayalakshmi²,

Nilavunesan³

et al. 2016

Water Environment Research

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The textile dyeing industry consumes a significant amount of high-quality water for processing, which stresses water resources. In recent decades, technologies have been developed to recover water from wastewater. This study describes the high recovery (greater than 92%) of reusable water from an industrial-scale hosiery dye-water recovery facility, consisting of three stages of reverse osmosis and ultrafiltration. The effluent was pre-treated before the membrane process was performed to prevent biofouling. The process performance results in the generation of a consistent water quality that is required for dyeing operations. An average feed flux of 15 l/mh was maintained in the reverse osmosis membrane by regular chemical dosing and cleaning. The integrated membrane process achieved a permeate with a pH of 6.5 and total dissolved solids (TDS) of 160 mg/l, with no other contaminants, which is of sufficient quality for reuse in the cotton hosiery dyeing process.

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“…Sulfate salts, such as barium sulfate or calcium sulfate, form a scale on the membranes during water recovery. Although the calcium sulfate scale is more soluble than other mineral scales such as CaCO 3, BaSO 4 , and SrSO 4 , once formed, it is difficult to eradicate mechanically and is insoluble in mineral acids and other conventional solvents [7][8][9]. Sulfate is present in high concentrations (~700 mg/L as SO 4 2 − ) in brackish groundwater in Qatar, resulting in limited water recovery in desalination systems.…”

Section: Contents Lists Available At Sciencedirectmentioning

confidence: 99%

Two-stage sulfate removal from reject brine in inland desalination with zero-liquid discharge

2015

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Incipient membrane scaling by calcium sulfate during desalination in narrow spacer-filled channels

Cited by 51 publications

References 30 publications

Reduction of Fouling and Scaling by Calcium Ions on an UF Membrane Surface for an Enhanced Water Pre-Treatment

Reduction of Fouling and Scaling by Calcium Ions on an UF Membrane Surface for an Enhanced Water Pre-Treatment

High Permeate Recovery for Concentrate Reduction by Integrated Membrane Process in Textile Effluent

Two-stage sulfate removal from reject brine in inland desalination with zero-liquid discharge

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