Impact of influent deviations on polymer coagulant dose in warm lime softening of synthetic SAGD produced water

Zhang, Lu; Mishra, Dinesh; Zhang, Kailun; Perdicakis, Basil; Pernitsky, David; Lu, Qingye

doi:10.1016/j.watres.2021.117202

Cited by 6 publications

(3 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, NaOH is the most common alkaline water-treatment agent, and Na 2 CO 3 insolubilizes Ca 2+ ions through CaCO 3 formation. In the Ca(OH) 2 + Na 2 CO 3 agent, the concentrations of Ca(OH) 2 and Na 2 CO 3 were set to 1.7 and 2.0 mol/L, respectively, based on the conventional softening protocol concerning the Ca 2+ and Mg 2+ concentrations in artificial seawater 47 . In the NaOH + Na 2 CO 3 agent, the NaOH and Na 2 CO 3 concentrations were set to 1.35 and 0.675 mol/L, respectively, according to those reported by Ayoub et al 26 .…”

Section: Agentsmentioning

confidence: 99%

Development of softening and ballasted flocculation as a pretreatment process for seawater desalination through a reverse osmosis membrane

Yadai

Suzuki

2023

npj Clean Water

View full text Add to dashboard Cite

Efficient desalination through a reverse osmosis (RO) membrane requires the prior removal of blockade-causing substances from raw seawater. To achieve ultrahigh-speed processing of a pretreatment process for seawater RO desalination, we combine traditional softening with ballasted flocculation (SBF) for Ca2+ and Mg2+ removal. An alkaline mixture of Ca(OH)2 and Na2CO3 was the most suitable softening agent for Ca2+ and Mg2+ removal with a reduced amount of generated sludge. This softening treatment simultaneously removed the suspended solids and bacteria from actual seawater. The settling velocity of the suspended solids generated via seawater softening was extremely low. Under the optimum conditions for desalinating actual seawater using an anionic polymer flocculant and microsand, the settling velocity exceeded 3.5 cm/s, 833 times higher than that of softening without ballasted flocculation. The amount of sludge after standing for 3 min was 76.5% lower in SBF than in conventional softening. The silt density index of the treated seawater met the water-supply standard of RO membranes (i.e., <3.0). Furthermore, the SBF-generated sludge exhibited considerably improved dewatering property than the sludge obtained via conventional softening. SBF can efficiently and quickly remove the causative substances of RO membrane fouling from seawater, thereby improving the treatability of generated sludge. SBF provides a new pretreatment process for seawater desalination using RO membranes.

show abstract

Section: Agentsmentioning

confidence: 99%

Development of softening and ballasted flocculation as a pretreatment process for seawater desalination through a reverse osmosis membrane

Yadai

Suzuki

2023

npj Clean Water

View full text Add to dashboard Cite

show abstract

“…Therefore, four types of alkaline agents, i.e., only Ca(OH) 2 , only NaOH, mixed Ca(OH) 2 and Na 2 CO 3 (Ca(OH) 2 + Na 2 CO 3 ), and mixed NaOH and Na 2 CO 3 (NaOH + Na 2 CO 3 ), were examined as softening agents in the present study. In the Ca(OH) 2 + Na 2 CO 3 agent, 1.7 mol/L of Ca(OH) 2 and 2.0 mol/L of Na 2 CO 3 were used based on the conventional softening protocol with respect to the Ca 2+ and Mg 2+ concentrations in arti cial seawater 47 . In the NaOH + Na 2 CO 3 agent, 1.35 mol/L of NaOH and 0.675 mol/L of Na 2 CO 3 were used as per the report by Ayoub et al 26 .…”

Section: Alkaline Agentsmentioning

confidence: 99%

Development of softening and ballasted flocculation as a pretreatment process for seawater desalination through a reverse osmosis membrane

Suzuki

Yadai

2022

Preprint

View full text Add to dashboard Cite

Efficient desalination through a reverse osmosis (RO) membrane requires the prior removal of blockade-causing substances from raw seawater. We achieve ultrahigh-speed processing by combining traditional softening with ballasted flocculation (SBF) for Ca2+ and Mg2+ removal. A mixture of Ca(OH)2 and Na2CO3 alkaline agents was most suitable for removing t Ca2+ and Mg2+ by softening and reducing the amount of generated sludge. In addition, the softening treatment simultaneously removed the suspended solids and bacteria from actual seawater. The settling velocity of the suspended solids generated via seawater softening was extremely low. In case of SBF under optimum conditions for desalinating actual seawater using an anionic polymer flocculant and microsand, the settling velocity exceeded 3.5 cm/s, 833 times higher than the settling velocity of softening without ballasted flocculation. The silt density index of the treated seawater met the water-supply standard of RO membranes (i.e., < 3.0). Furthermore, the dewatering property of the SBF-generated sludge was considerably improved compared with that of the sludge obtained via conventional softening. SBF can efficiently and quickly remove the causative substances of RO membrane fouling from seawater, thereby improving the treatability of generated sludge. SBF provides a new pretreatment process for seawater desalination using RO membranes.

show abstract

“…Lime addition to hard water (i.e., lime-softening) serves to increase the pH of water. In turn, bicarbonates transform into carbonates, where Ca 2+ and Mg 2+ are eliminated from water in the form of CaCO 3 and Mg(OH) 2 species, where such water softening is conceived for reducing the levels of calcium and magnesium ions [ 13 ]. Coagulation along with lime-softening has been proven to be an effective combination during water treatment processes for the removal of colloidal particles [ 14 ].…”

Section: Introductionmentioning

confidence: 99%

Kinetics and Thermodynamics of Adsorption for Aromatic Hydrocarbon Model Systems via a Coagulation Process with a Ferric Sulfate–Lime Softening System

Venegas-García

Wilson

2023

Materials

View full text Add to dashboard Cite

The adsorption mechanisms for model hydrocarbons, 4-nitrophenol (PNP), and naphthalene were studied in a coagulation-based process using a ferric sulfate–lime softening system. Kinetic and thermodynamic adsorption parameters for this system were obtained under variable ionic strength and temperature. An in situ method was used to investigate kinetic adsorption profiles for PNP and naphthalene, where a pseudo-first order kinetic model adequately described the process. Thermodynamic parameters for the coagulation of PNP and naphthalene reveal an endothermic and spontaneous process. River water was compared against lab water samples at optimized conditions, where the results reveal that ions in the river water decrease the removal efficiency (RE; %) for PNP (RE = 28 to 20.3%) and naphthalene (RE = 89.0 to 80.2%). An aluminum sulfate (alum) coagulant was compared against the ferric system. The removal of PNP with alum decreased from RE = 20.5% in lab water and to RE = 16.8% in river water. Naphthalene removal decreased from RE = 89.0% with ferric sulfate to RE = 83.2% with alum in lab water and from RE = 80.2% for the ferric system to RE = 75.1% for alum in river water. Optical microscopy and dynamic light scattering of isolated flocs corroborated the role of ions in river water, according to variable RE and floc size distribution.

show abstract

Impact of influent deviations on polymer coagulant dose in warm lime softening of synthetic SAGD produced water

Cited by 6 publications

References 24 publications

Development of softening and ballasted flocculation as a pretreatment process for seawater desalination through a reverse osmosis membrane

Development of softening and ballasted flocculation as a pretreatment process for seawater desalination through a reverse osmosis membrane

Development of softening and ballasted flocculation as a pretreatment process for seawater desalination through a reverse osmosis membrane

Kinetics and Thermodynamics of Adsorption for Aromatic Hydrocarbon Model Systems via a Coagulation Process with a Ferric Sulfate–Lime Softening System

Contact Info

Product

Resources

About