Evaluation of MF and UF as pretreatments prior to RO applied to reclaim municipal wastewater for freshwater substitution in a paper mill: A practical experience

Ordóñez, Ruth; Hermosilla, Daphne; Pío, Ignacio San; Blanco, Ángeles

doi:10.1016/j.cej.2010.10.016

Cited by 52 publications

(27 citation statements)

References 24 publications

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“…If the removal of contaminants takes place by charge neutralization, the maximum removal rate is close to the isoelectrical point and overdose is possible (restabilization occurs at charge reversal). However, with high dosages of aluminum salts, the main flocculation mechanism can be "sweep flocculation", where the contaminants are removed by enmeshment in the fresh precipitated flocs of Al(OH) 3 . In this case, optimum dosage of coagulant does not occur at the isoelectric point and there will not be overdose phenomena although reaching charge reversal [17].…”

Section: -Results and Discussionmentioning

confidence: 99%

“…Even at the tested dosages in jartests (up to 2500 ppm) at initial pH=8.3 final alkalinity was zero and almost zero at pH=9.5. At high dosages of alum sweep flocculation occurred increasing the TNC as Al(OH) 3 precipitates. After that, when pH decreased to around 4.5 and there was not hydroxyl groups to form more Al(OH) 3 , a dissolution of the fresh Al(OH) 3 precipitated occurred as at pH < 6 aluminum solubilizes in a high extent, causing a decrease in the TNC and MCS.…”

Section: 3-flocculation Monitoring By Fbrmmentioning

confidence: 99%

“…After that, when pH decreased to around 4.5 and there was not hydroxyl groups to form more Al(OH) 3 , a dissolution of the fresh Al(OH) 3 precipitated occurred as at pH < 6 aluminum solubilizes in a high extent, causing a decrease in the TNC and MCS. The maximum in the TNC curves appeared at higher dosages at higher initial pHs, because with a higher initial pH there is a higher alkalinity which allow the formation of more Al(OH) 3 precipitates. …”

Section: 3-flocculation Monitoring By Fbrmmentioning

confidence: 99%

“…The main differences between these products are their basicity, strength and the content of other species such as silica, calcium or even organic compounds [18][19][20]. Although the silica removal mechanism of polyaluminum coagulants is not well understood [17,21], there is a consensus in that they act by two primary coagulation mechanisms [18,22]: (1) charge neutralization of the negative particles by adsorption of positively charged dissolved aluminum species, and (2) enmeshment of particles in precipitated Al(OH) 3 .…”

Section: Introductionmentioning

confidence: 99%

“…Sustainable water use in the paper industry requires the closure of the water system without affecting paper machine runnability and product quality [1], which can be achieved by reusing the mill effluent after its advanced membrane treatment [2] and/or by the use of reclaimed water [3], depending on the availability of alternative water sources.…”

Section: Introductionmentioning

confidence: 99%

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Silica removal from newsprint mill effluents with aluminum salts

Latour

Miranda

Blanco

2013

Chemical Engineering Journal

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The main obstacle for the implementation of reverse osmosis (RO) in a treatment chain to reuse the effluent of a newsprint mill as fresh water is the high silica content of the water, which produces severe scaling on the membrane, thus, limiting its recovery. Coagulation is one of the preferred methods to reduce silica concentration. Five aluminum based coagulants have been tested at five dosages (500-2500 ppm) and three pHs (8.3, 9.5 and 10.5). All products showed their best efficiency at the highest dosage and pH, with the exception of alum, that was more efficient at intermediate dosages. A combination of a polyaluminum nitrate sulphate with a cationic quaternary polyamine (PANS-PA2), was the most efficient and versatile coagulant. It removed 97% of silica (5 ppm residual silica) at the optimal conditions (pH 10.5, 2500 ppm) and it was very efficient (76% silica removal) at pH 8.3, avoiding the need of any pH adjustment, and minimizing the conductivity and pH increase of the treated waters as well as obtaining some removal of the organic colloidal matter (≈25%).

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Section: -Results and Discussionmentioning

confidence: 99%

Section: 3-flocculation Monitoring By Fbrmmentioning

confidence: 99%

Section: 3-flocculation Monitoring By Fbrmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Silica removal from newsprint mill effluents with aluminum salts

Latour

Miranda

Blanco

2013

Chemical Engineering Journal

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Microfiltration

Chellam¹

2013

Encyclopedia of Membrane Science and Technology

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Microfiltration (MF) and ultrafiltration are popular in drinking water and wastewater treatment because integral membranes are absolute barriers for difficult‐to‐inactivate pathogenic protozoa, and the turbidity of membrane‐filtered water is well below current and anticipated regulations. The focus of this section is to provide a broad overview of MF from an environmental engineering viewpoint, including its capabilities and limitations, as it pertains to water and wastewater treatment, configuration and field testing of commercially available systems before full‐scale implementation, and mechanisms and control of fouling. Other industrial applications of microfiltration are also briefly discussed. Constant pressure and constant flux blocking laws to predict fouling mechanisms during dead‐end MF are briefly summarized. The use of chemical coagulation and electrochemical pretreatment to improve MF performance in terms of both fouling and filtered water quality (with respect to natural organic matter, disinfection by‐product precursors, and viruses) is also discussed.

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Fluorescence‐based fouling prediction and optimization of a membrane filtration process for drinking water treatment

et al. 2011

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A novel fluorescence‐based approach is proposed for modeling, predicting, and optimizing different fouling dynamics in an ultrafiltration (UF) process for drinking water treatment. Principal component analysis (PCA) was used to extract information in terms of principal components (PCs), related to major membrane foulant groups, from fluorescence excitation–emission matrix measurements captured during UF of natural river water. The evolution of PC scores during the filtration process was then related to membrane fouling using dynamic balances of latent variable values (PC scores). This approach was found suitable for forecasting fouling behaviors with good accuracy based solely on fluorescence data collected 15 min from the start of the filtration. The proposed approach was tested experimentally through model‐based optimization of backwashing times with the objective of minimizing the energy consumption per unit amount of water produced during the filtration process. This approach was also useful for identifying fouling groups contributing to reversible and irreversible fouling. © 2011 American Institute of Chemical Engineers AIChE J, 2012

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Evaluation of MF and UF as pretreatments prior to RO applied to reclaim municipal wastewater for freshwater substitution in a paper mill: A practical experience

Cited by 52 publications

References 24 publications

Silica removal from newsprint mill effluents with aluminum salts

Silica removal from newsprint mill effluents with aluminum salts

Microfiltration

Fluorescence‐based fouling prediction and optimization of a membrane filtration process for drinking water treatment

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