Integrated Coagulation-Membrane Processes with Zero Liquid Discharge (ZLD) Configuration for the Treatment of Oil Sands Produced Water

This study explores the feasibility of implementing five hybrid coagulation-membrane processes for the treatment of the boiler blow-down (BBD) water from an oil sands steam assisted gravity drainage (SAGD) operation. The processes involved (1) direct nanofiltration (NF) of the BBD water, (2) pre-treatment of the NF retentate using ion exchanger regeneration wastewater (IERW) as a chemical coagulant followed by NF, (3) pre-treatment of BBD water using IERW followed by NF, (4) dual pre-treatment of BBD water using IERW and soda ash (sodium carbonate, Na2CO3) followed by NF, and (5) forward osmosis (FO) treatment of the BBD water using IERW as a draw solution followed by NF treatment of diluted draw solution. These scenarios were compared based on total flux decline ratio (DRt), flux recovery ratio (FRR), and total dissolved solids (TDS) removal over the final NF treatment to suggest an efficient treatment technique to avoid an undesired increase in the capital and operating expenses. It was found that process-1 provided the highest selectivity toward dissolved solids (80%) with a flux decline and recovery ration of 89.6% and 97.4%, respectively. Considering the permeation flux, process-4 exhibited the lowest flux decline (86.1%) and highest recovery ratio (97.5%) compared to other processes, proving the successful role of soda ash softening, as a chemical pretreatment method, in improving the performance of membrane filtration. Process-2 presented a mediocre performance with DRt, FRR, and TDS rejection of 93.3%, 97.3%, and 74%, respectively. Finally, process-3 and process-5 showed the lowest performance among all the scenarios with low flux recovery and low permeability, respectively. In addition, process-3 was expected to be cost-efficient since it only uses an on-site generated waste as a coagulant for the chemical pretreatment of the membrane filtration unit. The optimum scenario was proposed to be the two-stage membrane process, with direct NF of BBD followed by the post-treatment of the retentate via a hybrid chemical conditioning using IERW and soda ash softening, followed by a second NF. Overall, this integrated process offered a highly efficient mean with a zero liquid discharge (ZLD) system for the treatment of high pH wastewaters into an uncontaminated stream for the boilers.

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Low-pressure membrane filtration with unconventional coagulation regimes

Water Science & Technology Water Supply ◽

10.2166/ws.2005.0032 ◽

2005 ◽

Vol 5 (5) ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

K.Y. Choi ◽

B.A. Dempsey

Keyword(s):

Activated Carbon ◽

Membrane Filtration ◽

Membrane Surface ◽

Cross Flow ◽

Chemical Cleaning ◽

Sand Filters ◽

Charge Neutralization ◽

Floc Size ◽

Filtration System ◽

Pre Treatment

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.

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Potential Pitfalls in Membrane Fouling Evaluation: Merits of Data Representation as Resistance Instead of Flux Decline in Membrane Filtration

Membranes ◽

10.3390/membranes11070460 ◽

2021 ◽

Vol 11 (7) ◽

pp. 460

Author(s):

Bastiaan Blankert ◽

Bart Van der Bruggen ◽

Amy E. Childress ◽

Noreddine Ghaffour ◽

Johannes S. Vrouwenvelder

Keyword(s):

Membrane Fouling ◽

Membrane Filtration ◽

Data Representation ◽

Strong Impact ◽

Experimental Conditions ◽

Permeable Membrane ◽

Dead End ◽

Flux Decline ◽

The Difference ◽

Filtration Flux

The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.

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Comparative environmental impact evaluation using life cycle assessment approach: a case study of integrated membrane-filtration system for the treatment of aerobically-digested palm oil mill effluent

Sustainable Environment Research ◽

10.1186/s42834-021-00089-5 ◽

2021 ◽

Vol 31 (1) ◽

Author(s):

Yeit Haan Teow ◽

Meng Teck Chong ◽

Kah Chun Ho ◽

Abdul Wahab Mohammad

Keyword(s):

Activated Carbon ◽

Life Cycle ◽

Palm Oil ◽

Membrane Filtration ◽

Electricity Consumption ◽

Sand Filters ◽

Unit Operations ◽

Filtration System ◽

Pre Treatment ◽

Aerobically Digested

AbstractAiming to mitigate wastewater pollution arising from the palm oil industry, this university-industry research-and-development project focused on the integration of serial treatment processes, including the use of moving bed biofilm reactor (MBBR), pre-treatment with sand filters and activated carbon filters, and membrane technology for aerobically-digested palm oil mill effluent (POME) treatment. To assess the potential of this sustainable alternative practice in the industry, the developed technology was demonstrated in a pilot-scale facility: four combinations (Combinations I to IV) of unit operations were developed in an integrated membrane-filtration system. Combination I includes a MBBR, pre-treatment unit comprising sand filters and activated carbon filters, ultrafiltration (UF) membrane, and reverse osmosis (RO) membrane, while Combination II excludes MBBR, Combination III excludes UF membrane, and Combination IV excludes both MBBR and UF membrane. Life cycle assessment (LCA) was performed to evaluate potential environmental impacts arising from each combination while achieving the goal of obtaining recycled and reusable water from the aerobically-digested POME treatment. It is reported that electricity consumption is the predominant factor contributing to most of those categories (50–77%) as the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides, and volatile mercury during the combustion of fossil fuels. Combination I in the integrated membrane-filtration system with all unit operations incurring high electricity consumption (52 MJ) contributed to the greatest environmental impact. Electricity consumption registers the highest impact towards all life cycle impact categories: 73% on climate change, 80% on terrestrial acidification, 51% on eutrophication, and 43% on human toxicity. Conversely, Combination IV is the most environmentally-friendly process, since it involves only two-unit operations – pre-treatment unit (comprising sand filters and activated carbon filters) and RO membrane unit – and thus incurs the least electricity consumption (41.6 MJ). The LCA offers insights into each combination of the operating process and facilitates both researchers and the industry towards sustainable production.

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Membrane filtration of wastewater effluents for reuse: effluent organic matter rejection and fouling

Water Science & Technology ◽

10.2166/wst.2001.0627 ◽

2001 ◽

Vol 43 (10) ◽

pp. 225-232 ◽

Cited By ~ 38

Author(s):

C. Jarusutthirak ◽

G. Amy

Keyword(s):

Organic Matter ◽

Membrane Filtration ◽

Treated Wastewater ◽

High Concentration ◽

Effluent Organic Matter ◽

Dead End ◽

Flux Decline ◽

Uf Membranes ◽

Stirred Cell ◽

Filtration Unit

The reuse of treated wastewater to augment natural drinking water supplies is receiving serious consideration. Treatment of secondary and tertiary effluent by membrane filtration was investigated by assessing nanofiltration (NF) membrane and ultrafiltration (UF) membranes in bench-scale experiments. It was found that secondary and tertiary effluent contained high concentration of effluent organic matter (EfOM), contributing EfOM-related fouling. Flux decline and EfOM rejection tests were evaluated, using a dead-end stirred cell filtration unit. Surface charge and molecular weight cut-off (MWCO) of membranes were significant factors in membrane performance including permeability and EfOM-rejection.

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Biofilms: their structure, activity, and effect on membrane filtration

Water Science & Technology ◽

10.2166/wst.2005.0637 ◽

2005 ◽

Vol 51 (6-7) ◽

pp. 181-192 ◽

Cited By ~ 18

Author(s):

Z. Lewandowski ◽

H. Beyenal

Keyword(s):

Membrane Filtration ◽

Membrane Separation ◽

Separation Processes ◽

Membrane Cleaning ◽

Underlying Assumption ◽

Structure Activity ◽

Membrane Biofouling ◽

Flux Decline ◽

Cleaning Procedures ◽

Near Future

The goal of this presentation is to identify biofouling mechanisms that cause undesirable effects to the membrane separation processes of flux decline and pressure drop. The underlying assumption of this presentation is that biofouling is unavoidable and that the operator cannot eliminate it entirely. This premise justifies research efforts toward understanding the mechanisms by which biofouling affects the membrane processes, rather than expecting that technology can entirely eliminate membrane biofouling in the near future. An improved understanding of biofouling mechanisms may lead to better membrane design, better membrane modules, and better membrane cleaning procedures.

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Characteristics of coagulation-flocculation of humic acid with effective performance of polymeric flocculant and inorganic coagulant

Water Science & Technology ◽

10.2166/wst.2003.0024 ◽

2003 ◽

Vol 47 (1) ◽

pp. 89-95 ◽

Cited By ~ 14

Author(s):

J. Yu ◽

D.D. Sun ◽

J.H. Tay

Keyword(s):

Humic Acid ◽

Membrane Fouling ◽

Membrane Filtration ◽

Molecular Size ◽

Aluminium Sulphate ◽

Fouling Control ◽

Effective Performance ◽

Water And Wastewater ◽

Pre Treatment ◽

Flocculation Process

Ferric chloride and aluminium sulphate as coagulants and positive charged flocculants PDDMAC ((PDDMAC = poly (diallyldimethylammonium chloride) were used for pre-treatment of water and wastewater for removing humic substance prior to RO membrane filtration. It was found that a combination of flocculant and coagulant enhanced the coagulation-flocculation process and humic acid removal. The optimum conditions of coagulation-flocculation were established in reference to the ratio of humic acid and coagulant. Zeta potential and the ratio of E4/E6 were investigated to explore the possible micro-mechanisms of coagulation-flocculation. The ratios of E4/E6 show the molecular size variations using different coagulants and flocculants, which are expected to benefit membrane-fouling control.

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Oily Wastewater Treatment Using Polyamide Thin Film Composite Membrane Technology

Membranes ◽

10.3390/membranes10050084 ◽

2020 ◽

Vol 10 (5) ◽

pp. 84 ◽

Cited By ~ 6

Author(s):

Sarah Elhady ◽

Mohamed Bassyouni ◽

Ramadan A. Mansour ◽

Medhat H. Elzahar ◽

Shereen Abdel-Hamid ◽

...

Keyword(s):

Activated Carbon ◽

Membrane Filtration ◽

Edible Oil ◽

Oily Wastewater ◽

Permeate Flux ◽

Treatment Unit ◽

Thin Film Composite ◽

Ro Membrane ◽

Pre Treatment ◽

Oil Wastewater

In this study, polyamide (PA) thin film composite (TFC) reverse osmosis (RO) membrane filtration was used in edible oil wastewater emulsion treatment. The PA-TFC membrane was characterized using mechanical, thermal, chemical, and physical tests. Surface morphology and cross-sections of TFCs were characterized using SEM. The effects of edible oil concentrations, average droplets size, and contact angle on separation efficiency and flux were studied in detail. Purification performance was enhanced using activated carbon as a pre-treatment unit. The performance of the RO unit was assessed by chemical oxygen demand (COD) removal and permeate flux. Oil concentration in wastewater varied between 3000 mg/L and 6000 mg/L. Oily wastewater showed a higher contact angle (62.9°) than de-ionized water (33°). Experimental results showed that the presence of activated carbon increases the permeation COD removal from 94% to 99%. The RO membrane filtration coupled with an activated carbon unit of oily wastewater is a convenient hybrid technique for removal of high-concentration edible oil wastewater emulsion up to 99%. Using activated carbon as an adsorption pre-treatment unit improved the permeate flux from 34 L/m2hr to 75 L/m2hr.

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Purification of Model Dairy Wastewaters by Ozone, Fenton Pre-treatment and Membrane Filtration

Periodica Polytechnica Chemical Engineering ◽

10.3311/ppch.15046 ◽

2020 ◽

Vol 64 (3) ◽

pp. 357-363 ◽

Cited By ~ 2

Author(s):

Mihály Zakar ◽

Dániel Imre Farkas ◽

Erika Hanczné Lakatos ◽

Gábor Keszthelyi-Szabó ◽

Zsuzsanna László

Keyword(s):

Protein Separation ◽

Membrane Filtration ◽

Separation Efficiency ◽

Dominant Role ◽

Sodium Caseinate ◽

Pollutant Removal ◽

Ion Concentration ◽

Fenton Reagents ◽

Pre Treatment ◽

Flocculation Effect

This study aimed to investigate the effect of ozone and Fenton-reaction as a pre-treatment before ultrafiltration of model dairy waste waters containing sodium caseinate. Filtration resistances and pollutant retentions were determined and compared. It was found, that both pre-treatment increased the retention, achieving almost 100 % pollutant elimination efficiency after short term pre-oxidation. The effect of Fe-ion concentration on Fenton pretreatment efficiency also was examined, and it was found that higher concentration resulted in decreased filtration resistances, revealing that coagulation-flocculation effect of reactants has dominant role in the protein separation efficiency. The presence of lactose also affects the pollutant removal efficiency, it promotes fouling in presence of Fenton reagents.

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Research experiences in direct potable water treatment using coagulation/ultrafiltration

Water Science & Technology ◽

10.2166/wst.2005.0641 ◽

2005 ◽

Vol 51 (6-7) ◽

pp. 221-229 ◽

Cited By ~ 9

Author(s):

A. Lerch ◽

S. Panglisch ◽

R. Gimbel

Keyword(s):

Membrane Filtration ◽

Potable Water ◽

Research Experiences ◽

Dead End ◽

New Concepts ◽

Capillary Membranes ◽

Pre Treatment ◽

High Flexibility ◽

Theoretical Considerations ◽

Potable Water Treatment

Recently, new concepts for direct or pre-treatment minimised processes for the treatment of surface waters to potable water have aroused more and more interest. The requirements of such concepts are various and express the desire for high flexibility, adaptation on various water qualities and expandability of the treatment process. These requirements can be nearly ideally achieved by membrane technology. This publication presents the actual approach in research, piloting and operation of selective plants, research institutions and universities for the hybrid process coagulation/ultrafiltration (UF), or microfiltration (MF) respectively. The focus is set on the discussion of the influences of the mass freight, coagulation conditions, temperature and theoretical considerations about the coating layer build-up in dead-end and IN/OUT-mode driven MF and UF capillary membranes with a coagulation step prior to membrane filtration.

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Investigation of membrane fouling in ultrafiltration using model organic compounds

Water Science & Technology ◽

10.2166/wst.2005.0627 ◽

2005 ◽

Vol 51 (6-7) ◽

pp. 101-106 ◽

Cited By ~ 7

Author(s):

J.H. Kweon ◽

D.F. Lawler

Keyword(s):

Organic Compounds ◽

Membrane Fouling ◽

Alginic Acid ◽

Membrane Surface ◽

Sem Images ◽

Membrane Processes ◽

Xps Spectra ◽

Relative Composition ◽

Flux Decline ◽

The City

Natural organic matter (NOM) is known to be the worst foulant in the membrane processes, but the complexities of NOM make it difficult to determine its effects on membrane fouling. Therefore, simple organic compounds (surrogates for NOM) were used in this research to investigate the fouling mechanisms in ultrafiltration. Previous research on NOM components in membrane processes indicated that polysaccharides formed an important part of the fouling cake. Three polysaccharides (dextran, alginic acid, and polygalacturonic acid) and a smaller carbohydrate (tannic acid) were evaluated for their removal in softening (the treatment process in the City of Austin). Two polysaccharides (dextran and alginic acid) were selected and further investigated for their effects on membrane fouling. The two raw organic waters (4 mg/L C) showed quite different patterns of flux decline indicating different fouling mechanisms. Softening pretreatment was effective to reduce flux decline of both waters. The SEM images of the fouled membrane clearly showed the shapes of deposited foulants. The high resolution results of the XPS spectra showed substantially different spectra of carbon, C(1s), in the membrane fouled by two raw organic waters. The XPS was beneficial in determining the relative composition of each fouling material on the membrane surface.

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