Hot Water Extraction Process Research Articles

Nanofibrillated cellulose originated from birch sawdust after sequential extractions: a promising polymeric material from waste to films

The residual cellulose of wood processing waste, sawdust, which was leftover after sequential hot-water extraction processes to isolate hemicelluloses and lignin in a novel forest biorefinery concept, was explored as the starting material for preparation of a highly value-added polymeric material, nanofibrillated cellulose (NFC) also widely termed as cellulose nanofiber, which has provided an alternative efficient way to upgrade sawdust waste. The residual cellulose in sawdust was converted to a transparent NFC suspension in water through the 2,2,6,6-tetramethylpiperidine-1-oxyl radical/NaClO/NaBr oxidization approach. The resultant NFC with a dimension of ca. 5 nm in width and hundreds of nanometers in length were further processed into NFC films. The morphological features of the NFC suspension and its films were assessed by transmission electron microscopy and scanning electron microscopy. Highly even dispersion of NFC fibrils in the films originated from sawdust feasibly contributes to the outstanding mechanical performance of the films. NFC suspension with higher carboxylate content and its resultant NFC films were found to show higher transmission of light.

Effects of anionic surfactant on extraction of free fatty acid from Chlorella vulgaris.

Microalgal lipid with a high free fatty acid (FFA) content was directly extracted from Chlorella vulgaris, using SDBS, in an acid-catalyzed hot-water extraction process. The total fatty acid content of C. vulgaris was 296.0 mg/g cell. Under the 1.0% sulfuric acid, 0.4% SDBS conditions, the FFA content of the lipid increased to 96.7%, and the lipid-extraction yield was 248.4 mg/g cell. Under the 2.0% sulfuric acid, 0.2% SDBS conditions, the FFA content of the lipid was 96.1%, and the lipid-extraction yield was 266.0mg/g cell. Whereas the FAME content of the microalgal lipid extracted by hexane-methanol was 76.4% at the 10.0% sulfuric acid concentration, the FAME content of the high-FFA microalgal lipid was increased to 70.1% at a sulfuric acid concentration of only 0.1%. By combined sulfuric acid/SDBS treatment, high-FFA microalgal lipid was extracted in large yields; moreover, the amount of catalyst was remarkably reduced in the esterification of FFA.

반응표면분석법을 이용한 인진쑥 열수추출물의 항산화적 특성

In order to examine antioxidative characteristics of Artemisia capillaris response surface methodology was used to optimize the hot water extraction process by analyzing and monitoring the extraction condition. For total phenolic compounds content, the optimal extraction temperature, time and amount of solvent per sample were 94.50℃, 2.06 hr and 25.03 ml/g, respectively. Also, the optimal conditions for electronic donating ability were 91.82℃, 2.90 hr and 20.88 ml/g, respectively. The nitrile scavenging ability (pH 1.2) was optimized using the extraction temperature of 97.36℃, extraction time 2.75 hr and 15.19 ml/g as the amount of solvent per sample. Regression equations of total phenolic compounds content, electron donating ability and nitrile scavenging ability as dependent variable were deduced from each analyzed extraction condition. And finally, their response surfaces were superimposed with the optimal conditions to obtain values for each extraction process factor. The predicted results through superimposing were extraction temperature 90∼95℃, extraction time 2.5∼3.5 hr and amount of solvent per sample 17~24 ml/g.

In Vitro Screening of 10 Edible Thai Plants for Potential Antifungal Properties

Growing rates of fungal infections and increasing resistance against standard antifungal drugs can cause serious health problems. There is, therefore, increasing interest in the potential use of medicinal plants as novel antifungal agents. This study investigates the antifungal properties of crude plant extracts from ten medicinal plant species. Crude samples were extracted using the hot water extraction process. The minimum inhibitory concentrations (MIC) and diameter zone of inhibition were determined in each extract against ten fungal strains, and fluconazole was used as a positive control. The cytotoxicity of crude extracts on in vitro human skin fibroblast (HSF) cell models was determined by MTT assay. Of the ten crude extracts, Psidium guajava L. exhibited the highest antifungal activity, diameter zone of inhibition, and percentage HSF cell viability. Although all extracts exhibited antifungal activity, Psidium guajava L. had the greatest potential for developing antifungal treatments.

Harnessing oil sands microbial communities for use in ex situ naphthenic acid bioremediation

The caustic hot water extraction process used to release bitumen from the Alberta oil sands generates large volumes of tailings waste, or oil sands process water (OSPW). OSPW contains several components of environmental concern including diluents, polyaromatic hydrocarbons, heavy metals, and naphthenic acids (NAs); the latter are of particular concern as they are acutely toxic to aquatic organisms and mammals. Studies have demonstrated that the naturally occurring OSPW bacteria are capable of metabolizing the NAs. However, this in situ process takes place over hundreds of years, and is incomplete, leaving a recalcitrant fraction of NAs intact. In this study we explore options for recovering and harnessing the naturally occurring OSPW bacteria for potential future use in an aerobic ex situ OSPW treatment system. Here we evaluate our recovered microbes on their ability to degrade two model NAs, cyclohexane carboxylic acid and cyclohexane acetic acid. Using OSPW as a source for a bacterial inoculum, we were able to compare single and multispecies OSPW cultures, grown as either a biofilm, or as a planktonic suspension. Furthermore, we examined the effect of available nutrients on the ability of these cultures to degrade NAs. All biofilms were grown using the Calgary Biofilm Device. GC–MS, and GC-FID reveal that multispecies biofilm and planktonic cultures are each capable of degrading both NAs; a trait not observed for single species cultures. Moreover, complementary carbon sources have a tangible effect on the ability of the cultures to initiate the degradation of the NAs.

Autohydrolysis Pretreatment of Mixed Softwood to Produce Value Prior to Combustion

Autohydrolysis is a hot water pretreatment to extract soluble components from wood that can be used prior to converting the woody residuals into paper, wood products, fuel, or other goods. In this study, mixed softwood chips were autohydrolyzed in hot water at 150, 160, 170, and 180 °C for 1 and 2 h residence times. The objective was to understand the tradeoff between the extraction of fermentable sugar and the residual solid total energy of combustion quantitatively. This process strategy will be referred to as “value prior to combustion”. High-performance liquid chromatography was used to determine chemical compositions (sugars and byproducts such as acetic acid, furfural, and hydroxymethylfurfural) of the extracted liquid and residuals; a bomb calorimeter was used to measure the heating value of original wood and solid residue. As the autohydrolysis temperature increased, material balances of the system indicated higher volatile byproducts loss. More hemicelluloses were solubilized by the hot water extraction process at higher temperatures and longer residence times, and a greater degree of sugar degradation was also observed. The maximum sugar yield was determined to occur at conditions of 170 °C for 2 h, during which 13 g of sugar was recovered from the extract out of 100 g of oven-dried wood. The heating value of the solid residues after extraction was greater than the original wood. The total energy content of the solid residual after extraction ranged from 85 to 98 % of the original energy content of the feed with higher temperatures reducing the total energy content.

Mineralogical and chemical composition of petrologic end members of Alberta oil sands

The Alberta oil sands ores are a combination of four petrologically different kinds of rocks, called “end members”, deposited in marine and estuarine sedimentary environments. The combination of the different end members affects the properties of the oil sands. Applying organic solvents for bitumen extraction from the oil sands is an alternative to the current commercial hot water extraction process. Certain minerals (mainly clay minerals) in the oil sands may affect processability of the ore during non-aqueous extraction.The aim of the present study was to perform mineral and chemical characterization of the four end members in order to better understand the mineralogical and geochemical factors affecting bitumen extraction and subsequent solvent recovery from the extraction tailings.The as-received end members and their different size fractions were examined using XRD, QXRD, FTIR, ICP-MS and C, H, N and S content analysis. The results revealed variable amounts of toluene insoluble organic carbon in the samples after bitumen removal. The amount was higher in the finer size fractions, indicating its association mainly with the clay minerals. Bitumen removal was the most effective in the coarse grained quartz-rich samples containing a minimal amount of the clay minerals. The four end members consisted of quartz, clay minerals (kaolinite, illite, mixed layer illite–smectite and chlorite), carbonates (calcite, dolomite and siderite), K-feldspar, TiO2 minerals (anatase and rutile) and pyrite. The highest relative amount of mixed layer illite–smectite was found in the finest fractions (<0.2μm). The expandability (SXRD) of illite–smectite was 10±2%. The quantitative mineralogical analysis correlated well with chemical composition analysis of the petrologic end members of the oil sands.

복분자의 효소 추출 공정의 최적화 및 성분 변화

The objective of this study is to investigate the optimal condition for macerating enzymatic extraction process that leads to the highest yield and the largest extracted amount of bio-active contents from Rubus coreanus Miq.fruit. The optimal extraction conditions were found as the following: The initial amount of the water added to the fruit was 20~30% by weight. The mixing ratio used for the macerating enzyme was 4: 1: 2 (w: w: w) for cellulase:pectinase:amylogucosidase, and the amount of the macerating enzyme added was 2%by weight. The extraction process was done at a temperature of 45~50℃ for 10 hours. The extraction yields on Rubus coream Miq. fruit by macerating enzymatic extraction process was increased by 84.3% compared to that of hot-water extraction process. The amounts of organic acids and vitamin found in the extract were also higher. The amount of polyphenol and anthocyanim contents in extract were 185% and 257% of those from hot-water extraction, respectively. These results suggest that macerating enzymatic extraction is an effective method to boost extraction yield and to increase the amount of extraction of bio-active contents from Rubus coreanus Miq. fruit.

The role of Donnan effect in kraft cooking liquor impregnation and hot water extraction of wood

Abstract In this article, a phenomenological model is proposed for alkali impregnation and hot water extraction of wood. Elementary reaction kinetics, ion exchange (IE) equilibrium, and mass transfer rates are considered in the model. IE is a consequence of the dissociation of the covalently bound uronic acid and phenolic groups in the wood fiber wall (FW). Due to this effect, the molality of cations is higher in the FW liquid than in the liquid external to the FW, whereas the opposite is true for anions. For the development of kinetic models under the participation of hydroxyl and hydrogen ions, the estimation of their molalities in these two liquid phases is crucial because of their ubiquitous presence in chemical reactions. This study applies a recently developed physicochemical modeling environment in which alkali impregnation and hot water extraction processes are considered. The simulations revealed that the IE effect is significant and affects the chemical reaction kinetics in both processes in focus. Furthermore, the IE effect does not remain constant but varies as a function of treatment time.

Use of pressurized hot water extraction and high performance liquid chromatography–inductively coupled plasma–mass spectrometry for water soluble halides speciation in atmospheric particulate matter

The feasibility of pressurized hot water extraction (PHWE) has been novelty investigated to speed up water soluble halide species (bromide, Br−; bromate, BrO3−; iodide, I− and iodate, IO3−) leaching from atmospheric particulate matter (PM10 and PM2.5). Total bromine and iodine and total water soluble bromine and iodine have been assessed by inductively coupled plasma—mass spectrometry (ICP–MS). Water-soluble bromine and iodine species were also measured by ICP–MS after anion exchange high performance liquid chromatography (HPLC). Variables inherent to the pressurized hot water extraction process (temperature, modifier concentration, static time, pressure, number of cycles and dispersing agent mass) were fully studied. Results showed that the pressurized leaching procedure can be performed in 9min (5min for pre-heating, 2min of static time, 1min of purge time, and 1min of end relief time). The use of diluted acetic acid as a modifier did not improve the target recoveries. Dispersing agent (diatomaceous earth) was not needed, which reduces the time for filling the cells. Water-soluble halides were reached under the following extraction conditions: extraction temperature of 100°C, pressure of 1500psi, static time of 2min and 1 extraction cycle. Optimized HPLC conditions consisted of an isocratic elution with 175mM ammonium nitrate plus 15% (v/v) methanol as mobile phase (optimum flow rate of at 1.5mLmin−1). Analytical performances, such as limits of detection and quantification, repeatability and analytical recoveries of the over-all procedure have been established. Results obtained show water soluble halides accounted for approximately 20.9±1.3 and 11.8±0.6% of the total bromine and total iodine, respectively. A 79 and 89% of bromine and iodine was non-water soluble, which may be organic non-water soluble species. Br− and IO3− were found to be the major species, and they accounted for 100% of the total water-soluble bromine and iodine.

Degradation and aquatic toxicity of naphthenic acids in oil sands process-affected waters using simulated wetlands

Oil sands process-affected waters (OSPWs) produced during the extraction of bitumen at the Athabasca Oil Sands (AOS) located in northeastern Alberta, Canada, are toxic to many aquatic organisms. Much of this toxicity is related to a group of dissolved organic acids known as naphthenic acids (NAs). Naphthenic acids are a natural component of bitumen and are released into process water during the separation of bitumen from the oil sand ore by a caustic hot water extraction process. Using laboratory microcosms as an analogue of a proposed constructed wetland reclamation strategy for OSPW, we evaluated the effectiveness of these microcosms in degrading NAs and reducing the aquatic toxicity of OSPW over a 52-week test period. Experimental manipulations included two sources of OSPW (one from Syncrude Canada Ltd. and one from Suncor Energy Inc.), two different hydraulic retention times (HRTs; 40 and 400d), and increased nutrient availability (added nitrate and phosphate). Microcosms with a longer HRT (for both OSPWs) showed higher reductions in total NAs concentrations (64–74% NAs reduction, p<0.05) over the test period, while nutrient enrichment appeared to have little effect. A 96h static acute rainbow trout (Oncorhynchus mykiss) bioassay showed that the initial acute toxicity of Syncrude OSPW (LC50=67% v/v) was reduced (LC50>100% v/v) independent of HRT. However, EC20s from separate Microtox® bioassays were relatively unchanged when comparing the input and microcosm waters at both HRTs over the 52-week study period (p>0.05), indicating that some sub-lethal toxicity persisted under these experimental conditions. The present study demonstrated that given sufficiently long HRTs, simulated wetland microcosms containing OSPW significantly reduced total NAs concentrations and acute toxicity, but left behind a persistent component of the NAs mixture that appeared to be associated with residual chronic toxicity.

Optimization of Process Parameters for Water Extraction of Stevioside using Response Surface Methodology

Hot water extraction process was used for the extraction of steviosides from dry stevia leaves. The independent variables were, leaf to water ratio (1:5 to 1:20), heating time (10 to 120 min), and temperature (30 to 90°C). The combined effects of these independent variables on the extracted stevioside concentration and color of the extract were studied. For optimizing the extraction process, central composite rotatable design in combination with response surface methodology was used. Significant regression models with coefficient of determination greater than 0.90 were established to study the effect of independent variables on the responses. The optimum conditions are: temperature of water: 78°C, time of heating: 56 min and leaf to water ratio: 1:14 (g:mL).

Autohydrolysis pretreatment of mixed hardwoods to extract value prior to combustion

Biomass pretreatment by autohydrolysis uses hot-water to extract soluble components from wood prior to converting the woody residuals into paper, wood products, or fuel, etc. Mixed hardwood chips were autohydrolyzed in hot-water at 150, 160, 170, and 180 ºC, for 1 and 2 h. The tradeoff between fermentable sugar yield and caloric value of the residual solids was studied for a process that will be referred to as “value prior to combustion”. The extracted liquid was treated with dilute sulfuric acid to break down sugar oligomers into fermentable monomers. Material balances were performed around autohydrolysis to evaluate the role of temperature and residence time on sugar production and residual solid heating value. The composition (sugars and byproducts) of the extracted liquid was determined. As the autohydrolysis temperature increased, the material balance became less precise, presumably due to more volatile byproducts being formed that were not quantified. More hemicelluloses were extracted from the wood by the hot water extraction process under higher temperature and longer residence time, but a greater degree of sugar degradation was also observed. After hot-water extraction the heating value of the solid residues was higher than the original wood. The total energy content of the residual solid after extraction ranged from 74 to 95% of the original energy content of the feed.

Pretreatment of rice straw using an extrusion/extraction process at bench-scale for producing cellulosic ethanol

A combination of a twin-screw extrusion and an acid-catalyzed hot water extraction process performed at a bench-scale was used to prepare high monomeric xylose hydrolysate for cellulosic production. The influences of the screw speed (30–150rpm), barrel temperature (80–160°C) and corresponding specific mechanical energy of the extruder on the structural properties of the pretreated rice straw, sugar concentration and conversion were investigated. The optimal condition for the extrusion step was determined to be 40rpm with 3% H2SO4 at 120°C; the optimal condition for the extraction step was determined to be 130°C for 20min. After the pretreatment at the optimal condition, 83.7% of the xylan was converted to monomeric xylose, and the concentration reached levels of 53.7g/L. Finally, after the subsequent enzymatic hydrolysis, an 80% yield of the total saccharification was obtained.

Evaluation of the suspending properties of &lt;i&gt;adansonia Digitata&lt;/i&gt; gum on sulphadimidine suspension

Adansonia digitata gum was extracted from the dried leaves of Adansonia digitata using hot and cold water extraction processes yielding 16 and 18 % w/w respectively. The suspending properties of the hot (HWE) and cold water (CWE) gum extracts, used at 1-5 % w/w concentration levels were evaluated and compared with Compound Tragacanth (4% w/v) in sulphadimidine suspension. Sedimentation volume and rate, rheology, and ease of redispersion were employed as evaluation parameters. The results showed that both hot and cold water extracts of the gum used at 2-3 % w/v produced a better suspending property than 4 % w/v Compound Tragacanth gum. The suspending ability of the gums was in the order of: CWE > HWE > Compound Tragacanth. When the viscosity of HWE was compared with CWE for 15 days, they were found to differ significantly (P< 0.05). Also, when the viscosity of either hot or cold water gum extracts were compared with that of Compound Tragacanth at the same concentration for 15 days, there was a significant difference (P< 0.05). At all concentrations of gums used, the CWE had the better suspending property. Keywords: Adansonia digitata , suspending agents, rheology, ease of re-dispersibility, sedimentation rate

Application of oxy-fuel CO2 capture for in-situ bitumen extraction from Canada’s oil sands

Abstract The CO2 Capture Project, along with Praxair, Devon Canada, Cenovus Energy and Statoil ASA are executing a project to demonstrate oxy-fuel combustion as a practical, economic and commercially ready technology for CO2 capture from once through steam generators (OTSGs) used in the in-situ production of bitumen. While in-situ extraction methods are less invasive than mining and have less local environmental impacts, the current technology for in-situ extraction - steam assisted gravity drainage (SAGD) is more energy intensive, and will result in greater GHG emissions per barrel of oil produced as compared to conventional mining and hot water extraction processes. SAGD requires large quantities of steam for injection, which is produced by multiple large once-through steam generators (OTSGs) that each produce up to 250 kt/yr of CO2, depending on their size. Given this expected growth in the total GHG emissions from OTSG units in the oil sands, the Participants have initiated a project to prove and validate process designs for oxy-fuel combustion on OTSG boilers. The three phase project will assess the feasibility, cost and schedule required to utilize oxy-fuel combustion at a typical commercial site. The study will include a short term boiler test and a longer term pilot evaluation. The goal of the project is to develop a reliable, lower cost solution for capturing CO2 from OTSG boilers that is deployable at commercial scale. The primary technology provider for this project is Praxair. Other members include Devon Canada, Cenovus Energy, Statoil ASA and the CO2 Capture Project. The CO2 Capture Project is a joint venture research consortium that includes BP, Chevron, ConocoPhillips, ENI, Petrobras, Shell and Suncor.

Studies on Transport of Vanadium (V) and Nickel (II) from Wastewater Using Activated Composite Membranes

Third International Conference on Engineering for Waste and Biomass Valorization, May 2010, Beijing, China. The metals such as vanadium, nickel and iron are identified in the typical crude oils extracted from oil bearing rocks. The produced water contains salts, heavy metals, emulsified oil and other organics after the hot water extraction process (HWEP) of bitumen from oil sands. This is a serious environmental problem waiting for technically and economically feasible solutions. Membrane technologies such as ultra filtration, nanofiltration, and reverse osmosis are widely used in water purification and they are also applied for produced-water (wastewater stream in oil and gas production) purification. This study focuses on the transport of Vanadium (V) and Nickel (II) through activated composite membranes (ACMs) based on carrier Aliquat 336, in cyclohexane and dodecane. Reagents and materials, without further purification, and double distilled water were used. The UV-visible spectrophotometer and Atomic Absorption Spectrometer (FAAS) were utilised for measuring the concentrations of metal ions from aqueous solutions. Optimum conditions for both feed (pH 8) solutions, the influence of hydrodynamic conditions, the concentration of carrier on membrane (0.2, 0.5 and 0.7 M), the influence of aqueous feed acidity (4 < pH < 7), the influence of permeate reagents (NH3, HNO3, and Na2CO3) and the efficiency of separation process were established. The experiments were carried out at 20°C and low concentrations of V (V) and Ni (II), between 5 and 25 ppm, for modelling, as good as possible, one matrix of industrial wastewaters which contain V (V) and Ni (II) after HWEP. The coupled transport of vanadium from aqueous solutions following the reactions: $$ \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{Cl}}^{ - } } \right) \, _{\text{org}} \, + {\text{ VO}}_{ 2} \left( {\text{OH}} \right)_{ 2}^{ - } \rightleftarrows \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{VO}}_{ 2} \left( {\text{OH}} \right)_{ 2}^{ - } } \right)_{\text{org}} + {\text{ Cl}}^{ - } $$ $$ \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{VO}}_{ 2} \left( {\text{OH}} \right)^{ - }_{ 2} } \right)_{\text{org}} + {\text{ 2 OH}}^{ - } \rightleftarrows \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{OH}}^{ - } } \right)_{\text{org}} \, + {\text{VO}}_{ 3} {\text{OH}}^{ 2- } \, + {\text{ H}}_{ 2} {\text{O}} $$ The removal of V (V) and Ni (II) from wastewater samples was found to be governed by the carrier concentration used as well as the conditions of the aqueous feed and permeate solutions. The good efficiency of activated composite membranes separation was observed in case of V (V). The selectivity of Aliquat 336 based ACM toward V (V) and Ni (II) is presented and discussed. Selectivity demonstrated that vanadium ions were removable from mixtures due to the different extraction strength of Aliquat 336. Such selectivity is based on the difference of the dynamic behaviour of the metal ions transport.

Analysis of naphthenic acids in aqueous solution using HPLC-MS/MS

During the oil sand hot water extraction process, naphthenic acids are extracted from the bitumen into the oil sands process water, which leaves the water acutely and chronically toxic to aquatic biota. Because these acids can have toxic effects even at relatively low concentrations, depending on their composition and age, it is important to have analytical techniques sensitive enough to quantify the amounts of naphthenic acids in the aqueous environment. In this study, a new HPLC-MS/MS method was developed to separate and analyze mixtures of naphthenic acids. Using this method, inorganic salts are separated from the acids without any sample pre-treatment, such as an extraction step. Different naphthenic acids give characteristic retention times due to their structures, thus enabling measurements of the individual concentrations. Adsorption characteristics of certain naphthenic acids were explored using the new analytical method. It is expected that this analytical method could be employed to determine the fate and stability of individual naphthenic acids in the environment and thus provides insight to potential environmental impacts of oil sands processing.

Recovery of Phytochemicals from Kokum (Garcinia indica choisy) Using Pressurized Hot Water

A novel process has been developed for the recovery of phytochemicals such as, ? -HCA from kokum (Garcinia indica choisy) rinds using hot water pressurized with carbon dioxide, followed by its purification. The performance of the pressurized hot water extraction (PHWE) process has been evaluated to ascertain the optimum process parameters for maximizing the recovery of ? -HCA. A systematic parametric study has been undertaken by varying the important parameters in the ranges of 30-120 °C for temperature, 1-20 atm for pressure, 30-60 min of extraction time, 4 - 22 ml/g of water to feed ratio, 1-3 number of stages , 0-350 rpm of stirring, presence of salt, nature of feed, and grinding. Ethanol is added to the aqueous extract from kokum rinds for the removal of pectinous materials by precipitation. Quantification of ? -HCA in the product has been carried out by the titration method with 0.1N NaOH solution. The maximum recovery is obtained when PHWE is carried out at 90 °C above which the recovery decreases. Pressure does not have much effect on the recovery of ? -HCA beyond a certain pressure required to maintain the extractant in the liquid phase. More ?-HCA is recovered by 2-stage PHWE from ground dry kokum than from salty kokum rinds.

Filterability of oil sands tailings

In Canadian oil sands mining operations, bitumen is extracted from oil sands using the hot water extraction process, which produces tremendous amounts of tailings. Currently, these tailings are disposed of in large ponds, in which coarse particles settle out relatively quickly and fine particles remain suspended in water and settle very slowly. After years of settling, the fine particles form a stable suspension in water known as mature fine tailings (MFTs). Long-term storage of the MFT is costly and poses a major environmental liability. Oil sands companies are now actively investigating different approaches to replace or reduce the use of oil sands tailings ponds. Filtration of the tailings to produce “dry tailings” for stacking is now being investigated as an alternative by a number of companies. Fast water drainage is a critical step for the filtration process. In this paper, we use simple laboratory-scale filtration tests to evaluate the filterability of the oil sands tailings and to generate a parameter that can be used in filtration scale-up. It was found that the filterability of the original coarse oil sands tailings was relatively low. However, after the fines are flocculated with the coarse particles to form uniform flocs the filterability was improved by several orders of magnitude. The results demonstrate that filtration of the flocculated coarse tailings to produce the “dry” stackable tailings may be viable.