Grantee Research Project Results
Final Report: Novel Materials for Facile Separation of Petroleum Products from Aqueous Mixtures Via Magnetic Filtration
EPA Grant Number: R827015C010Subproject: this is subproject number 010 , established and managed by the Center Director under grant R827015
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for the Study of Metals in the Environment
Center Director: Allen, Herbert E.
Title: Novel Materials for Facile Separation of Petroleum Products from Aqueous Mixtures Via Magnetic Filtration
Investigators: Apblett, Allen W.
Institution: Oklahoma State University
EPA Project Officer: Aja, Hayley
Project Period: August 1, 2000 through January 31, 2001 (Extended to July 31, 2001)
RFA: Integrated Petroleum Environmental Consortium (IPEC) (1999) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research
Objective:
The major objective of this research is to develop magnetic extractants that can be used in conjunction with a magnetic filter to efficiently and economically remove petroleum products from aqueous solutions and mixtures. The project will synthesize three types of magnetically-active materials that are capable of absorption of hydrocarbons so that the latter can be rapidly and efficiently removed from water using magnetic filtration technology. Initial tests were performed with aqueous mixtures of decane, a typical alkane. The possibility of using magnetic extractants for breaking of oil in water emulsions was also tested.
Summary/Accomplishments (Outputs/Outcomes):
Preparation of Magnetic Extractants
Several different approaches for the preparation of magnetic extractants were developed in this investigation.
Magnetically-Active Activated Carbon
We developed a method for making magnetically-active activated carbons that are simply prepared by impregnating paper towels with an aqueous solution of iron gluconate mixture and then firing at 500oC under a nitrogen atmosphere. X-ray powder diffraction showed that the resulting material contained nanocrystalline magnetite while infrared spectroscopy demonstrated the presence of an activated carbon phase. A similar procedure using a nickel gluconate/ iron gluconate mixture yielded a nickel-ferrite impregnated activated carbon. Magnetic testing of the powders with a strong bar magnet indicated that the magnetite and ferrite-containing powders were strongly and completely ferromagnetic. Furthermore, none of the powders demonstrated any remnant magnetization outside of a magnetic field, an important property so that the powder will not stick to non-magnetized steel. Also, in the case of the magnetite, the lack of a remnant magnetization means that we have achieved our goal of creating particles too small to become permanently magnetized. As expected, the nickel ferrite-containing material exhibits the strongest response to a magnetic field. A second approach to higher surface area activated carbons that was investigated utilized sawdust and a conventional activated carbon preparation process that involved impregnating the sawdust with sulfuric acid before firing. In our experiments, iron and nickel salts were added to the sulfuric acid solution. Firing at 500oC yielded magnetically-active carbon with surface areas between 250 and 300 m2/g. XRD analysis demonstrated the presence of magnetite or nickle ferrite particles with an average crystallite size less than 30 nm. Also present was calcite and calcium sulfate derived from calcium present in the sawdust.
Magnetically-Active Polydimethylsiloxane/Iron Composites
A recent report indicated that polydimethylsiloxane (PDMS) is a good absorbant for phenanthrene prompted us to prepare composites of PDMS with iron metal, hematite, and magnetite. These were prepared by cross-linking a PDMS polymer at moderate temperature (150oC) in a mixture with the magnetic substrate. Two different PDMS oils were used as starting materials: a low viscosity (10 centistokes) material and a moderate viscosity material (1000 centistokes). These yielded strikingly different materials, a homogenous thinly-coated powder in the first case and a rubbery composite in the latter.
Poly-octadecyl methacrylate/Iron Composites
A composite material was prepared by coating a fine iron powder with poly-octadecyl methacrylate (average molecular weight of 170,000). The polymer was purchased as a toluene solution that was mixed with iron and allowed to evaporate yielding a waxy solid with imbedded iron particles. The proportions of the polymer and iron could be varied to provide a magnetic extractant that was neutrally buoyant (useful for removing soluble hydrocarbons) or which floats on water (useful for removing hydrocarbon slicks from water).
Octadecylsilsesquioxane-Coated Magnetic Powders
Magnetic extractants were prepared by treating iron and magnetite powders with octadecyltrimethoxysilane. This reagent condenses with surface hydroxyls on the iron or iron oxide surface, leading to a monolayer of pendant octadecyl groups grafted to the metal surface via a cross-linked silica layer.
Testing of Magnetic Extractants
The testing of the extractants was initiated using a 104 ppm aqueous solution of decane. 20 g of solution was treated with 0.5 g of extractant. After filtration, 6 g the aqueous solution was extracted with 1 g hexane and the extracts were analyzed for decane by GC/MS. The results are as follows:
Extractant | Final Decane Concentration | Extent of Decane Removal |
---|---|---|
Magnetite/Activated Carbon | 61.2 ppb | 99.94% |
Nickel Ferrite/Activated Carbon | 59.1 ppb | 99.94% |
Magnetite/Activated Carbon* | 10400 ppb | 0% |
Polyoctadecylmethacrylate/iron | 93.9 ppb | 99.91% |
Octadecylsilsesquioxane/iron | 3332 ppb | 99.53% |
Octadecylsilsesquioxane/magnetite | 1037 ppb | 99.85% |
PDMS-10/Iron | 34.6 ppb | 99.97 % |
PDMS-10/Magnetite | 187 ppb | 97.40 % |
PDMS-10/Hematite | 261 ppb | 99.96% |
PDMS-1000/Iron | 7.8 ppb | 99.995 % |
PDMS-1000/Magnetite | <1 ppb** | 100 % |
PDMS-1000/Hematite | 261 ppb | 99.96% |
* Prepared using sawdust/sulfuric acid
** Below detection limit
Thus, all of the extractants tested (except for one) performed very well and can reduce the concentration of decane, a representative alkane, to the parts per billion level. t can be expected that less water-soluble alkanes will partition even better.The one exception was the activated cabon derived from sawdust. The behavior of this material is peculiar considering it?s high surface area. Since decane will adsorb to an iron oxide surface to some extent. the complete failure of this material implies a highly charged lipophobic surface. The best magnetic extractants for decane were the polydimethylsiloxane/iron composites. The results also suggest that organic content should be maximized and that a monolayer of C-18 chains does not provide the best results. Thus, the octadecylsilsesquioxane derivatives did not perform optimally.
Testing of Magnetic Extractants for Breaking of an Emulsion
A stable emulsion was prepared by diluting a 35:20:45 weight percent paraffin oil/triethanolamine/oleic acid mixture to 1000 ppm in water. This yielded an indefinitely stable white emulsion. Ten grams of this emulsion was treated with 0.5 g of the nickel ferrite/activated carbon extractant by briefly shaking the two materials together in a glass vial. The mixture was then passed through a magnetic filter consisting of a glass pipet packed loosely with steel wool and taped to the side of a bar magnet. The solution passed through the filter was much clearer. The extent of emulsion removal was then assessed by measuring the solution?s absorption at 500 nm. Before treatment the absorbance was 1.66 while after it was 0.21. In terms of transmission, an increase from 2 to 62% was observed. Thus, magnetic extractants are capable of breaking emulsions and these initial results suggest that optimization of the magnetic extractant could result in complete breaking of an oil in water emulsion. Notably, the emulsion used in this study was very high in surfactant and extremely stable and it is likely that real world samples may not be as challenging.
This project is still active and is being investigated by two OSU graduate students - one supported by SABIC and the other by a teaching assistantship. We are pursuing the PDMS composites and the activated carbons. Also testing of phenanthrene removal from water and emulsion breaking is being investigated.
This proof of concept proposal demonstrated that magnetic extractants in combination with magnetic filtration are capable of removing hydrocarbons from water and in breaking oil in water emulsions.
Journal Articles:
No journal articles submitted with this report: View all 3 publications for this subprojectSupplemental Keywords:
water, drinking water, adsorption, solvents, organics, DNAPL, NAPL, effluent, discharge, remediation, cleanup, environmental chemistry, petroleum industry., RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Waste, Water, TREATMENT/CONTROL, POLLUTANTS/TOXICS, Waste Treatment, Contaminated Sediments, Remediation, Environmental Chemistry, Chemicals, Hazardous Waste, Environmental Monitoring, Ecological Risk Assessment, Hazardous, Environmental Engineering, hazardous waste management, hazardous waste treatment, sediment treatment, risk assessment, advanced treatment technologies, petroleum contaminants, cleanup, remediation technologies, contaminated sediment, PAH, aqueous mixtures, treatment, hazadous waste streams, oil spills, hydrocarbons, technology transfer, magnetic filtrationRelevant Websites:
http://ipec.utulsa.edu/Ipec/10.d/10_Q3.pdf (PDF) Exit
http://ipec.utulsa.edu/Ipec/Conf/apblett_101.pdf (PDF) Exit
http://ipec.utulsa.edu/Ipec/10.d/Abstract.html Exit
Main Center Abstract and Reports:
R827015 Center for the Study of Metals in the Environment Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R827015C001 Evaluation of Road Base Material Derived from Tank Bottom Sludges
R827015C002 Passive Sampling Devices (PSDs) for Bioavailability Screening of Soils Containing Petrochemicals
R827015C003 Demonstration of a Subsurface Drainage System for the Remediation of Brine-Impacted Soil
R827015C004 Anaerobic Intrinsic Bioremediation of Whole Gasoline
R827015C005 Microflora Involved in Phytoremediation of Polyaromatic Hydrocarbons
R827015C006 Microbial Treatment of Naturally Occurring Radioactive Material (NORM)
R827015C007 Using Plants to Remediate Petroleum-Contaminated Soil
R827015C008 The Use of Nitrate for the Control of Sulfide Formation in Oklahoma Oil Fields
R827015C009 Surfactant-Enhanced Treatment of Oil-Contaminated Soils and Oil-Based Drill Cuttings
R827015C010 Novel Materials for Facile Separation of Petroleum Products from Aqueous Mixtures Via Magnetic Filtration
R827015C011 Development of Relevant Ecological Screening Criteria (RESC) for Petroleum Hydrocarbon-Contaminated Exploration and Production Sites
R827015C012 Humate-Induced Remediation of Petroleum Contaminated Surface Soils
R827015C013 New Process for Plugging Abandoned Wells
R827015C014 Enhancement of Microbial Sulfate Reduction for the Remediation of Hydrocarbon Contaminated Aquifers - A Laboratory and Field Scale Demonstration
R827015C015 Locating Oil-Water Interfaces in Process Vessels
R827015C016 Remediation of Brine Spills with Hay
R827015C017 Continuation of an Investigation into the Anaerobic Intrinsic Bioremediation of Whole Gasoline
R827015C018 Using Plants to Remediate Petroleum-Contaminated Soil
R827015C019 Biodegradation of Petroleum Hydrocarbons in Salt-Impacted Soil by Native Halophiles or Halotolerants and Strategies for Enhanced Degradation
R827015C020 Anaerobic Intrinsic Bioremediation of MTBE
R827015C021 Evaluation of Commercial, Microbial-Based Products to Treat Paraffin Deposition in Tank Bottoms and Oil Production Equipment
R827015C022 A Continuation: Humate-Induced Remediation of Petroleum Contaminated Surface Soils
R827015C023 Data for Design of Vapor Recovery Units for Crude Oil Stock Tank Emissions
R827015C024 Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells
R827015C025 A Continuation of Remediation of Brine Spills with Hay
R827015C026 Identifying the Signature of the Natural Attenuation of MTBE in Goundwater Using Molecular Methods and "Bug Traps"
R827015C027 Identifying the Signature of Natural Attenuation in the Microbial
Ecology of Hydrocarbon Contaminated Groundwater Using Molecular Methods and
"Bug Traps"
R827015C028 Using Plants to Remediate Petroleum-Contaminated Soil: Project Continuation
R827015C030 Effective Stormwater and Sediment Control During Pipeline Construction Using a New Filter Fence Concept
R827015C031 Evaluation of Sub-micellar Synthetic Surfactants versus Biosurfactants for Enhanced LNAPL Recovery
R827015C032 Utilization of the Carbon and Hydrogen Isotopic Composition of Individual Compounds in Refined Hydrocarbon Products To Monitor Their Fate in the Environment
R830633 Integrated Petroleum Environmental Consortium (IPEC)
R830633C001 Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells (Phase II)
R830633C002 A Continuation of Remediation of Brine Spills with Hay
R830633C003 Effective Stormwater and Sediment Control During Pipeline Construction Using a New Filter Fence Concept
R830633C004 Evaluation of Sub-micellar Synthetic Surfactants versus Biosurfactants for Enhanced LNAPL Recovery
R830633C005 Utilization of the Carbon and Hydrogen Isotopic Composition of Individual Compounds in Refined Hydrocarbon Products To Monitor Their Fate in the Environment
R830633C006 Evaluation of Commercial, Microbial-Based Products to Treat Paraffin Deposition in Tank Bottoms and Oil Production Equipment
R830633C007 Identifying the Signature of the Natural Attenuation in the Microbial Ecology of Hydrocarbon Contaminated Groundwater Using Molecular Methods and “Bug Traps”
R830633C008 Using Plants to Remediate Petroleum-Contaminated Soil: Project Continuation
R830633C009 Use of Earthworms to Accelerate the Restoration of Oil and Brine Impacted Sites
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
Main Center: R827015
120 publications for this center
16 journal articles for this center