Grantee Research Project Results
2019 Progress Report: OSMOsis-Driven ReclAmation of Water (OSMODRAW)
EPA Grant Number: SU839457Title: OSMOsis-Driven ReclAmation of Water (OSMODRAW)
Investigators: Sadmani, Dr AHM Anwar , Villarruel-Moore, Angel , Tanelus, Johnci , Smith, Susanna , Olimattel, Kunal
Institution: University of Central Florida
EPA Project Officer: Callan, Richard
Phase: I
Project Period: January 1, 2019 through December 31, 2019 (Extended to April 30, 2020)
Project Period Covered by this Report: January 1, 2019 through December 31,2019
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2018) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources
Progress Summary:
The purpose of this study was to investigate a functionalized OSMODRAW system to reclaim water from urban runoff using a composite FO membrane with multiple functionalities. The overarching goal is to develop an osmosis-driven integrated approach to treat an impaired quality water, urban runoff while utilizing another impaired quality water [e.g., brackish water RO (BWRO)] concentrate using polyelectrolyte (PE) functionalized FO membranes. The specific objectives were:
1) To develop methods of fabrication of multifunctional FO membranes via conformal coating of polyacrylic acid (PAA)/polyallylamine hydrochloride (PAH), followed by embedding zero valent iron nanoparticles (nZVI) within the films;
2) To investigate the effect of nZVI-integrated PE multilayer films on the removal of nutrients, selected metals, and selected organic contaminants from urban runoff via FO;
3) To determine the overall efficiency of modified FO in reclaiming water from urban runoff using BWRO concentrate.
Table 1. Phase I proposed schedule of tasks and accomplishments to date
Specific Research Task | Jan ’19 | Feb ’19 | Mar ’19 | Apr ’19 | May ’19 | Jun ’19 | Jul ’19 | Aug ’19 | Sep ’19 | Oct ’19 | Nov ’19 | Dec ’19 |
Task 1: FO membrane functionalization |
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Accomplishment till 12/31/2020 |
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Task 2: Membrane characterization |
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Accomplishment till 12/31/2020 |
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Task 3: Bench-scale FO unit procurement |
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Accomplishment till 12/31/2020 |
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Task 4: Feed and draw solution preparation and characterization |
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Accomplishment till 12/31/2020 |
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Task 5: Establishment of test protocols and conduct experiments |
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Accomplishment till 12/31/2020 |
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Task 6: Evaluation of modified FO system performance |
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Accomplishment till 12/31/2020 |
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Task 7: Comparison and cost analysis |
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Accomplishment till 12/31/2020 |
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Task accomplished/in progress | Task not commenced yet | Additional work required |
The scope of this study consisted of functionalization and characterization of FO membranes, procurement and setting up of bench-scale FO filtration apparatus, feed and draw solutions preparation and characterization, and establishing test protocols and conducting experiments for performance evaluation. The goals have not changed from the original application, but additional experimental trials were needed. The Phase I project commenced on January 1, 2019. Table 1 shows the schedule of proposed tasks and accomplishments during the reporting period (01/01/2019–12/31/2019).
Preliminary Results and Evaluations
The preliminary data/results associated with each task obtained during the project period are discussed below.
Task 1. FO Membrane Procurement and Functionalization. In Task 1, forward osmosis membrane samples were procured from Sterlitech (FTSH2O cellulose triacetate [CTA] flat-sheet membrane, Sterlitech, Kent, WA). The FO membrane specimens were modified by depositing polyacrylic acid (PAA)/polyallylamine hydrochloride (PAH) coatings conformally on membranes followed by crosslinking and loading nZVI within the PAA/PAH layers. The PAA/PAH multilayers were deposited following both fluidic assembly and dip-coating methods (Richardson et al., 2015). A cross-flow flat-sheet membrane apparatus (model: CF042-FO, Sterlitech, Kent, WA) was used for conformal coating of membranes. The number of bilayers was varied (from 3 to 10) to test their effectiveness in immobilizing nZVIs. During our initial trials, the fluidic assembly method was not yielding uniform bilayers and was deemed resource consuming. Hence, researchers decided to utilize dip coating method for further experiments so that more uniform, homogenous polyelectrolyte (PE) bilayers could be obtained.
Task 2. Characterization of FO Membranes. The composition and thickness of PAA/PAH and PAA/PAH/nZVI films on the membrane were examined using a scanning electron microscope (SEM). This has been guiding researchers on the number of PE bilayers to be deposited on the membrane. The elemental composition of PAA/PAH with loaded metallic iron was analyzed by energy dispersive spectroscopy (EDS) in SEM. Zeta potential measurements were carried out using an Anton-Paar Electrokinetic Analyzer. A Rame-Hart Goniometer was used to measure contact angles (to determine hydrophobicity) via sessile drop technique. Atomic force microscopy (AFM) was applied to study the surface topography of virgin membrane and that functionalized by nZVI-integrated PE films using a Digital Instrument NanoscopeTM Atomic Force Microscope.
The SEM images show that PAA/PAH bilayers deposited via dip coating appear to cover the membrane surface with a somewhat homogeneous distribution of the PE complex (Fig. 1). The polyelectrolyte multilayer films (PMFs) are thin enough that the original grid pattern of the FO membrane underneath is still visible. We are hypothesizing that the PMFs can serve as a hindrance toward contaminants and foulants during FO operation. AFM study indicated that the surface roughness increased slightly for the functionalized FO membrane, but this may not affect flux adversely. EDS spectrum analysis indicated that an appreciable amount of nZVI (up to 7.5%) could be immobilized when depositing 10 PE bilayers. Zeta potential measurements revealed that the PE functionalized membrane generally had a more negatively charged surface (-19.28 mV at pH 7) compared to the virgin membrane (-10.24 mV at pH 7). This implies that the membrane can develop enhanced resistance to organic fouling due to electrostatic repulsion
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Figure 1. SEM images of a) virgin membrane, and b) PAA/PAH-coated CTA based FO membrane
surfaces (FTS-FO membrane)
Task 3. Bench-scale FO Unit Procurement. The OSMODRAW system that was assembled consists of laboratory-scale FO membrane cells (model: CF042-FO), flow control valves, pressure gauges, flow meters, feed solution (FS) and draw solution (DS) tanks, tubings, and fittings obtained from Sterlitech. The FS and DS delivery pump for FO cells were purchased from Cole Parmer. The assembled bench-scale OSMODRAW setup is shown in Fig. 2.
Figure 2. Bench-scale FO experimental
setup. a) assembled setup; b) flux measurement.
Task 4. FS and DS Preparation and Characterization. This task involves preparation of synthetic urban runoff following a recipe by Li et al., 2014. Suwannee River Humic Acid (SRHA) is used as a surrogate for natural organic matter (NOM). As organic contaminants, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) will be tested for their removal during FO treatment. Preliminary flux measurements using a synthetic FS containing 5 mg/L humic acid and a DS containing 20,000 ppm NaCl demonstrated that feedwater recovery was not markedly impacted by the conformal coating of PAA/PAH. 24-h flux test showed that the DS mass, when using a virgin membrane, increased by approximately 123 g while that for the PAA/PAH modified (10 PE bilayers to ensure immobilization of adequate amount of nZVI) membrane increased by approximately 92 g over the same time period of operation. The optimum number of PE bilayers that will ensure immobilization of adequate amount of nZVI within the PMFs without compromising flux is yet to be determined. A solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been adapted from the EPA Method 537 Rev. 1.1 (USEPA 2009) for the analysis of PFOS and PFOA.
Task 5. Establishment of Test Protocols and Conduct Experiments. A bench-scale FO-equipped OSMODRAW system has been assembled (see Task 3). Blank runs and preliminary flux measurements have been conducted. Bench-scale will be conducted during the next reporting period to determine the removal of nutrients, and selected metals and organic contaminants using FO.
Task 6. Modified OSMODRAW System Performance Evaluation. The efficiency of OSMODRAW operation using the functionalized membrane (with optimized PMFs and nZVI) will be evaluated in terms of removal of nutrients (nitrogen for this study), selected metals (Pb, Zn, Cu), and PFOA and PFOS. This task was not completed during the reporting period.
Task 7. Comparison and Cost Analysis. Preliminary cost analysis of the PAA/PAH/nZVI-functionalized membrane system will be performed and compared with unmodified FO membrane treatment using a cost model developed by Ang et al. (2017) based on Verberne Cost Model. This task will be conducted during the next reporting period. Tasks 6 and 7 were impacted by lab closure due to the COVD-19 situation.
Key Personnel Involved in the Project
The project commenced by the students: Angel Villarruel-Moore, Johnci Tanelus, Susanna Smith, and Kunal Olimattel under the guidance of the PI Dr. Anwar Sadmani. However, two students, Angel Villarruel-Moore and Susanna Smith, who graduated halfway through the project, were replaced by another student, Fnu Joshua, who carried out the rest of the project tasks along with the other students.
Expenditures
The project expenditures were not significantly different than originally estimated as shown in Table 2. The remaining balance was $18.23.
Table 2. Project expenditures to date.
Funded Budget [1] | Expenditures | Balance [2] | |||
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Actuals | Encumbrances | PreEncumberances | |||
Salary & Fringe Benefits | $121.00 | $0.00 | $0.00 | $0.00 | $121.00 |
Other Direct Expenses | $6,930.00 | $7,877.00 | $0.00 | $0.00 | $(947.10) |
Travel | $3,016.00 | $2,177.81 | $0.00 | $0.00 | $838.19 |
Facilities & Admin (Overhead) | $4,933.00 | $4,926.86 | $0.00 | $0.00 | $6.14 |
PoeopleSoft Balance | $15,000.00 | $14,981.77 | $0.00 | $0.00 | $18.23 |
[1] Funded Budget: Project funded budget recorded in teh financial systems of UCF Finance & Accounting (RCF-FA) or USF Research Foundation (UCF-RF). [2] Balance: Computed by (Funded Budget) minus (Expenditures) |
Quality Assurance
The EPA quality assurance requirements were followed in this project as appropriate for the type of data collected. QA/QC activities for the equipment included those activities recommended by the manufacturer and experimental data evaluations of water quality followed methods described by the U.S. EPA or that in Standard Methods for the Examination of Water and Wastewater (Standard Methods). The analytical instruments and methods were in accordance with appropriate
procedures and holding times, as specified by the documented methods used. The collection and analysis of QC blanks, spikes, and instrument calibration check samples, and replicates were ensured. Significance of Results Obtained
The project outcomes during the reporting period have been discussed in pages 4–6. PMFs with different number of ‘bilayers’ were successfully deposited onto the commercial FO membrane surfaces. The immobilization of nZVI within the PMFs increases with increasing number of bilayers. The PE functionalized membrane became more negatively charged when compared to the virgin membrane, implying that the membrane can develop enhanced resistance to organic fouling. Preliminary flux measurements using synthetic FS and DS demonstrated that feedwater recovery was not markedly impacted by the conformal coating of PE complex. It is recommended that the investigated approach to embrane functionalization and its efficiency in water recovery should be extended to the hollow fiber FO membranes that are being currently produced by the manufacturers. The project relates to pollution prevention/control by proposing an innovative integrated approach
to remove pollutants from two impaired quality waters (urban runoff and concentrate from brackish water desalination plant) that would otherwise be typically discharged into the environment with little or no treatment. The objective of this study can be linked to EPA’s authorizing statute CWA: Clean Water Act--Section 104.
Future Activities:
Planned Activities for the Subsequent Reporting Period:
Planned activities for the subsequent reporting period include determining the optimum number of PMFs on the FO membrane in the OSMODRAW system that will ensure immobilization of adequate amount of nZVI within the PMFs without compromising flux, membrane characterization using FE-SEM and EDS, and evaluating the efficiency of the functionalized FO membranes in removing selected stormwater derived contaminants.
Journal Articles:
No journal articles submitted with this report: View all 1 publications for this projectRelevant Websites:
Bio: Dr. Anwar Sadmani Exit
CECE Student Projects Receive Two Awards from U.S. Environmental Protection Agency Exit
Progress and Final Reports:
Original AbstractThe 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.