Progress 08/01/22 to 07/31/23
Outputs
Target Audience:Our poster presentation at the Air & Waste Management Association Annual Conference reached stakeholders in government and consulting who deal with clean water issues. Changes/Problems:As mentioned above, various methods of forming granules from the chosen adsorbents had to be explored because the initial method did not work. This caused several months of delay. What opportunities for training and professional development has the project provided?Dr. Sasha Jones obtained the skills of use of tube furnace and muffle furnace and formation of granules. How have the results been disseminated to communities of interest?Results were presented at the Air & Waste Management Association Annual Conference. This conference reached stakeholders in government and consulting who deal with clean water issues. Results were also presented to the stakeholders forming the Advisory Group. Additional dissemination will occur during the project extension. What do you plan to do during the next reporting period to accomplish the goals?The primary goal during the extension period is to complete objective, Obj. 4, "Evaluate PreSorb and MultiSorb using column tests" and conduct additional outreach.
Impacts
What was accomplished under these goals?
Major activities completed/experiments conducted during Year 2 included: Obj. 1. Prepare/characterize adsorbents from rice husk and sewage sludge, using varied pre-treatments. Obj. 1was completed during Year 1. Obj. 2. Develop and test PreSorb for removing natural organic matter, using batch tests. FESEM, Optical Microscopy and EDS analyses were completed for Presorb. Other items related to Obj. 2 were completed during Year 1. Obj. 3. Develop and test MultiSorb for removing perfluorinated compounds (PFAS) and pharmaceutical and personal care products (PPCPs), using batch tests. Final Multi-sorb candidates were chosen and tested in triplicate. FESEM, Optical Microscopy and EDS analyses were completed for Multisorb. Other items related to Obj. 3 were completed during Year 1. Obj. 4. Evaluate PreSorb and MultiSorb using column tests, which better simulate actual water treatment systems. Various methods of forming granules from the chosen adsorbents were explored. Several binders were tested (Molasses, Bentonite Clay); however, the granules would dissolve in water. To make the granules hard, heating was included to dry the mixture overnight, but it did not help. The literature was consulted to find alternative ways of producing the granules. Several articles suggested that the granules should be formed first, and then physical/chemical activation of the adsorbents conducted. This approach was tried successfully. A different binder (methylcellulose) was used this time. The raw Rice husk was mixed with binder at 5:1 ratio as well as chemical activation agent (H3PO4 for Presorb and ZnCl2 for Multisorb) at 2:1. The mixture was then dried and placed in Tube furnace. The durability was also tested by keeping the granules in water for 7 days. Granules were formed (RH-500-P for Presorb and RH-800-Zn for Multisorb) and during the extension period will be placed in a column and tested using real wastewater mixture with spiked concentration of PFAS and PPCP. Obj. 5. Compare costs for wastewater treatment using PreSorb/MultiSorb with commercial activated carbon. Obj. 5 was completed during Year 1.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Chakraborty, Mithila; Sattler, Melanie; Bhatt, Arpita. Waste-made Multisorber: A Solution to PFAS, PPCP and Heavy Metals in Leachate. Air & Waste Management Association National Conference, Orlando, FL, June 2023.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2022
Citation:
Chakraborty, Mithila. Multisorb: A Low-Cost Approach to Remove Multiple Metals and Organics from Leachate and Wastewater, Ph.D. Dissertation, University of Texas at Arlington, Aug. 2022
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Progress 08/01/21 to 07/31/22
Outputs
Target Audience:Our poster presentation at the Air & Waste Management Association AnnualConference reached stakeholders in government and consulting who deal with clean water issues. Changes/Problems:For KOH-activated adsorbents, activation at 650 and 800C could not be conducted because of high temperature generation inside the tube furnace due to chemical reaction. The adsorbents melted inside, and the tube broke several times due to high temperature. KOH activated adsorbents were only activated at 500C. The real wastewater samples had humic acid below the level of detection (<1000 ppm), so the results for hydrophobic fulvic acid only were considered. Samples from 6 water resource recovery facilities did not have the target pollutants above detection level. So, a mixture of wastewaters was spiked with the target PFAS and PPCPs, as has been done in other research studies. What opportunities for training and professional development has the project provided?Training for the Ph.D. student on the following instruments/analytical techniques: Liquid Chromatography-Mass Spectrometry (LC-MS/MS) for PFAS and PPCP analysis. Scanning Electron Microscopy (SEM) for morphology study. Fourier-transform infrared spectroscopy (FT-IR) for functional groups. How have the results been disseminated to communities of interest? Results were presented via poster at two conferences: Chakraborty, Mithila; Sattler, Melanie; Bhatt, Arpita. "Upgrading Wastewater for Irrigation Use: A Sustainable Approach to Removing Multiple Organics of Emerging Concern." Student poster, 115th Annual Conference of the Air & Waste Management Association. San Francisco, California, June 2022. Chakraborty, Mithila; Sattler, Melanie; Bhatt, Arpita. "Upgrading Wastewater for Irrigation Use: A sustainable Solution," UTA College of Engineering Innovation Day, April 2022. The first conference reached stakeholders in government and consulting who deal with clean water issues. The majority of dissemination will occur in year 2. What do you plan to do during the next reporting period to accomplish the goals?The primary goal during the next reporting period is to address the remaining objective, Obj. 4. Evaluate PreSorb and MultiSorb using column tests, which better simulate actual water treatment systems.
Impacts
What was accomplished under these goals?
Major activities completed/experiments conducted during Year 1 included: Obj. 1. Prepare/characterize adsorbents from rice husk and sewage sludge, using varied pre-treatments. Waste materials (rice husk, rice huck ash, sewage sludge, and sewage sludge char) were characterized for moisture content, solids content, volatile organic carbon, CHN content, and leaching of metals and organics. 48 adsorbents were attempted to be prepared using 3 different chemicals (ZnCl2, H3PO4, KOH) at 3 different temperatures (500, 650 and 800 deg. C) (4 wastes * 4 chemicals, including no chemical activation as a control * 3 temperatures = 48). They were also physically activated by steam. For KOH-activated adsorbents, activation at 650 and 800C could not be conducted because of high temperature generation inside the tube furnace due to chemical reaction. The adsorbents melted inside, and the tube broke several times due to high temperature. Thus, KOH-activated adsorbents were only activated at 500C. This gave 46 total adsorbents. Adsorbents were characterized individually using FESEM and optical microscopy (morphology); surface area, pore volume, and pore diameter (BET analysis); elemental composition (EDS) and functional groups (FT-IR). Mesopore-dominated adsorbents (all those chosen for Presorb and Multisorb) were found to be good adsorbers for PFAS (long chain PFOA, shorter chain PFBA) and PPCPs. For chemical activation, 500-650°C proved to be better activation temperatures than 800°C. ZnCl2 proved to be a better activating agent than KOH and H3PO4, in terms of creating adsorbents with high potential for removal of NOM, PFAS, and PPCP. Obj. 2. Develop and test PreSorb for removing natural organic matter, using batch tests. The 48 adsorbents prepared in Obj. 1, along with the 4 unaltered waste materials and commercial activated carbon as controls, were tested using synthetic wastewater and real effluent from 2 wastewater recovery facilities. 0.1 g of each adsorbent was placed in 120 ml bottles and a synthetic solution of humic acid was added to check adsorption. To reduce costs, only humic acid was added as a NOM source. After 24 hrs. of shaking, the solution was filtered and analyzed using method ISO 19822. Based on the data, the 23 adsorbents which performed better than commercial activated carbon (CAC) were shortlisted. For the shortlisted adsorbents, real effluent from 2 water resource recovery facilities (WRRF) was added, and the same procedure was followed. The real wastewater samples had humic acid below the level of detection (<1000 ppm), so the results for hydrophobic fulvic acid only were considered. Fulvic acid was found to be better adsorbed by 14 waste-made adsorbents compared to CAC. Among them, the best performing adsorbent, rice husk chemically modified with H3PO4 at 800 deg. C (RH-800-P), was then finalized as Presorb. The Presorb was then tested again with a spiked wastewater mix from 4 different WRRFs in triplicate, along with CAC. Presorb adsorbed hydrophobic fulvic acid on average than CAC. FESEM, Optical Microscopy and EDS analyses are being done for Presorb currently. The FT-IR data showed the presence of silanol, oxygen and carbonyl functional groups that favor the adsorption of NOM. Obj. 3. Develop and test MultiSorb for removing perfluorinated compounds (PFAS) and pharmaceutical and personal care products (PPCPs), using batch tests. The 48 adsorbents prepared in Obj.1, along with the unaltered waste materials and commercial activated carbon as controls, were tested using synthetic wastewater to determine the subsets most effective at adsorbing PFAS and PPCP. The top performers across the board were rice husk activated with zinc at 650 and 800C, equaling or slightly exceeding performance of commercial activated carbon (CAC) for all contaminants, most often adsorbing all of the contaminant in solution. Sewage sludge activated with zinc at 650 and 800 C were also top performers, equaling the performance of CAC for 4 of the 6 contaminants. 23 samples, which equaled the performance of CAC for at least one contaminant besides PFOA, were carried forward into the next phase for testing with real wastewater. The LC-MS/MS analysis found that the real effluent samples collected from 2 WRRFs did not have all of the target PFAS and PPCPs above the limit of detection, so samples were collected from 4 different WRRFs. The newly collected samples from WRRF facilities also did not have the target pollutants above detection level. So, the 4 different WWRF effluents were mixed together and spiked with the target PFAS and PPCPs, as has been done in other research studies. To be on the safe side, the concentration of pollutants achieved through spiking was 3 times higher than the detection level of the LC-MS/MS. Several adsorbents performed better than the CAC. Among them, the best performer for all the PFAS and PPCP was rice husk chemically modified with ZnCl2 at 800 deg. C. This adsorbent was shortlisted as Multisorb. The Multisorb was then tested with spiked wastewater solution in triplicate. The two CAC were also tested in triplicate. PFOA adsorption by Multisorb was found to be less than CAC. The PPCP adsorption, especially triclosan adsorption, was higher than one CAC. The FESEM, Optical Microscopy and EDS analysis are being done for Multisorb. The FT-IR data showed the presence of aromatic rings, silicon, oxygen, nitrogen containing functional groups. Obj. 4. Evaluate PreSorb and MultiSorb using column tests, which better simulate actual water treatment systems. This objective will be addressed in Year 2. Obj. 5. Compare costs for wastewater treatment using PreSorb/MultiSorb with commercial activated carbon. The total cost of producing waste-made adsorbents was compared to cost of producing CAC. All stages of the life cycled were considered. Neither type of adsorbent was assumed to be regenerated; regeneration would lower costs per lb of pollutant removed. The waste-made adsorbents' cost was found to be 22% of the cost of CAC.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
Chakraborty, Mithila; Sattler, Melanie; Bhatt, Arpita. Upgrading Wastewater for Irrigation Use: A sustainable Solution, poster for UTA College of Engineering Innovation Day, April 2022.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2022
Citation:
Chakraborty, Mithila; Sattler, Melanie; Bhatt, Arpita. Upgrading Wastewater for Irrigation Use: A Sustainable Approach to Removing Multiple Organics of Emerging Concern. Student poster, 115th Annual Conference of the Air & Waste Management Association. San Francisco, California, June 2022.
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