Recipient Organization
RECINTO UNIVERSITARIO MAYAGUEZ
259 BLVD ALFONSO VALDES
MAYAGUEZ,PR 00680-6475
Performing Department
(N/A)
Non Technical Summary
The present research addresses the Water Resources priority through the development of a novel column-based filtration system using recycled and biocompatible materials for municipal wastewater reuse for crop irrigation. This project is relevant to the interest of USDA because it addresses the importance of reusing municipal wastewater efficiently and safely for future demands in agriculture. It includes an outreach component to train K-12 teachers and students in the importance of water resources and water remediation technologies through workshops, seminars and hands-on experience. The main goal is the development and upscale of a reproducible, cost-effective, environmental friendly columnar filtrations system for wastewater reuse for crop irrigation. Column filters made out of recycled (tire crumb rubber (TCR) and bio-compatible composite polymers made of Calcium alginate, chitosan, chitin and cellulose will provide innovative and safe alternatives for the removal of disinfection by products (DBPs) from wastewater. Composite materials offer the advantages of simultaneously removing a wide spectrum of contaminants of organic and inorganic origin including metals. The major milestones are: synthesis of the composite adsorbents; the determination and optimization of uptake capacity of DBPs including the adsorption/desorption reuse cycles; kinetic parameters and isotherm models; design and scale up of the columnar filtration system; evaluation of its efficiency using real effluents form wastewater treatment plant; the involvement K-12 teachers and students in hands-on experience research; dissemination of findings. This project will develop the necessary skills to prepare the postdoctoral fellow to enter the workforce in area that is fundamental to agriculture.
Animal Health Component
40%
Research Effort Categories
Basic
20%
Applied
40%
Developmental
40%
Goals / Objectives
Technological goals: the development of a green, in-situ filtration system to remove disinfection by-product (DBP) contaminants from wastewaters intended for reuse in agricultural related practices (ARPs) using recycled (tire crumb rubber; TCR) and bio-compatible materials (e.g., chitin, cellulose, chitosan, alginates). Scientific/Research goals: the development of broad spectrum green adsorbent materials with enhanced removal properties; elucidation of the removal mechanisms involved in the adsorbate/adsorbent systems through batch and column experiments; determination of optimum parameters to develop an on-site filtration system for water reuse in ARPs. Commercialization vision: targeting of possible commercial and patenting opportunities related to green, cheap and efficient adsorbent materials for the filtration of treated wastewater intended for reuse in ARPs. Educational goal: design and implement of special topic courses at the graduate and undergraduate level emphasizing the essentials and importance of green remediation technologies (GRTs) and its applications in areas of interest to USDA such as water reuse, food safety, among others. Outreach goals: Collaborate in an effective mentoring program to recruit the next generation of scientists in the U.S. in GRTs and Agriculture; encouragement of school students and teachers of all levels in active learning activities (development of hands-on classroom experiments, summer research initiatives, motivational lectures and seminars, visits to on/off campus agriculture related facilities, improvement of scientific communication skills). All activities will be strongly coordinated with the fellow mentor who is also Director of CETARS; which foresees education and outreach activities to impact the pipeline in Agriculture related fields from the K-12 to the Ph.D. level. The USDA-NIFA fellow will be part of these activities. Overall vision: To become a highly qualified and competitive researcher and educator in the development and application of technologies pertinent to the conservation of the water resources in Agriculture.?
Project Methods
Methods1. Adsorbents TCR is provided by Rubber Recycling and Manufacturing Company Inc., (REMA), Puerto Rico. TCR mesh 30 (average diameter 0.67 mm) will be washed with deionized water for 24 hours in order to remove dirt or other type of particles that might remain on TCR prior and after the shredding process. Then, TCR is dried at room temperature.2. Synthesis of Chitosan Beads (CB):The synthesis of CB will be carried out by a previous protocol develop by Padilla et al.. Chitosan powder (2% w/v) will be dissolved in glacial acetic acid solution (5%). The resulting viscous chitosan solution will be pumped through a peristaltic pump and added dropwise into a 1.0 M aqueous NaOH solution to form uniform CB. The aqueous NaOH solution will be placed in a magnetic stirrer and continuously stirred at 200 rpm. After gelling in a 1.0 M NaOH solution, the beads will be rinsed with deionized water to remove excess NaOH. The content will be filtrated using a filter paper (Whatman filter paper No. 1), and finally dried at room temperature or at 60 °C.3. Synthesis of Ca-Alginate Beads (CAB):The synthesis of CAB will be prepared following Sanchez-Rivera et al. and Luna-Pineda et al. protocols. A 2% solution of low-viscosity sodium alginate will be added drop-wise into [0.01-0.5M] CaCl2 aqueous solutions under gentle mechanical stirring. Synthesized beads remain in contact with the calcium solution for 24 hours at room temperature. At the end of this contact period, the beads are recovered, rinsed with deionized water and aerated to accelerate their drying.4. Synthesis of TCR entrapped in Ca-Alginate Beads (TCR/CAB):The synthesis of the TCR/CAB will be prepared following López-Morales et al. protocol. The TCR/CAB (diameter, 1.6 mm) will be synthesized using a mixture 2% w/v alginic acid and 1.5% w/v TCR solutions in a dropwise addition at 0.70 ml/minute in 500 mL of a 0.1M CaCl2 solution. The resulting beads are magnetically agitated at 60 rpm for 24 hours, allowing the cross-linking reaction and immobilization of the rubber in the polymeric matrix of the CAB. After 24 hours, the beads are washed three times with 100 ml portions of deionized water (Barnstead, 18.2 MΩ) and allowed to dry at room temperature (25 °C) for another 72 hours.5. Materials Characterization:UV-Vis spectroscopy will be used to evaluate the optical properties of the CB and CAB. Structural characterization of the materials prior and after the sorption processes will be carried out using XRD, Raman and FT-IR techniques. Likewise, size and morphology of CB and CAB and their modifications will be examined by TEM, HRTEM and SEM techniques; EDAX will be used to determine the qualitative chemical composition of the adsorbent surfaces prior and after the sorption process. The net surface charge of the CB and CAB will be determined by the method of point of zero charge (pHpzc) described by López-Morales et al.. BET will be used to determine the specific surface area of the CB and CAB.6. Analyses:Analyses will be performed using Electrospray Ionization-Liquid Chromatography-Mass Spectrometry (ESI-LC-MS) in negative mode. The chromatographic conditions will be optimized for single and multi-component matrices.7. Adsorption and Desorption Experiments: Adsorption experiments will be performed in batch mode for single and multi-component matrices using 120-ml amber bottles containing100 mL of the adsorbate solutions. The different adsorbents (1g/L-10g/L) will be placed in contact with the adsorbate solutions at different concentrations using a thermostat controlled shaker at different temperatures (°C). Adsorption experiments will be carried out in a pH range of 3 to 9. Obtained data will be used to calculate the corresponding adsorption isotherms and assess the adsorbent capacity of each sorbent material. Desorption experiments will be performed in batch mode for single and multi-component matrices using the same conditions as in the adsorption experiments. The adsorbents with the loaded adsorbates will be removed from the solution by filtration, washed with de-ionized water, then vacuum dried for 30 minutes and later transferred to clean amber bottles containing different eluents (water at various pH, methanol, and ethanol). Then, the bottles will be placed in a shaker using conditions previously described. All experiments will be performed in triplicates.8. Adsorption/Desorption Cycles:Successive adsorption/desorption experiments will be performed for five cycles using the conditions previously described in proposal to evaluate the adsorbents uptake capacity and their potential as reusable adsorbent materials. All experiments will be performed in triplicates.9. Column Experiments and Adsorption Kinetic Studies:Data acquired from previous experiments will be used to determine the optimal concentration of adsorbate/adsorbent materials for the column tests. Columns packed with the adsorbents and mixtures of the adsorbents at different w/w ratios will be used to determine the optimum matrix for contaminant removal. Adsorbate solutions (single and multi-component matrix) will be loaded into each column by a peristaltic pump and intervallic analysis of the eluate will be analyzed to confirm breakthrough. Column parameters such as bed length flow and adsorbate concentration will be evaluated to obtain the respective breakthrough curves. Saline solutions will also be loaded to the packed columns to evaluate salt filtration using these materials. Sorption/desorption capabilities will be tested as well during the column tests. Adsorption kinetic studies are essential to obtain the rate of the adsorbates uptake on the adsorbents, which controls the equilibrium time. The kinetic of the adsorption data generated in the batch and column experiments will be evaluated using three kinetic models: the pseudo-first order, pseudo-second-order and Elovich equations.10. Project evaluation: The evaluation of the performance (scientific and educational outcomes) of the NIFA fellow will be based on monthly progress assessments based on the intended outcomes through meetings with the mentor and involved students. The Report of the Academic Competitiveness Council, May 2007, Federal STEM Goals and Metrics, Education Undergraduate National Goals and Metrics will also be used to evaluate undergraduate students. Involved students and teachers and their outputs (presentations, modules, science fair projects, presentations at conferences, publications) will be considered to evaluate the fellow's work. The scientific productivity of the fellow will be evaluated based on the number of peer-reviewed publications (he is expected to produce at least 4 manuscripts by the end of the fellowship), patent applications and presentations at USDA-NIFA meeting and other national conferences.11.Dissemination plan:the fellow will present his work at scientific meetings (Nanotech, ACS and others) and publish it in peer-reviewed journals, e.g. Journal of Agricultural and Food Chemistry, Environmental Science and Technology, Water Research and Materials Characterization, among others. The progress of the research will be posted in José L. López-Morales profile at LinkedIn professional network. The fellow will also prepare periodical reports for a wide audience and present them on the UPRM webpage, UPRM newsletter and UPRM YouTube channel.