eNews July 2019

NMSU Graduate Student Synthesizing Highly Porous Monoliths to Adsorb Chromium Ions from Groundwater

By Catherine Ortega Klett, NM WRRI Senior Program Manager

Last year, Zahra Abbasian, a graduate student in the NMSU Department of Chemical and Material Engineering, received an NM WRRI Student Water Research Grant entitled: Recyclable Monolithic Aerogels as Efficient Adsorbents for Chromium VI Removal from Rural Ground-Water Resources. The award was funded through the Bureau of Reclamation-NMSU Cooperative Agreement, Center for the Development and Use of Alternative Water Supplies. Zahra is working under the guidance of her faculty advisor Dr. Reza Foudazi, Associate Professor of Chemical and Material Engineering at NMSU. She presented her student grant research in Las Cruces at NM WRRI’s 63rd Annual New Mexico Water Conference in October 2018 and commented, “Attending the conference gave me a great opportunity to interact with local water experts in person.” She added that she has become more connected with relevant academic research being conducted in the area and has been able to share research challenges and ways to tackle her research project.

In July 2017, the Los Alamos National Laboratory detected chromium, Cr, in their sole source regional groundwater aquifer at a level that was five times the amount designated as safe according to the groundwater standards for New Mexico. This was due to the presence of the highest oxidation state of chromium ions, Cr(VI), which is a highly toxic carcinogen.

The most common conventional method for removal of Cr(VI) is to lower the oxidation state and use lime to precipitate out the chromium as insoluble chromium hydroxide. This approach is not very cost effective because it produces a large amount of sludge. Other approaches are based on the adsorption of Cr(VI) by a variety of natural and synthetic materials such as activated carbon, biological materials, porous minerals such as zeolites, and industrial wastes. The focus of Zahra’s research is the synthesis of a porous monolith by using polymerized high internal phase emulsions, polyHIPEs, containing polypyrrole. The result is a nanocomposite porous monolith that is an efficient and recyclable adsorber of Cr(VI). In addition to common synthetic polymers, chitosan will also be used. Chitosan is obtained from chitin, which is the natural structural chemical used to build exoskeletons in crustaceans like shrimp, crabs, and lobsters. It is easily made by treating chitin with an alkaline substance like sodium hydroxide (lye); the result is an inexpensive water-soluble polymer. Polypyrrole is a key component in Cr(VI) removal. In her experimental method, Zahra oxidizes pyrrole in solution with chitosan or polyHIPEs in the presence of a dye, methyl orange, which promotes the formation of nanotubes in the resulting porous monolith.

Results to date suggest these porous monoliths act as a high capacity adsorber of Cr(VI). Furthermore, they are synthesized out of relatively eco-friendly and inexpensive materials. Compared to other existing adsorbents, it also has the advantages of being recyclable, and its production generates a relatively small amount of waste material. It is anticipated that this approach to Cr(VI) removal will have a beneficial impact on the general problem of providing safe drinking water by the removal of metal ion contaminants.

Zahra expects to complete her studies and graduate from NMSU with a PhD in chemical engineering in August of 2021. She received her BS degree (2005) from Shiraz University, and her MS degree (2009) from Iran University of Science & Technology (IUST), both located in her home country of Iran. Given the growing demand for drinking water worldwide, and the concomitant growth in the production of industrial wastes, Zahra hopes to make a significant contribution, in academia or industry, in the disciplines of water quality and wastewater treatment.

eNews July 2019

NM WRRI Hosts Border Water Resources Research Workshop

By Ashley Page, NM WRRI Program Specialist

Approximately 50 attendees from the United States and Mexico participated in the Innovative, Multidisciplinary Water Research to Address the Needs of the US-Mexico Border Corridor workshop at New Mexico State University (NMSU) on June 11, 2019. NMSU and the New Mexico Water Resources Research Institute hosted the event in collaboration with colleagues at the Autonomous University of Chihuahua.

The event began with a welcome address from NMSU Vice President of Research, Dr. Luis Cifuentes. Researchers with expertise in a variety of disciplines presented talks on critical border water issues; their presentations framed the afternoon’s small group discussions. Five small theme groups, based on the interests of attendees, were established. The theme groups – transboundary aquifers, water quality, watersheds, water education, and urban water – each brainstormed an innovative research project that met the multidisciplinary strengths of their team. The groups then presented their research project ideas to expert panelists for feedback. Teams will use this feedback to revise their proposals in the coming months to ensure their objectives are fundable and best meet the needs of the border region.

The workshop in Las Cruces took place as part of a larger effort by the National Science Foundation sponsored Border Solutions Alliance (BSA). The BSA is a multi-university collaboration that includes NMSU, University of Arizona, University of California at San Diego, University of Texas at El Paso, and University of Texas at San Antonio. The Alliance hosted two workshops in June – one in San Diego and Tijuana (June 5-7, 2019) and one in El Paso and Las Cruces (June 10-12, 2019) – that sought to facilitate research partnerships among border region experts. The San Diego and Tijuana workshop focused on  advanced manufacturing and digital services, intelligent mobility and safe borders, and urban resilience. In addition to the border water resources topic, the El Paso and Las Cruces workshop highlighted disaster management and healthcare.

eNews July 2019

USGS 104B Award Announced by NM WRRI

By Carolina Mijares, NM WRRI Accountant

NM WRRI announced its faculty grant award associated with the Research Grant between US Geological Survey and New Mexico State University, 104B State Water Resources Research Institute Program. The 104B program focuses on providing water quality and quantity information, understanding water availability, addressing the influence of climate on water resources, and responding to water-related emerging needs. Director Sam Fernald is the Lead PI on the program.

In response to the NM WRRI 2019 Request for Proposals, faculty receiving the new 104B award are Dr. Daniel Cadol, New Mexico Tech, and Dr. Talon Newton, New Mexico Bureau of Geology and Mineral Resources. Dr. Cadol describes the project below.

Evaluating focused aquifer recharge in arid regions using chloride profile analysis

Groundwater recharge is challenging to measure, yet it is the cornerstone of sustainable water use in semi-arid regions such as New Mexico. Aquifers that are not recharged represent economic time bombs: communities built on such finite resources have a finite lifetime. Accurately assessing recharge is fundamental to determining the stability of social-hydrological systems.

Recent work, conducted at the Jornada Experimental Range, suggests that small, essentially un-mapped channels (commonly termed ‘zeroth-order channels’) may be an important location for such focused recharge in creosote-vegetated rangelands of the Chihuahuan Desert (Schreiner-McGraw and Vivoni, 2017). Previously, creosote was thought to preclude recharge due to the high soil tensions created by the water extractive capabilities of its roots (e.g., Sandvig and Phillips, 2006).

The scientific goal of this project is to test the hypothesis that significant aquifer recharge occurs in these zeroth-order channels in the Jornada Experimental Range. We will test this hypothesis by analyzing the accumulated chloride within the soil and sediment profile underlying these small channels and their surrounding interfluves or hillslopes. A lack of chloride in the sediment profile under these small channels would suggest that downward-percolating water, focused into these channels during overland runoff, had transported the atmospherically deposited chloride below the root zone, and presumably to the aquifer below. A persistent chloride bulge would indicate the lack of water infiltrating below the root zone, meaning the vegetation community uses all infiltrated water to supply transpiration.

Should the findings of Schreiner-McGraw and Vivoni (2017) hold, this insight into aquifer recharge from precipitation onto basin piedmont geomorphic surfaces would fundamentally change our perception of water-use sustainability in these regions. This recharge would represent an untapped resource in a water-limited region.