Production of Lithium Carbonate from Geothermal Brine by Selective Extraction of Lithium Using a Novel Ion Sieve Method

The project implements a novel approach to extract lithium from a geothermal brine with minimal water loss. Production of high-capacity lithium-ion (Li-ion) batteries for electric vehicles (EV) is believed to be the way to reduce dependence on fossil-fuel based vehicles. Currently, most of the lithium in the world comes from the mining of lithium or the evaporative/concentration of the brine. Mining is not environmentally friendly, and the evaporative process takes 12 months for the completion of the extraction process and results in a large amount of water loss which can lead to scarcity of water. The brines constitute 82% of world reserves while the other 17% is the ore mineral. Hence, there is a need to transition to a sustainable brine extraction process to keep up with the demand of lithium in the market. To address these issues, we are designing and developing a method to efficiently extract lithium from a geothermal brine using a low-cost, simple, easily scalable, and low-water-use adsorption technique. We will produce and utilize the H4Mn4.9Zr0.1O12 compound for the adsorption of lithium from the brine and then use HCl for the desorption of lithium. In the end, we will produce high-purity lithium carbonate that can be used in a Li-ion battery. The major benefit of the system is that the excess geothermal water can eventually be recycled back as there is no production of toxic chemical substances. The process will significantly increase the domestic production of lithium which will eventually eliminate the need for lithium import to produce electric vehicles. The health hazards caused by lithium mining will also be eliminated by the application of this process. Since most of the chemicals are recycled back, net waste during the extraction process is minimum.https://digitalcommons.odu.edu/gradposters2023_engineering/1003/thumbnail.jp

Reduced metal nanocatalysts for selective electrochemical hydrogenation of biomass-derived 5-(hydroxymethyl)furfural to 2,5-bis(hydroxymethyl)furan in ambient conditions

Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures, i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests the formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits a slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg exhibits more than two times higher ECH performance without compromising the selectivity for 5-(HydroxyMethyl) Furfural (HMF) to 2,5-bis(HydroxyMethyl)-Furan (BHMF) formation in comparison to the Ag film. Moreover, a similar ECH current density was recorded at a reduced working potential of 220 mV for rAg. This high performance of rAg is attributed to the formation of new catalytically active sites during the Ag oxidation and reduction processes. This study demonstrates that rAg can potentially be used for the ECH process with minimum energy consumption and a higher production rate

Lithium Extraction From Aqueous Solution Using Magnesium Doped Lithium Ion-Sieve Composite

This study focused on the development of a magnesium doped ion-sieve composite to extract lithium from an aqueous solution using adsorption process. The extraction process will provide a sustainable alternative to the currently practiced solar evaporation/concentration method which is very slow (takes 24 months) and water intensive. Currently, most of the lithium in the world comes from the mining of lithium or from the evaporative extraction process from the brine. Additionally, the Salton Sea area geothermal brines are recognized as potentially important domestic sources of lithium. Lithium concentration in geothermal brines from the Salton Sea area is reported to be as high as 400 mg/L where the process of adsorption can be implemented to gain maximum removal percentage of lithium. In this study, a novel low-cost, simple, and low water use adsorption process was developed using a magnesium doped ion-sieve composite material for extracting lithium from aqueous solution. Composites with chemical formula H4Mn5-xMgxO12 where x= 0,0.1, 0.5 were used as an adsorbent and chose the best adsorbent for further studies. The synthesized Mg-doped H4Mn4.5Mg0.5O12 showed the removal percentage of 48% for the lithium in 4 hours. On the other hand, the undoped adsorbent took long time (about 24 hours) to attain equilibrium. The optimum dose that led to achieve the result was 25 mg in 25 ml of solution with 62 ppm lithium concentration. Additionally, the adsorption process at room temperature showed the optimum condition for achieving maximum lithium adsorption. Furthermore, a pH of 11 was found to be the most favorable condition for the adsorption process. The experimental desorption amount at equilibrium point was found to be 30 mg.g-1

Carriage of Extended-Spectrum-β-Lactamase- and AmpC-β-Lactamase-Producing Enterobacteriaceae (ESBL-PE) in Healthy Community and Outpatient Department (OPD) Patients in Nepal

Background. Extended-spectrum β-lactamase (ESBL)- and AmpC-β-lactamase-producing Enterobacteriaceae have recently emerged as a public threat in the treatment of nosocomial as well as community-acquired infections. Very little information is currently available about its existence in Nepal. We, therefore, aim to determine the prevalence of ESBL and AmpC-β-lactamase-producing Enterobacteriaceae and also to determine their drug resistance pattern. Methods. During a 6-month period (November 2014–April 2015), a total of 190 stool specimens from 190 participants were obtained from different population. Of the total 260 fecal isolates, 152 from outpatient department (OPD) and 108 from healthy volunteer were collected. Stool specimens were cultured and enterobacterial isolates were subjected to antimicrobial susceptibility tests according to the standard microbiologic guidelines. ESBL was screened using ceftazidime (CAZ, 30 μg) and cefotaxime (CTX, 30 μg) disks and confirmed by double-disk synergy test. AmpC-β-lactamase enzyme production was detected by the aminophenylboronic acid inhibitor-based detection method. Antibiotic susceptibility test was performed for ESBL-positive isolates as per the Kirby-Bauer disk diffusion method, and interpretation was done according to CLSI (Clinical and Laboratory Standard Institute). Results. The prevalence of ESBL, AmpC-β-lactamases, and coproducer (ESBL + AmpC-β-lactamase) producing Enterobacteriaceae in OPD participants were 30.92%, 18.4%, and 13.81%, respectively, while 25%, 6.4%, and 1.8% in healthy population. ESBL-producing E. coli was 70.2% followed by K. pneumoniae (12.7%), and among AmpC-β-lactamase producer, E. coli were detected in half of the isolates (14/28, 50.0%) among OPD patients. Similarly, E. coli remained the most frequent ESBL producers 21/27 (77.8%) followed by K. pneumoniae 4/27 (14.21%) in healthy participants, and K. pneumoniae 5/7 (71.42%) and C. freundii 2/7 (28.57%) were detected highest among AmpC-β-lactamase-producing isolates. All isolates were highly sensitive (100%) to imipenem in both OPD and healthy participants. Conclusion. Our study revealed a high prevalence of ESBL- and AmpC-β-lactamase-producing enteric pathogen in Nepalese OPD and healthy population. The significant increase of these isolates and increased rate of drug resistance indicates a serious threat that stress the need to implement the surveillance system and a proper control measure so as to limit the spread of ESBL-producing Enterobacteriaceae (ESBL-PE) in both OPD as well as in community. Therefore, healthcare providers need to be aware that ESBL- and AmpC-β-lactamase-producing strains are not only circulating in hospital environments but also in the community and should be dealt with accordingly