Much of Nepal lacks access to clean drinking water, and many water sources are contaminated with arsenic at concentrations above both World Health Organization and local Nepalese guidelines. While many water treatment technologies exist, it is necessary to identify those that are easily implementable in developing areas. One simple treatment that has gained popularity is biochar—a porous, carbon-based substance produced through pyrolysis of biomass in an oxygen-free environment. Arizona State University’s Engineering Projects in Community Service (EPICS) has partnered with communities in Nepal in an attempt to increase biochar production in the area, as it has several valuable applications including water treatment. Biochar’s arsenic adsorption capability will be investigated in this project with the goal of using the biochar that Nepalese communities produce to remove water contaminants. It has been found in scientific literature that biochar is effective in removing heavy metal contaminants from water with the addition of iron through surface activation. Thus, the specific goal of this research was to compare the arsenic adsorption disparity between raw biochar and iron-impregnated biochar. It was hypothesized that after numerous bed volumes pass through a water treatment column, iron from the source water will accumulate on the surface of raw biochar, mimicking the intentionally iron-impregnated biochar and further increasing contaminant uptake. It is thus an additional goal of this project to compare biochar loaded with iron through an iron-spiked water column and biochar impregnated with iron through surface oxidation. For this investigation, the biochar was crushed and sieved to a size between 90 and 100 micrometers. Two samples were prepared: raw biochar and oxidized biochar. The oxidized biochar was impregnated with iron through surface oxidation with potassium permanganate and iron loading. Then, X-ray fluorescence was used to compare the composition of the oxidized biochar with its raw counterpart, indicating approximately 0.5% iron in the raw and 1% iron in the oxidized biochar. The biochar samples were then added to batches of arsenic-spiked water at iron to arsenic concentration ratios of 20 mg/L:1 mg/L and 50 mg/L:1 mg/L to determine adsorption efficiency. Inductively coupled plasma mass spectrometry (ICP-MS) analysis indicated an 86% removal of arsenic using a 50:1 ratio of iron to arsenic (1.25 g biochar required in 40 mL solution), and 75% removal with a 20:1 ratio (0.5 g biochar required in 40 mL solution). Additional samples were then inserted into a column process apparatus for further adsorption analysis. Again, ICP-MS analysis was performed and the results showed that while both raw and treated biochars were capable of adsorbing arsenic, they were exhausted after less than 70 bed volumes (234 mL), with raw biochar lasting 60 bed volumes (201 mL) and oxidized about 70 bed volumes (234 mL). Further research should be conducted to investigate more affordable and less laboratory-intensive processes to prepare biochar for water treatment.

Using DFT calculations and GAMESS computational software, porphine and its derivatives were analyzed for unique sites to accept the adsorbates As(III), As(V) and P(V) in order to compare resulting adsorption energies and determine if any of these molecules prefer arsenic oxyanions over phosphate. Pure porphine preferred As(III) over P(V) with a resulting adsorption energy of -0.7974 eV. Of the functionalized porphyrins tested, carboxyl porphyrin preferred As(V) over P(V) with a total adsorption energy of -0.7345 eV. Ethyl, methyl, chlorine and amino porphyrin all preferred As(III), with energies of -0.7934, -0.8239, -0.7602, and -0.8508 eV, respectively. Of the metalated porphyrins tested, copper and vanadium porphyrin preferred As(V) over P(V) with adsorption energies of -0.7645 and -2.0915 eV. Chromium, iron and magnesium porphyrin all preferred As(III) over P(V) with energies of -0.5993, -1.4539, and - 1.0790 eV, respectively.

With an estimated 19.3 million cases and nearly 10 million deaths from cancer in a year worldwide, immunotherapies, which stimulate the immune system so that it can attack and kill cancer cells, are of interest. Tumors are produced from the uncontrolled and rapid proliferation of cells in the body. Cancer cells rely heavily on glutamine for proliferation due to its contribution of nitrogen for nucleotides and amino acids. Glutamine enters the tricarboxylic acid (TCA) cycle as α-ketoglutarate via glutaminolysis, in which glutamine is converted into glutamate by the enzyme glutaminase (GLS). Cancer cell proliferation may be limited by using glutaminase inhibitor CB-839. However, immune cells also rely on these metabolic pathways. Thus, a method for restarting the metabolic pathways in the presence of inhibitors is attractive. Succinate, a key metabolite in the TCA cycle, has been shown to stimulate the immune system despite the presence of metabolic inhibitors, such as CB-839. A delivery method of succinate is through microparticles (MPs) or nanoparticles (NPs) which may be coated in polyethylene glycol (PEG) for improved hydrophilicity. Polyethylene glycol succinate (PEGS) MPs were generated and tested in vivo and were shown to reduce tumor growth and prolong mouse survival. With the success in stimulating the immune system with MPs, NPs were investigated for an improved immune response due to their smaller size. These PES NPs were generated in this study. For clinical settings, it is necessary to scale-up the production of particles. Two methods of scale-up were proposed: (1) a combination of multiple small batches into a mixed batch, and (2) a singular, big batch. Size and release properties were compared to a small batch of PES NPs, and it was concluded that the big batch more closely resembled the small batch compared to the mixed batch. Thus, it was concluded that batch-to-batch variability plays a larger role than volume changes when scaling-up. In clinical settings, it is recommended to produce the particles in a big batch rather than a mixed batch.

Utilizing DFT calculations, various substitutions on the AlPO-5 zeolite were screened for adsorption of common air molecules. Furthermore, free energy analyses using the Helmholtz free energy equation were performed to determine candidates for selective adsorption of one specific air molecule, and their operating temperature range. Through this study, it was found that Cerium- (92-542 K), Germanium- (69-370 K), Chromium- (35-293 K), and Praseodymium- (0-420 K) substituted AlPO-5 selectively adsorbs to O2 molecules for the given temperature ranges. In addition, Palladium-substituted AlPO-5 selectively adsorbs to CO within 430-755 K.