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- Creators: School of Life Sciences
The main objective of this study was to compare the synergic disinfection potential of titanium dioxide (TiO2) or peracetic acid (PAA) with UV for viruses and bacteria in water.
Both bench-scale and pilot-scale evaluation was done. A bench-scale collimated beam was included to evaluate the inactivation of P22 and E. coli by UV with and without TiO2 or PAA. A Purifics Photo-Cat system which is an integrated UV/ceramic membrane reactor was used for the pilot-scale TiO2-UV AOP experiments. For pilot-scale PAA-UV AOP experiments, an in-line D222 UV reactor unit provided by NeoTech Aqua Solutions, Inc. was used.
TiO2 doses of 1, 10, and 40 mg/L were applied in the collimated beam and the Photo-Cat system. Higher TiO2 doses resulted in a higher inactivation in the Photo-Cat and lower inactivation in the collimated beam apparatus. Adding 40 mg/L of TiO2 in the photo-Cat system improved P22 inactivation by 25% while it slightly decreased P22 inactivation in collimated beam apparatus.
PAA doses of 0.25 or 0.5 ppm were continuously injected upstream of the UV light and a 53% or 90% increase in inactivation was observed for E. coli, respectively, as compared to UV alone. However, P22 required higher dose with PAA-UV AOP and PAA concentrations of 1 or 10 ppm resulted in an 18% and 70% increase in the inactivation respectively, as compared to UV alone. Interestingly, when the same condition was applied to water with more organics (UVT 79%), E. coli exhibited the same level of susceptibility to PAA-UV AOP while P22 inactivation decreased.
The results provide new insight on the effectiveness and applicability of adding AOP to UV for microbial inactivation in water. PAA-UV AOP can potentially enhance existing UV disinfection systems with minimal chemical addition, and a simple retrofit to existing UV units.
The objective of this study was to develop an innovative and simple method to remove Cs+ present at low concentrations by engineering a proteoliposome transporter composed of an uptake protein reconstituted into a liposome vesicle. To achieve this, the uptake protein, Kup, from E. coli, was isolated through protein extraction and purification procedures. The new and simple extraction methodology developed in this study was highly efficient and resulted in purified Kup at ~1 mg/mL. A new method was also developed to insert purified Kup protein into the bilayers of liposome vesicles. Finally, removal of CsCl (10 and 100 ppb) was demonstrated by spiking the constructed proteoliposome in lab-fortified water, followed by incubation and ultracentrifugation, and measuring Cs+ with inductively coupled plasma mass spectrometry (ICP-MS).
The ICP-MS results from testing water contaminated with 100 ppb CsCl, revealed that adding 0.1 – 8 mL of Kup proteoliposome resulted in 0.29 – 12.7% Cs removal. Addition of 0.1 – 2 mL of proteoliposome to water contaminated with 10 ppb CsCl resulted in 0.65 – 3.43% Cs removal. These removal efficiencies were greater than the control, liposome with no protein.
A linear relationship was observed between the amount of proteoliposome added to the contaminated water and removal percentage. Consequently, by adding more volumes of proteoliposome, removal can be simply improved. This suggests that with ~ 60-70 mL of proteoliposome, removal of about 90% can be achieved. The novel technique developed herein is a contribution to emerging technologies in the water and wastewater treatment industry.
This thesis has three related elements for organics control in drinking water. First, coagulation chemistry for Alum and Aluminum Chlorohydrate (ACH) was optimized for significant organics removal to address membrane fouling issue at a local municipal water treatment plant in Arizona. Second, Rapid Small Scale Column Tests were conducted for removal of Perfluorinated compounds (PFC), PFC were present in groundwater at a local site in Arizona at trace levels with combined concentration of Perfluorooctaneoic Acid (PFOA) and Perfloorooctanesulfonic Acid (PFOS) up to 245 ng/L. Groundwater from the concerned site is used as drinking water source by a private utility. PFC Removal was evaluated for different GAC, influent concentrations and particle sizes. Third, a new testing protocol (Mini Carbon Block (MCB)) for bench scale study of POU water treatment device, specifically carbon block filter was developed and evaluated. The new bench scale decreased the hydraulic requirements by 60 times approximately, which increases the feasibility to test POU at a lab scale. It was evaluated for a common POU organic contaminant: Chloroform, and other model contaminants.
10 mg/L of ACH and 30 mg/L of Alum with pH adjustment were determined as optimal coagulant doses. Bituminous coal based GAC was almost three times better than coconut shell based GAC for removing PFC. Multiple tests with MCB suggested no short circuiting and consistent performance for methylene blue though chloroform removal tests underestimated full scale carbon block performance but all these tests creates a good theoretical and practical fundament for this new approach and provides directions for future researchers.
TSPO was discovered in 1977 and it’s function is still currently unknown. Significant research has suggested that TSPO functions in steroidogenesis to import cholesterol from the mitochondrial outer membrane (MOM) to the mitochondrial inner membrane (MIM) where it is converted into steroids. There were two indications that this is TSPOs main function: its elevated levels in steroidogenic tissue and its primary location in the MOM. There is evidence of TSPO binding cholesterol with high affinity, however there is not currently evidence of TSPO transporting cholesterol. STAR, ACBD1, and ACBD3 are proteins thought to be associated with TSPO and steroidogenesis. However, the distribution of these proteins in various eukaryotes show little similarity suggesting that TSPO functions independently. The function of TSPO in steroid synthesis has been called into question because a well-cited research paper claimed that TSPO knockdown resulted in embryonic lethal mice, however there was no evidence presented from their study and this experiment did not produce the same results when repeated in later studies. There are also studies that show TSPO may not be involved in regulation of sterols, but instead may regulate cell stress. The elevated levels of TSPO during inflammation suggest a role for TSPO in cellular stress. Binding interactions with porphyrins and heme also support that TSPO may modulate stress levels. We used the phylogeny of TSPO in order to gain greater insight into the evolutionary function of TSPO. NCBI BLAST searches revealed that TSPO was present in bacteria and had a widespread but patchy distribution in a small set of eukaryotes. From these initial results, we were prompted to search a larger set of eukaryotes for TSPO. All of the prokaryotic and eukaryotic TSPO sequences were used to create a phylogenetic tree that would provide greater insight into the evolution and function of TSPO. If TSPO was from a common ancestor, it is probable that its function is related to sterol regulation whereas if gained in eukaryotes by horizontal gene transfer from bacteria its function is related to stress regulation. The phylogenetic tree was most consistent with an ancestral origin of TSPO with an evolutionary function related to steroid synthesis regulation. However, there is not sufficient research to confirm the function of TSPO.
Recent studies indicate that words containing /ӕ/ and /u/ vowel phonemes can be mapped onto the emotional dimension of arousal. Specifically, the wham-womb effect describes the inclination to associate words with /ӕ/ vowel-sounds (as in “wham”) with high-arousal emotions and words with /u/ vowel-sounds (as in “womb”) with low-arousal emotions. The objective of this study was to replicate the wham-womb effect using nonsense pseudowords and to test if findings extend with use of a novel methodology that includes verbal auditory and visual pictorial stimuli, which can eventually be used to test young children. We collected data from 99 undergraduate participants through an online survey. Participants heard pre-recorded pairs of monosyllabic pseudowords containing /ӕ/ or /u/ vowel phonemes and then matched individual pseudowords to illustrations portraying high or low arousal emotions. Two t-tests were conducted to analyze the size of the wham-womb effect across pseudowords and across participants, specifically the likelihood that /ӕ/ sounds are paired with high arousal images and /u/ sounds with low arousal images. Our findings robustly confirmed the wham-womb effect. Participants paired /ӕ/ words with high arousal emotion pictures and /u/ words with low arousal ones at a 73.2% rate with a large effect size. The wham-womb effect supports the idea that verbal acoustic signals tend to be tied to embodied facial musculature that is related to human emotions, which supports the adaptive value of sound symbolism in language evolution and development.
On March 11th, COVID-19 was declared a pandemic by the World Health Organization. The ensuing months saw an extensive allocation of resources toward combating the virus and the development of a vaccine. Despite extensive research on SARS-CoV-2, there remains little information regarding the implications of SARS-CoV-2 gastrointestinal shedding on COVID-19 disease. It is hypothesized that SARS-CoV-2 RNA is shed in the stool for up to several weeks and that viral protein persists in the GI tract. This study also explored calprotectin and zonulin levels, markers of inflammation, and intestinal permeability, respectively, to assess if increased viral shedding is associated with elevated levels of either. This study utilized RT-qPCR assays to confirm the presence of viral RNA. Subsequently, RT-qPCR positive samples were heat-inactivated and SARS-CoV-2 spike detection enzyme-linked immunosorbent assay (ELISA) was used to ascertain viral protein shedding. Additional ELISA was performed to assess zonulin and calprotectin levels. Results indicated that 30 of the 758 unique samples were confirmed SARS-CoV-2 positive by RT-qPCR. Spike protein was ultimately not detected by ELISA. Additionally, no significant increase in zonulin was observed in patient samples when comparing RT-qPCR positive and negative Samples. A notable upwards trend approaching significance in calprotectin levels existed for patients who tested positive for SARS-CoV-2 by RT-qPCR, though, it was found that no correlation existed between SARS-CoV-2 copy number and calprotectin levels. Understanding the interaction between SARS-CoV-2 and the GI tract may therefore have significant clinical implications and this study demonstrates the need for additional studies to garner a more comprehensive understanding.
