Oil Adsorption Capacities of Organic Materials

Overview

With over 4.9 million liters of raw petroleum being released into the oceans each year, a simple, cost-effective, and easily replicable method of oil removal must be found, both for the safety of our marine ecosystems and the economic impact lost oil has on industry. This experiment was conducted to determine which natural oleophilic material has the highest adsorption capacity for motor oil, a safer sand-in for raw petroleum. Out of 6 tested sorbents: cotton, kapok, duck feathers, peat-moss, wheat-straw, and rice-husk, the hypothesis predicted that raw cotton would have the highest adsorption capacity due to its waxy fiber structure. All tested sorbents were prepared by removing foreign contaminants and cutting the samples to a uniform size. To contain these sorbents, each pre-weighed sample was placed inside a nylon mesh bag. For each trial, the nylon mesh was placed into a plastic container containing 2L of saltwater and 150mL of oil. The sorbents, placed on the surface, were turned over after 2 hours and removed after 4 hours. Polypropylene pads cleaned the remaining oil from the containers. These pads were weighed and used to determine the mass of oil adsorbed by the sorbent. A control trial (no sorbent in the nylon bag) determined whether or not the nylon adsorbed a significant amount of oil. Next, 6 trials were performed for each sorbent. Graphing the data with SEM error bars suggested that a significant difference between the adsorption capacities of the different sorbents existed. T-tests determined that the adsorption capacity of the cotton, kapok, and duck feathers was significantly greater than the control value, with duck feathers having both the greatest adsorption capacity (12.08g/g) and the greatest significant difference from the control. Therefore, the hypothesis was refuted; the experiment suggests that duck feathers are the more efficient oleophilic sorbent. Extracellular Vesicles as Biomarkers for Acute Respiratory Distress Syndrome Kevin Fan Academic Magnet High School North Charleston, South Carolina Research Mentor: Dr. Goodwin & Dr. Li Medical University of South Carolina Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Acute respiratory distress syndrome (ARDS) is a secondary disease that may follow sepsis and is characterized by inflammation, increased vascular permeability, and endothelial cell dysfunction. Currently, there are no approved pharmacological treatments. Extracellular vesicles (EVs) are membranous microvesicles secreted from the endosomal compartment or plasma membrane of cells. Recent evidence suggests that circulating EVs from septic patients are associated with inflammation and vascular permeability, so we investigated circulating EVs as potential biomarkers for sepsis-induced ARDS. To do this, we collected plasma samples from 85 ICU-administered septic patients, 21 of whom developed ARDS, as well as healthy controls. EVs were extracted from these samples and subsequently added to HMVECs. Transendothelial electrical resistance (TEER) assays were performed on the HMVECs, and the resulting data was used as an indication of vascular permeability. We found that EVs from ARDS patients (n=21) have a higher chance (81% vs 37.5%) to induce TEER compared to non-ARDS patients (n=64). These findings may eventually lead to a screening strategy to determine a patient’s risk of ARDS development based on their EVs. We also wanted to explore potential explanations for this phenomenon. Previous studies suggest that EVs containing caspase-1 induce endothelial cell injury, so we determined caspase-1 activity in the EVs and discovered that EVs from septic patients contain significantly higher caspase-1 activity than healthy controls, and EVs from ARDS patients have higher caspase-1 activity than EVs from septic patients without ARDS.