Carley Pinel, Karishma Nathaniel, Raj Boopathy, Darcey Wayment

Per- and polyfluorinated alkyl substances (PFASs), more commonly known as “forever chemicals”, are compounds that have a high chemical stability due to their C-F bonds which causes them to persist in the environment. PFASs are widely used in commercial and industrial products such as food packaging, fire-retardant and fire-extinguishing products, pesticides, paints, personal care products, and surfactants. Once the PFASs are introduced to the environment, they accumulate and can be transported via waterways. If humans ingest, inhale, or come in contact with PFAS, it is possible for it to accumulate in the body and cause negative health effects. Both natural and constructed wetlands have shown the ability to reduce potentially harmful substances by acting as a natural filtration system with the aid of plant bioremediation. The purpose of this study is to determine the ability of Nicholls State University’s newly constructed wetland in reducing the amount of PFASs in the water. Water samples were collected at the inlet and outlet of the constructed wetland and analyzed using LC/MS to detect the presence of PFASs in Bayou Folse and in the wetland. The results will be discussed.

Raymond Antwi, Christopher Chappell, Zhu. H. Ning, Yaw Twumasi

Healthy soils are paramount to forest ecosystems for the provision of resources required to drive net primary productivity. This review provides an overview of rural and urban forest ecosystems in terms of soil fertility and management strategies in select areas. The Bobiri Forest Reserve (BFR), Ghana, was chosen as a representative of the rural forest whilst Independence Community Park (ICP), Baton Rouge, Louisiana, was selected to represent an urban forest. A literature search on soil fertility and management strategies of rural and urban forest ecosystems were conducted. The history of soil fertility and the management of rural and urban forest soils were concisely discussed. The USDA web soil survey was conducted to identify the soil types and characteristics of the ICP. The soil types of BFR were also identified and discussed. It emerged from the review that urban forests face a high risk of soil degradation through compaction, landfilling, construction, depletion of soil nutrients, loss of capacity to retain soil water and inhibition of soil carbon sequestration. To ensure that informed management decisions are taken for the development and policy planning of the forest ecosystems, a list of progressive recommendations has been provided, including maintaining optimum forest soil conditions that favor regeneration and long-term survival of desired forest vegetation.

Md Firoz Al Mamun, Enmin Zou

Chromium (Cr), one of the prevalent heavy metal contaminants in aquatic environments, is reportedly present in crustacean exoskeleton. Using the blue crab, Callinectes sapidus, as the model crustacean, this study sought to address during which phase of the molting cycle Cr is deposited to the exoskeleton and how Cr in different valencies impacts such a process and exoskeletal mineralization. It was hypothesized that owing to Cr II and calcium (Ca) being both divalent, Cr II would promote Cr incorporation into the shell during post-ecdysial mineralization, thereby adversely affecting mineralization, more than either Cr III or Cr VI. Post-ecdysial blue crabs were injected with 0 and 2µg Cr/g wet weight in chromium chloride (Cr II), chromium potassium sulfate (Cr III) or sodium chromate (Cr VI). Thereafter, exoskeletal Cr, Ca, and magnesium (Mg) content was analyzed using ICP-OES. We found that Cr (VI) and Cr (III) resulted in a 2.94- and 2.52-fold increase in exoskeletal Cr content, respectively, while Cr (II) had no effect. Additionally, both Cr (III) and Cr (VI), not Cr (II), were found to significantly reduce the Ca and Mg content per unit shell area, suggesting that both Cr (III) and Cr (VI) inhibit the flux of Ca and Mg to the shell during mineralization. These results are not in agreement with the hypothesis. Discussion on the mechanism driving the effects of Cr (III) and Cr (VI) is presented.

Shila Kandel, Abubakar Abdulkadir, Raphyel Rosby, Md. Ekhtear Hossain

4-Aminodiphenylamine (4-ADPA) is an antioxidant additive in rubber tires that enhances durability by preventing drying, cracking, and degradation from heat, oxygen, and ozone exposure. However, it raises environmental concerns as microscopic tire wear particles (TWPs) containing 4-ADPA are released into the environment during tire use. These particles can contaminate waterways through stormwater runoff, contributing to pollution and potentially harming aquatic ecosystems and marine life. The current study examines the ecotoxicological effects of 4-ADPA on the aquatic plant Lemna minor (L. minor), focusing on its impact on relative growth and physiological biomarkers. Several parameters were assessed to evaluate ecotoxicity, including frond morphology, fresh biomass, total frond number, chlorophyll content, and starch accumulation. L. minor was grown for seven days under controlled laboratory conditions using Hoagland media with varying concentrations of 4-ADPA (10 - 100 µg/L), while a control group was maintained in media without 4-ADPA. The results showed that exposure to 4-ADPA led to a dose-dependent reduction in fresh biomass, total frond number, and chlorophyll levels. Lugol’s staining revealed increased starch accumulation in the fronds after exposure to 4-ADPA. The biological effects observed in L. minor following exposure to 4-ADPA, even at environmentally relevant concentrations, indicate a significant ecotoxicological impact on aquatic ecosystems.