Event Registration 

Evaluation of Bio-Inspired Hempcrete Through Mycelium presented by Dr. Shihui Liu

Hemp is at the core of an important productive system, whose products span from food (oil, seeds, flour, etc.) to non-food (textiles, mats, ropes, bricks, bio-fuel, phytoremediation, etc.). However, to improve the competitiveness of the industry based on this crop, it needs to be inserted into a circular economy philosophy. The development of myco-composites based on hemp by-products can be an opportunity in this sense. One of the emerging topics in sustainable construction building materials is the use of bio-composite materials, such as mycelium. Mycelium is comprised of hyphae and root-like plant structures with the ability to allow the fungus to consume the nutrients from its waste substrate. Mycelium could bind the material together by growing into its substrate. Mycelium from fungi can serve as the matrix or as a self-grown binder in a biocomposite. The reinforcing component may consist of various combinations of agro-based waste in short fiber or powder form. These materials have initially been proposed as a replacement for polystyrene foams, and the characterization is concentrated on compression performance and acoustic and thermal insulation properties. The present review concentrates on substrates that originated from the large productive system based on hemp (shives or hurds, waste fibers, and mats). Attention is paid to the performance obtained and to the amount of waste that is possibly employed to serve as the substrate.

Microplastics in Stormwater Runoff: Investigating Fate, Transport, and Contaminant Uptake presented by Dr. Maryam Salehi

The growing accumulation of discarded plastics needs urgent attention, globally. In urban areas, microplastics (MPs) pose a severe threat to freshwater ecosystems and human health. Stormwater runoff plays a critical role in transporting MPs from urban hotspots and roadways to surrounding water bodies. This study investigates the impacts of MPs’ aging on their heavy metals’ [Pb, Zn, Cu] uptake and aggregation behavior under varying water chemistry conditions. Additionally, a model has been developed to better understand the transport mechanism of MPs in an urban residential setting, considering MPs that have either lower or greater density than water. Low density polyethylene (LDPE) pellets and particles were selected as representative MPs for heavy metal uptake and aggregation experiments, respectively. Photodegraded MPs were generated through UVA radiation. The competition of Cu, Zn, and Pb species for the accumulation onto sediments and new and photodegraded MPs was examined through 48 h kinetics experiments. The results showed the creation of oxidized carbon functional groups on MPs and their more negative surface charge due to the photodegradation. Moreover, significantly greater levels of Cu, Zn, and Pb accumulations were found on photodegraded MPs than on new MPs in either the absence or presence of sediments. Heavy metal uptake by sediments when photodegraded MPs were present was reduced. The aggregation study showed that the presence of natural organic matter (NOM) reduced the aggregation tendency of new LDPE MPs due to enhanced steric hindrance and electrostatic repulsion. The photodegradation reduced the tendency to form the MPs aggregate and enhanced their inclination to remain dispersed in water. A greater tendency for aggregation of photodegraded MPs was found in the stormwater than in ultrapure water. The modeling effort revealed that for MPs with a greater density than water, the particles with higher densities settle more rapidly, leading to earlier removal from stormwater runoff. Results also indicated that flow depth and the size distribution of MPs notably influenced their transport mechanisms compared to sediment particles. This knowledge is crucial for assessing the risks MPs pose to ecological systems and devising effective mitigation strategies.