John Glaser

By John A. Glaser

Polymers present to modern society remarkable performance characteristics desired by a wide range of consumers but the fate of polymers in the environment has become a massive management problem. Polymer applications offer molecular structures attractive to product engineers desirous of prolonged lifetime properties. These characteristics also figure prominently in the environmental lifetimes of polymers or plastics. Recently, reports of microbial degradation of polymeric materials offer new emerging technological opportunities to modify the enormous pollution threat incurred through use of polymers/plastics. A significant literature exists from which developmental directions for possible biological technologies can be discerned. Each report of microbial mediated degradation of polymers must be characterized in detail to provide the database from which a new technology developed. Part of the development must address the kinetics of the degradation process and find new approaches to enhance the rate of degradation. The understanding of the interaction of biotic and abiotic degradation is implicit to the technology development effort.

Part of the book: Plastics in the Environment

By John A. Glaser

Microplastics are global pollutants in water media ranging from drinking water to freshwater streams to oceanic pollutant gyres. Besides the obvious appearance involving a scattered presence in the environmental landscape, microplastics are ubiquitous across modern society in products, food, and beginning to have strong economic effects too. Ingestion of microplastics is virtually unavoidable for each of us as we consume food, breathe air, or drink liquids. For example, beer has been found to be contaminated with plastic materials having the dimensions of micro- and nanoparticles. In the environment, the formation of biofilms on microplastics is widely observed and this can significantly alter properties important to environmental and human health. Significant research has been conducted on the role of biofilms in the fate and effect of microplastics on environmental and human health, with a general message to avoid contact with microplastics in the environment until more complete strategies for cleanup are developed.

Part of the book: Bacterial Biofilms

By John A. Glaser, Endalkachew Sahle-Demessie and Te’ri L. Richardson

A spectrum of plastics has been produced in the last 70 years, and plastic production has increased faster than any other manufactured material. Current recycling of all plastic materials is pegged at 10% or less. The social value that plastics enjoys is reflected in its myriad uses for engineered durability to single-use applications. Disposable or single-use plastic items have become a significant problem. Plastic debris has become ubiquitous to the landscape and aquatic resources, leading to human health, ecological concerns, and sustainability issues. Past disposal practices relied on waste plastic flows to certain countries for disposal, but these have been summarily curtailed, needing alternatives as productive and environmentally conscious recycling technology. Waste plastics can be repurposed using purification, decomposition, or conversion processes that are based on established and emerging mechanical and chemical technologies. Plastic recycling technologies, such as thermal, chemical, and biological depolymerization processes, including pyrolytic technologies using plastics-to-fuel strategies, are under development ranging from bench-scale demonstrations to full-scale implementation. The ideal of closed supply chain constraints offers optimal solutions to plastic recycling. Evaluation of new processes requires performance assessment to understand better how plastics recycling technologies contribute to the environment and the sustainable reuse of plastic materials.

Part of the book: Waste Material Recycling in the Circular Economy