Glass is a versatile material that offers innumerable applications in many areas. One widely used application is to store food and beverages. Besides being impervious to foreign objects, it is an inert material and provides practically infinite recycling potential. It is considered easy to recycle glass bottles and jars by crushing them to an appropriate size, then cleaning and sorting the cullet to remove contaminants. However, the process becomes more difficult when the glass breaks into smaller and smaller pieces during recovery, transportation and sorting. These pieces are called glass fines, which make their way to landfills because they are unfit for recycling due to high levels of contamination. This problem is very frequent in Material Recovery Facilities (MRFs) due to the volume of glass being sorted and processed.
The City of Peoria serves as a leader in adopting new methods and technologies to demonstrate its commitment to sustainability. The City aims to identify strategies to effectively manage glass fines. This project was undertaken by a graduate student from the Environmental Resource Management program
to research novel applications of fine glass residue in partnership with the City of Peoria and ASU Project Cities.
This report presents research about the novel applications of glass fines, peer community survey, cost-benefit analysis, and the life cycle assessment (LCA) of the glass production process. The literature review reveals crucial information behind the application of fine glass. Many researchers have tried to incorporate glass fines in concrete in various proportions and have been successful in finding appropriate weight percentages for the highest mechanical strength. This application helps address another menacing issue, a reduction in the amount of cement used in making concrete, thereby reducing CO2 emissions. Other applications of glass fines are involved in manufacturing foam concrete, ceramic pavers, and decorative objects like lampshades and stoneware. Following the literature review, a cost-benefit analysis was performed to review existing recycling practices used by the City. Currently, Peoria
sends its recyclables to the City of Phoenix’s North Gateway Transfer Station and Waste Management Northwest Regional Landfill for further sorting and processing. As per the analysis, this contract is beneficial to Peoria as it has started receiving revenue for its recyclables beginning in October 2021.
The next step in this project involved surveying adjacent municipalities to explore how nearby cities manage glass waste. These cities tend to rely on contracting with other municipalities to dispose of or recycle the waste. Most adjacent cities do not own a MRF, and some have removed the glass from their recycling programs. This step was followed by searching for vendors that recycle glass fines in Arizona. Additionally, the LCA of glass bottle production from recycled glass versus virgin glass was modeled. It was found that the recycled glass bottle production process generates almost half of the environmental impacts as compared to the virgin glass bottle production process.
Key recommendations in this project include exploring the construction sector to reuse glass fines, continuing to contract with the City of Phoenix to process recyclables, contacting GlassKing Recovery & Recycling to provide a testing sample, and reaching out to other active recyclers for premiere management of glass fines.