Date of Award
M.S. in Engineering Science
University of Mississippi
The need for alternative water sources is dramatically increasing. Therefore, it is essential to develop alternative water sources to meet the current water scarcity challenges. Water reclamation, recycling, and reuse involving treated municipal and or animal wastewater address these challenges by resolving water resource issues and creating new sources of high-quality water supplies. However, the presence of bacteria, high levels of nutrients, and turbidity, as well as the occurrence of chemicals of emerging concern (CECs) in the treated wastewater, combined with the willingness of the public to use treated wastewater can undermine the wide application of water reuse. Implementing affordable but effective low-cost water treatments represents a key option to overcompensate the current limitations of water reuse. The objectives of this research were to 1) assess the ability of graphene-coated sand to improve water quality, expressed in terms of turbidity, nutrients, chemical oxygen demand (COD), and bacteria removal, and 2) investigate the ability of graphene-coated sand to remove CECs. Flow-through columns (length: 62 cm, ID: 5.2 cm) were used throughout the study. Three types of sand with different shapes and mineralogical compositions, Ottawa, Masonry, and Concrete, were used. Additionally, treated municipal wastewater (pre-UV) collected at the University of Mississippi Wastewater Treatment Plant was used as feed water for the different columns. Results from the study highlighted the ability of the proposed materials to successfully remove turbidity (> 85%), total coliforms (> 99%) and E. coli (> 99%), moderately remove COD (< 65%), and poorly remove nitrate (< 30%) and CECs (< 20%) with the exception of one type of sand, activated graphene-coated sand, and one CEC, sulfamethoxazole). Even though nitrate removal was limited, it was consistently higher compared to previously published results. Results from the study suggested that the ability of the graphene-coated sand to remove nitrate was partially able to overcompensate the nitrification process occurring within the different columns. The presence of a post-treatment (e.g., activated graphene-coated sand) was able to enhance the ability of the columns packed with the raw materials and outperformed the columns packed with graphene-coated sand.
Barber, Madelyn, "Can graphene-coated sand enhance water reuse by improving water quality in the presence of municipal treated wastewater?" (2023). Electronic Theses and Dissertations. 2479.