Water Resources Research Act Program

Details for Project ID 2019PR228B

Nanotechnology-based wastewater treatment for reuse

Institute: Puerto Rico
Year Established: 2019 Start Date: 2019-06-01 End Date: 2020-05-31
Total Federal Funds: $20,000 Total Non-Federal Funds: $21,226

Principal Investigators: Oscar J. Perales-Perez

Project Summary: Industry consumes large amounts of water in steam generation, cooling, washing, sanitation, consumption, irrigation, among others. According to USGS, the 2015 US consumption of water was about 322 billion gallons per day (Bgal/d); 14.8 Bgal/d came from surface water and 2.70 Bgal/d from groundwater sources. These demands of water come from the producers of food, paper, chemicals, refined petroleum, and primary metals. These levels of water consumption give an idea of the volumes of wastewater that will be discarded to the public sewer system and would mostly discharge to the sea. At a local level, the Environmental and Natural Resources Department (DRNA, for its Spanish acronym) revealed that Puerto Rico’s annual demands for 2005 were 21,246.2 Millions of gallons (MG) which will reach 25,407.9 MG for agricultural purposes only in 2025 [1]. Regarding sanitary water generation in 2015, it averaged 232 MG/day according to the Aqueducts and Sewers Authority (AAA)[2][2]. There is no concrete data on the amount of water that is reused, however, it is known that there are initiatives of private sectors that have implemented these practices in their industries. The regulations established by the EPA and the regulation of the water quality standards of Puerto Rico and the Clean Water Act, encourages water reuse. However, there would be two factors that complicate the implementation of reuse projects: the high initial costs of the facilities to process the water, and the low political priority. The priority in water reuse processes is the reduction of the risk of the potential spread of diseases, especially if sanitary water is used. Pathogenic microorganisms can exist in the water that is planned to be reused for agricultural irrigation. Evidently, new sources of water for general reuse, particularly for agricultural applications, became indispensable. Accordingly, the present research will investigate and develop additional alternatives that will bring these waters suitable for future reuse. Recently, several works about the use of nanostructured materials in water treatment have been developed. One approach is related to the use of magnetic ferrites as the dispersed phase within polymer-based nanocomposites. The synergistic co-existence of these two materials (magnetic and bactericidal properties of the magnetic nanomaterials and the sorbent characteristics of the polymeric matrix) opens a new window of possibilities for its application in biotechnology and environmental engineering. Although few reports suggested the bactericidal capacity of magnetic nanoparticles, however, there is still a lack of systematic research about the corresponding mechanisms and how the bactericidal capacity could be enhanced by proper control of the nanomaterial composition and surface chemistry. In turn, the development of a net surface charge onto bacterium surface and the possibility of tuning the surface charge of nanoscale ferrites just by suitable control of pH or surface chemistry (use of surfactants or other adsorbed species) open the possibility of taking advantage of a strong electrostatic interaction, i.e. nanoscale ferrites will attract oppositely charged bacterium and both being removed by application of a moderate external magnetic field. Based on the above considerations, the novelty of the present research relies on the use of magnetic ferrites as a functional bactericide agent: direct bacterium population growth inhibitor and electrostatic and environmentally friendly bacterium removal agent. As a bonus, the polymeric matric (porous Calcium alginates beads) that will host nanosized ferrites, in the so-called magnetic nanocomposites, will also exhibit adsorption capacity for different types of inorganic and organic pollutants, commonly found in sanitary waters. The first phase of the research will be focused on the nanocomposite synthesis and followed by maximization of the bactericide and bacteria removal capacity of the Ca-alginate beads/cobalt ferrite nanocomposite.