Student/presenter: Katherine Coyle, M.S. student, Environmental Soil Chemistry
Format: Oral presentation
Title: Investigating adsorption capacities of WWTP products and their potential use as fertilizer
Katherine Coyle1, Lindsey Slaughter1, Christian Alvarez-Pugliese2, Gerardine Botte2, and Matthew Siebecker1
1Texas Tech University, Department of Plant & Soil Science
2Texas Tech University, Department of Chemical Engineering
As the global population rapidly grows, food producers of the world are faced with the task of feeding as many as ten billion people by 2050. The current state of fertilizer use cannot support this growth, and the overuse and poor management of synthetic/organic fertilizers has degraded soil, water, and air quality over time. Several studies have shown that the recovery efficiency of N by crops is only 55% due to the fast dispersion/loss of applied fertilizers to the environment. This leaching of fertilizer components often leads to eutrophication and hypoxia of surrounding water bodies, creating further pollution. A potential solution to this issue is the use of biosolids and recycled nutrients from wastewater treatment plants (WWTP) as a fertilizer. Biosolids are insoluble biological solid residue resulting from varying sewage treatment processes and have been shown to increase organic matter and nutrient content when applied to soils. This research will examine nutrient adsorption from two types of WWTP products onto soils. The first product is an ion exchange nitrogen/phosphorous based fertilizer produced via municipal wastewater being pumped through a synthetic zeolite mineral (ZeoNPBF). Zeolites are open 3D frameworks comprised of SiO44- and AlO45- tetrahedral sheets with open channels that can filled by extra-framework cations, such as NH4+. These minerals possess a high cation exchange capacity that allows them to adsorb nutrient cations that are essential to plant growth, thereby making wastewater-treated zeolites a potential fertilizer resource. The second product that will be investigated is waste activated sludge, a byproduct of municipal wastewater treatment, that has been electrochemically treated to remove pathogens (EWAS). These solid materials will be used in a batch adsorption study and reacted with local and potting soils, and analyzed to determine the adsorption capacities of N, C, and OC from the ZeoNPBF and EWAS to the soil.