The Effects of Allophane on Carbon Sequestration and Nutrient Availability in Compost Derived from Food Waste
Poster Number
041
College
College of Arts and Sciences
Department
Chemistry, Physics, Geology, & the Environment
Faculty Mentor
Scott Werts, Ph.D.
Abstract
In America, 21% of all material in landfills is derived from food waste. Nearly all carbon contained in that waste will be converted to methane under anaerobic decomposition pathways. However, food waste that is composted rather than entering the waste stream contains 35-55% carbon, which can be utilized as soil amendments and fertilizer. Allophane, an aluminosilicate clay derived from weathered volcanic ash, is known to create complexed compounds and stabilize the organic carbon in natural environments for longer periods of time. The purpose of this experiment is to determine whether allophane affects the carbon loss from food-waste-derived compost and whether it modifies any of the nitrogen or phosphorus cycling in the compost. Five sets of three pots with a compost/topsoil mixture and increasing amounts of allophane ranging from 0-50% by mass were established, and samples were analyzed. Overall, the carbon content of all the compost decreased over time. While the total amount of available nitrogen decreased over time, the compost with higher amounts of allophane had more available nitrogen in the forms of ammonia and nitrate. Ammonium availability in the compost showed a constant decrease over time, while nitrate showed a large spike followed by a nitrate depression period. The total phosphorus availability increased with increasing allophane and spiked during the nitrate depression period. Overall, the increasing amounts of allophane reduce the levels of greenhouse gas emissions from the compost, but also depress the nutrient cycling in the compost.
Previously Presented/Performed?
American Geophysical Union (AGU) Fall Meeting, Washington, D.C., December 2018
Grant Support?
Supported by a grant from the Winthrop University Research Council
Start Date
12-4-2019 2:15 PM
End Date
April 2019
The Effects of Allophane on Carbon Sequestration and Nutrient Availability in Compost Derived from Food Waste
Richardson Ballroom – DiGiorgio Campus Center
In America, 21% of all material in landfills is derived from food waste. Nearly all carbon contained in that waste will be converted to methane under anaerobic decomposition pathways. However, food waste that is composted rather than entering the waste stream contains 35-55% carbon, which can be utilized as soil amendments and fertilizer. Allophane, an aluminosilicate clay derived from weathered volcanic ash, is known to create complexed compounds and stabilize the organic carbon in natural environments for longer periods of time. The purpose of this experiment is to determine whether allophane affects the carbon loss from food-waste-derived compost and whether it modifies any of the nitrogen or phosphorus cycling in the compost. Five sets of three pots with a compost/topsoil mixture and increasing amounts of allophane ranging from 0-50% by mass were established, and samples were analyzed. Overall, the carbon content of all the compost decreased over time. While the total amount of available nitrogen decreased over time, the compost with higher amounts of allophane had more available nitrogen in the forms of ammonia and nitrate. Ammonium availability in the compost showed a constant decrease over time, while nitrate showed a large spike followed by a nitrate depression period. The total phosphorus availability increased with increasing allophane and spiked during the nitrate depression period. Overall, the increasing amounts of allophane reduce the levels of greenhouse gas emissions from the compost, but also depress the nutrient cycling in the compost.
