Harris, Alyssa

The Solid Waste Authority (SWA) of Palm Beach County collects leachate from its landfill in a gravity pipe leachate collection system (LCS), which is experiencing clogging due to calcium carbonate scale. An investigation was conducted to determine the solids composition and provide engineering solutions to this challenge.
During testing, it was found that aerated leachate produced foam, which after vibration and evaporation, formed crystalline solids similar to those found in the SWA LCS. The following tests were conducted to determine the water quality of the leachate and the properties of the solids: pH, turbidity, chemical reactivity, biological growth, surface characteristics, and microscopic analysis.
After five days of evaporation, the solids collected in all samples represented 46-47% of the leachate’s initial weight. On visual observation, the leachate remnants left both a crystalline and a dark slimy solid, with larger particles in the aerated samples, a possible source of the clogging.

The purpose of this study is to utilize information and data gathered from previous studies pertaining to the BioRock® method, patented by Dr. W. Hibertz and T.J. Goreau in 1974. Biorock® stimulates the growth of coral reefs utilizing natural reef processes and electrochemistry to remove CO2 from the atmosphere. Our aim is to make the process more efficient to achieve large scale atmospheric carbon dioxide sequestration. A pH sensor in the water and CO2 sensor is in place to quantify and confirm the reduction of CO2 in the water and air above, all within a sealed tank. The first experiment in this study used an iron mesh with an electric current running through it to collect the limestone that serves as the base for a reef. However, the iron oxidized instead of collecting limestone. Future testing will utilize a lead plate as it is less susceptible to rusting.