A comparison of landfill leachates based on waste composition. (May 2017)

• Record Type: Journal Article
• Authors: Moody, Chris M.; Townsend, Timothy G.
• Is Part Of: Waste management. Volume 63(2017)
• Page Start: 267
• Page End: 274
• Publication Date: 2017-05
• Subjects: Landfill leachate -- MSWI ash -- MSW -- Wastewater; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2016.09.020
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Leachate composition was analyzed to from MSW landfills and landfills with MSWI ash. Leachate heavily influenced by ash will be composed of primarily TDS while MSW leachate is complex. Chemical oxygen demand was determined to include the oxygen demand from non-carbonaceous sources. Leachate pH of MSWI ash samples was lower than expected due to the low buffering capacity. MSW leachate requires complex treatment whereas MSWI ash leachate will require simple treatment. Abstract: Samples of leachate were collected from fourteen landfills in the state of Florida, United States that contained primarily putrescible waste (municipal solid waste, MSW, and yard waste), MSW incinerator (MSWI) ash, or a combination of both. Assessment of leachates included trace metals, anions, and nutrients in order to create a mass balance of total dissolved solids (TDS). As expected from previously literature, MSW leached a complex matrix of contaminants while MSWI ash leachate TDS was more than 98% metallic salts. The pH of the MSWI ash leachate samples was slightly acidic or neutral in character, which is contradictory to the results commonly reported in the literature. The cause of this is hypothesized to be a short-circuiting of rainfall in the landfill due to low hydraulic conductivities reported in ash landfills. The difference in pH likely contributed to the findings with respect to MSWI ash-characteristic trace metals in leachates such as aluminum. The authors have concluded that the research findings in this study are an indication of the differences between laboratory leachate quality studies and the conditions encountered in the field. In addition, a characterization of organic matter using qualitative and quantitative analyses determined that COD is not an accurate indicator of organic matter in leachates from landfills with a significant fraction of MSWI ash.