Beneficial Reuse and Sustainability: The Fate of Organic Compounds in Land‐Applied Waste

Abstract

Land application systems, also referred to as beneficial reuse systems, are engineered systems that have defined and permitted application areas based on site and waste characteristics to determine the land area size requirement. These terrestrial systems have orders of magnitude greater microbial capability and residence time to achieve decomposition and assimilation compared with aquatic systems. In this paper we focus on current information and information needs related to terrestrial fate pathways in land treatment systems. Attention is given to conventional organic chemicals as well as new estrogenic and pharmaceutical chemicals of commerce. Specific terrestrial fate pathways addressed include: decomposition, bound residue formation, leaching, runoff, and crop uptake. Molecular decomposition and formation of bound residues provide the basis for the design and regulation of land treatment systems. These mechanisms allow for assimilation of wastes and nondegradation of the environment and accomplish the goal of sustainable land use. Bound residues that are biologically produced are relatively immobile, degrade at rates similar to natural soil materials, and should present a significantly reduced risk to the environment as opposed to parent contaminants. With regard to leaching and runoff pathways, no comprehensive summary or mathematical model of organic chemical migration from land treatment systems has been developed. For the crop uptake pathway, a critical need exists to develop information for nonagricultural chemicals and to address full-scale performance and monitoring at more land application sites. The limited technology choices for treatment of biosolids, liquids, and other wastes implies that acceptance of some risks and occurrence of some benefits will continue to characterize land application practices that contribute directly to the goal of beneficial reuse and sustainability.

Irrigated urban vegetable production in Ghana: characteristics, benefits and risk mitigation

“…The higher frequency of detection as well as higher concentrations of estrogens seen in lettuce compared to spring onion and green bell pepper suggested that either the lettuce roots were better capable of directly taking up the estrogens and translocating them into leaves or estrogens were being directly deposited on foliage during irrigation or as dust. Other studies have found that nonagricultural organic compounds associated with waste are more likely to be found as deposits on plant foliage left by waste application rather than through translocation from shoots (Overcash et al 2005). No accumulation of estrogens in plant tissue was observed during the sampling period.…”

Modeling the pH-mediated extraction of ionizable organic contaminants to improve the quality of municipal sewage sludge destined for land application

“…Antibiotics, an important class of contaminants falling into this category, have been detected widely in the environment including in MSS ( n = 14), even when their sorption coefficients are low (Batt et al, 2006; Kummerer, 2003; McClellan and Halden, 2010). Leaching of antibiotics from soils has been identified as one of the most important pathways for contamination of water bodies (Overcash et al, 2005; ter Laak and Gebbink, 2006; Thiele-Bruhn, 2003). Batch sorption experiments conducted in the laboratory showed that the interaction between antibiotics and soil particles were governed predominantly by solution pH (Hari et al, 2005; ter Laak and Gebbink, 2006).…”

Sustainable Land Application

“…General summaries of each topic's “state‐of‐the‐science” and research priorities are given below. Details are provided in the individual plenary papers on Nutrients (Pierzynski and Gehl, 2005), Metals (Basta et al, 2005), Organics (Overcash et al, 2005), Pathogens (Gerba and Smith, 2005), and Interpreting Science in the Real World (Bastian, 2005).…”