Theory and Application of Landfarming to Remediate Polycyclic Aromatic Hydrocarbons and Mineral Oil‐Contaminated Sediments; Beneficial Reuse

Abstract

When applying landfarming for the remediation of contaminated soil and sediment, a fraction of the soil-bound contaminant is rapidly degraded; however, a residual concentration may remain, which slowly degrades. Degradation of polycyclic aromatic hydrocarbons (PAHs) and mineral oil can be described using a multi-compartment model and first-order kinetics, in which three degradable fractions are distinguished; (1) rapid, (2) slowly, and (3) very slowly degradable. Using this model populated with data from long-term experiments (initiated in 1990), it is shown that time frames from years to decades can be necessary to clean the soil or sediment to obtain a target below regulatory guidelines. In passive landfarms without active management, three principal potentially limiting factors can be identified: (1) availability of appropriate microorganisms, (2) supply of oxygen for the biodegradation process, and (3) bioavailability of the pollutants to the microorganisms. Bioavailable PAHs and mineral oil are readily biodegradable contaminants under aerobic conditions, and presence and activity of microorganisms are not problems. The other two factors can be limiting and are theoretically described. Using these descriptions, which are in agreement with field experiments of 10 to 15 yr, it is shown if and when optimization of the biodegradation process is an option. Because a long time period is necessary to degrade the slowly and very slowly degradable fractions, passive landfarming should be combined with beneficial use of the land area. Examples include the development of natural environments, use in constructions, growing of biomass for energy production, including biofuels, and use as cover for landfills.

A comprehensive overview of elements in bioremediation

“…This technology involves the application of contaminated material that has been excavated onto the soil surface and periodically tilled to mix and aerate the material (Maciel et al 2009;Harmsen et al 2007). The contaminants are degraded, transformed and immobilized by means of biotic and abiotic reactions (Rubinos et al 2007).…”

Remediation of Contaminated Sites

“…This technology involves the application of contaminated material that has been excavated onto the soil surface and periodically tilled to mix and aerate the material [35][36]. The contaminants are degraded, transformed and immobilized by means of biotic and abiotic reactions.…”

Evaluation of PAH removal efficiency in an artificial soil amended with different types of organic wastes

“…Among several treatment technologies available to remove PAHs from soil, bioremediation is one of the most suitable to deal with these environmental contaminants [15,37]. Considering that PAHs biodegradation is a complex natural chemico-biological process, it can be influenced by limiting factors such as microorganism nature, water content, aeration, physico-chemical properties of contaminants, their concentration, and bioavailability [27,34,37].…”