This technique has been used for years in the management and disposal of drill cuttings, oily sludge and other petroleum refinery wastes. The equipment employed in land farming is typical of that used in agricultural operations. These land farming activities cultivate and enhance microbial degradation of hazardous compounds. As a rule of thumb, the higher the molecular weight (i.e., the more rings within a polycyclic aromatic hydrocarbon), the slower the degradation rate. Also, the more chlorinated or nitrated the compound, the more difficult it is to degrade.[4]
Limitations
Factors that may limit the applicability and effectiveness of the process include:
large space requirements
the conditions advantageous for biological degradation of contaminants are largely uncontrolled, which increases the required length of time until complete degradation, particularly for recalcitrant compounds
inorganic contaminants are not biodegraded
the potential of large amounts of particulate matter released by operations
the presence of metal ions may be toxic to microbes and may leach from the contaminated soil into the ground.
high levels of hydrocarbon contamination (>7%) are toxic to the microbes and will not degrade
the microbes convert hydrocarbons to greenhouse gases
^Julie Van Deuren; Teressa Lloyd; Shobha Chhetry; Raycharn Liou; James Peck (January 2002), "4.13 Landfarming", Remediation Technologies Screening Matrix and Reference Guide, 4th Edition, U.S. Army Environmental Center, MD: Federal Remediation Technology Roundtable (FRTR)
^Dennis R. Heldman, ed. (2003), Encyclopedia of Agricultural, Food, and Biological Engineering, CRC Press, p. 114, ISBN978-0824709389, Landfarming is mostly conducted in lined or unlined soil beds that...