Bench-Scale Phytoremediation of Polycyclic Aromatic Hydrocarbon-Contaminated Marine Sediment with Tropical Plants

Abstract

Elevated levels of polycyclic aromatic hydrocarbons (PAHs) were found in dredged marine sediment from Pearl Harbor. The degradation of PAHs was investigated with soil-sediment systems (washed and unwashed) and 20 plant species. Marine sediment was diluted with native soil in the first experiment. Sediment was washed with gypsum solution and water in the second and third experiments, respectively, prior to soil dilution. Soil dilution ratios were 0, 6, 16, and 37% by weight in the first experiment, 0, 37, 64, and 100% in the second and 0, 18, 64, and 100% in the third. Seven tree, nine shrub, and four grass species were grown for 12 weeks in a glasshouse. A "no plant" control was used in all the experiments. Several plant species yielded up to 90% PAH degradation in the first experiment when compared with no plant control. In the second planting, dwarf hau (Hibiscus tiliaceus) and vetiver (Vetiver zizanoides) appeared to cause the greatest PAH reduction, while paspalum (Paspalum vaginatum) and naupaka (Scaevola sericea) did not. The greatest difference between control and planted soil for both benzo[a]pyrene and total PAH occurred at the highest sediment ratios.

Nature and role of root exudates: Efficacy in bioremediation

“…Improved degradation of high molecular weight polycyclic aromatic hydrocarbons (PAH) during phytoremediation has provoked examinations of controlling plant/microbe interactions (Paquin et al, 2002). A number of scientist established chemotaxis of PAH degrading rhizosphere bacteria (Pseudomonas alcaligenes, Pseudomonas stutzeri and P. putida) to naphthalene, phenanthrene and root exudates (Ortega et al, 2003).…”

Phytoremediation Using Terrestrial Plants

“…Selection of appropriate technology is based on the environmental chemistry of the contaminant, along with the uses and type of soil or aqueous streams contaminated as they might infl uence to a great extent on biomass production (Cunningham and Ow 1996;Dushenkov 2003 ). Several species of plants can stimulate microbial growth and facilitate biodegradation of hydrocarbons, particularly those that cannot be taken up because of their hydrophobicity (Paquin et al 2002 ). Others have been reported as efficient absorbing different metals with unknown biological function such as cadmium, chromium, and lead inter alia (Tangahu et al 2011 ), principally those from tropical environments where long plant-growing seasons and increased soil temperature can accelerate degradation (Paquin et al 2002 ).…”

“…Plant selection criteria for most phytoremediation prospects are evapotranspiration potential, enzymes produced, growth and survival rate, biomass production, root system, and their ability to tolerate the contaminant (Paquin et al 2002 ;Prasad 2003 ). Mechanisms and effi ciency of this technology, called phytoremediation, depend on the type of contaminant, bioavailability, and substrate properties (Cunningham and Ow 1996).…”

“…Several species of plants can stimulate microbial growth and facilitate biodegradation of hydrocarbons, particularly those that cannot be taken up because of their hydrophobicity (Paquin et al 2002 ). Others have been reported as efficient absorbing different metals with unknown biological function such as cadmium, chromium, and lead inter alia (Tangahu et al 2011 ), principally those from tropical environments where long plant-growing seasons and increased soil temperature can accelerate degradation (Paquin et al 2002 ). Plants can counteract, absorb, or stabilize different contaminants, making them unavailable for other organisms (Merkl et al 2004 ).…”

Phytoremediation in subtropical Hawaii—A review of over 100 plant species

“…Five-day biological oxygen demand (CBOD5), chemical demand (COD), total suspended solids (TSS), fecal coliform, and ammonia mass removal were monitored, among others. (Hue et al, 2002;Paquin et al, 2002) High salinity in marine sediments is one of the challenges to phytoremediation. Pearl Harbor-dredged sediment contained high levels of polycyclic aromatic hydrocarbons (PAHs) and heavy metals.…”