Phytoremediation of dredged marine sediment: monitoring of chemical and biochemical processes contributing to sediment reclamation.
In this study, a pilot phytoremediation experiment was performed to treat about 80 m(3) of silty saline sediments contaminated by heavy metals and organic compounds. After preliminary mixing with a sandy soil and green compost application, three different plant treatments [Paspalum vaginatum (P); P. vaginatum + Spartium junceum (P + S); P. vaginatum + Tamarix gallica (P + T)] were compared to each other and to an unplanted control (C) in order to evaluate the plant efficiency in remediating and ameliorating agronomical and functional sediment properties. The experiment was monitored for one year after planting by taking sediment samples at two depths and performing several chemical and biochemical analyses. After one year, the increase in hydrolytic enzyme and dehydrogenase activities indicated the stimulation of sediment functionality. Additionally, the availability of energy sources derived from organic matter application and plant-root activity promoted the formation of a stable organic matter fraction. Finally, P + S and P + T were also effective in decontaminating polluted marine sediments from both organic (total petroleum hydrocarbons, TPH) and inorganic (heavy metal) pollutants.
National Research Council, Institute of Ecosystem Study, Via Moruzzi 1, 56124 Pisa, Italy.
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Masciandaro
National Research Council, Institute of Ecosystem Study, Via Moruzzi 1, 56124 Pisa, Italy.
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Di Biase
National Research Council, Institute of Ecosystem Study, Via Moruzzi 1, 56124 Pisa, Italy.
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Macci
National Research Council, Institute of Ecosystem Study, Via Moruzzi 1, 56124 Pisa, Italy.
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Peruzzi
University of Pisa, Department of Engineering for Energy, Systems, Territory and Constructions, Via Gabba 22, 56122 Pisa, Italy.
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Iannelli
National Research Council, Institute of Ecosystem Study, Via Moruzzi 1, 56124 Pisa, Italy. Electronic address: serena.doni@ise.cnr.it.
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Doni
D001673:Biodegradation, Environmental; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry; D006838:Hydrocarbons / Q000032:analysis / Q000378:metabolism*; D019216:Metals, Heavy / Q000032:analysis / Q000378:metabolism*; D031781:Paspalum / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D031302:Spartium / Q000378:metabolism*; D032363:Tamaricaceae / Q000378:metabolism*
D006838:Hydrocarbons; D019216:Metals, Heavy; D012989:Soil Pollutants
Heavy metals; Humification process; Phytoremediation; Sediment decontamination; Total petroleum hydrocarbons