TY - JOUR
T1 - Ultrasound to decontaminate organics in dredged sediments
AU - Meegoda, Jay N.
AU - Veerawat, Kanya
N1 - Funding Information:
This research was sponsored by a grant from the National Science Foundation (Grant # CMS-9700318). The program manager at NSF was Dr. Pricilla P. Nelson. Authors would also like to acknowledge the NSF grant ECS-9214571 to NJIT to
PY - 2002
Y1 - 2002
N2 - Sediments contaminated with organics compounds due to past disposal practices threaten the environment and require remediation. This study was an attempt to develop a technology to decontaminate organics in dredged sediments using ultrasound coupled with vacuum pressure. A set of laboratory scale experiments were carried out using simulated dredged sediments from New York/New Jersey harbor, category III sediments that failed to meet USEPA requirements for toxicity or bioaccumulation, and required secure disposal. Acoustic cavitation due to ultrasound energy coupled with vacuum pressure was used to facilitate the removal of p-terphenyl (the selected organic contaminant) from the sediments. Two coupled processes were used to separate and to treat both coarse (Process 1) and fine (Process 2) fractions of sediments. Selected variables for evaluation of Process 1 were ultrasound power, solvent to sediment ratio, vacuum pressure, and sonication time. Process 2 was evaluated without and with surfactants. Process 2 without surfactant had three variables: power, solvent to sediment ratio, and sonication time, while Process 2 with surfactant had four variable contributing to its performance: power, solvent to sediment ratio, surfactant concentration, and sonication time. Laboratory-scale experiments were carried out with various combinations of these parameters according to the factorial design. Experimental test results showed that Process 1 had 99% contaminant removal efficiency at 60% power (900 Watts), 15:1 solvent to sediment ratio, 15 psi vacuum pressure, and 9 min of sonication time. Similarly, Process 2 without the surfactant had 55% contaminant removal efficiency at 80% power (1200 Watts), 50:1 solvent to sediment ratio, and 90 min of sonication time. Modification of Process 2 with the addition of a surfactant produced 89% contaminant removal efficiency at 80% power (1200 Watts), 50:1 solvent to sediment ratio, 0.1% surfactant concentration, and 60 min of sonication time. The study showed that the proposed treatment technique is effective for treating dredged sediments.
AB - Sediments contaminated with organics compounds due to past disposal practices threaten the environment and require remediation. This study was an attempt to develop a technology to decontaminate organics in dredged sediments using ultrasound coupled with vacuum pressure. A set of laboratory scale experiments were carried out using simulated dredged sediments from New York/New Jersey harbor, category III sediments that failed to meet USEPA requirements for toxicity or bioaccumulation, and required secure disposal. Acoustic cavitation due to ultrasound energy coupled with vacuum pressure was used to facilitate the removal of p-terphenyl (the selected organic contaminant) from the sediments. Two coupled processes were used to separate and to treat both coarse (Process 1) and fine (Process 2) fractions of sediments. Selected variables for evaluation of Process 1 were ultrasound power, solvent to sediment ratio, vacuum pressure, and sonication time. Process 2 was evaluated without and with surfactants. Process 2 without surfactant had three variables: power, solvent to sediment ratio, and sonication time, while Process 2 with surfactant had four variable contributing to its performance: power, solvent to sediment ratio, surfactant concentration, and sonication time. Laboratory-scale experiments were carried out with various combinations of these parameters according to the factorial design. Experimental test results showed that Process 1 had 99% contaminant removal efficiency at 60% power (900 Watts), 15:1 solvent to sediment ratio, 15 psi vacuum pressure, and 9 min of sonication time. Similarly, Process 2 without the surfactant had 55% contaminant removal efficiency at 80% power (1200 Watts), 50:1 solvent to sediment ratio, and 90 min of sonication time. Modification of Process 2 with the addition of a surfactant produced 89% contaminant removal efficiency at 80% power (1200 Watts), 50:1 solvent to sediment ratio, 0.1% surfactant concentration, and 60 min of sonication time. The study showed that the proposed treatment technique is effective for treating dredged sediments.
KW - Decontamination and experimental design
KW - Dredged sediments
KW - P-Terphenyl
KW - Surfactant
KW - Ultrasound
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U2 - 10.1080/20025891106718
DO - 10.1080/20025891106718
M3 - Article
AN - SCOPUS:0036007929
SN - 1058-8337
VL - 11
SP - 91
EP - 116
JO - Soil and Sediment Contamination
JF - Soil and Sediment Contamination
IS - 1
ER -