Date of Award
Doctor of Philosophy in Civil Engineering - (Ph.D.)
Civil and Environmental Engineering
Jay N. Meegoda
Taha F. Marhaba
Bruno M. Goncalves da Silva
Ivan L. Guzman
The Passaic River is 129km long and flows through the northern New Jersey. During the mid-twentieth century, the U.S. census indicated that there were approximately 2,900 industries along the river bank. The amount of industries established next to the river indicated the inevitable river pollution, which was compounded by lenient environmental protection laws. One of the major contributors of the river pollution was Diamond Alkali Co., which started production of chemicals around 1951 at the 4km marker in the Passaic River.
In 1970, the United States Environmental Protection Agency (U.S. EPA) identified the Passaic River as the second most polluted river in the United States, where in 1983 a Diamond Alkali site investigation showed extremely high levels of hazardous chemicals. Contaminants in the river included PAHs, PCDD/F, PCBs, DDT, pesticides and their byproducts, and heavy metals including Hg, Cr, and Pb. This made the contaminated river eligible for cleanup funds under the federal Superfund program. Hence, the U.S. EPA initiated investigations to identify the severity of the river pollution. In 2016, the U.S. EPA proposed a cleanup program to mitigate the impact of the pollution in the river sediments.
Scrutinizing the U.S. EPA remediation plan brings up concerns that will impact the current condition of the river. The dredging exposing the contaminated sediments to freshwater, capping to prevent future dredging, and others such as dewatering and the transportation of the dredged sediments impacting the community during the cleanup are some of the major concerns. Hence, identifying a better and complete technology to remediate the Passaic River's contaminated sediments is a necessity. This remediation plan should have the capability to be carried out in-situ, where the negative impacts from the current plan can be mitigated.
This research is on developing a novel in-situ technology to remediate the Passaic River sediments by using ultrasound and ozone nano-bubbles. The study identifies key parameters that will enhance the removal of organic and inorganic pollutants from the contaminated sediments. The key parameters that impact the proposed technology are temperature, pH level, ozone nano-bubble size, dissolved ozone concentration, ultrasound power, dwell time, and the duration of ultrasound treatment.
Each parameter is varied while observing its impact on the removal efficiency of organic and inorganic contaminants in contaminated sediments. The solution temperature has a direct impact on Ozone levels in water, where organic material removal indicates high removal efficiencies at low temperatures. The maximum removal efficiencies of organics were 92%. The inorganic contaminant used during the investigation is chromium. The removal efficiency of the chromium does not show a significant impact due to temperature, where the study shows a 98% removal efficiency. The test results show that the combination of ozone, nano-bubbles, and ultrasound to treat contaminated sediments is a reliable and implementable technology. The data obtained from the laboratory experiments can be used to develop a pilot scale study for possible field application.
Hewa Batagoda, Janitha, "Decontamination of the passaic river sediments using ultrasound with ozone nano-bubbles" (2018). Dissertations. 1368.