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Green Ports and Green Ships
Published in Petros A. Ioannou, Intelligent Freight Transportation, 2008
Christopher F. Wooldridge, Thomas H. Wakeman, Sotiris Theofanis
Many industrialized harbors now face difficulties in performing new construction and maintenance dredging because of historic contamination of their sediments. For many years the polluted sediments were considered benign, but research in the 1960s and 1970s revealed that contaminants could magnify in the food web and impact human health. 9 Why is dredging and disposal of contaminated sediment a problem? First, there is potential release of contaminants during dredging when sediments are resuspended. 10 Mobilized contaminants can be biologically available for uptake and accumulation in edible aquatic species. Second, after these dredged materials are excavated, they must be placed in a location that will contain their toxic constituents and protect the environment from degradation and human health from impairment. 11 Disposal of maintenance material from berths and channels is considered to be potentially the most environmentally harmful because it typically is composed almost exclusively of fine-grained sediments. This size fraction contains the greatest percentage of contaminants. 12
Exam Questions and Solutions
Published in Volodymyr Ivanov, Environmental Microbiology for Engineers, 2020
Either chemical substances or microbial biomass may be used to enhance the bioremediation of polluted sediments. Nitrate as well as the biomass of Bacillus sp. 12KT were used to enhance the bioremediation of marine sediments polluted with aromatic hydrocarbons. These bacteria are able to degrade the hydrocarbons by denitrification (nitrate respiration) under anoxic conditions. The kinetics of bioremediation can be expressed as a first-order reaction: S=S0e−kt
Mercury Toxicity
Published in Edgardo R. Donati, Heavy Metals in the Environment, 2018
Mohammed H. Abu-Dieyeh, Kamal Usman, Haya Alduroobi, Mohammad Al-Ghouti
Mercuric environmental persistence suggests the need for the exploration of many remedial methods to effectively decontaminate polluted environments. Capping and dredging are commonly employed to actively remediate polluted sediments in water (Randall and Chattopadhyay, 2013). Dredging results in the recovery of water circulation and removal of bottom sediments (Barbosa and de Almeida, 2001). Capping may be in situ, which involves the placement of a layer of separating sand between contaminated sediment and the water (Palermo, 1998).
Detoxification of polluted marine sediments using water treatment sludge
Published in Journal of Environmental Science and Health, Part A, 2018
Visnja Orescanin, Robert Kollar, Karlo Nad, Ivan Halkijevic, Marin Kuspilic
The treatment of the contaminated sediments could be generally divided into in situ and ex situ approaches. The most in situ methods are based either on the isolation of the contaminated sediments by covering with the layer of pure, nonpermeable material or geomembranes or by mixing with various additives having high sorption capacity in order to alleviate the leaching of the contaminants into aquatic environment. Bioremediation, phytoremediation, in situ oxidation, and Fenton oxidation are also used for the remediation of polluted sediments.[4]