This technical note describes a study on the effect of different dispersing agents and the quantity of same on the grain-size distribution and in particular the percentage of clay size. The results confirm that the existing practice of using 100 mL of standard dispersing agent, viz. sodium hexametaphosphate and sodium carbonate solution, is suitable for marine clays also. The clay size fraction in a marine soil exists in the form of flocs, and hence a dispersing agent is imperative in determining the percentage of clay size fraction. This paper shows that the clay size fraction can vary significantly (4 to 45%) for the marine clays depending upon the dispersing agent used. It also brings out the importance of the need for using an initially moist sample for grain-size analysis in the case of marine clays. Initial air/oven drying before testing induces irreversible aggregation.
Currently, there is an effort under way to encourage remedial project managers at contaminated sites to use passive sampling to collect freely dissolved concentrations (Cfree) of hydrophobic organic contaminants to improve site assessments. The objective of the present study was to evaluate the use of passive sampling for measuring water column Cfree for several hydrophobic organic contaminants at 3 US Environmental Protection Agency Superfund sites. Sites investigated included New Bedford Harbor, Palos Verdes...
The quantity of organic matter in seawater is important in the research and monitoring of marine pollution as an indicator of organic pollution. The salt content in seawater is typically about 3.5 %, but using the Shimadzu total organic carbon analyzer, it is possible to measure the TOC directly without dilution or other pretreatment procedures. Here, we introduce an example of measurement of organic carbon in aqueous solutions of sodium chloride using the TOC-LCSH total organic carbon analyzer with the high-salt...
We as scientists do have a responsibility and I hope to be able to contribute in some way“
Ken Buesseler, researcher at the Wood Hoods Oceanographic Institute is investigating the radioactivity leaked from the Fukushima nuclear power station, initially from data facilitated by the TEPCO (Tokyo Electric Power Company) and then from samples gathered in situ. He believes that official bodies in Japan have not done enough to analyse and to take the situation in hand, and has thus called for the participation...
Location: Queen of Saanich Ferry, B.C.Owner: British Columbia Ferry Services Inc.Description: The technical verification of the Hydroxyl Systems Inc. CLEANSEATM Model No. BCM-50 was conducted aboard the M/V Queen of Saanich car ferry in British Columbia, Canada for Lloyd,s Register, North America, Inc., using municipal wastewater generated aboard the ferry. The evaluation consisted of eleven days of testing over an eighteen day period. A total of 11 composite influent samples and 82 grab effluent samples were...
The number of microbiological contact tests for marine sediments is low, although microorganisms enable a rapid screening and monitoring of sediment quality and a high resolution of hazard assessment. As no single biotest
can provide reliable answers concerning the potential hazard of environmental samples, a combination of bioassays needs to be applied to serve this purpose. In order to cover as many potential effects as possible, test organisms should have different sensitivities; assays should cover different...
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