Marine environment chemical treatment

Why does Chemistry in the Marine Environment deserve separate treatment within the Issues in Environmental Science and Technology series Is it not true that chemical principles are universal and chemistry in the oceans must therefore simply abide by these well-known laws What is special about marine chemistry and chemical oceanography ... 

In summary, the marine environment contains a wealth of plants, animals and microorganisms. Due to their unique adaptations to their ocean habitat, they contain a wide diversity of natural products. These compounds have shown activity in a variety of assays which have relevance to human diseases. As our understanding of the molecular basis of disease expands, these compounds and ones yet to be discovered will provide lead compounds for human therapeutic treatment. Innovations in synthesis, fermentation of symbionts as well as in manipulation of biosynthetic genes will allow us to produce sufficient material for clinical use of the compounds. Marine organisms provide a unique opportunity for access to chemical diversity. 

It is useful to be familiar with the treatment process, to monitor the changes that occur after the introduction of the treatment, to characterize chemically and microbiologically the treated efQuent, and to determine its dispersion in the receiving waters. It appears that, at least in the UK, the impact of sewage discharge on the marine environment is relatively minor and the main factor responsible for this is high initial dilution [154]. Without sufficient dilution, eutrophication is the most likely consequence, as demonstrated for example by a case study [155]. 

Horton et al. [55] observed that when steels containing Cu and Ni are exposed in industrial and marine atmospheres, the Cu and Ni appear in the mst layers both in the loose outer and adherent inner mst on skyward and ground ward surfaces. Also it was shown by chemical analysis that Ni, Cu, Cr and Mn from weathering steel appear in the mst layer and provides protection. Presence of chlorides in the atmosphere accelerates corrosion of steels leading to the formation of basic Fe ", Fe chlorides and jS FeOOH. Townsend et al. [56] conducted 8-year atmospheric corrosion tests on weathering steel in mral, industrial and marine environments with different heated conditions and indicated that heat treatments have no effect on the corrosion resistance/performance of weathering steels. 

The on-line monitoring of the concentrations of toxic metals such as lead, cadmium and mercury in industrial effluents, river water, drinking water, lake water and marine water has become an important aspect of environmental control. Ideally, in any on-line system for monitoring of industrial effluents which flow into the environment, the sampling, chemical treatment to remove interferences (if required), data manipulation, data reporting and all other necessary operations are completely automated. In the present era of chemical instrumentation, normally this means that all operations from the start of the experiment (sampling) to preparation of the final report are under microprocessor control. 

There are many instances where the results of one study have not been confirmed by the results of another study using the same chemical. Such disturbing discrepancies may be explained in part by differences in protocol for chemical administration (food, ambient water or injection) or dose or duration of the treatment. Furthermore, over 30 different model species from marine, freshwater, tropical, temperate and cold-water environments have been used. Also, fish have rarely been at a comparable physiologic state or stage of development or maturation and have been held under diverse environmental conditions. If indeed, as seems to be the case, variations in thyroidal responses to ecotoxicants can be explained in part by variations in species, environmental conditions and physiologic state, then selection of a standardized... 

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