Adsorptive separation of toxic metals from aquatic environment using agro waste biochar: Application in electroplating industrial wastewater

Life of living or non-living being depends on water; in short, water is life. But these days, with the growing industrialization, it is spoiling a lot. Wastewater contains contaminants like acids, bases, toxic organic and inorganic dissolved solids, and colors. Out of them, the most undesirable are colors caused mainly by dyes. Color and other compounds present in water are always not desirable for domestic or industrial needs. The wastes of dyes are predominant amongst all the complex industrial wastewater. This water is dark in color and highly toxic, blocking the sunlight and affecting the ecosystem. Among all the dyes, azo dyes contribute to commercial dyes used widely in textile, plastic, leather, and paper industries as additives. The removal and degradation of azo dyes in aquatic environment is important because they are highly toxic to aquatic organisms. For every industry, clean technology has become an important concern. In this chapter, the authors discuss about existing processes as well as promising new technologies for textile wastewater decolorisation.

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Unionacean Clams as Indicators of Persistent Substances in Fresh Water

Water Science & Technology ◽

10.2166/wst.1983.0187 ◽

1983 ◽

Vol 15 (S1) ◽

pp. 37-42

Author(s):

A Forester

Keyword(s):

Fresh Water ◽

Food Chain ◽

Toxic Metals ◽

Aquatic Environment ◽

Extended Period ◽

Coastal Pollution ◽

Biological Availability ◽

Abundance Distribution ◽

Secondary Function ◽

Shield Lakes

Measurement of total or nominal pollutant concentration in the physical compartment of the aquatic environment (water, sediments, etc.) seldom gives a valid indication of the ultimate threat to the ecosystem. An alternative is to use a living organis to reflect the biological availability of the contaminant and to integrate its changing levels in the environment by monitoring over an extended period. Pelecypods have been used as indicators of marine coastal pollution, but have received relatively little attention in fresh waters. The large, unionacean clams and mussels show a number of features which suggest that they would be useful as monitors of biological availability of freshwater pollutants: ability to accumulate a wide variety of contaminants; mode of feeding; position on food chain; longevity; sedentary habits; facility with which their age can be determined; abundance; distribution; size and hardiness. The current programme is concerned with: (1) evaluating unionaceans as potential indicators and the factors that affect pollutant uptake; (2) development of the methodology for monitoring; and (3) characterisation of the pollutant status of Ontario shield lakes which are subject to direct inputs of toxic metals with the precipitation and their mobilisation through the ecosystem as a secondary function of environmental acidification.

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