Sources of Waste from Chemical Production

As with safety, environmental considerations are usually left to a late stage in the design. However, like safety, early decisions can often lead to difficult environmental problems that later require complex solutions. Again, it is better to consider effluent problems as the design progresses in order to avoid complex waste treatment systems. 

The effects of pollution can be direct such as toxic emissions providing a fatal dose of toxicant to fish, animal life and even human beings. The effects can also be indirect. Toxic materials that are nonbiodegradable such as insecticides and pesticides, if released to the environment, are absorbed by bacteria and enter the food chain. These compounds can remain in the environment for long periods of time, slowly being concentrated at each stage in the food chain until ultimately they prove fatal, generally to predators at the top of the food chain such as fish or birds. 

emissions must not exceed levels where they are considered to be harmful. There are two approaches to deal with emissions  

Treat the effluent using thermal oxidation, biological digestion, and so on, to a form suitable for discharge to the environment, the so-called end-of-pipe treatment. 

Reduce or eliminate the production of the effluent at source through clean process technology by waste minimization. 

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