Things that can cause toxicity include many of the following:
Metals: lead, antimony, copper, zinc, chromium, cadmium, nickel, manganese
Oxidizers: chlorine, chloramines, any of the group VII compounds in the
periodic table, permanganates, ozone, fluorine, iodine, peroxides, and
All of these compounds are direct toxins, because they directly interfere
with the biological cycles in the cell and the cell enzymes.Some organic materials are resistant because they are chlorinated, and chlorination makes them substantially harder to deal with. Others are toxic because they are phenolics. Phenol was the first major disinfectant. It can be biodegraded readily but it takes some work.
The point is that complex organic materials have some ability to biodegrade, if the conditions are correct. However, all biological treatment is as follows: The art of engineering a system so that the bacteria do what they will and want to do in a manner that coincides with your objectives. Stated in another way: ‘‘Given any combination of temperature, pressure, nutrients,and substrate, the bugs will do as they damn well please.’’3 You have to understand what you are treating and how it degrades.
One of the best sources for information on biodegradability of all organic
compounds is Karl Verschueren’s Book, ‘‘Handbook of Environmental Data on Organic Chemicals,’’ by Van Nostrand Rheinhold, NY. The book is quite complete and has excellent data on biodegradability for specific organic compounds. Much of the rate information in the book is unavailable elsewhere.