Organic contaminants contain a mixture of complex products which, usually, have to be broken down into single components. If there is time, the process is automatically carried out within the nature cycle. Nature provides necessary hydrolysis of the complex through enzymes derived from microorganisms present in waste water. In view of growing pollution and considering the need of accelerating this process, a modern ways of treatment have been recently applied. The natural microorganisms have been replaced by bio-products which provide for sufficient concentration of enzymes and bacteria.