Abstract Water containing organic contaminants is treated with an oxygencontaining gas and thereafter passed through a biologically effective active-carbon stage divided into at least two activated-carbon beds for biodegradation of the microorganisms in the raw water. Between these beds at least a major proportion of the water emerging from the first bed is treated with ozone before entering the next bed. The two beds constitute a biological purification stage from which the effluent may be passed to an adsorption stage in which activated carbon is used to remove residual organic impurities by contact absorption. The final effluent is chlorinated with at least 0.05 mg/liter chlorine or treated with an equivalent quantity of another disinfectant.
The method defined in claim 1 wherein said major portion of said effluent is treated in step (b) with an ozone and oxygen-containing gas stream. 3. The method defined in claim 2 wherein the ozone-treated portion of said first effluent from step (b) is retained for a period of 2 to 5 minutes in a reaction vessel prior to step (c).
Claim 2
Dependent Claim
28 words
The method defined in claim 2 wherein the ozone-treated portion of said first effluent is contacted with an activated-carbon bed prior to step (c) to eliminate excess ozone.
Claim 3
Dependent Claim
26 words
The method defined in claim 2, further comprising the step of branching a minor portion of said first effluent directly to step (c) without intervening ozonization.
Claim 4
Dependent Claim
23 words
The method defined in claim 2, further comprising the step of passing said second effluent prior to disinfection through an activated-carbon adsorption filter.
Claim 5
Dependent Claim
20 words
The method defined in claim 6, further comprising the step of continuously regenerating the activated carbon of said adsorption filter.
Claim 6
Dependent Claim
23 words
The method defined in claim 7 wherein the activated carbon of said adsorption filter is passed countercurrent to the second effluent traversing same.