Treatment of highly colored wastewaters
First Claim
1. A process for purifying wastewater containing organic and color-causing pollutants comprising the steps:
- (a) providing a primary aerobic treatment zone including an aeration zone and a quiescent zone for treating the wastewater;
(b) introducing wastewater into said aeration zone;
(c) aerating the wastewater in said aeration zone with an oxygen-containing gas in the presence of sufficient amounts of powdered adsorbent solids and biologically active aerobic solids to reduce the organic and color-causing pollutants to desired levels, said thus-treated wastewater and solids transferred from said aeration zone to said quiescent zone;
(d) retaining said thus-treated wastewater and solids in the quiescent zone for a sufficient time for solids therein to settle by gravity and produce a first settled solids phase and a first aqueous phase substantially free of solids;
(e) transferring said first aqueous phase from said primary treatment zone to an oxidizer contact zone;
(f) contacting said first aqueous phase with a chemical oxidizer in the oxidizer contact zone for a sufficient time to remove a further portion of said organic and color-causing pollutants;
(g) transferring said thus-treated aqueous phase from the oxidizer contact zone to an adsorbent contact zone;
(h) agitating said thus-treated aqueous phase in the adsorbent contact zone in the presence of powdered adsorbent solids for an agitation period sufficient to further reduce the organic and color-causing pollutants to desired levels;
(i) terminating agitation and allowing adsorbent solids in said adsorbent-treated aqueous phase to settle by gravity for a settling period sufficient to produce a clarified, substantially solids-free, second aqueous phase and a second solids phase; and
(j) separating said second aqueous phase from said second solids phase and discharging said second aqueous phase to the environment or to further use.
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Accused Products
Abstract
The invention is a process for purifying wastewater containing organic and color-causing pollutants. The three unit processes include a first stage aerobic or anaerobic biophysical treatment, a second stage oxidizer treatment, and a third stage adsorbent contact treatment. The biophysical treatment removes the majority of the pollutants while the oxidizer treatment destroys residual organics and color-causing pollutants. The adsorbent contact treatment destroys any residual oxidizer in the wastewater and/or adsorbs any residual oxidation products. The preferred adsorbent is powdered activated carbon and the preferred oxidizer is some form of chlorine, e.g. sodium hypochlorite. The process may be operated in either a continuous flow mode or a batch flow mode.
157 Citations
34 Claims
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1. A process for purifying wastewater containing organic and color-causing pollutants comprising the steps:
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(a) providing a primary aerobic treatment zone including an aeration zone and a quiescent zone for treating the wastewater; (b) introducing wastewater into said aeration zone; (c) aerating the wastewater in said aeration zone with an oxygen-containing gas in the presence of sufficient amounts of powdered adsorbent solids and biologically active aerobic solids to reduce the organic and color-causing pollutants to desired levels, said thus-treated wastewater and solids transferred from said aeration zone to said quiescent zone; (d) retaining said thus-treated wastewater and solids in the quiescent zone for a sufficient time for solids therein to settle by gravity and produce a first settled solids phase and a first aqueous phase substantially free of solids; (e) transferring said first aqueous phase from said primary treatment zone to an oxidizer contact zone; (f) contacting said first aqueous phase with a chemical oxidizer in the oxidizer contact zone for a sufficient time to remove a further portion of said organic and color-causing pollutants; (g) transferring said thus-treated aqueous phase from the oxidizer contact zone to an adsorbent contact zone; (h) agitating said thus-treated aqueous phase in the adsorbent contact zone in the presence of powdered adsorbent solids for an agitation period sufficient to further reduce the organic and color-causing pollutants to desired levels; (i) terminating agitation and allowing adsorbent solids in said adsorbent-treated aqueous phase to settle by gravity for a settling period sufficient to produce a clarified, substantially solids-free, second aqueous phase and a second solids phase; and (j) separating said second aqueous phase from said second solids phase and discharging said second aqueous phase to the environment or to further use. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A process for purifying wastewater containing organic and color-causing pollutants comprising the steps:
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(a) providing a primary anaerobic treatment zone including a mixing zone and a quiescent zone for treating the wastewater; (b) introducing wastewater into said anaerobic mixing zone; (c) mixing the wastewater in said mixing zone by mixing means in the presence of sufficient amounts of powdered adsorbent solids and biologically active anaerobic solids to reduce the organic and color-causing pollutants to desired levels, said thus-treated wastewater and solids transferred from said mixing zone to said anaerobic quiescent zone; (d) retaining said thus-treated wastewater and solids in the quiescent zone for a sufficient time for solids therein to settle by gravity and produce a first settled solids phase and a first aqueous phase substantially free of solids; (e) transferring said first aqueous phase from said primary anaerobic treatment zone to an oxidizer contact zone; (f) contacting said first aqueous phase with a chemical oxidizer in the oxidizer contact zone for a sufficient time to remove a further portion of said organic and color-causing pollutants; (g) transferring said thus-treated aqueous phase from the oxidizer contact zone to an adsorbent contact zone; (h) agitating said thus-treated aqueous phase in the adsorbent contact zone in the presence of powdered adsorbent solids for an agitation period sufficient to further reduce the organic and color-causing pollutants to desired levels; (i) terminating agitation and allowing adsorbent solids in said adsorbent-treated aqueous phase to settle by gravity for a settling period sufficient to produce a clarified, substantially solids-free, second aqueous phase and a second solids phase; and (j) separating said second aqueous phase from said second solids phase and discharging said second aqueous phase to the environment or to further use. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification