Pollutant removal from oily wastewater discharged from car washes through sedimentation-coagulation.
Wastewater from car washes represents a potential problem for the sewer system due to its emulsified oils and suspended material. Treatment of wastewater discharged from four car washes was investigated by sedimentation and coagulation. The effect of the coagulants Servical P (aluminium hydroxychloride), Servican 50 (poly(diallyldimethylammonium chloride)), aluminium sulfate and ferric chloride was evaluated. The achieved removal using sedimentation was of 82%, 88% 73% and 51% for oils, total suspended solids, COD, and turbidity, respectively. In the treatment by coagulation we achieved average efficiencies nearly to 74% for COD removal, greater than 88% in the case of total suspended solids removal and 92% in the case of turbidity and except the performance of Servican 50 greater than 90% in oil removal. We concluded that the oil residual concentration and COD in the treated water allows pouring it in the sewer system complying with the limits of the Mexican rule NOM-002-ECOL-1996 and it is possible even its reuse, at least in the case of the chassis washing of cars.
Rubí
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InterAmerican Center of Water Resources, Autonomous University of the State of Mexico, 50091 State of Mexico, Mexico.
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Ortega
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D000534:Alum Compounds / Q000737:chemistry; D000536:Aluminum Hydroxide / Q000737:chemistry; D001336:Automobiles; D002712:Chlorides; D005290:Ferric Compounds / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
D000534:Alum Compounds; D002712:Chlorides; D005290:Ferric Compounds; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C041524:aluminum sulfate; D000536:Aluminum Hydroxide; C016976:aluminum chlorhydrate; C024555:ferric chloride