Pollutant removal from oily wastewater discharged from car washes through sedimentation–coagulation

Abstract

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.

Divergence Between Respirometry and Physicochemical Methods in the Fractionation of the Chemical Oxygen Demand in Municipal Wastewater

“…The Mamais method not only uses a coagulant, but also requires adjustment of the pH of the sample to 10.5 before the filtrations. On the contrary, the conditions that are required, in general, to break the emulsions are acidic (Lissant, 1983; Rubí et al, 2009)—for example, sulfuric acid (H 2 SO 4 ), a known oil‐emulsion breaker. Therefore, the basic pH of the flocculation method amplified the emulsions.…”

Layered double hydroxides and LDH-derived materials in chosen environmental applications: a review

“…The wide family of aqueous pollutants includes inorganic pollutants (toxic heavy metals such as As, Pb, Cd, Ni, Zn and Cr for example (Lehmann et al 1999;Yang et al 2005;El-Sayed et al 2016;Wan et al 2017)), organic pollutants (mainly dyes from paper and textile industries (Tzompantzi et al 2011;Ahmed and Gasser 2012;de Sá et al 2013;Shan et al 2014), but also drugs and pharmaceuticals (Chuang et al 2008;Zhao et al 2015;Yu et al 2017)). Many approaches have been proposed for water treatment, including coagulation (Zou et al 2016a, b), precipitation (Barrera-Díaz et al 2012;Cheng et al 2015), sedimentation (Rubí et al 2009;Guo et al 2009), sorption (Karickhoff 1984;Fosso-Kankeu et al 2010;Alila et al 2011), and ion exchange (Leinonen et al 1994;Mazur et al 2016). Regarding the literature, sorption is the most versatile process for removing pollutants at relatively low concentrations, and it is environmentally friendly.…”

Synthesis and performances for treating oily wastewater of polyether copolymers based on polyethyleneimine

“…There are various methods for treating oily wastewater, such as electro sedimentation, supersonic demulsification, centrifugation, and chemical demulsification . Chemical demulsification plays a major role in treating of oily wastewater.…”