Treatment of oil-in-water emulsions: Performance of a sawdust bed filter

• Published in: Journal of hazardous materials Vol. 131; no. 1; pp. 195 - 199
• Main Authors: Cambiella, Ángel, Ortea, Enrique, Ríos, Guillermo, Benito, José M., Pazos, Carmen, Coca, José
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 17-04-2006; Elsevier
• Subjects: Adsorption; Applied sciences; Chemical engineering; Coagulant salt; Deep bed filtration; Dust; Emulsions - chemistry; Exact sciences and technology; Filtration; Liquid-liquid and fluid-solid mechanical separations; Oil removal; Oils - analysis; Pollution; Sawdust; Waste Disposal, Fluid - methods; Waste emulsion; Water Pollutants - analysis; Coagulant salt; Deep bed filtration; Sawdust; Oil removal; Waste emulsion; Filter medium; Filtration; Stability; Coagulation; Sulfates; Operating conditions; Emulsion; Adsorption; Flocculation reagent; Flocculation; Breakdown; Physicochemical purification; Coalescence; Sorbent
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2005.09.023

The effect of operating conditions on the performance of a sawdust bed filter used for the treatment of an oil-in-water emulsion was investigated. A metalworking fluid (3
vol.% oil) was used as oil-in-water emulsion and sawdust as filter medium and sorbent. Because of the high stability of the emulsion, small amounts of inorganic salt (calcium sulphate) were mixed with the sorbent, acting as coagulant to achieve the emulsion breakdown. The influence of flow rate, bed height, temperature and the amount of coagulant salt added was studied. Experimental results show that several processes are involved in oil removal from oil-in-water emulsions, i.e. coagulation, coalescence, adsorption or straining. More than 99% of oil content in the influent stream was removed. Experimental results show that low-cost sorbents like sawdust are feasible to be used in the treatment of oil-in-water emulsions if small amounts of coagulant salts are added to the filter media.