Filtration of contaminated suspended solids for the treatment of surface water

As few technologies exist worldwide for the treatment of contaminated surface water, a new approach is currently under development consisting of an in situ water treatment system based on a floating filtration process for adsorbed contaminants such as heavy metals. Laboratory filtration tests were performed for the removal of contaminated suspended solids (SS) from surface water. SS, chemical oxygen demand (COD), and organic carbon (OC) were monitored. Of the four filters (two non-woven geotextiles, a woven geotextile and a sand filter) evaluated, filter I (a non-woven geotextile) was the most effective for removal % of the total suspended solids. The results demonstrated excellent efficiency by filter No. 1, for reducing turbidity by 93-98%, as well as SS by up to 98.9% and COD by 65-71% for three sites with initial turbidities of 70, 20, and 120 NTU, respectively. The level of heavy metal removal was 98.9% due the heavy metal content of the suspended solids (60 mg kg(-1) of Cu, 90 mg kg(-1) of Ni, 130 mg kg(-1) of Zn, 200 mg kg(-1) of Cr, and 80 mg kg(-1) of Pb). The development of this technology could potentially protect the public and aquatic plants and animals from dangerous contaminants such as heavy metals adsorbed onto the suspended solids. (C) 2008 Elsevier Ltd. All rights reserved.