%0 Journal Article
%T Geochemical and Geophysical Study in a Degraded Area Used for Disposal of Sludge from a Water Treatment Plant
%A Ricardo Cosme Arraes Moreira
%A Geraldo Resende Boaventura
%A Sandra Alves Nunes
%A Luciano de Almeida Pinheiro
%A Carlos Tadeu Carvalho do Nascimento
%A Davi Rodrigues da Silva
%A Christiane de Pinna Lira
%J Applied and Environmental Soil Science
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/489182
%X The effects of disposal of sludge from water treatment plant (WTS) in area damaged by laterite extraction and its consequences to soil and groundwater were investigated. Therefore, the presence and concentration of anthropogenic elements and chemical compounds were determinated. WTS disposal's influence was characterized by electroresistivity method. The WTS's geochemical dispersion was noticed in the first meters of the nonsaturated zone from the lending area. Lateritic profiles were characterized due to the large variation in chemical composition between the horizons. Infiltration and percolation of rainwater through the WTS have caused migration of total dissolved solids to the groundwater. WTS's disposing area has more similarities to local preserved vegetation than to gravel bed area. WTS can be considered a noninert residue if disposed in degraded areas located in regions with similar geological and hydrochemical characteristics. 1. Introduction The global scale environmental changes resulting from anthropic process of space occupation and urbanization impose fees which are incompatible with the carrying capacity of natural ecosystems. In this context, surface waters have been increasingly penalized with several launches of waste resulting from populational growth and disorderly occupation of protected areas. Thus, water quality worsens, and making it drinkable requires treatment with greater quantities of chemicals than usual to be applied. As a result, waste increases in water treatment plants (WTPs) such as the sludge generated in clarifiers and water resulting from the filter washing. In Brazil, there are about 7,500 WTPs, called conventional or traditional, which use coagulation/flocculation/sedimentation and filtration systems for water treatment. These systems generate wastes in the clarifiers and filters that, in most cases, are released directly into rivers, lakes, and reservoirs, aggravating the environmental issue [1¨C3]. The chemical sludge produced by the water treatment plants is an extremely gelatinous material composed by aluminum hydroxides, inorganic particles such as clay and silt, color colloids and microorganisms including plankton, and other organic and inorganic materials, which are removed from the treated water, or from the chemicals added to the process [4, 5]. Its pH range is from 5 to 7, which is insoluble in the range of natural water pH. It is estimated that in Brazil about 2,000£¿tons/day of WTS are dumped directly into waterways without any treatment [6]. This practice contributes to the organic pollution, which may
%U http://www.hindawi.com/journals/aess/2011/489182/