Integrated Technologies Based on the Use of Activated Carbon and Radiation to Remove Contaminants Present in Landfill Leachates

摘要

Landfills remain a prime concern of waste management systems throughout the world and have been identified as one of the main threats to groundwater resources. The two most serious environmental effects of landfills are related to the leachate formedduring decomposition from the percolation of rainwater through the waste layer and to the toxic byproducts generated by chemical and biological processes during waste leaching. Once landfill leachate is released into the environment, it can pollute soils, surface water, groundwater, and wildlife, due to its toxicity. Various organic pollutants and chemical species have been detected in the composition of landfill leachates, including: i) plasticizers and organic esters added to polymers in order to improve the properties of the final product, ii) antioxidants or stabilizers used to improve the durability of materials, and iii) herbicides/pesticides or other widely-used anti-pest' compounds. This chapter is concerned with conventional and novel technologies for the elimination of pollutants present in landfill leachates stand out: (a) Photocatalysis in the presence of activated carbon; (b) Photolysis with the participation of HO* y S0_4-radicals; (c) Application of gamma radiation to generate oxidativeand reductive species; and (d) adsorption on activated carbon. Thus, the objective of this chapter is to summarize the main technologies applied to the elimination of contaminants present in landfill leachates. The chapter will be divided in four main topics.