Strategy for Investigation of Filter Material for Wastewater Treatment

Abstract

This paper presents a strategy for an investigation to give a comprehensive picture of a biological filter aimed for treatment of different kinds of wastewaters, such as landfill leachate, stormwater and wastewater from vehicle washes. The strategy is based on batch equilibrium experiments and includes three main parts. Under focus is the ability of the filter material to simultaneously remove organic and inorganic pollutants from wastewater, as well as the environmental impact of using materials that would normally be waste to build filters, on one hand, and of disposing of used filter material on the other. The filter material used in these tests is naturally occurring materials such as peat and residual products such as carboncontaining ash. A filter material in a treatment system needs eventually to be exchanged either because it has been saturated by pollutants or because the hydraulic conductivity has decreased too much. After usage the filter material is considered solid waste and is to be classified and handled according to that. Several possible alternatives for further handling, i.e. landfilling, combustion or composting can be selected. A characterization of filter material used for three years in a full-scale filter system for landfill leachate treatment has revealed that energy recovery at an incineration plant could be a possible handling alternative for the used filter material.