Incorporation of sludge from effluent treatment plant of an industrial laundry into heavy clay ceramics

Abstract

The textile sector, in particular the laundries, is one of the industrial sectors that generates large quantity of wastes that require an appropriate treatment before their disposal in the environment. In addition to productive costs increasing, the deposition of wastes in appropriate sanitary landfills is the least noble alternative as regards the inverted pyramid for solid waste management hierarchy. In this context, the traditional ceramics industries which produce primarily bricks and roofing tiles represents one of the best alternatives to use a huge variety of industrial solid wastes. The main objective of this work is to assess the technical, environmental and the economic feasibility to use the dried textile sludge as raw material for the traditional ceramic industry. The results demonstrated that the presence of organic matter in the waste resulted in a high loss on ignition, which increased the ceramic porosity, generating an increase in water absorption and firing linear shrinkage and a mechanical strength reduction. However, although this waste has impaired the properties, the values of all of them were within the limits required by Brazilian standards for bricks. In addition, heat release occurred during the volatilization of the organic compounds in the dried textile sludge, which may contribute to energy saving during the ceramic firing stage. In relation to the environmental analysis, it can be concluded that this waste can be used as by-product for traditional ceramics industries without causing significant damage to the environment.