The chief wastes from the wool scouring industry are wool grease sludges, which arise from partial effluent treatment. In the United Kingdom alone, the wool scouring industry produced some 30,000 tonnes of wet sludge per annum.
The exact composition of the sludges depends on the origin of the wool, but they will normally contain dirt and wool grease as well as mixtures of short fibres, fibre fragments, suint and vegetable and mineral matter. They also contain relatively high levels of organic material, including potentially toxic sheep dip pesticides and processing auxiliaries. These sludges are being produced in ever increasing amounts, as scouring companies are progressively being required by domestic and European legislation to treat their effluent more stringently prior to discharge.
Currently, landfill offers an economic and readily available means of disposal of these sludges. The implication of increasingly stricter EU legislation on the disposal of wastes to landfill is that the UK wool scouring industry will not be able to continue to utilise their current disposal route. If no alternative route is found, then it is likely that the UK wool scouring industry will be forced to close, with the loss of many hundreds of jobs. The likely knock-on effect of this is that spinning and weaving companies in the UK will go under, resulting in a further major round of job losses.
This paper investigates the viability of incineration as a more environmentally friendly and acceptable long-term solution to the problem. Pilot plant studies on a specially built rotary kiln incinerator have revealed the effectiveness of incineration not only in minimising the amount of waste significantly, but also in eliminating most of the harmful components of the sludge. The overall commercial viability of incineration is demonstrated in a full-scale trial, using a commercial incinerator in the North of England.
By: Dr J S Pearson, Dr X F Lu and Dr K L Gandhi Department of Textiles, University of Huddersfield, UK
Submit Date: 6/7/2010 18:00