Generation of methane from textile desizing liquors.

A new strategy for the biological transformation of sugar-containing wastewaters from the textile desizing process to biogas was developed. Here, industrial liquors were separated from the following washing step by squeezing the impregnated fabrics after desizing. These waters exhibit a chemical oxygen demand of 40 g/L and allow a direct use in microbial biogas reactors without further treatment or accumulation. After reaching balanced conditions, the microbes continuously produce biogas. Moreover, the chemical oxygen demand can be reduced up to 75%. This new technology seems to be practicable and even attractive for small- and medium-sized enterprises with an annual cotton production down to 2000 t. At this stage, a reliable eco-balance of the overall process is still pending. Further investigations will be carried out soon.