"Protecting the Environment through Waste Water Recycling and Heat Recovery in Textile Finishing"

It is difficult for textile finishing to escape the image of being an industry which causes emissions. However, there are ways to drastically reduce the difficulties associated with wet chemical processes. The report describes the increasing global problems in the area of water and energy policies, and presents a case study which demonstrates how it can be possible to run waste water free textile finishing operations.

Within the textile industry, textile finishing is one of the main sources of emissions. As a supplier of modern high-performance textile finishing machines which are both energy and water efficient, Benninger has now gone one step further and now also offers a new range of machines which are specifically designed to save even more water and energy. The key to this range are the diaphragm filtration systems which allow water, valuable materials and waste energy to be recovered (Figure 1: Zero Discharge).

Global water and energy shortages

In future, water is set to become an increasingly scarce and therefore extremely valuable resource. Demand for water is growing at more than twice the rate at which the world's population is growing. During the last 100 years, the world's population has increased threefold, while water consumption has risen by a factor of seven in the same period. Since 1970, the available amount of water per capita has been reduced by 40% as a result.

It takes around 2,500 - 3,000 litres of water to manufacture a single cotton shirt. The bulk of this is required to grow the cotton, but this is followed in second place by the wet finishing process. The first consequences of water shortages and waste water problems are already starting to be felt in the textile finishing industry. For example, new companies in China and India have not been granted approval to set up operations if they have not been able to present a convincing case to the authorities in terms of their approach to solving the issues of water consumption and waste water. In Europe, companies face closure for the same reason. Textile centres in Asia are reporting rapidly dwindling groundwater reservoirs and heavily salinated groundwater. As a result, many companies face challenges which threaten their very existence.