Zero emissions

This month we are focusing once more on India as the country sets itself an incredible target of 20% annual growth to the year 2010 when it hopes to achieve US$7 billion in leather and related exports against a current projected level of $3 billion and a growth rate for 2006/7 of 9.24%. The government also want the leather industry to double in size over the same time scale, creating another half million jobs. This will have a profound knock-on effect on the environmental sustainability of the industry. The industry has set itself the aim of zero liquid emissions from its tanneries and some are already achieving this. While this is very laudible, it tends to put the emphasis on end of pipe treatment rather than cleaner technologies and it does not tackle the issue of salt at all. In India, tanneries which cannot manage zero emissions must engage in expensive and high maintenance reverse osmosis treatment. And the salt recovered from the clean-up process is currently being piled up at the tanneries just waiting for the next monsoon to arrive and wash it all into the surrounding land. There has been a very worthwhile project on salinity reduction in tannery effluent running in recent years which involved Australia and India in a joint CLRI-CSIRO-ACIAR project. We first reported on this project in January 2006 when it was well established and we have included an update in this issue as the project nears its end. The latest report concludes with the words: Recently the main focus for Tamil Nadu tanneries has been zero discharge, not salt reduction measures. Both approaches will be necessary to achieve satisfactory environmental outcomes: low TDS in effluent and less waste salt. At the Lerig meeting in January, president of the All-India Skin and Hide Tanners and Merchants Association, Rafeeque Ahmed asked tanneries and leather manufacturers to make the changes needed for eco-friendly production, even if it was costly. Acknowledging the commitment already shown by tanneries in Tamil Nadu, Sukumar Devotta, director of the National Environmental Engineering Research Institute, said: 'The kind of investment being made in Tamil Nadu is not seen in other parts of the country and the challenge is to see that the Tamil Nadu model is followed across India.' It is not just India and Australia who have salt related problems. Land locked countries and those with water shortages are the hardest hit. I recently received a paper from Syed Muhammad Ather Raza Zaidi, Cluster Development Agent, Trade Development Authority of Pakistan, on the use of Cleaner Production Techniques: reduced amount of salt for preservation of hides/skins. He concluded that: 'If the hide and skin dealers in Pakistan reduced their salt application by 75% for curing hides and skins, about 19,500 tons of salt would be saved annually. Nor is the issue a new one. In our special centenary issue in September 1967 we stated that: A replacement for common salt for preservation was high on the agenda and despite the introduction of alternatives such as chilling and biocides, the salt (TDS) in tannery effluent is still a proving to be a problem today.