Reaping the whirlwind

Due to sedimentation, over a period of time, the basins fill up and they are
abandoned. These overburdens are a typical feature of Solvay soda ash production units across the world. During summer, the top surface dryness leads to dust pollution. Many European Solvay soda ash process units are closed since these units are not able to operate as per the stringent norms of those countries.

Sustainable development issues, as well as emerging stringent pollution control norms, encouraged Tata Chemicals to take on the challenge of finding a resolution to this environmental issue. Tipping the balance, houses were built without planning permission around the designated no-housing-allowed waste storage areas at Malara. The whirling clouds of dust became a health hazard for the new residents. Now, a community was also endangered and it became a problem howling for a solution.

The company tried a number of things to contain this menace, including spraying seawater, and making attempts to grow plants to provide oxygen cover. But we were unsuccessful,' says NS Subramanyam, manager, environment management systems, overseeing the operations here. "The lime beds do not support plant life. Besides which," he continues, "the only way to hold dust down is to grow thick plants which need soil and water, both of which are scarce due to this being a drought prone area." But, Tata Chemicals was not easily daunted.

Technology to the rescue! The company searched for the right technology partner and eventually tied up with The Energy Research Institute (TERI), New Delhi. TERI is headed by RK Pachauri, chairman of the Nobel Prize-winning Intergovernmental Panel on Climate Change, alongside former US vice president Al Gore in 2007. TERI and Tata Chemicals made a combined effort to reclaim these alkaline and chloride rich sediments by planting the appropriate green cover on a pilot scale. A joint task force collected and analysed sediment samples, sought to understand the cause of the problem, and suggest possible solutions. The team tried to change the chemical composition of the sediment by adding precipitated gypsum (low pH) and organic manure. Initial trials of sowing seeds did not give results.

Meanwhile, TERI scientists developed a way to grow plants on fly ash heap. They studied plants that grow under these harsh conditions; they isolated and cultured the bacteria needed to aid the growth of these plants, creating a consortium ofmicrobes that supply nourishment to the plant. The bacteria were then attached to the plants in the fly ash through mycorrhizal technology. The team proceeded to monitor the growth. In the first three months on 2.5 acres, the results were starkly disappointing. The second time around, it was mildly successful, since they were able to ground the sediments without any soil support. Finally, in the next attempt, most of the plants survived and the Malara Green Cap project was a success. The green cover is now there for all to see.

This is, in a way, a small bio-technological miracle, one that could be replicated in soda ash industries the world over. Today, the team proudly points out to the fruits of their labour: vegetable patches of tomatoes and chillies and the salvadora persica called pilu, a semi-saline candidate that can tolerate salt. The confidence is now high and the team has expanded the method to about 22 acres, providing oxygen and a green cover, where there were whirlwinds of ash

Sourced from ‘Tata Planet & People Initiatives’ Published by Group Corporate Affairs Copyright Tata Sons Limited, 2009.