H acid: a dye intermediate
In India, H-acid (1-amino, 8-napthol, 3,6-disulphonic acid) is manufactured mainly by small and medium-sized enterprises with a production capacity of between ten and 100 tonnes per month. The promotion of such enterprises has created multi-media pollution problems. As the West stopped making toxic dye intermediates, such enterprises mushroomed in industrialising countries.
Due to the usage of high-strength acids and alkalis in the manufacture of H-acid, the combined wastewater stream is contaminated with high chloride and sulphate content. In addition, the presence of toxic naphthalene-based dye intermediates in the wastewater made it non-biodegradable. Effluents from H-acid manufacturing factory are deep red in colour and can contaminate the groundwater in a huge area around the plant if not treated properly.
One such notorious case is that of Bichchri. O P Agarwal set up a chain of chemical factories on the land, situated upstream of Bichchri, on the eastern slopes of a series of hillocks which flank Udaisagar canal. The two H-acid units, Silver Chemicals and Jyoti Chemicals, ruined the groundwater from the only source for at least 400 agricultural families in drought-prone Bichchri. The villagers of Bichchri have not got justice till date. And almost two decades since the factory began, the groundwater in still red coloured in Bichchri.