Industrial Green Chemistry World

Profitability from Industrial Green Chemistry and Engineering

The H-acid Effluent Problem


H-acid is one of the leading dye intermediates in the world, used in manufacture of black dyes. India is the second largest manufacturer of H-Acid in the world after China. However, H-acid is responsible for the most polluting industrial effluent in the dye and dye intermediate sector.


Did you know that manufacturing 1 kg of H-acid, results in the generation of 50 kg waste ?

 In other words, it has an E-Factor of 50. In fact, the final isolation step is responsible for 50% of the overall waste generated. The waste is of dark color, strong acidity and contains substituted derivatives of naphthalene compounds. These organic substances are toxic, non-biodegradable, difficult to decolorize and resistant to conventional treatment. It has a very high COD of 1,50,000.

China and India – The hubs of H-acid manufacturing

Having considered the ill effects of H-acid manufacturing process, the developed countries of the world, with their strict environmental norms, gradually phased it out. Currently most of the developed world has banned it. However, the demand for H-acid continues – there is no other alternative on the horizon. For this reason, the manufacturing was outsourced to countries like China and India where environmental norms are not as strict.

The Bichhri Industrial Pollution Incident

 The extent of the damage possible due to the generated waste is evident from the Bichhri industrial pollution incident. Bichhri, a small town near Udaipur was home to several H-acid plants. However, the toxic wastewater from the plants was left untreated and left to be absorbed into the earth, badly damaging the groundwater and soil, rendering it unfit for cultivation. H-acid plants in Jaitpur and Ratlam were also closed down for similar reasons.

What is the way ahead ?

In India, the bulk of the manufacturing happens in the states of Gujarat and Maharashtra by small and medium enterprises (SMEs) which are considered employment generators. Most of the H-acid is exported, bringing in valuable foreign exchange to our country. Considering these realities in mind, it is necessary to find a balance between environment protection and economic development. To achieve this objective, it is essential to incorporate the principles of green chemistry and green engineering in this process.

Author: igcw

Industrial Green Chemistry World is India's first flagship platform that brings together the mainstream issues concerning Green Chemistry and Green Engineering to all stakeholders of Chemical Industry. Join us at the IGCW-2015 Symposium & Expo in Mumbai, India. Through your participation, be assured of an enriching exposure to diverse successful endeavors in the industry that can transform your thinking on your technological and business practices with world leading practices and global trends. In line with the success of IGCW-2009, IGCW-2011, IGCW-2013, the IGCW-2015 Symposium and Expo will provide business leaders at all levels with insights into developing and enhancing profitable and sustainable means for implementing Green Chemistry and Green Engineering practices. Successful practitioners and experts in the field will present on the many current and future green and sustainable opportunities in the chemical industry.

5 thoughts on “The H-acid Effluent Problem

  1. A chemical Engineer can do perfect zero discharge system for H acid if the unit is positive enough to spend money after it.We can use Hydrogenation of Nitro mass instead of Iron powder.The mother liquid during isolation requires perfect crystallization and concentration before being used to manufacture dispersing agents which are various naphthelene sulphonic acids.
    Pranav Jobanputra
    Chemical Engg.
    RPM Consultancy

  2. Good information for environmental awareness

  3. Are you aware of Bodal Chemicals of Ahmedabad, a leading producer of H Acid. How good is their effluent treatment

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