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Zero Effluent Discharge Solution implemented at Unimark Remedies Limited, Bavla, Gujarat

The Company:

Unimark is engaged in the manufacture of bulk drugs and active pharmaceutical ingredients (API) at its two facilities at Vapi and Ahmedabad, aggregating a Turnover of more than US $ 25 Million (2001/2002).

Its products include anti-infectives, anti-biotics, musculo-skeletals etc. Set up by first generation entrepreneurs, it has grown into being one of the largest manufacturers of few of the bulk drugs in the international and domestic markets. It has continuously upgraded the facilities and carried out capacity expansions at both the facilities. Swiss Tec invested Rs. 40.0 million in September 2000 to part finance a capacity expansion in Ahmedabad.

Unimark was incepted in 1993 manufacturing Quality Active Pharma Ingredients (API) complying with stringent environmental and safety standards. Currently total installed manufacturing capacity is 10,66,000 Litres. It has attained global leadership in Manufacturing of Nalidixic Acid, Nimesulide, Albendazole, Oxolinic Acid and Pefloxacin. It has also been benchmarked as a reliable source by leading Multinational as well as leading Pharmaceutical companies. The coverage of Unimark is more than 70% of the Indian Formulation companies market base. Manufacturing activity is fully integrated with its state-of-the-art plants situated at: Vapi and Ahmedabad in the state of Gujarat.

The Problem:

The effluent generated from the production of formulations varies when the product changes, i.e. the characteristics of the effluent changes day to day depending upon the product taken into the manufacturing plan. The plant is located in a landlock area and hence there is no possibility of discharging the effluent.

The effluent generated, contains very high levels of COD, TDS and Chlorides. The simpler streams were sent to the conventional ETP for treatment. The complex effluent streams which could not be sent to the ETP, were incinerated. But as is known, the costs of incineration are very high. Moreover the time of one cycle of the ETP to treat the water was also long. Production had to be restricted as the then existing ETP could not cope up with the discharge from
the production unit and also the costs of incineration were very high.

For its Effluent treatment, Mr. Sandip Parekh, Technical Director of Unimark Remedies Ltd., approached Chem Process Systems Pvt. Ltd., Ahmedabad, a name in the Vacuum & Evaporation Technology, for a comprehensive solution for handling and treating their effluent.

The Solution:

The technical team at Chem Process Systems, after a thorough analysis, concluded that the following were to be addressed simultaneously:

  • Segregation of high COD, high TDS and high volatiles streams, hereinafter referred to as complex streams
  • Segregation of low COD, low TDS streams to ETP – hereinafter referred to as simpler streams – and then to RO for pure water recovery
  • Removal of volatiles from the complex streams
  • Selection of materials – to resist chloride attacks and for a long plant life
  • Water Recovery – for reuse in process or for gardening purposes
  • Salt/Solids generation – to be sent to incinerator

Chem Process suggested the simpler streams be sent to the ETP for treatment and then either be reused or sent for gardening purposes. For treating the hazardous effluent, Chem suggested the application of an Evaporation process in place of the Incineration process, as the cost of effluent treatment through the Evaporation Process would be significantly lower than that of the Incineration Process. A Multiple Effect Evaporation Plant was thus suggested.

Since the effluent contains mainly chlorides, the choice for the material of construction was narrowed down to either Titanium or Cupronickel. As Austenitic Stainless Steels are also corroded by the chlorides at high temperatures, Chem did not advise the same to handle effluent containing largely chlorides. Cupronickel was also ruled out as there was a presence of free ammonia and the cupronickel alloy is not resistant to the corrosion attack by the same. Hence the only choice left was the usage of Titanium, which is immune to corrosion caused by high temperature chlorides. Since titanium is a very expensive material, the capital investment would have been very high. To reduce the capital investments and still use the titanium metal, Chem suggested a Triple Effect Plate Type Evaporator, where all the plates would be of Titanium construction, as it could procure titanium plates at a very low price.

Before sending the effluent to the Evaporator, it was sent through a stripper, operating under low vacuum, to remove the low volatiles with high COD’s. The resultant effluent is then fed into the Triple Effect Plate Type Evaporation Plant. 80% of water is recovered, while the 20% concentrated effluent is sent directly to the incinerator. The recovered water at 60-70ºC is used as feed to the boiler.
Evaporation Plant Inlet Feed Analysis

Sr. No




1 Total Qty KL 60
2 TDS Mg/ltr 40000 – 50000
3 COD Mg/ltr 70000 – 90000

Recovered Condensate Analysis

Sr. No




1 Total Qty KL/day 48
2 TDS Mg/ltr 150 – 200
3 COD Mg/ltr 800 – 1200
4 pH 7 – 8


The Benefits:

  • Effluent free bulk drugs manufacturing unit
  • Major environmental problem avoided
  • Conformation to government norms as Zero Discharge achieved
  • Enhancement in profits because of increase in production capacities
  • Reduced costs of effluent treatment
  • Avoidance of liability costs
  • Improved corporate image and brand equity
  • Un-interrupted production

The company is now looking to expand its operation and Chem Process has been asked to develop the Effluent Treatment Facility to cope up with the eventual additional load with different characteristics.

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