Zero Effluent Discharge Solution implemented at Ralchem Limited, Patancheru
Ralchem Limited, India’s premier company in agrochemicals and life sciences, is a wholly owned subsidiary of Rallis India Limited, a TATA group company having a turnover of USD 25 Million. Rallis India is the undisputed leader in the domestic pesticide market, with well-known brands such as Contaf, Rogor, Tatamida, Reeva, Tatametri and more. Additionally, it produces a range of specialty fertilizers like calcium nitrate, Tracel and Solubar, as well as quality seeds. Rallis has the most comprehensive portfolio of agricultural inputs and services in India.
One of its manufacturing facilities is located 34 kms from Hyderabad in Andhra Pradesh. It is a multipurpose plant for the production of the following products:
- Phosalone (exclusively for Rhone Poulenc)
- Diethylthiophosphoryl Chloride (DETC)
- Choline Chloride on 50% silica carrier/veg carrier
The effluent generated from the production of the agro-chemicals has very high levels of COD, BOD and TDS. This effluent when sent to the conventional ETP would disturb it and treatment would not take place. The effluent was so complex that when treated with the ETP, it would not achieve the parameters as required to discharge to the CETP or for agriculture. Rallis had evaporation ponds for handling the complex effluent, but the same could be achieved very limited evaporation and could not cope up with the production capacities required. To facilitate production, Rallis has to incinerate the entire quantity of effluent, the costs of which were very prohibitive. Because of the effluent treatment related problems production was hampered on a regular basis.
For its effluent treatment, Dr. Garg, then Chief of Operations at Ralchem Limited approached Chem Process Systems Pvt. Ltd., Ahmedabad, a name in the Vacuum and Evaporation Technology, for a comprehensive solution for Effluent Evaporation.
The technical team at Chem Process Systems, after a thorough analysis, conducted that the following were to be addressed simultaneously:
- Stream Segregation
- Selection of Materials of Construction
- Water Recovery
- Salt/Solids Generation from concentrate
- Incineration of residual sludge
Chem Process suggested the segregation of streams, after which the simpler streams would be sent to ETP for treatment, the treated water from which would be used for gardening purposes.
The characteristics of the complex effluent streams were analyzed and it was found that they were high in chlorides and various other mixed components having salting properties. Also the behavior of the effluent during various tests determined the application of a Multiple Effect Evaporation Plant consisting of a Double Effect Forced Circulation. Since the effluent contains many chlorides, the choice for the material of construction was narrowed down to either Titanium or Cupronickel. As Austenitic Stainless Steels are corroded by the chlorides at high temperatures. Chem did not advise the same to handle effluent containing largely chlorides. Cupronickel was selected as presence of free ammonia was not detected.
The effluent is fed into the Multiple Effect Evaporation Plant. More than 80% of water is recovered, while the 20% concentrated effluent is sent to the settler for salt recovery. The salt is decanted and the bleed is sent to the incinerator. The salt recovered is of a mixed type and is sent to solid waste disposable sites.
Analysis of the Inlet to the Evaporator
|2||TDS||Mg/ltr||120000 – 150000|
|3||COD||Mg/ltr||25000 – 40000|
Analysis of Condensed Recovered
|2||TDS||Mg/ltr||100 – 125|
|3||COD||Mg/ltr||350 – 450|
|4||pH||7 – 8|
- Effluent free agrochemicals manufacturing unit
- Environmental Problems avoided
- Avoidance of liability costs
- Compliance to governmental norms due to achievement of Zero Effluent Discharge
- Expansion of facilities possible
- Un-interrupted production
- Enhancement in profits due to increase in production
- Improved corporate image and brand equity