In India, 2.6 billion liters of alcohol is produced every year. For every liter of alcohol produced, 10 – 15 times as much wastewater is generated. The distillery industry in India could benefit from new methods to treat this residual liquid to produce a high volume of nutrients for many beneficial uses. The Central Salt & Marine Chemicals Research Institute (CSMCRI) in Gujarat has a developed a new coagulation process to do just that. [1]
CSMCRI’s process is designed to separate the main source of pollution — potash and biodegradable organic matter — from the distillery wastewater. The first stage involves recovering potash and evaporation of the remaining wastewater to yield recycled water and residues. In the second stage, the residues are mixed with the potash to make organic matter, potassium nitrate and reclaimed water. These reclaimed resources can be used for animal feed formulations, fertilizer and reusable in the molasses fermentation process. [2]
This process yields a high amount of complex organics and potassium nitrate. In addition, about 80% of the water is recycled. [3] The great benefits include: compliance with the Central Pollution Control Board’s mandated zero liquid discharge (ZLD) action plans, accomplishing up to 10% of India’s potassium-based fertilizer requirements (cutting down on imports), and encouraging distilleries to explore production of ethanol for blending with petrol (cutting India’s oil import bill making it more profitable for sugarcane growers).
[1] Kateshiya, Gopal B. “CSIR lab cracks it: Sugar waste to fertiliser.” 18 05 2018. The Indian Express. Web. 23 05 2018.
[2] CSIR. “Technologies.” n.d. Central Salt & Marine Chemicals Research Institute. Web. 23 05 2018.
[3] Kateshiya, Gopal B. “CSIR lab cracks it: Sugar waste to fertiliser.” 18 05 2018. The Indian Express. Web. 23 05 2018.
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