PVA recovery plant at Alok saves money & reduces pollution

This system helps to recover 90 percent of the PVA out of the waste liquor which in turn saves 50 percent of the cost, Alok incurs in a month on PVA sizing.

PVA is used as a yarn size formulation to achieve required yarn performance properties during weaving. Using 100-percent PVA formulations for certain fabrics significantly increases chemical oxygen demand (COD) or biochemical oxygen demand (BOD) levels compared to starch and also presents opportunities for reclaiming and reusing size.  

“The (COD) in waste PVA is very high and reaches approximately 40,000 ppm. Alongside its biodegradability is also very low. By recovering PVA, COD in the waste water is reduced by around 80 percent, the remaining, which can easily be treated by an ETP plant”, CEO of Alok Industries - Mr SS Aich informed fibre2fashion.

Explaining the mechanism of the plant, Mr Aich said, “The waste water collected from desizing machine is filtered properly, after which some chemicals are added and the processed through a centrifugal force, where the suspended PVA is separated from the waste liquor.

“The waste water extracted from this process is sent for effluent treatment. The recovered PVA is then sent to a pressured filter where it forms a cake, which is then dissolved in acid to keep PVA in liquid form”, he added.

On the need to install the PVA recovery plant, he revealed, “PVA is a high-priced imported chemical. The recovery plant helps in saving valuable foreign exchange which would otherwise have been spent on buying fresh PVA. Though the initial investment is high, the avoidable water treatments and raw material savings can result in a quicker-than expected payback”.

Alongside, Alok Industries has also taken steps to recycle packaging materials, recycling of waste water, recovery of caustic being used in mercerization and reuse of hot water from waste dye liquor aggressively.  

Fibre2fashion News Desk - India