KURARAY PVA Gel For Waste Water Treatment

Kuraray PVA Gel

Through over a decade of research and development, KURARAY company has established PVA gel beads as an effective biological wastewater treatment technology. PVA (Polyvinly alcohol) gel is a porous hydrogel that is ideally suited for immobilization of microorganisms essential for the degradation of environmental pollutants.

Advantages of PVA Gel Beads

  • It is formed as 4 mm spherical beads having specific gravity of 1.025±0.01
  • PVA gel has a network of minute pores about 20 micron in diameter tunneling through each bead
  • Useful bacteria can thus be enriched in large numbers in the protective core of the beds greatly reducing sloughing of biomass while maintaining stable treatment effectiveness often at rates in excess of 25kg BOD/m3-gel-d
  • Treatment yields less excess sludge as compared to conventional biological method.
  • Polymerized PVA gel is essentially insoluble in water and is not known to be biodegradable
Advantages of PVA gel

Treatment Of BOD Removal

An existing wastewater treatment plant is considered that has 250 m3 activated sludge tank and a 45m3 clarifier. The plant is originally designed to handle 150 m3/d with an influent BODs of 1000 mg/L. However the plant is now in need of an upgrade to handle an increased flow of 300 m3/d (with the same BOD) for which three design options are shown in slide. A conventional activated sludge system would require about twice the existing tank volumes to treat the increased loading.

Treatment For Nitrogen Removal

In the following example an influent wastewater flow of 300 m3/d is considered with total nitrogen (T-N) of 60 mg/L.

Nitrification reaction (aerobic)

  • Ammonia form nitrogen is converted to nitrite and then nitrate(requiring sufficient dissolved oxygen and minimal interference from organic carbon)

Denitrification reaction (anoxic)

  • Nitrate is converted to nitrite and then nitrogen gas (requiring sufficient organic carbon and minimal interference from dissolved oxygen)
PVA Gel Plant