(JP4066188-A)      Sulphuric acid is added to polyvinylalcohol (PVA) contg. waste water. The waste water is treated with peroxysulphate and heated above 70 deg.C to separate PVA from it.    Four pts.wt. of peroxysulphate and 10 pts.wt. 50 deg. Be H2SO4 were admixed with 1000 pts.wt. of waste water which contained 1.0-1.2 wt.% PVA; the mixt. was heated at 95 deg.C for 10 min.; it was neutralised with NaOH; insolubilsed PVA was sepd. from the waste water, dehydrated, and dried. The dried PVA was used as a fuel with 4000-4600 cal/g.    USE/ADVANTAGE -   PVA which contains waste water discharged from textile treatment processes can be completely removed from it. The amt. of peroxysulphate like ammonium peroxysulphate is reduced. The water content of the PVA sepd. is quite lower of 60-70%, so that PVA can be dried easily. The dried PVA is used as a fuel.    (US5110481-A)      Polyvinyl alcohol (PVA) is precipitated from its aq. soln. by adding a peroxodisulphate, pref. NH4 dioxopersulphate to the soln., acidified with H2SO4, and heating the soln. above 70 deg.C.. The aq. soln. is waste water contg. PVA obtd. during pretreatment of a textile product with PVA.    ADVANTAGE -   A higher recovery rate than previously is achieved irrespective of the mol. wt. of the PVA; the amount of residual sludge is minimised.    (JP94030770-B2)      Polyvinyl alcohol is sepd. from an aq. soln. by adding a peroxydisulphate to the soln. and heating at above 70 deg. C. Pref., sepn. of PVA is from an acid soln., esp. after addn. of H2SO4. The disulphate is (NH4)2S2O8 and the soln. is a textile waste water.    USE/ADVANTAGE -   Polyvinyl alcohol (PVA) is used in the textile industry as a size to prevent fibre breakage during weaving, and occurs in the waste water. PVA is recovered almost completely as a prod. contg. 60-70% of water, compared with 90% in known processes. It is non-tacky, and insol. in acid and alkali, and the properties do not change with time. It can easily be dried and used as a fuel.    (JP94030771-B2)      Polyvinyl alcohol is sepd. from an aq. soln. by adding a peroxydisulphate to the soln. and heating at above 70 deg. C. Pref., sepn. of PVA is from an acid soln., esp. after addn. of H2SO4. The disulphate is (NH4)2S2O8 and the soln. is a textile waste water.    USE/ADVANTAGE -   Polyvinyl alcohol (PVA) is used in the textile industry as a size to prevent fibre breakage during weaving, and occurs in the waste water. PVA is recovered almost completely as a prod. contg. 60-70% of water, compared with 90% in known processes. It is non-tacky, and insol. in acid and alkali, and the properties do not change with time. It can easily be dried and used as a fuel.