title: Improvement of biodegradability of PVA-containing wastewater by ionizing radiation pretreatment.
abstract: BACKGROUND
  Polyvinyl alcohol (PVA) has been widely used as sizing agents in textile and manufacturing industry, and it is a refractory compound with low biodegradability.
  
  
  OBJECTIVE
  The objective of this paper was to treat the PVA-containing wastewater using gamma irradiation as a pretreatment strategy to improve its biodegradability and to determine the roles of different kinds of radical species played during pretreatment.
  
  
  METHODS
  Gamma radiation was carried out in a (60)Cobalt source station, PVA concentration was analyzed by using a visible spectrophotometer and specific oxygen uptake rate (SOUR, milligram of O(2) per gram of mixed liquor volatile suspended solids (MLVSS) per hour) was measured by a microrespirometer.
  
  
  RESULTS
  The results showed that the biodegradability of PVA-containing wastewater with low initial concentration (e.g., 327.8 mg/l) could be improved greatly with increasing irradiation dose. However, PVA gel formation was observed at higher initial PVA concentration (e.g., 3,341.6 mg/l) and higher irradiation dose, which inhibited PVA degradation by aerobic microorganisms. However, the formed gel could be separated by microfiltration, which led to more than 90% total organic carbon (TOC) removal.
  
  
  CONCLUSIONS
  Ionizing radiation could be used as a pretreatment technology for PVA-containing wastewater, and its combination with biological process is feasible.
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Sun
authors.forename: Jinping
authors.initials: J
authors.lastname: Tian
authors.forename: Lujun
authors.initials: L
authors.lastname: Chen
authors.forename: Shijun
authors.initials: S
authors.lastname: He
authors.forename: Jianlong
authors.initials: J
authors.lastname: Wang
mesh_terms: D001673:Biodegradation, Environmental / Q000528:radiation effects; D003037:Cobalt Radioisotopes; D005720:Gamma Rays; D010100:Oxygen / Q000378:metabolism; D011142:Polyvinyl Alcohol / Q000378:metabolism* / Q000528:radiation effects; D012722:Sewage / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
chemical_list: D003037:Cobalt Radioisotopes; D012722:Sewage; D014874:Water Pollutants, Chemical; D011142:Polyvinyl Alcohol; D010100:Oxygen