Electron beam irradiation induced degradation of polyvinyl alcohol in aqueous solution

Background: Polyvinyl alcohol(PVA) has been widely used in the industry of textile,however,its aqueous solution was difficult to be biodegraded under natural conditions.Purpose: In this study,the PVA in aqueous solution was degraded by electron beam irradiation.Methods: Radioactive ray from electron accelerator was used for degradation of PVA aqueous solution.The effects of different radiation dose and pH on the CODCr and BOD5 values of PVA aqueous solution were investigated.The precipitation generated from acidic irradiated PVA aqueous solution was used for infrared spectroscopy analysis.Results: CODCr values of neutral and alkaline PVA aqueous solution were not significantly changed in the radiation dose range of 0 30 kGy.Acidic PVA aqueous solution after 20 30 kGy dose irradiation produced precipitation obviously.The CODCr values were significantly reduced by 97% 98%.Infrared spectrum analysis showed that precipitation was cross-linked PVA.With radiation dose increasing,BOD5 values of different pH of PVA aqueous solution was gradually reduced,the acidic BOD5 values were minimal under the same radiation dose.The B/C values of neutral and alkaline PVA aqueous solution irradiated by the dose range of 0 30 kGy was no significantly changed.However,the B/C values of acidic PVA aqueous solution increased obviously after 20 30 kGy irradiation,and it increased 14 16 times.Conclusions: This study indicated that under the acidic circumstance,the CODCr values of PVA aqueous solution decreased significantly,PVA in aqueous solution was removed efficiently by electron beam irradiation,and the potential of biodegradation was also improved.