超声化学法降解水中聚乙烯醇的研究

SONOCHEMICAL DEGRADATION OF POLYVINYL ALCOHOL IN AQUEOUS SOLUTIONS

采用超声波辐射法降解聚乙烯醇(PVA)溶液,考察了初始浓度、反应温度、超声频率、溶解气体、pH值,添加氧化剂H2O2、盐和Fe2+等因素对降解效果的影响。结果表明,在超声频率40kHz、温度30℃、pH5.5和PVA初始浓度60 mg/L的条件下,140min时的降解率可达34%。外加Fe2+、H2O2可明显提高PVA的降解率。气相色谱、红外光谱的检测结果证实降解过程中生成含C=O基团的中间化合物,最终PVA可完全矿化为CO2和H2O。

The effect of some factors, such as initial concentration, reaction temperature, ultrasonic frequency, dissolved gas, pH value, H2O2 dosage, salt and Fe^2＋ on ultrasonic degradation ofpolyvinyl alcohol in aqueous solutions was studied. The degradation rate of PVA reached to 34% within 140 min under the experimental conditions of ultrasonic frequency 40 kHz, pH 5.5, and temperature 30℃, and when the initial PVA concentration was 60 mg/L, the degradation rates were enhanced in the presence of Fe^2＋ and H2O2, while it is negative to the salt. GC and FT-IR results showed that intermediates containing C=O groups were formed during degradation reaction. The PVA was fully mineralized to CO2 and H2O.