氧化钙协同臭氧降解脱色木醋液转化液的研究

Degradation of wood vinegar conversion solution by calcium oxide combined with ozone for decolorization

以氧化钙为碱催化剂,对木醋液转化液(以醋酸钙为主的溶液)进行催化臭氧化降解脱色。考察了反应时间、氧化钙质量对木醋液转化液降解脱色效果的影响以及催化降解过程中木醋液转化液pH的变化情况,明确了降解脱色完成后残余固体的性质。结果表明,随着氧化钙质量的增加,降解脱色效果显著提高,其中木醋液转化液中加入4 g/L氧化钙效果最佳;臭氧化降解是一个不断酸化的过程,氧化钙提供了碱性溶液环境,促使羟基自由基的产生,加快分解大分子有机物生成小分子有机酸类物质;降解脱色完成后木醋液转化液中的残余固体为二水合草酸钙。

Calcium oxide as a base catalyst is used for catalytic ozonation degradation and decolorization of wood vinegar conversion solution(calcium acetate-based solution).Effects of reaction time and calcium oxide dosage on the degradation of wood vinegar conversion solution are investigated.In addition,both the change of pH value of wood vinegar conversion solution and the nature of residual solid products are studied.Results show that the increase of calcium oxide content results in improvement of degradation reaction.The optimum dosage of calcium oxide is determined to be 4 g·L^-1.Ozonation degradation is proven to be a process of continuous acidification.Calcium oxide as a typical alkaline can promote the generation of hydroxyl radicals in the process of catalytic reaction.As a result,the degradation of macromolecular organic compound is enhanced to form small molecular organic acids.It is indicated that the residual solid in wood vinegar conversion solution after degradation is compose of calcium oxalate dihydrate.