废新闻纸浆在碱性/酸性催化H_2O_2漂白过程中DCS产生量的研究

A study on DCS generation in H_2O_2 bleaching alkaline/acid catalysed for waste newsprint pulp

研究了脱墨浆碱性H2O2漂白和酸性钼酸盐催化H2O2漂白过程中的DCS产生规律,探讨了两种漂白过程中对DCS释放有较大影响的因素,并总结出其最佳漂白工艺。结果表明:H2O2漂白会导致DCS的增加,碱性条件下溶出较多,酸性条件下溶出较少。而且在碱性条件下,随着H2O2和NaOH用量的增加,DCS溶出量也随之增加。在酸性催化H2O2漂白中,H2O2用量、pH值和钼酸盐用量是影响DCS溶出量的主要因素。另外,对漂白过程中生成的DCS进行了定量分析,结果发现DCS样品中灰分含量都在65%以上,说明DCS中含有大量无机成分(如可溶性盐),DCS样品中水相组分含量在80%以上,说明其中降解的溶解性碳水化合物占较大比重,还有少许无机物。

The forming rules of DCS in deinked pulp bleaching which were bleached by hydrogen peroxide in alkaline/catalytic acidic environment were studied, especially the related factors of the two bleaching process to find out the optimum parameter of bleaching. The experimental results show that more DCS will generate when the waste newsprint pulp is bleached by H2O2, there are more DCS generated from bleaching of deinking pulp by hydrogen peroxide in alkaline environment than in acidic environment. The related factors of the release of DCS in alkaline environment are the dosage of hydrogen peroxide and sodium hydroxide, the dissolution of the DCS would be more if the percent of H2O2 and NaOH are increased. The relative factors of the release of DCS in catalytic acidic environment are pH, the dosage of hydrogen peroxide and molybdate. In addition, the quantitative analysis of DCS was studied, the experimental results show that DCS generated from bleaching of deinking pulp contain many inorganic substances, because ash content accounts for more than 65% of the DCS. Watersoluble DCS account for more than 80% in DCS, which carbohydrates account for the vast majority and inorganic account for a small proportion.