纸浆中代表性酚类对二苯并-对-二噁英/二苯并呋喃氯化生成多氯代二噁英的影响

Effect of representative phenols in pulp on the chlorination of dibenzo-p-dioxin/dibenzofuran into polychlorinated dibenzo-p-dioxins and dibenzofurans

二苯并-对-二噁英/二苯并呋喃(DBD/F)的直接氯化是纸浆氯漂白过程中形成多氯代二噁英(PCDD/Fs)的重要途径.纸浆中的酚类在氯化漂白过程中也将消耗氯而生成氯化产物.本文在模拟纸浆氯漂白的实验条件下,对实验环境中的DBD/F进行检测,排除了背景DBD/F值对实验的干扰后,研究了纸浆中含量较高的酚类(苯酚、愈创木酚和儿茶酚)对DBD/F氯化生成PCDD/Fs的转化率和同系物模式的影响.发现酚类的加入使DBD/F氯化生成PCDD/Fs的氯化度下降;一定剂量酚类的加入会使体系中DBD/F氯化生成PCDD/Fs的转化率增大,当超出剂量范围后,DBD/F氯化生成PCDD/Fs得到抑制,不同酚类的效应大小各不相同.

Direct chlorination of dibenzo-p-dioxin/dibenzofuran(DBD/F)is an important way to form polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)during chlorine bleaching of pulp.The phenols in the pulp also consume chlorine during the chlorine bleaching process to produce corresponding chlorinated products.In this study,under the condition of simulating the chlorine bleaching of pulp,the DBD/F in the experimental environment was detected,and the background DBD/F value was excluded from the experiment.The effect of phenols(phenol,guaiacol and catechol)with high content in pulp on the conversion efficiency and homolog distribution of PCDD/Fs generated from DBD/F chlorination was studied.It was found that the degree of chlorination of PCDD/Fs decreased with the addition of phenols.The addition of a certain amount of phenols increased the conversion rate of DBD/F to PCDD/Fs in the system.When the phenolic dosage was exceeded,the chlorination of DBD/F to PCDD/Fs was inhibited,and the effects of different phenols were different.