【摘要】 造纸过程中会产生大量的二英,本文从动力学和热力学角度综述了国内外制浆和氯漂白过程中二英的主要来源及反应机理.二英生成的途径主要包括二苯并对二英或二苯并呋喃的直接氯化、由前驱体转化为二苯并对二英或二苯并呋喃或其类似物再氯化、由外源氯酚直接缩合.同时讨论了未漂浆卡伯值、漂白中氯的用量、体系pH值、反应时间、温度等因素对二英生成的影响,可为有效地控制造纸过程中二英的生成提供参考.更多还原

【Abstract】 Pulp and paper industry produces large amounts of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans( PCDD / Fs). This paper reviews the mechanisms of PCDD / Fs formation in pulping and chlorine bleaching in detail from the point of kinetics and thermodynamics.There are three main mechanisms: direct chlorination of dibenzo-p-dioxin and dibenzofuran( DBD/F),chlorination of DBD/F or DBD/F analogs transferred from other precursors,and condensation from chlorophenols. Meanwhile, the Kappa number of unbleached pulp,chlorine dosage,pH, reaction time, temperature and other factors on the formation of PCDD / Fs are discussed, which provide some references to effective control of PCDD / Fs formation in the papermaking process.更多还原