碱析分离法处理造纸红液

采用碱析分离法处理浓缩造纸红液，研究了体系pH值、碱析剂加入量、反应温度和时间等因素对碱析反应的影响，确定了碱析反应的优化工艺条件，并对碱析反应机理进行了讨论。实验结果表明，pH值对木质素磺酸盐与钙离子间络合作用影响显著，氢离子可与木质素磺酸盐螯合，从而导致Ca²⁺与木质素磺酸盐的螯合作用降低，由此碱析分离法需在较高pH值下进行反应。以10mL造纸浓缩红液为处理对象，碱析反应的优化条件为：pH值为13，碱板剂Ca²⁺加入量为8g/L，反应温度为40℃，反应时间为30min时，木质素沉淀量最大为4.5g/10mL。

Treatment of papermaking wastewater by a precipitation method

The effects of varying pH value, amount of precipitation reagent (Ca²⁺）, reaction temperature, and reaction time on the recovery of lignosulfonates from concentrated red liquor have been investigated in order to determine the optimum conditions. The mechanism of the precipitation reaction was also studied. It was found that pH value played an important role in the chelation of Ca²⁺ by lignosulfonates. In the concentrated red liquor, the Hyolrogen ion would chelated with lignosulfonate, so complexing effect between lignosulfonates and calcium was waken. As to treating 10mL concentrated red liquer, under the optimum conditions of pH=13, ρ（Ca²⁺）=8g/L, reaction temperature 40℃ and reaction time 30min, the lignosulfonate precipitation capacity was 4.5g/10mL. 