废液晶显示器偏光片水热法降解的实验研究

Experimental Study of Waste Liquid Crystal Display Polarizer under Hydrothermal Reaction Conditions

利用管式间歇反应器对废液晶显示器中的偏光片进行水热降解实验研究,考察了反应温度、反应时间、水的用量和氧化剂对液相有机碳和偏光片分解率的影响,并对反应后的液相产物进行HPLC分析。结果表明,反应温度、反应时间和氧化剂的投加量均对偏光片的分解率具有显著影响;液相产物中的TOC随着反应温度、反应时间、用水量和氧化剂投加量的增加都存在一个先增加后减少的趋势,当反应温度为300℃,反应时间为5 min,H2O(230%)的投加量为0.2 mL时,TOC高达14 586 mg/L,此时,偏光片中的碳元素向水相转化的迁移量最多,液相产物中有乙二酸、乳酸、乙酸、马来酸、富马酸、丙烯酸等有机酸以及甘油醛和5-羟甲基-2-糠醛(HMF)生成,最有利于废弃偏光片后续水热资源化处理的开展。

Decomposition of waste liquid crystal display polarizer was investigated by hydrothermal reaction in tube batch reactor. Effects of reaction temperature, reaction time, water volume and oxidant on TOC and decomposition rate were studied. Liquid products were analyzed by HPLC. Results indicated that reaction temperature, reaction time and oxidant volume had a significant impact on the decomposition rate of polarizer. TOC all increased at first and then declined with increasing temperature, time, water and oxidant volume. The optimum conditions for hydrothermal resourceful treatment of waste polarizer were reaction temperature 300 ~C, reaction time 5 rnin, amount of hydrogen peroxide （30%） 0.2 mL. In this case, TOC reached 14 586 mg/L, amount of carbon element in water phase reached the maximum, organic acid including oxalic acid, lactic acid, acetic acid, maleic acid, furmaric acid and acrylic acid, glyceric aldehyde and 5-hydroxymethyl-2- furaldehyde（HMF）were detected in liquid products.