水中典型溴系阻燃剂污染控制技术研究

发布时间：2018-07-09 20:06

本文选题：四溴双酚A + 十溴二苯醚　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：溴系阻燃剂(BFRs)是一类新兴的持久性有机污染物,其中多溴联苯醚(PBDEs)、四溴双酚A(TBBPA)和六溴环十二烷(HBCD)是最主要的三种,在PBDEs中十溴二苯醚(BDE-209)的使用量最大。PBDEs、TBBPA和HBCD在东江支流工业排水中被检出。目前针对溴系阻燃剂去除的实用技术不多,缺乏多种溴系阻燃剂存在下的的去除技术方案。本文选取TBBPA、BDE-209和HBCD为研究对象,用氧化法和光降解法对这三种典型溴系阻燃剂进行去除研究,探索适用于实际水体中去除典型溴系阻燃剂的技术方案。研究结果表明,臭氧和高锰酸钾氧化对TBBPA均有较好的去除效果。臭氧氧化TBBPA速率很快,较大的臭氧投加量、碱性条件、高温、较小的底物初始浓度有利于TBBPA的去除。但臭氧过量投加时会产生溴酸盐。高锰酸钾氧化TBBPA的反应速率也很快,去除率随高锰酸钾浓度的增加而增大,随pH值、底物初始浓度的增加而减小。高锰酸钾过量时,高锰酸钾氧化TBBPA的反应对TBBPA是一级反应。但臭氧和高锰酸钾氧化对BDE-209和HBCD均无去除效果。254 nm紫外光降解可以很好的对BDE-209和TBBPA进行去除。两者初始浓度均为0.3μmol/L时,分别在反应120 min和60 min可以实现完全去除。为进一步提高光降解反应速率,在同一紫外光源照射下加入Na_2SO_3,对BDE-209和TBBPA进行去除研究。两者的去除率较单独UV下均有所提高。UV和UV/Na_2SO_3对典型溴系阻燃剂的降解反应均符合一级反应动力学方程。同时用254 nm紫外光降解对HBCD进行了去除研究,结果表明,反应速率较为缓慢。针对较难去除的HBCD,又采用了185 nm紫外光对其进行降解。结果表明,HBCD初始浓度为0.3μmol/L时,在79 W/185 nm紫外光照射下仅需2 h可降解完全。同时对TBBPA和BDE-209也进行了降解研究,结果表明,21 W/185nm紫外光照射下两者分别仅需20 min和40 min可降解完全。通过上述各方法对典型溴系阻燃剂TBBPA、BDE-209和HBCD的去除研究可以得出,当实际水体中只有TBBPA时,优先选用高锰酸钾氧化技术;当水体中存在BDE-209时,优先选用Na_2SO_3/UV(254 nm)高级还原技术;当存在HBCD时,选用185 nm紫外光降解。
[Abstract]:Brominated flame retardants (BFRs) are a class of emerging persistent organic pollutants, of which polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are the most important ones. Decabromodiphenyl ether (BDE-209) was used most in PBDEs. TBBPA and HBCD of PBDEs were detected in industrial drainage of Dongjiang tributaries. At present, there are few practical technologies for removal of bromine flame retardants, and there is a lack of removal technology in the presence of many bromine flame retardants. In this paper, TBBPA-BDE-209 and HBCD were selected as the research objects, the removal of these three typical bromine flame retardants was studied by oxidation and photodegradation methods, and the technical scheme suitable for removing typical bromine flame retardants in actual water was explored. The results showed that both ozone and potassium permanganate oxidation had better removal effect on TBBPA. The rate of TBBPA oxidized by ozone is very fast, and the removal of TBBPA is facilitated by large amount of ozone, alkaline condition, high temperature and small initial concentration of substrate. But when ozone is overdosed, bromate is produced. The reaction rate of potassium permanganate oxidation of TBBPA is also very fast. The removal rate increases with the increase of potassium permanganate concentration, and decreases with the increase of pH value and the initial concentration of substrate. In excess of potassium permanganate, the oxidation of TBBPA by potassium permanganate is a first order reaction. However, ozone and potassium permanganate oxidation had no removal effect on BDE-209 and HBCD. 254nm UV photodegradation could effectively remove BDE-209 and TBBPA. When the initial concentration of both was 0.3 渭 mol / L, the complete removal could be achieved at the reaction time of 120 min and 60 min, respectively. In order to further improve the photodegradation reaction rate, NaAs _ 2SO _ 3s _ 3 was added under the same ultraviolet light source to study the removal of BDE-209 and TBBPA. The removal rates of both of them were higher than those under UV alone. The degradation of typical bromine flame retardants by UV and UV / Na _ 2SO _ 3 were in accordance with the first-order reaction kinetics equation. At the same time, the removal of HBCD by 254 nm UV photodegradation was studied. The results showed that the reaction rate was relatively slow. For HBCD which is difficult to be removed, 185 nm UV light was used to degrade it. The results show that when the initial concentration of HBCD is 0.3 渭 mol / L, it can be degraded completely in only 2 hours under the irradiation of 79 W / 185 nm ultraviolet light. The degradation of TBBPA and BDE-209 was also studied. The results showed that the degradation of TBBPA and BDE-209 required only 20 min and 40 min under UV irradiation of 21 W / 185nm, respectively. The removal of typical bromine flame retardant TBBPA-BDE-209 and HBCD by the above methods shows that potassium permanganate oxidation technology is preferred when there is only TBBPA in actual water, and Na2SO3 / UV (254 nm) advanced reduction technology is preferred when BDE-209 exists in water body. In the presence of HBCD, 185 nm UV light was used for degradation.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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