摘要
利用超临界水氧化技术(Super Critical Water Oxidation,SCWO)能迅速彻底氧化各种有机污染物的特点,将其应用于废水总有机碳(Total Organic Carbon,TOC)的检测。自行构建了一套利用超临界水氧化法连续检测废水TOC的试验装置。选取邻苯二甲酸氢钾作为典型有机污染物,首先在p=24.0MPa,T=380～440℃,m=1.0～20.0条件下,验证了本方法的可行性与可重复性。通过试验初步研究了超临界水氧化温度与氧化系数m对TOC检测的影响机制,得出测试水样TOC转化率随反应温度和氧化系数m的增加先增加而后趋于平稳;并得出随着反应温度的升高、氧化系数的增大,TOC降解率也随之提高,当m≥6.0,T≥420℃时,TOC几乎完全降解。测试水样邻苯二甲酸氢钾溶液适宜检测条件为T=420℃,p=24MPa,m=6.0,此时TOC降解率达到99%。同时,分别用岛津TOC分析仪(高温催化燃烧法)和SCWO-NDIR装置对葡萄糖和苯酚混合溶液的TOC进行了测定,两者的测定结果线性拟合关系较好,证明利用超临界水氧化法测定TOC可行。
This paper takes it as its research goal to construct a TOC measuring unit based on the supercritical water oxidation and demonstrate the preliminary experiment results by using the unit based on the advantage of supercritical water oxidation （SCWO）. We have managed to lay out and conducted the measuring experiments of total organic carbon （TOC） of sewage, via which various kinds of organic pollutants can be oxidized quickly, smoothly and thoroughly. The TOC measuring unit we have developed consists of a low pressure gradient mixer, a permanent pressure pump, a supereritical reactor, a temperature- pressure-regulatory system, a gas-liquid separator and a NDIR（Non-Dispersive Infra-Red） detector, whose purpose is to measure the TOC of polluted sewage. In the said unit, we have chosen potassium hydrogen phthalate as the organic pollutant model, which helps to degrade the sewage via SCWO at the pressure of 24.0 MPa, temperature range from 380 ℃ to 440 ℃ and at the oxidation coeffi- cient from 1.0 to 20.0. The results demonstrate that it is feasible and repeatable to measure the TOC of sewage by SCWO. Meanwhile, the effects of temperature and oxidation coefficient on the result of TOC measuring are studied via preliminary experiment. The results of our experiments show that the expected conversion percentage of TOC tends to increase first and then come to steady with the increase of the temperature or oxidation coefficient. We have also found that the higher the degradation rate is, the higher the temperature or oxidation coefficient would be. The oxidative degradation of the organic pollutants is expected to get totally degraded on the condition when m ≥ 6.0 and T ≥ 420 ℃. In addition, it has been confirmed that the TOC of sewage can be measured with the sample organic pollutant in an appropriate condition when T = 420 ℃ and m = 6.0, under which the rate of degradation of potassium hydrogen phthalate is expected to reach 99%. At the same time, we have also discovered that the mixed solution of glucose and phenol can be chosen as an ex- perimental subject, whose TOC can be measured both with the SCWO -NDIR and the normal TOC instrument （high-temperature catalytic combustion method）. Results show that the linear regressions of the two methods are perfect, hence indicating the measuring method is available for testing TOC with SCWO - NDIR.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第4期162-165,共4页
Journal of Safety and Environment
基金
2010浙江省研究生创新科研项目(YK2010032)
浙江省自然科学基金项目(Y12B070047)
关键词
环境工程学
超临界水氧化
总有机碳
连续检测
温度
氧化系数
environmental engineering
supercritical water oxida-tion
total organic carbon
continuous measure
temper-ature
oxidation coefficient
