Treatment of methyl methacrylate from semiconductor wastewater by catalytic wet oxidation
Treatment of methyl methacrylate from semiconductor wastewater by catalytic wet oxidation
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DOI：
10.1016/j.jtice.2009.06.003
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发表时间：
2010-03
影响因子：
5.7
通讯作者：
Dar-Ren Ji;Chia-Chi Chang;Yi-Ling Wu;Ching-Yuan Chang;Wen-Kai Tu;Jyi-Yeong Tseng;Ten-Tsai Wang;Chiung-Fen Chang;C. Chiu;Yi-Hung Chen
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文献类型：
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作者：
Dar-Ren Ji;Chia-Chi Chang;Yi-Ling Wu;Ching-Yuan Chang;Wen-Kai Tu;Jyi-Yeong Tseng;Ten-Tsai Wang;Chiung-Fen Chang;C. Chiu;Yi-Hung Chen
研究了催化湿式氧化法（CWAO）处理半导体废水中甲基丙烯酸甲酯（MMA）的效果.考察了主要操作参数对系统性能的影响，即MMA和COD相对于初始值的归一化浓度，即CMMA/CMMA 0和CCOD/CCOD 0。这些参数包括（1）操作的设定温度TST、（2）催化剂Pt/Al 2 O3的存在、（3）工作气体的存在、（4）Pt/Al 2 O3的量（mPt）和（5）O2的分压（[公式：见正文]）。通过考察CWAO反应过程中pH值的变化，探讨了MMA的分解程度和COD的矿化程度。结果表明，在无催化剂的单一湿式氧化（WAO）条件下，TST对CMMA/CMMA_0的影响很大。在反应时间tFR= 180 min时，CMMA/CMMA 0从TST=180°C时的0.89降低至200°C时的0.62和220°C时的0.09，[公式：见正文]（基于180°C的参考温度Trf）。对于WAO，TST对CCOD/CCOD_0的影响不大，在160-220°C的温度范围内，在tFR= 180 min时，CCOD/CCOD_0仅下降到0.78-0.87左右。对于mPt=30.38g的Pt/Al 2 O3存在下的CWAO，TST在160°C和180-220°C下，tFR= 180 min时CMMA/CMMA 0分别大幅降低至0.15和0.01-0.05，而CCOD/CCOD 0在TST在160-220°C下降低至约0.16-0.34。Pt/Al 2 O3的使用不仅提高了MMA和COD的去除率，而且降低了有效去除MMA和COD所需的TST，节省了所需的能量。实验结果还表明，CWAO对COD的有效矿化需要O2等氧化性气体。然而，如果供给的[式：见正文]足够高，例如1- 2 MPa，以在具有足够溶解氧的液相中进行CWAO，则增加[式：见正文]的增强效果不显著。CWAO对MMA废水COD的去除效果优于直接紫外光（UV）、单独臭氧化（OZ）和OZ与UV联合的高级氧化工艺。本研究所获得的信息有助于CWAO系统的正确运行和合理设计，以有效地处理半导体工业中含MMA的废水。
Treatment of methyl methacrylate (MMA) from semiconductor wastewater via catalytic wet oxidation (CWAO) was studied. Effects of major operating parameters on the system performances in terms of the normalized concentrations of MMA and chemical oxygen demand (COD) relative to their initial values, namely CMMA/CMMA0and CCOD/CCOD0, were investigated. These parameters include (1) the setting temperature TSTof operation, (2) the presence of catalyst Pt/Al2O3, (3) the presence of working gas, (4) the amount of Pt/Al2O3(mPt) and (5) the partial pressure of O2( [Formula: see text] ). The change of pH value during the course of CWAO was also examined to elucidate the extents of decomposition of MMA and mineralization of COD. The results indicate that the effects of TSTon the CMMA/CMMA0are very vigorous for the case of sole wet oxidation (WAO) without catalyst. At the reaction time tFR=180min, the CMMA/CMMA0decreases from 0.89 at TST=180°C to 0.62 at 200°C and 0.09 at 220°C with [Formula: see text] (based on the reference temperature Trfof 180°C). The effects of TSTon the CCOD/CCOD0are not strong for the WAO, reducing the CCOD/CCOD0only to about 0.78–0.87 at tFR=180min with TSTin 160–220°C. As for the CWAO in the presence of Pt/Al2O3with mPt=30.38g, the CMMA/CMMA0reduces greatly to 0.15 and 0.01–0.05 at tFR=180min with TSTat 160°C and in 180–220°C, respectively, while the CCOD/CCOD0decreases to about 0.16–0.34 with TSTin 160–220°C. The use of Pt/Al2O3not only improves the removal of MMA and COD but also reduces the TSTrequired for the efficient removal of MMA and COD, saving the energy needed. The results also reveal that the oxidizing gas such as O2is required for effective mineralization of COD via CWAO. However, the enhancement effect of increasing [Formula: see text] is not significant if the supplied [Formula: see text] is high enough, say 1–2MPa, to proceed the CWAO in liquid phase with sufficient dissolved oxygen. Further, the CWAO is more efficient than the advanced oxidation processes of direct ultra violet irradiation (UV), sole ozonation (OZ) and combined process of OZ and UV for the effective removal of COD in the treatment of MMA. The information obtained in this study is useful for the proper operation and rational design of the CWAO system for the effective treatment of MMA-containing wastewater from the semiconductor industry.