摘要
本文研究了天青B、2,4-二硝基苯肼等20种有机物质在紫外/双氧水(UV/H2O2)体系下的降解速率和物质结构的相关关系。该实验在T=298 K、pH=4条件下使用波长λ=254 nm的紫外光和过量的H2O2(投加量为8ml/L)进行。有机物的去除率采用色度去除率(Rcolor)来表示。在反应的初始阶段,色度的去除遵循伪一级反应动力学,并通过一级动力学公式计算得出有机物去除的一级动力学常数,Kcolor。运用Gaussian09和Material Studio(MS)7.0计算了这些有机物的18种量子化学参数,并用SPSS构建了这些量子化学参数与lnKcolor的关系模型,得出了最优的定量构效关系(QSAR)模型:lnKcolor=-4.837+12.996^*EHOMO+5.655^*q(C)max+28.764^*f(-)min+39.293^*q(CH)max-18.230^*q(CH)min。该模型表明在UV/双氧水体系下,这20种有机物的反应动力学常数与EHOMO、q(C)max、f(-)min、q(CH)max和q(CH)min具有相关关系,q(C)max、q(CH)max和q(CH)min揭示了有机物发生氧化反应最可能的活性位点,EHOMO反映了有机物分子的供电子能力,而f(-)min则对应着有机物反应中最不易发生亲电进攻的位点,反之则是最易发生亲核反应的位点。该模型的R2=0.873,内部验证q^2=0.626,外部验证Q^2ext=0.908,验证结果表明模型具有良好的预测能力及稳定性。
In this paper, 20 kinds of organics, including Azure B, DNP and so on were selected to study the relationship between degradation rates and structures in UV/H2O2 process. All the experiments were conducted under the condition of T=298 K, pH=4,λ=254 nm and H2O2=8 ml/L. The removal rates of organics were characterized by the color removal rates(Rcolor). The results show that Rcolor obeys the pseudo-first-order kinetic reaction formula at the first stage of oxidation process, from which the reaction kinetic constants of organics(Kcolor) can be obtained. Eighteen kinds of quantum parameters were calculated using Gaussian 09 and Material Studio(MS) 7.0. The relationship between quantum parameters and lnKcolor constructed by using SPSS, and several models were obtained. The results show that the optimal QSAR model is lnKcolor=-4.837 +12.996^*EHOMO + 5.655^*q(C)max + 28.764^*f(-)min + 39.293^*q(CH)max-18.230^* q(CH)min. The model shows that lnKcolor is mainly related with EHOMO, q(C)max, f(-)min, q(CH)max and q(CH)min in UV/H2O2 process. q(C)max,q(CH)max and q(CH)min can reveal the most active site in the oxidation progress, EHUMO reflects the electrondonating ability of organics, and f(-)min corresponds to the sites on which electrophilic reaction is difficult to occur, on the other words, f(-)min corresponds to the site on which nucleophilic reaction is easy to occur. This model with R-squared(R2), internal R-squared(q^2) and external R-squared(Q^2ext) of 0.889, 0.792 and 0.830,respectively, shows good stability and prediction ability after verification.
作者
李琬莹
程治文
陆丛蕊
申哲民
LI Wanying;CHENG Zhiwen;LU Congrui;SHEN Zhemin(School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China)
出处
《计算机与应用化学》
CAS
北大核心
2019年第2期107-114,共8页
Computers and Applied Chemistry
基金
水体污染控制与治理专项(2017ZX07202005-005)
