Substituted naphthalene reaction rates with peroxy-acid treatment: prediction of reactivity using PEST

Persistent organic contaminants in the environment pose an environmental risk due to widespread occurrence and toxic properties. Advanced oxidation processes (AOPs) are treatment methods that have been used to successfully degrade organic contaminants in water, soil, sediments and sludge. Reaction rate constants (k) for peroxy acid treatment of 10 substituted naphthalene compounds were determined. The treatment method utilized acetic acid, hydrogen peroxide and a sulphuric acid catalyst to degrade the polyaromatic structures found in the compounds. Molecular structures of the selected compounds were derived at the B3LYP/6-31G* level of theory. Property-encoded surface translator (PEST) descriptors were calculated from B3LYP/6-31G* optimized structures and were found to have significant levels of correlation with k. Models using minimum local ionization potential (PIP.MIN) and a histogram [bin] of the gradient of the K electronic kinetic energy normal to the isosurface (DKN) were evaluated and found to agree within 10% of experimentally derived values of k in most instances. Results show that a combination of PEST descriptors could be used to predict reactivity by the peroxy-acid process. The PEST technology could prove to be a valuable asset for effective remediation design by predicting reaction outcomes for substituted naphthalene compounds and possibly other hydrophobic organic compounds (HOCs).

环境中的持久性有机污染物（Persistent organic contaminants）因分布范围广泛且具备毒性特性，对生态环境构成显著风险。高级氧化工艺（Advanced oxidation processes, AOPs）是一类已被成功应用于降解水、土壤、沉积物及污泥中有机污染物的处理技术。本研究测定了10种取代萘类化合物经过氧酸处理的反应速率常数（k）。该处理体系采用乙酸、过氧化氢与硫酸催化剂，以降解目标化合物中的多环芳烃结构。所选化合物的分子结构基于B3LYP/6-31G*理论水平进行了计算推导。基于B3LYP/6-31G*优化后的构型，研究人员计算得到了属性编码表面转换器（Property-encoded surface translator, PEST）描述符，且该类描述符与反应速率常数k存在显著相关性。本研究对采用最小局域电离势（PIP.MIN）以及垂直于等值面的K电子动能梯度直方图[组距]（DKN）的预测模型开展了评估，结果显示在绝大多数场景下，模型预测值与实验测得的k值偏差均在10%以内。研究结果表明，PEST描述符的组合可用于精准预测过氧酸氧化工艺的反应活性。PEST技术通过预测取代萘类化合物乃至其他疏水有机化合物（hydrophobic organic compounds, HOCs）的反应结果，有望成为高效环境修复方案设计中的宝贵工具。