Quantitative Structure–Activity Relationship (QSAR) for the Oxidation of Trace Organic Contaminants by Sulfate Radical

Abstract

The sulfate radical anion (SO4•–) based oxidation of trace organic contaminants (TrOCs) has recently received great attention due to its high reactivity and low selectivity. In this study, a meta-analysis was conducted to better understand the role of functional groups on the reactivity between SO4•– and TrOCs. The results indicate that compounds in which electron transfer and addition channels dominate tend to exhibit a faster second-order rate constants (kSO4•–) than that of H–atom abstraction, corroborating the SO4•– reactivity and mechanisms observed in the individual studies. Then, a quantitative structure activity relationship (QSAR) model was developed using a sequential approach with constitutional, geometrical, electrostatic, and quantum chemical descriptors. Two descriptors, ELUMO and EHOMO energy gap (ELUMO–EHOMO) and the ratio of oxygen atoms to carbon atoms (#O:C), were found to mechanistically and statistically affect kSO4•– to a great extent with the standardized QSAR model: ln kSO4•– = 26.8–3.97 × #O:C – 0.746 × (ELUMO–EHOMO). In addition, the correlation analysis indicates that there is no dominant reaction channel for SO4•– reactions with various structurally diverse compounds. Our QSAR model provides a robust predictive tool for estimating emerging micropollutants removal using SO4•– during wastewater treatment processes.

UV-Catalyzed Persulfate Oxidation of an Anthraquinone Based Dye

“…Furthermore, according to Liu et al [66], a Hirshfeld charge may be successfully employed to determine the reactive sites of the electrophilic reactions. Apart from the oxygen atoms, which are probably not involved in the reactions reported in this study, and a high O/C ratio is often correlated with a slow reaction between the molecules and the oxidants [67], the N atom of AB129 may be characterized by the smallest Hirshfeld charge (−0.424), which is even smaller than the second nitrogen (N1: −0.398) from the primary amine located on the anthraquinone. This may provide further confirmation that the first and crucial reaction of the sulfate radical with AB129 is an electron transfer from the -NH-moiety, which splits the AB129 molecule and creates the anthraquinone derivative.…”

Rapid Life-Cycle Impact Screening Using Artificial Neural Networks

“…55 However, studies also showed that simpler ANN models based on smaller training data sets can still provide meaningful results. 14,21,26,30 Given the limited availability of LCI data sets for training, we aimed at developing a simpler ANN model. Data Collection and Preprocessing.…”

Exploring the role of quantum‐mechanical descriptors in the concentration‐dependent adsorption of aromatic organic compounds by multiwalled carbon nanotubes

“…Moreover, the adsorption by CNTs involve quantum size effects; therefore, quantum‐mechanical descriptors for its prediction should be explored . One of our previous study had examined the risk assessment of MWCNTs through the quantum‐mechanical models for the adsorption of biomolecules by MWCNTs.…”

“…Moreover, the adsorption by CNTs involve quantum size effects; therefore, quantum-mechanical descriptors for its prediction should be explored. [29,[31][32][33][34] One of our previous study [6] had examined the risk assessment of MWCNTs through the quantum-mechanical models for the adsorption of biomolecules by MWCNTs. The quantum-mechanically computed mean polarizability and the descriptors accounting for instantaneous interactions between the electrons (the electron correlation) were found to be quite reliable in the quantitative prediction of the adsorption coefficients.…”