Dataset on the degradation of losartan by TiO2-photocatalysis and UVC/persulfate processes

Losartan is a highly consumed antihypertensive worldwide and commonly found in effluents of municipal wastewater treatment plants. In the environment, losartan can promote harmful effects on organisms. Thus, an option to face this pollutant is the treatment by photochemical advanced oxidation processes. This dataset has two main components: 1) theoretical calculations on reactivity indexes for losartan, and 2) degradation of the pollutant throughout TiO2-photocatalysis and UVC/persulfate (UVC/PS). The first part of the work presents the data about HOMO and LUMO energies, optimized geometry, dipolar moment, HOMO/LUMO energy gap and total density distribution, in addition to ionization energy, electron affinity, chemical potential, hardness, softness and electrophilicity for losartan. Meanwhile, the second one depicts information on the routes involved in the degradation of the pharmaceutical by the oxidation processes, mineralization, toxicity evolution and losartan removal from a complex matrix (synthetic fresh urine). The data reported herein may be utilized for further researches related to elimination of pharmaceuticals in primary pollution sources such as urine. Moreover, this work also provides experimental and theoretical data useful for the understanding of the response of losartan to oxidative and photochemical processes.


a b s t r a c t
Losartan is a highly consumed antihypertensive worldwide and commonly found in effluents of municipal wastewater treatment plants. In the environment, losartan can promote harmful effects on organisms. Thus, an option to face this pollutant is the treatment by photochemical advanced oxidation processes. This dataset has two main components: 1) theoretical calculations on reactivity indexes for losartan, and 2) degradation of the pollutant throughout TiO 2photocatalysis and UVC/persulfate (UVC/PS). The first part of the work presents the data about HOMO and LUMO energies, optimized geometry, dipolar moment, HOMO/LUMO energy gap and total density distribution, in addition to ionization energy, electron affinity, chemical potential, hardness, softness and electrophilicity for losartan. Meanwhile, the second one depicts information on the routes involved in the degradation of the pharmaceutical by the oxidation processes, mineralization, toxicity evolution and losartan removal from a complex matrix (synthetic fresh urine). The data reported herein may be utilized for further researches related to elim-ination of pharmaceuticals in primary pollution sources such as urine. Moreover, this work also provides experimental and theoretical data useful for the understanding of the response of losartan to oxidative and photochemical processes.
© Value of the data • Data are useful to analyze similarities and differences between TiO 2 -photocatalysis and UVC/Persulfate for degrading pharmaceuticals such as losartan antihypertensive. • Data can benefit people researching on elimination of antihypertensives by photochemical advanced oxidation processes in aqueous matrices. • Data can be utilized for further insights about degradation of pharmaceuticals in a complex matrix, such as hospital effluents. • Data are valuable for future works on oxidation processes, photochemistry and organic reactions of losartan.

Data Description
Dataset presented in this work have two main parts, the first component deals with computational calculations on losartan and the second one contains information about the degradation of the pharmaceutical by two advanced oxidation processes (i.e., TiO 2 -photocatalysis and UVC/persulfate). These photochemical processes are widely used for degrading organic pollutants in aqueous matrices [1][2][3][4] . It should be mentioned that for double bonds in alkenes and aromatic rings (as contained in losartan structure), frontier orbitals (i.e., highest occupied molecular orbital-HOMO and in the lowest unoccupied molecular orbital-LUMO) can be useful to predict radical attack positions [5] . Then, energies of HOMO and LUMO, in addition to optimized geometry, dipolar moment, HOMO/LUMO energy gap and total density distribution, were theoretically stated, this information is presented in Tables 1-2 . Meanwhile, Table 3 contains other reactivity indexes (such as ionization energy, electron affinity, chemical potential, hardness, softness and electrophilicity) for losartan.
Regarding losartan degradation by the AOPs, in Fig. 1 is shown the antihypertensive evolution during the treatment in distilled water using TiO 2 -photocatalysis (TiO 2 PC). Fig. 1 also presents data on removal by photolysis (UVA), the pollutant degradation in presence of potassium iodide and isopropanol scavengers (TiO 2 PC/KI and TiO 2 PC/IPA, respectively) and replacing water media by acetonitrile solvent (TiO 2 PC/ACN) to provide information about the routes involved in the process [ 1 , 2 ]. In turn, Fig. 2 presents the degradation of losartan by the UVC/PS system, control experiments (action of persulfate-PS or the light-UVC), plus the dataset for experiments when isopropanol (UVC/PS/IPA, which is a scavenger of hydroxyl and sulfate radicals [6] ) is added.
In Fig. 3 is presented the evolution of total organic carbon (TOC) and phytotoxicity under the two processes, for comparative purposes, the TOC removal ( Fig. 3 A) and toxicity ( Fig. 3 B) were measured at two normalized times: 1 (when losartan is 100% degraded) and 2 (the double of time required to 100% remove the antihypertensive). Fig. 4 . compares the treatment of losartan in distilled water and synthetic fresh urine by TiO 2 -photocatalysis ( Fig. 4 A) and UVC/PS ( Fig. 4 B) processes. Table 4 depicts the synthetic fresh urine composition and Table 5 summarizes the literature search on the interaction/reaction among hydroxyl or sulfate radicals with the urine components, in addition to the pseudo-first order rate constants for losartan degradation by TiO 2 -photocatalysis and UVC/PS.

eV
Total density distribution

Reagents
Acetonitrile, isopropanol, methanol, potassium iodide, potassium persulfate, sodium acetate, sodium chloride, sodium dihydrogen phosphate, sodium hydroxide, sodium sulfate, and urea were provided by Merck. Ammonium chloride, formic acid, calcium chloride and magnesium chloride were provided by PanReac. Titanium dioxide was provided by Evonik. Losartan was pur-

Table 5
Rate constants of the reactions between the radical species and the components of fresh urine.

Reaction
Second order rate constant (k 2nd , L mol -1 s -1 ) References Pseudo-first order rate constant (k, min -1 ) for degradation of losartan by the processes TiO 2-photocatalysis 0.004 In this work UV/PS 0.029 In this work chased from La Santé S.A. The solutions of losartan were prepared using distilled water. In all cases, the initial losartan concentration was 43.38 μmol L -1 .

Reaction systems
A homemade aluminum reflective reactor containing UVC lamps (OSRAM HNS®, 60 W of light power) with main emission at 254 nm was used for the UVC/PS process. Losartan solutions (50 mL) were placed in beakers (100 mL of capacity) under constant stirring. The TiO 2photocatalysis process was carried out in the same reactor but equipped with UVA lamps (Philips BLB, 75 W of light power) having main emission peak at 365 nm. Losartan solutions (50 mL) were also placed in beakers under constant stirring. Additionally, the adsorption/desorption equilibrium on TiO 2 catalyst was reached after 30 min in dark.
Aliquots of 0.5 mL were taken periodically from the rectors for kinetics analyses by UHPLC (no more than nine aliquots were considered to avoid modifications of the sample volume higher than 10%). For total organic carbon and toxicity measurements, independent experiments were performed and the whole sample was considered in each case per point of the analyses.
Mineralization was established using 10 mL of sample by measuring of total organic carbon (TOC), through a Shimadzu LCSH TOC analyzer (previously calibrated), according to Standard Methods 5310, by combustion with catalytic oxidation at 680 °C using high-purity oxygen gas at a flow rate of 190 mL/min. The apparatus had a non-dispersive infrared detector.
Toxicity against radish seeds ( Raphanus sativus) was established by interaction of target solution with the indicator seeds. The solution to be tested (5 mL) was placed in a petri dish; then, ten (10) Raphanus sativus seeds were submerged into the solution. The seeds and solution were in contact during 72 h. Afterward, the length of germinated plants was measured, subsequently a mean value and standard deviation for each tested solution were calculated.