Electrochemical oxidation of paraquat in neutral medium

Cartaxo, M.A.M.; Borges, Carlos; Pereira, M.I.S.; Mendonça, M.H.

doi:10.1016/j.electacta.2015.07.099

Cited by 27 publications

(5 citation statements)

References 36 publications

(46 reference statements)

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“…Among the methods available to treat contaminated water, electrochemical technology has been used to remove various kinds of organic compounds, such as dyes [6][7][8][9][10][11][12], pharmaceuticals [12][13][14][15][16][17][18][19], pesticides [1,12,[20][21][22][23], or plasticizers [24][25][26]. High levels of energy consumption and low current efficiencies can be the main possible drawbacks of this technology; however, if an adequate choice of hydrodynamic conditions, applied current density, and anode material is made, high removal degrees can be attained at relatively low energy expenses.…”

Section: Introductionmentioning

confidence: 99%

Comparative electrochemical degradation of the herbicide tebuthiuron using a flow cell with a boron-doped diamond anode and identifying degradation intermediates

Pereira

Silva²,

Oliveira

et al. 2017

Electrochimica Acta

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The electrochemical degradation of tebuthiuron (TBH; 100 mg L À1) was carried out under enhanced mass transport conditions (using a flow cell with a BDD anode), while investigating the effect of solution pH, absence and presence of Cl À ions in the supporting electrolyte solution (0.1 mol L À1 Na 2 SO 4), and current density (j = 10, 30, 50 mA cm À2) on the herbicide degradation and resulting oxidation intermediates. The enhanced mass transport conditions led to significantly improved performances, comparatively to previous results obtained with a common electrochemical cell. The solution pH or presence of Cl À ions did not affect the TBH removal rate. However, the COD removal rate, despite being independent of pH, was significantly faster in the presence of Cl À ions, most probably due to false results caused by organochlorinated intermediates. In the absence of Cl À ions in solution, the TBH removal rate increased with j, whereas the COD removal rate was not affected, but significantly increased removal rates were attained in the presence of Cl À ions, most probably because of increased formation of organochlorines. As expected, higher values of the general and mineralization current efficiencies as well as lower energy consumptions per unit TOC mass removed (EC TOC) were attained at 10 mA cm À2 ; in the absence of Cl À ions, complete removal of TBH and 80% removal of TOC were attained with EC TOC = 0.2 kW h g À1 (less than 1/10 of those for electrolyses using a conventional electrochemical cell). From the identified intermediates, an initial TBH oxidation pathway like those of coupled processes involving photochemistry is expected. Most carboxylic acid intermediates were removed or being removed by the end of the electrolyses (except tartronic acid, which accumulated). As expected, organochlorinated intermediates were identified in the presence of Cl À ions, but were completely removed by the end of the electrolyses. In summary, the electrochemical degradation of TBH in the presence of Cl À ions is not advantageous; no significant improvement in the TBH and TOC removal rates, or in the energy expense, is achieved and the formation of organochlorines is a real possibility.

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Section: Introductionmentioning

confidence: 99%

Comparative electrochemical degradation of the herbicide tebuthiuron using a flow cell with a boron-doped diamond anode and identifying degradation intermediates

Pereira

Silva²,

Oliveira

et al. 2017

Electrochimica Acta

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“…Furthermore, disappearance of the peaks associated with PQ (m/z = 144, 171, 186) or decline in their peak intensity (m/z = 185) marks the removal of PQ from the solution while increase in the intensity for m/z = 216 shows the formation of new product i.e. dipyridone which is less toxic than PQ (Cartaxo et al, 2015). Finally at the end of the process, m/z = 94 (8%) and 216 (16%)…”

Section: Mineralization Studymentioning

confidence: 99%

Elucidating Synergistic Effect of In-Situ Hybrid Process Towards Paraquat Abatement

Pandey,

Dhindsa,

Verma

et al. 2024

Preprint

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Presence of non-biodegradable organic compounds, mainly pesticides in water bodies peril humans as well as aquatic life. Paraquat (PQ) is one such widely used Class II herbicide associated with Parkinson’s disease. Herein, pristine TiO2 (PT), as well as metal (Fe-PT, Ni-PT) and nonmetal (C-PT, S-PT), modified TiO2 was synthesized using hydrothermal treatment for mineralization and degradation of PQ. The crystallite size from XRD exhibited the prepared catalysts to be nanomaterials while FESEM confirmed the nanorod formation. Moreover, morphological analysis established the occurrence of doping in PT. Through optical properties, reduction in band gap from 3.2 eV to 2.4 eV was found which was accompanied by decrease in electron-hole recombination rate. Further, nanocomposites were investigated for PQ removal with S-PT depicting 93% degradation under solar radiations followed by Fe-PT degrading 87% PQ indicating that with optimum doping levels and proper reduction of band gap, TiO2 can be made more enthusiastic towards degradation and remediation process. Further, hybrid process employing photocatalysis and photo-Fenton simultaneously was utilised by synthesising Fe-S-PT, a codoped catalyst. This codoped Fe-S-PT resulted in a sharp decrement of 47% in processing time which is attributed to the presence of OH˙ and e−. Moreover, a degradation mechanism for Fe-S-PT was proposed along with the evaluation of extent of mineralization taking place. Lately, intermediates formed during the process were identified. Overall, study is extremely significant towards providing a practical and economical solution for PQ degradation using hybrid process within 80 mins at the benign pH of 6.3.

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“…Several techniques, such as ozonation [25], photocatalytic processes, Fenton reactions [25, 26], and adsorption, have been applied to remove contaminated PQ from water sources. Among the many techniques, adsorption is one of the best methods for treating wastewater, with high efficiency, low cost, ease of operation, and absence of hazardous by-product formation [27, 28]. Various adsorbents have been used for wastewater treatment, including natural adsorbents [29, 30], activated carbon [31], carbon-based materials (carbon nanotubes), and biochar.…”

Section: Introductionmentioning

confidence: 99%

Efficient Removal of Paraquat Pollutants Using Magnetic Biochar Derived from Corn Husk Waste: A Sustainable Approach for Water Remediation

Damdib,

Siyasukh,

Vanichsetakul

et al. 2023

Adsorption Science & Technology

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Due to the widespread production of maize, the waste created by this crop has become a serious concern. This study applied the concept of waste circulation to the production of magnetic biochar from corn husk waste to remediate paraquat-contaminated water. Magnetic biochar (MB) was produced by impregnating maize husks with iron and carbonizing the residue in a nitrogen environment. Carbonized MB at the temperature of 850°C (MB-01-850) exhibited a combination of microporous and mesoporous structures ( V meso = 0.30 c m 3 / g , V micro = 0.12 c m 3 / g ), while biochar created only a microporous structure ( V micro = 0.11 c m 3 / g ). According to the findings, Fe(NO3)3 significantly affected the increase in mesopore formation after carbonization. In addition, biochar exhibits excellent magnetic responsiveness. MB-01-850 reached equilibrium within approximately 20 min in synthetic water. Batch adsorption studies showed that MB-01-850 had maximum adsorption capacities ( Q 0 ) of 34.97 mg/g and 31.63 mg/g for synthetic and natural water, respectively. The unmodified biochar (without mesopores) had a Q 0 of 4.08 mg/g. This indicates that the presence of mesopores improves the effectiveness of paraquat adsorption. Additionally, the adsorption performance of magnetic biochar exhibited no statistically significant variance when tested under natural water conditions. Furthermore, magnetic biochar demonstrates impressive regeneration capacity, allowing it to be regenerated almost entirely for a minimum of four cycles using a sodium hydroxide (NaOH) solution with a concentration equal to or greater than 0.5 M.

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Electrochemical oxidation of paraquat in neutral medium

Cited by 27 publications

References 36 publications

Comparative electrochemical degradation of the herbicide tebuthiuron using a flow cell with a boron-doped diamond anode and identifying degradation intermediates

Comparative electrochemical degradation of the herbicide tebuthiuron using a flow cell with a boron-doped diamond anode and identifying degradation intermediates

Elucidating Synergistic Effect of In-Situ Hybrid Process Towards Paraquat Abatement

Efficient Removal of Paraquat Pollutants Using Magnetic Biochar Derived from Corn Husk Waste: A Sustainable Approach for Water Remediation

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