Humic acid and trihalomethane breakdown with potential by-product formations for atmospheric air plasma water treatment

Sarangapani, Chaitanya; Lü, Peng; Behan, Patrice; Bourke, Paula; Cullen, Patrick J.

doi:10.1016/j.jiec.2017.10.042

Cited by 21 publications

(6 citation statements)

References 77 publications

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“…In both cases the treatment duration was set to 8 min and TN was measured with intervals of 2 min. The nitrogen fixation appeared to be strongly dependent on the type of discharge adopted with TN increasing around 8 times faster with surface discharge with respect to underwater discharge due to the hydrolysis of the NO x produced when the plasma discharge takes place in contact with air [ 35 , 36 ]. To investigate TN evolution in a more complex mixture, the same experiment was repeated replacing ultrapure water with a solution of Natural Organic Matter (NOM) 10 mg/L.…”

Section: Resultsmentioning

confidence: 99%

PFAS Degradation in Ultrapure and Groundwater Using Non-Thermal Plasma

Palma

Papagiannaki²,

Lai³

et al. 2021

Molecules

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Perfluoroalkyl substances (PFAS) represent one of the most recalcitrant class of compounds of emerging concern and their removal from water is a challenging goal. In this study, we investigated the removal efficiency of three selected PFAS from water, namely, perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA) and pefluorooctanesulfonic acid (PFOS) using a custom-built non-thermal plasma generator. A modified full factorial design (with 2 levels, 3 variables and the central point in which both quadratic terms and interactions between couple of variables were considered) was used to investigate the effect of plasma discharge frequency, distance between the electrodes and water conductivity on treatment efficiency. Then, the plasma treatment running on optimized conditions was used to degrade PFAS at ppb level both individually and in mixture, in ultrapure and groundwater matrices. PFOS 1 ppb exhibited the best degradation reaching complete removal after 30 min of treatment in both water matrices (first order rate constant 0.107 min−1 in ultrapure water and 0.0633 min−1 in groundwater), while the degradation rate of PFOA and PFHxA was slower of around 65% and 83%, respectively. During plasma treatment, the production of reactive species in the liquid phase (hydroxyl radical, hydrogen peroxide) and in the gas phase (ozone, NOx) was investigated. Particular attention was dedicated to the nitrogen balance in solution where, following to NOx hydrolysis, total nitrogen (TN) was accumulated at the rate of up to 40 mgN L−1 h−1.

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Section: Resultsmentioning

confidence: 99%

PFAS Degradation in Ultrapure and Groundwater Using Non-Thermal Plasma

Palma

Papagiannaki²,

Lai³

et al. 2021

Molecules

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“…Tests were performed using 96 well plates. In addition, the contribution of radical scavengers to the degradation efficiency of antibiotics was investigated by adding tBuOOH (tertiary butyl alcohol is considered as an affective hydroxyl radical scavenger) and CCl 4 (hydrogen radical scavenger) to the aqueous antibiotics solutions 77 .…”

Section: Methodsmentioning

confidence: 99%

Degradation kinetics of cold plasma-treated antibiotics and their antimicrobial activity

Sarangapani

Ziuzina

Behan

et al. 2019

Sci Rep

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Antibiotics, such as ofloxacin (OFX) and ciprofloxacin (CFX), are often detected in considerable concentrations in both wastewater effluents and surface water. This poses a risk to non-target organisms and to human health. The aim of this work was to study atmospheric cold plasma (ACP) degradation of antibiotics in water and meat effluent and to explore any residual antimicrobial activity of samples submitted to the plasma process. The results revealed that ACP successfully degraded the studied antibiotics and that the reaction mechanism is principally related to attack by hydroxyl radicals and ozone. According to the disk diffusion assay, the activity of both antibiotics was considerably reduced by the plasma treatment. However, a microdilution method demonstrated that CFX exhibited higher antimicrobial activity after ACP treatment than the corresponding control revealing a potentially new platform for future research to improve the efficiency of conventional antibiotic treatments. Importantly, short-term exposures to sub-lethal concentrations of the antibiotic equally reduced bacterial susceptibility to both ACP treated and untreated CFX. As a remediation process, ACP removal of antibiotics in complex wastewater effluents is possible. However, it is recommended that plasma encompass degradant structure activity relationships to ensure that biological activity is eliminated against non-target organisms and that life cycle safety of antibiotic compounds is achieved.

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“…The range of region IV corresponds to the small molecular structure of organic matter [35]. The V region indicates to humic-like fluorescence [42,43]. It is clear that the fluorescence intensity of the five regions all diminished and gradually disappeared from 0 min (Figure 6a) to 15 min (Figure 6b) and 60 min (Figure 6c), which further proved that the HA molecular structure was decomposed and mineralized in this collaborative system.…”

Section: Ha Decomposition Mechanismmentioning

confidence: 65%

“…The scanning spectrum was divided into five regions because of the complexity of spectral response and scanning sample. The range of I and II can represent aromatic proteins in organic compounds which related to the structure of aromatic ring amino acids in NOM [42]. III region indicates fulminate-like substances related to hydroxyl and carboxyl groups in the humus structure.…”

Section: Ha Decomposition Mechanismmentioning

confidence: 99%

Humic Acid Removal in Water via UV Activated Sodium Perborate Process

et al. 2022

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Humic acid (HA) has complex molecular structure and is capable of adsorption, ion exchange, and chelation with organic and inorganic pollutants in water bodies, worsening water quality and jeopardizing human health and ecological environment. How to effectively remove HA from water is one of the research focuses of this paper. In this study, the UV-activated sodium perborate (SPB) synergistic system (UV/SPB) was established to eliminate HA in water. The effects of initial HA concentration, SPB dose, and initial pH value on the HA elimination were determined, and the main mechanisms of the synergy and HA degradation were explored. The outcomes show that the HA elimination ratio by the sole UV and only SPB system were only 0.5% and 1.5%, respectively. The HA removal of UV/SPB reached 88.8%, which can remove HA more effectively than other systems. Free radical masking experiment proved that hydroxyl radical produced by SPB activation is the main active substance for HA removal. The results of UV-vis absorption spectrum, absorbance ratio, specific UV absorbance, and excitation–emission matrix spectroscopy verified that the UV/SPB system can effectively decompose and mineralize HA.

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Humic acid and trihalomethane breakdown with potential by-product formations for atmospheric air plasma water treatment

Cited by 21 publications

References 77 publications

PFAS Degradation in Ultrapure and Groundwater Using Non-Thermal Plasma

PFAS Degradation in Ultrapure and Groundwater Using Non-Thermal Plasma

Degradation kinetics of cold plasma-treated antibiotics and their antimicrobial activity

Humic Acid Removal in Water via UV Activated Sodium Perborate Process

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