Occurrence and degradation of emerging antibiotic-resistant bacteria in riverine environment with sono, photo, and sonophotocatalytic oxidation under low-frequency ultrasound and sunlight.

The current study reports the prevalence of antibiotic-resistant bacteria, Escherichia coli (E. coli) in riverine environments and their removal using advanced oxidation processes such as sonocatalysis (ultrasound), photocatalysis (sunlight), and sonophotocatalysis (ultrasound/sunlight) techniques utilizing zinc oxide (ZnO) as the catalyst. Results showed that about 96% of the E.

FeS-based nanocomposites: A promising approach for sustainable environmental remediation - Focus on adsorption and photocatalysis - A review.

Population expansion, industrialization, urban development, and climate changes increased the water crisis in terms of drinking water availability. Among the various nanomaterials for nanoremediation towards water treatment, FeS-based nanocomposites have emerged as promising candidates in the adsorptive and photocatalytic removal of contaminants. This paper, therefore, evaluates the potential of FeS-based nanocomposites for environmental applications, more specifically the combined use of adsorption and photocatalysis.

Electrochemical oxidation of Florfenicol in aqueous solution with mixed metal oxide electrode: Operational factors, reaction by-products and toxicity evaluation.

Veterinary antibiotics have become an emerging pollutant in water and wastewater sources due to excess usage, toxicity and resistance to traditional water and wastewater treatment. The present study explored the degradation of a model antibiotic- Florfenicol (FF) using electrochemical oxidation (EO) with Ti-RuO/IrO anode. The anode material was characterized using SEM-EDS studies expressing stable structure and optimal interaction of the neighboring metal oxides with each other.

Degradation and transformation of carbamazepine in aqueous medium under non-thermal plasma oxidation process.

Carbamazepine (CBZ) is a pharmaceutical compound detected in various water resources. With a view to removing this contaminant, the applicability of non-thermal plasma (NTP) oxidation process has been widely tested in recent years. This study utilized NTP from a dielectric barrier discharge reactor in the treatment of CBZ.

Occurrence and distribution of steroid hormones (estrogen) and other contaminants of emerging concern in a south indian water body.

Steroid hormones (SHs) are among the important classes of Contaminants of Emerging Concern (CECs) whose detection in aquatic environments is vital due to their potential adverse health impacts. Their detection is challenging because of their lower stability in natural conditions and low concentrations. This study reports the presence of steroid hormones in a major river system, the Periyar River, in Kerala (India).

Degradation studies of bisphenol S by ultrasound activated persulfate in aqueous medium.

The degradation of recalcitrant organic pollutants by sulphate radical (SO) represents one of the most recent developments in oxidation-based water treatment. In most cases, persulfate (PS) acts as a precursor of sulphate radicals. This study employed ultrasound-activated PS to generate reactive species, facilitating the degradation of bisphenol S (BPS), a well-known contaminant of emerging concern (CECs).

Singlet oxygen in the removal of organic pollutants: An updated review on the degradation pathways based on mass spectrometry and DFT calculations.

The degradation of pollutants by a non-radical pathway involving singlet oxygen (O) is highly relevant in advanced oxidation processes. Photosensitizers, modified photocatalysts, and activated persulfates can generate highly selective O in the medium. The selective reaction of O with organic pollutants results in the evolution of different intermediate products.

Advanced oxidation processes for the removal of mono and polycyclic aromatic hydrocarbons - A review.

Aromatic hydrocarbons (AHs) are toxic environmental contaminants presented in most of the environmental matrices. Advanced oxidation processes (AOPs) for the removal of AHs in the account of complete mineralization from various environmental matrices have been reviewed in this paper. An in-depth discussion on various AOPs for mono (BTEX) and polyaromatic hydrocarbons (PAHs) and their derivatives is presented.

Cavitation based cleaner technologies for biodiesel production and processing of hydrocarbon streams: A perspective on key fundamentals, missing process data and economic feasibility - A review.

The present review emphasizes the role of hydrodynamic cavitation (HC) and acoustic cavitation in clean and green technologies for selected fuels (of hydrocarbon origins such as gasoline, naphtha, diesel, heavy oil, and crude oil) processing applications including biodiesel production. Herein, the role of cavitation reactors, their geometrical parameters, physicochemical properties of liquid media, liquid oxidants, catalyst loading, reactive oxygen species, and different types of emulsification and formation of radicals, formation as well as extraction of formed by-products are systematically reviewed. Among all types of HC reactors, vortex diode and single hole orifices revealed more than 95 % desulfurization yield and a 20 % viscosity reduction in heavy oil upgrading, while multi-hole orifice (100 holes) and slit Venturi allowed obtaining the best biodiesel production processes in terms of high (%) yield, low cost of treatment, and short processing time (5 min; 99 % biodiesel; 4.

Simultaneous removal of heavy metals and dyes in water using a MgO-coated FeO nanocomposite: Role of micro-mixing effect induced by bubble generation.

This study focused on the development of a nano-adsorbent for contaminant removal without the use of any external energy. An eco-friendly FeO@MgO core-shell nanocomposite was synthesized and tested for the removal of a heavy metal, lead (Pb) and a dye, rhodamine B (RhB). The addition of HO into the system enabled the self-mixing of the aqueous solution containing FeO@MgO through the generation of bubbles.

Occurrence, distribution and removal of organic micro-pollutants in a low saline water body.

A low saline backwater canal, mainly utilized for domestic and agricultural purposes, has been analyzed for the possible presence of organic micropollutants (OMP) and their potential removal was explored by multilayered microfiltration membranes. The qualitative as well as quantitative analysis were carried out for a span of one year using the technique of liquid chromatography connected with high resolution mass spectrometry (LC-Q-TOF-MS). The identification of the formally unknown compounds was initially done using non-target analysis based on the mass accuracy, isotopic pattern and MS/MS spectral interpretation.

Insights into the Mechanism of Hydroxyl Radical Mediated Oxidations of 2-Aminopurine: A Computational and Sonochemical Product Analysis Study.

Mechanistic details of hydroxyl radical (OH) mediated oxidations of 2-aminopurine (2AP) in the aqueous phase have been established in this study via a combination of DFT calculations (at the M05-2X/6-311+G(d,p) level with SMD solvation) and sonochemical end product analyses by the LC-Q-TOF-MS/MS method. Rate constants and branching ratios for single electron transfer (SET), two H-abstractions (HA), and seven radical adduct formation (RAF) reactions of OH with 2AP were evaluated using transition state theory (TST). The RAF at the C8-position of 2AP is noted as the dominant process, which constitutes almost 46.

In situ chemical oxidation of contaminated groundwater using a sulfidized nanoscale zerovalent iron-persulfate system: Insights from a box-type study.

We report the potential of a sulfidized nanoscale zerovalent iron-persulfate (S-nZVI-PS) system for in situ chemical oxidation (ISCO) of groundwater pollutants. The study was conducted using a sand-filled rectangular box with a permeable reactive barrier of S-nZVI as a facsimile of the ISCO system. Synthetic water contaminated with a target pollutant (reactive black-5, RB-5) was continuously passed through the box.

Sonochemical degradation of benzenesulfonic acid in aqueous medium.

Degradation of benzenesulfonic acid (BSA), the simplest aromatic sulfonic acid with extreme industrial importantance, by sonochemically generated hydroxyl radical (OH) have been thoroughly investigated. A reasonable reduction (∼50%) in the total organic carbon (TOC) was achieved only after prolonged irradiation (∼275 min, 350 kHz) of ultrasound, although a short irradiation of less than an hour is enough to degrade significant amount of BSA. The degradation efficiency of ultrasound has been reduced in lower and extremely higher frequencies, and upon increasing the pH.

Role of in-situ nitrite ion formation on the sonochemical transformation of para-aminosalicylic acid.

The sonochemical transformation of para-aminosalicylic acid (PAS), a widely used antibiotic and an identified Emerging Pollutant (EP) under the class of Pharmaceuticals and Personal Care Products (PPCPs), have been investigated in aqueous medium. Ultrasound having frequency of 350kHz and power of 80W was utilized for the degradation of PAS. A complete degradation (100%) of PAS after 60min and about 83% of COD removal after 120min of sonication, were obtained.

Ultrasound based AOP for emerging pollutants: from degradation to mechanism.

Ultrasound is known to degrade organic compounds by pyrolysis and by the reaction of free radicals. In this work, sonolytic degradation of an identified water pollutant, coomassie brilliant blue (CBB), has been carried out in pure water as well as in river water. In the case of pure water, 90 % degradation was obtained after 30 min of sonication (350 kHz frequency, 60 W power), whereas in river water, the same efficiency was achieved only after 90 min.

Influence of inorganic ions and selected emerging contaminants on the degradation of Methylparaben: A sonochemical approach.

The study on the possible pathway of hydroxyl radicals mediated sonolytic degradation of paraben in water is reported. Methylparaben (MPB) which is the most utilized of paraben family is selected as a model emerging pollutant. The influence of common anions and some selected emerging contaminants that may coexist in typical water matrix on the degradation pattern is analyzed alongside.

Sonochemical degradation of Coomassie Brilliant Blue: effect of frequency, power density, pH and various additives.

Coomassie Brilliant Blue (CBB), discharged mainly from textile industries, is an identified water pollutant. Ultrasound initiated degradation of organic pollutants is one among the promising techniques and forms part of the Advanced Oxidation Processes (AOPs). Ultrasonic degradation of CBB under different experimental conditions has been investigated in the present work.