Kinetic modeling of sulfonamide degradation by UV/HO: Deduction of R modeling and application.

Eight sulfonamide (SA) antibiotics were effectively degraded using a UV/HO process in a quasi-collimated beam apparatus, utilizing optimized fluence quantification. Fluence-based rate constants (kk') for the UV/HO process were established. A curve-fitting method, derived from R modeling, was developed for the UV/HO process to quantitatively assess the impact of critical factors, including water quality and direct UV photolysis.

Ultrasound-induced structural changes in partial nitrification sludge: Unravelling the mechanism for improved nitrogen removal.

Low-intensity ultrasound, as a form of biological enhancement technology, holds significant importance in the field of biological nitrogen removal. This study utilized low-intensity ultrasound (200 W, 6 min) to enhance partial nitrification and investigated its impact on sludge structure, as well as the internal relationship between structure and properties. The results demonstrated that ultrasound induced a higher concentration of nitrite in the effluent (40.

Quenching residual HO from UV/HO with granular activated carbon: A significant impact of bicarbonate.

UV/HO has been used as an advanced oxidation process to remove organic micropollutants from drinking water. It is essential to quench residual HO to prevent increased chlorine demand during chlorination/chloramination and within distribution systems. Granular activated carbon (GAC) filter can quench the residual oxidant and eliminate some of the dissolved organic matter.

Effect of ultrasound on the stability of partial nitrification: Under the interference of aeration rate.

The fluctuation of dissolved oxygen is one of the primary cause of disruptions to the consistent operation of partial nitrification, and the level of dissolved oxygen is mainly controlled by the aeration rate. This study investigated the influence of ultrasonic treatment on the stability of partial nitrification of activated sludge under different aeration conditions. After being treated with ultrasound (energy density = 0.

Ethanol-diluted turbidimetry method for rapid and accurate quantification of low-density microplastics in synthetic samples.

Retention and transport behaviours of microplastics (MPs) and their associated pollutants in porous media are of great concern. The homogeneity of the studied MPs in artificially controlled lab-scale studies makes rapid and accurate MP quantification feasible. In this study, an economical ethanol-diluted turbidimetry method for polypropylene (PP) and polyethylene (PE) MPs was developed.

Interactions between HO and dissolved organic matter during granular activated carbon-based residual HO quenching from the upstream UV/HO process.

Granular activated carbon (GAC) filtration can be employed to synchronously quench residual HO from the upstream UV/HO process and further degrade dissolved organic matter (DOM). In this study, rapid small-scale column tests (RSSCTs) were performed to clarify the mechanisms underlying the interactions between HO and DOM during the GAC-based HO quenching process. It was observed that GAC can catalytically decompose HO, with a long-lasting high efficiency (>80% for approximately 50,000 empty-bed volumes).

Removal of recalcitrant organics in reverse osmosis concentrate from coal chemical industry by UV/HO and UV/PDS: Efficiency and kinetic modeling.

The lack of stability in catalytic ozonation treatment of reverse osmosis (RO) concentrate from coal chemical industry calls for new advanced oxidation processes. Herein, UV/HO and UV/PDS were employed to remove the bulk recalcitrant organics in the RO concentrate with a focus on the process efficiency and kinetic modeling. Results show that UV/HO overmatched UV/PDS in reducing the COD and DOC of the wastewater and the advantage became more evident in aspects of biodegradability improvement and energy cost.

Computational fluid dynamics modelling of quasi-collimated beam apparatus - a typical bench scale UV apparatus for water treatment.

Quasi-collimated beam apparatus (QCBA), a typical bench scale UV apparatus, is crucial for the biodosimetry determination of UV dose in target reactors. However, the key parameters for the QCBA construction are usually estimated via rule-of-thumb calculations. Computational fluid dynamics models are applied in this study to simulate the UV fluence rate (FR) distributions in QCBAs.

Effect of low-intensity ultrasound on partial nitrification: Performance, sludge characteristics, and properties of extracellular polymeric substances.

Ultrasound technology, which is environment-friendly and economical, has emerged as a novel strategy that can be used to enhance the partial nitrification process. However, its effect on this process remains unclear. Therefore, in this study, partial nitrification sludge was subjected to low-intensity (0.

Effective abatement of 29 pesticides in full-scale advanced treatment processes of drinking water: From concentration to human exposure risk.

This study investigated the occurrence and removal of 29 pesticides in 4 drinking water treatment plants (DWTPs) with conventional and advanced treatment processes (i.e., ozonation + biological activated carbon, and ultrafiltration) in Shanghai, China from 2018 to 2019.

Effects of low-intensity ultrasound on nitrite accumulation and microbial characteristics during partial nitrification.

Ultrasound technology has attracted increasing attention in the field of sewage sludge treatment. This study investigated the nitrite accumulation ratio (NAR) and microbial characteristics of the partial nitrification (PN) process in a sequencing batch reactor employing ultrasonic treatment (ultrasound density = 0.25 W/mL, irradiation time = 10 min).

Enhancement in the partial nitrification of wastewater sludge via low-intensity ultrasound: Effects on rapid start-up and temperature resilience.

The partial nitrification process can reduce the aeration energy consumption in bioreactors by 25%. Low-intensity ultrasound (0.25 W·mL) was applied during the partial nitrification process to evaluate its effects on start-up and temperature resilience.

Deiodination of iopamidol by zero valent iron (ZVI) enhances formation of iodinated disinfection by-products during chloramination.

Iodinated X-ray contrast media (ICM) is considered as one of iodine sources for formation of toxic iodinated disinfection byproducts (I-DBPs) during disinfection. This study investigated transformation of a typical ICM, iopamidol (IPM) by zero valent iron (ZVI) and the effect of transformation on the formation of I-DBPs during chloramination. It was found that the presence of ZVI could deiodinate IPM into I and the transformation of IPM exhibited a pseudo-first-order kinetics.

Promoted oxidation of diclofenac with ferrate (Fe(VI)): Role of ABTS as the electron shuttle.

Reaction of Fe(VI) with 2,2'-azino-bis-(3-ethylbenzothiazoline -6-sulfonate) (ABTS) is widely adopted to determine aqueous ferrate (Fe(VI)) concentration based on ABTS formation. Interestingly, this study found that the addition of ABTS could accelerate the oxidation of diclofenac (DCF) by Fe(VI) significantly. Observed first-order rate constant of DCF in the presence of 30μM ABTS was found to be 36.

Degradation of nitro-based pharmaceuticals by UV photolysis: Kinetics and simultaneous reduction on halonitromethanes formation potential.

This study investigated the degradation kinetics and halonitromethanes formation potential (HNMsFP) of two nitro-based pharmaceuticals (i.e., ranitidine (RNTD) and nizatidine (NZTD)) during ultraviolet (UV) photolysis.

UV photolysis kinetics of sulfonamides in aqueous solution based on optimized fluence quantification.

The ultraviolet (UV) photolysis kinetics of eight sulfonamide (SA) antibiotics was investigated in a quasi-collimated beam apparatus. By using a micro fluorescent silica detector to monitor online the dynamic irradiance fluctuation, the accuracy in fluence quantification could be increased by up to 15%. Solution pH governed the speciation of selected SAs, thus impacting significantly their molar absorption coefficients (ε), fluence-based photolysis rate constants (k'), and quantum yields.