A novel microwave photochemical reactor for the oxidative decomposition of Acid Orange 7 azo dye by MW/UV/H2O2 process

Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet

The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well describe COD removal from pesticide-containing wastewater by MWEUV/Fenton, and the apparent rate constant (k) was 0.0125 min(-1). The optimal conditions for MWEUV/Fenton process were determined as initial pH of 5, Fe(2+) dosage of 0.8 mmol/L, and H2O2 dosage of 100 mmol/L. Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively. Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min. The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions.

Detection of proteins by hyphenated techniques with endogenous metal tags and metal chemical labelling

The absolute and relative quantitation of proteins plays a fundamental role in modern proteomics, as it is the key to understand still unresolved biological questions in medical and pharmaceutical applications.

Microwaves and their coupling to advanced oxidation processes: enhanced performance in pollutants degradation

This review assesses microwaves (MW) coupled to advanced oxidation processes (AOPs) for pollutants degradation, as well as the basic theory and mechanisms of MW dielectric heating. We addressed the following couplings: MW/H2O2, MW/UV/H2O2, MW/Fenton, MW/US, and MW/UV/TiO2, as well as few studies that tested alternative oxidants and catalysts. Microwave Discharge Electrodeless Lamps (MDELs) are being extensively used with great advantages over ballasts. In their degradation studies, researchers generally employed domestic ovens with minor adaptations. Non-thermal effects and synergies between UV and MW radiation play an important role in the processes. Published papers so far report degradation enhancements between 30 and 1,300%. Unfortunately, how microwaves enhance pollutants is still obscure and real wastewaters scarcely studied. Based on the results surveyed in the literature, MW/AOPs are promising alternatives for treating/remediating environmental pollutants, whenever one considers high degradation yields, short reaction times, and small costs.

Oxidative decomposition of atrazine in water in the presence of hydrogen peroxide using an innovative microwave photochemical reactor

The simultaneous application of microwave (MW) power and UV light leads to improved results in photochemical processes. This study investigates the oxidative decomposition of atrazine in water using an innovative MW and UV photochemical reactor, which activates a chemical reaction with MW and UV radiation using an immersed source without the need for a MW oven. We investigated the influence of reaction parameters such as initial H(2)O(2) concentrations, reaction temperatures and applied MW power and identified the optimal conditions for the oxidative decomposition of atrazine. Atrazine was completely degraded by MW/UV/H(2)O(2) in a very short time (i.e. t(1/2) = 1.1 min for 20.8 mg/L in optimal conditions). From the kinetic study, the disappearance rate of atrazine can be expressed as dX/dt = k(PH)[M](0)(b-X)(1-X), where b ≡ [H(2)O(2)](0)/[M](0)+k(OH)[·OH]/k(PH)[M](0), and X is the atrazine conversion, which correlates well with the experimental data. The kinetic analysis also showed that an indirect reaction of atrazine with an OH radical is dominant at low concentrations of H(2)O(2) and a direct reaction of atrazine with H(2)O(2) is dominant when the concentration of H(2)O(2) is more than 200 mg/L.