Performance and mechanism of methylene blue degradation by an electrochemical process

Abstract

An exciting electrochemical oxidation (EO) process has been developed.

Removal of methylene blue dye using nano zerovalent iron, nanoclay and iron impregnated nanoclay – a comparative study

“…The hydroxyl radical formed from the Fenton reaction in an acidic medium cleaves the chromophore from the methylene blue molecular structure and changes it into various byproducts. 72,73 The nZVI or iron found in the composite is oxidized with the products of iron(II) and peroxide (eqn ( 6)). The peroxide further reacts with iron(II) and produces iron(III), hydroxide ions, and hydroxide radicals (eqn ( 7)).…”

“…from the nZVI and increases the negative surfactants of the adsorbents. 72 This phenomenon increases the negative zeta potentials of the nanoparticles, contributing to adsorption of the cationic pollutants from solution. 67,68,76 Similar trends were observed in this study.…”

Carbonated hydroxyapatite‐assisted visible light degradation of methylene blue

“…Literature reports that when MB (C 16 H 18 N 3 SCl) is placed in water, its dissolves and Clis detached from the MB chain. 28 The authors suspect that the remaining MB chain is adsorbed onto the CHAp surface and through nucleophilic reaction via the reactive free radicals, N-CH 3 chains of the MB are attacked and further oxidized the -CH 3 into HCOOH. The C-S and C-N elements on the main MB heterocyclic ring are further attacked by the free radicals into aromatic heterocyclic (benzothiazole: C 7 H 5 NS) form and finally degrade into inorganic components (CO 2 , H 2 O, SO 4 2-, and NO 3 ).…”

“…The C-S and C-N elements on the main MB heterocyclic ring are further attacked by the free radicals into aromatic heterocyclic (benzothiazole: C 7 H 5 NS) form and finally degrade into inorganic components (CO 2 , H 2 O, SO 4 2-, and NO 3 ). 19,28 The inorganic components return to the water solution and create available free sites in the CHAp, thus maintaining the concentration gradient between the CHAp and the surrounding MB water solution, resulting in the high rate constant value of 0.0786 M/min compared to the rate constant (0.0457 M/min) under dark conditions. When there is no VL exposure and hence little MB breakdown, the MBs then compete for available lattice sites, and upon saturation, a stronger electrostatic repulsive interaction is formed between the absorbed and unabsorbed MBs.…”

Methylene Blue Removal From Residual Water Using Fir Wood Sawdust as Adsorbent

“…The transmission bands under 720 cm -1 are assigned to C-H groups in cellulose [29]. The sawdust spectrum showed at 667 cm -1 a specific band for C-H groups [29]; for sample 5 this band is splitted into two bands (671 and 660 cm -1 ) that are found at the same wavenumbers in the methylene blue solution spectrum, and are specific for the skeleton vibration mode of C-S-C [30]. This shows an interaction between sawdust and the methylene blue dye by adsorption process.…”