Dye degradation in aqueous solution by dithionite/UV-C advanced reduction process (ARP): Kinetic study, dechlorination, degradation pathway and mechanism

Because −NH2 and −NH− in poly-[Formula: see text]-phenylenediamine (P[Formula: see text]PD) can interact strongly with the empty orbitals of Cu to show unique electrochemical activity, P[Formula: see text]PD is suitable for the removal of Cu[Formula: see text] by electrochemical oxidation–reduction process. In this study, with P[Formula: see text]PD and its carbon dot composite (CDs/P[Formula: see text]PD) as working electrodes, the electrochemical reduction and removal of Cu[Formula: see text] in the aqueous solution were carried out with the potentiostatic method. According to effects of voltage, pH of the solution, initial concentration of Cu[Formula: see text], and electrochemical reduction time on the Cu[Formula: see text] removal, the Cu[Formula: see text] removal ratios of P[Formula: see text]PD and CDs/P[Formula: see text]PD were up to 64.69% and 73.34%, respectively, at −0.2 V and the optimal pH. Additionally, results showed that these processes were in line with the quasi-first order kinetic model. Both P[Formula: see text]PD and CDs/P[Formula: see text]PD showed good reproducibility in six cycles. After five times of repeated usage, the regeneration efficiencies of P[Formula: see text]PD and CDs/P[Formula: see text]PD dropped to 77.04% and 79.36%, respectively.

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Kinetic study on preparation of substoichiometric tungsten oxide WO2.72 via hydrogen reduction process

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-018-7966-4 ◽

2018 ◽

Vol 137 (2) ◽

pp. 389-397 ◽

Cited By ~ 3

Author(s):

Dan Qiao ◽

Yue Wang ◽

Fan Li ◽

Daya Wang ◽

Baijun Yan

Keyword(s):

Kinetic Study ◽

Tungsten Oxide ◽

Hydrogen Reduction ◽

Reduction Process

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Kinetic study of hydrate formation for argon + TBAB + SDS aqueous solution system

The Journal of Chemical Thermodynamics ◽

10.1016/j.jct.2017.08.030 ◽

2018 ◽

Vol 116 ◽

pp. 121-129 ◽

Cited By ~ 8

Author(s):

Saeideh Babaee ◽

Hamed Hashemi ◽

Amir H. Mohammadi ◽

Paramespri Naidoo ◽

Deresh Ramjugernath

Keyword(s):

Aqueous Solution ◽

Kinetic Study ◽

Hydrate Formation ◽

Solution System

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Treatment of Aqueous Bromate by Superparamagnetic BiOCl-Mediated Advanced Reduction Process

Catalysts ◽

10.3390/catal7050131 ◽

2017 ◽

Vol 7 (12) ◽

pp. 131 ◽

Cited By ~ 2

Author(s):

Xiaowei Liu ◽

Lili Wang ◽

Zhe Sun ◽

Yu Shao ◽

Tingchao Yu

Keyword(s):

Reduction Process ◽

Advanced Reduction

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Congo Red Decolorization and Detoxification by Aspergillus niger: Removal Mechanisms and Dye Degradation Pathway

BioMed Research International ◽

10.1155/2018/3049686 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 19

Author(s):

Nedra Asses ◽

Lamia Ayed ◽

Neila Hkiri ◽

Moktar Hamdi

Keyword(s):

Molecular Structure ◽

Aspergillus Niger ◽

Azo Dyes ◽

Lignin Peroxidase ◽

Congo Red ◽

Manganese Peroxidase ◽

Dye Degradation ◽

Degradation Pathway ◽

Effects Of Ph ◽

Maximum Decolorization

Congo red is one of the best known and used azo dyes which has two azo bonds (-N=N-) chromophore in its molecular structure. Its structural stability makes it highly toxic and resistant to biodegradation. The objective of this study was to assess the congo red biodegradation and detoxification by Aspergillus niger. The effects of pH, initial dye concentration, temperature, and shaking speed on the decolorization rate and enzymes production were studied. The maximum decolorization was correlated with lignin peroxidase and manganese peroxidase production. Above 97% were obtained when 2 g mycelia were incubated at pH 5, in presence of 200 mg/L of dye during 6 days at 28°C and under 120 to 150 rpm shaking speed. The degraded metabolites were characterized by using LC-MS/MS analyses and the biodegradation mechanism was also studied. Congo red bioconversion formed degradation metabolites mainly by peroxidases activities, i.e., the sodium naphthalene sulfonate (m/z = 227) and the cycloheptadienylium (m/z = 91). Phytotoxicity and microtoxicity tests confirmed that degradation metabolites were less toxic than original dye.

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