As the environment preservation gradually becomes a matter of major social concern and more strict legislation is being imposed on effluent discharge, more effective processes are required to deal with non-readily biodegradable and toxic pollutants. Synthetic organic dyes in industrial effluents cannot be destroyed in conventional wastewater treatment and consequently, an urgent challenge is the development of new environmentally benign technologies able to mineralize completely these non-biodegradable compounds. This review aims to increase the knowledge on the electrochemical methods used at lab and pilot plant scale to decontaminate synthetic and real effluents containing dyes, considering the period from 2009 to 2013, as an update of our previous review up to 2008. Fundamentals and main applications of electrochemical advanced oxidation processes and the other electrochemical approaches are described. Typical methods such as electrocoagulation, electrochemical reduction, electrochemical oxidation and indirect electro-oxidation with active chlorine species are discussed. Recent advances on electrocatalysis related to the nature of anode material to generate strong heterogeneous OH as mediated oxidant of dyes in electrochemical oxidation are extensively examined. The fast destruction of dyestuffs mediated with electrogenerated active chlorine is analyzed. Electro-Fenton and photo-assisted electrochemical methods like photoelectrocatalysis and photoelectro-Fenton, which destroy dyes by heterogeneous OH and/or homogeneous OH produced in the solution bulk, are described. Current advantages of the exposition of effluents to sunlight in the emerging photo-assisted procedures of solar photoelectrocatalysis and solar photoelectro-Fenton are detailed. The characteristics of novel combined methods involving photocatalysis, adsorption, nanofiltration, microwaves and ultrasounds among others and the use of microbial fuel cells are finally discussed.

Decontamination of wastewaters containing synthetic organic dyes by electrochemical methods. An updated review

2.2. Fenton’s Chemistry 6575 2.2.1. Origins 6575 2.2.2. Fenton Process 6575 2.3. Photo-Fenton Process 6577 3. H2O2 Electrogeneration for Water Treatment 6577 3.1. Fundamentals 6578 3.2. Cathode Materials 6579 3.3. Divided Cells 6580 3.4. Undivided Cells 6583 4. Electro-Fenton (EF) Process 6585 4.1. Origins 6585 4.2. Fundamentals of EF for Water Remediation 6586 4.2.1. Cell Configuration 6586 4.2.2. Cathodic Fe2+ Regeneration 6586 4.2.3. Anodic Generation of Heterogeneous Hydroxyl Radical 6587

Electro-Fenton process and related electrochemical technologies based on Fenton's reaction chemistry

Adsorption of methylene blue on low-cost adsorbents: A review

The science of the total environment

Fouling in membrane bioreactors used in wastewater treatment

Operational optimization of air conditioning cooling water system with UF―RO desalination

The invention discloses a sequence batch type film bioreactor craft to reinforce denitrifying dephosphorize in sewage disposal and middle water reclaimed technical domain of environmental engineering, which comprises the following steps: cascading anaerobic or anoxybiotic reactor and sequence batch type film bioreactor; using inflow COD to complete the storage of PHB and relive phosphorous; polymerizing phosphoric bacterium under the anaerobic condition of the anaerobic or anoxybiotic reactor; proceeding aerobic nitrated and degraded organic material; yielding water at the same time; mixing the polyphosphoric sludge enriched with PHB and the nitrated liquid enriched with nitrate in the two reactor through sludge diversion and nitrated liquid backflow; removing nitrogen; polymerizing the phosphoric bacterium; choosing nitrate as electron acceptor; excess-absorbing phosphor; realizing synchronous denitrification dephosphorize without adding carbon source and nitrate This invention possesses simple flow process and convenient management, which can be fit for disposing urban sewage with low carbon and high nitrogen phosphor

Intensified anti-nitrated phosphorous-removal sequencing batch membrane bioreactor technique

Prussian blue/graphene (PB/GE) nanocomposite was successfully synthesized and the oxygen reduction reaction (ORR) activities were studied in our previous work. In this study the PB/GE nanocomposite and PB were deposited on the surface of active carbon particles, and the resulted particles were placed in two microbial fuel cells (MFC) as the three-dimensional cathode electrodes for oxygen reduction. The two MFCs were labeled as PB/GE-MFC and PB-MFC, and their performances were evaluated in the long term operation. A series of characterization methods showed the successful deposition of PB/GE and PB on the particles. After the long term operation, the cell voltage and maximum power density of PB-MFC decreased sharply, which dropped from 530 mV and 15.63 W/m −3 to 395 mV and 7.5 W/m −3 , while those of PB/GE-MFC were decreased slightly, which dropped from 530 mV and 16.26 W/m −3 to 470 mV and 15.88 W/m −3 . The Tafel constants showed that PB/GE-MFC cathode had higher kinetic activity and faster reactions than PB-MFC cathode. PB/GE had stable performance in the MFC during the long term operation, and it can be used as a novel cathode as an effective alternative to platinum for oxygen reduction in MFC.

Prussian blue/graphene-modified electrode used as a novel oxygen reduction cathode in microbial fuel cell

The use of PLS algorithms and quantum chemical parameters derived from PM3 hamiltonian in QSPR studies on direct photolysis quantum yields of substituted aromatic halides.

Functionalized polypyrrole (PPy) films were prepared by incorporation of anthraquinonedisulphonate (AQDS) as doping anion during the electropolymerization of pyrrole (Py) monomer at a glassy carbon electrode from aqueous solution. The electrochemical behavior of the PPy-bound AQDS modified electrode and cathodic reduction of oxygen on the resulting polymer film were studied. An obvious surface redox reaction corresponding to AQ/H 2 AQ was observed and the dependence of this reaction on the solution pH was also illustrated. The electrocatalytic ability of the PPy-bound AQDS modified electrode was demonstrated by the electroreduction of oxygen at the optimized pH of 6.3 in a phosphate buffer. The reduced AQDS (H 2 AQ) is responsible for the extraordinary catalytic activity to the oxygen reduction reaction. The PPy layers not only act as an electron mediator, but also facilitate the stability of the modified electrode. It was found that the catalytic reaction occurred in the presence of the bound AQDS and O 2 is in agreement with an electrochemical–chemical (EC) mechanism. The kinetic parameters of oxygen reduction were determined using Koutecky–Levich equation and Tafel polarization technique.

Fenglin Yang

Papers

Operational optimization of air conditioning cooling water system with UF―RO desalination

Intensified anti-nitrated phosphorous-removal sequencing batch membrane bioreactor technique

Prussian blue/graphene-modified electrode used as a novel oxygen reduction cathode in microbial fuel cell

The use of PLS algorithms and quantum chemical parameters derived from PM3 hamiltonian in QSPR studies on direct photolysis quantum yields of substituted aromatic halides.

The effect of polypyrrole-bound anthraquinonedisulphonate dianion on cathodic reduction of oxygen