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

Field study on soil water content variation just after irrigation period in the reed colony of shuangtai wetland, china

A carbon membrane-aerated biofilm reactor was developed to treat municipal wastewater. Tests were conducted to investigate oxygen transfer ability of carbon membrane, the bacteria adhesion and reactor's set-up performance. The optimum parameters were determined in terms of intra-membrane pressure, COD and nitrogen ratio and hydraulic retention time (HRT). The results showed that compared with that of other hollow fibres, bacterial suspended exhibited a high degree of adhesion onto carbon membrane and that oxygen transfer coefficient of carbon membrane was 0.36 m/h, so that it was feasible to serve as both biofilm carrier and aerator. NH4(+) -N removal, denitrification and COD removal efficiency could reach 95%, 92% and 88%, respectively, under the conditions of intra-membrane pressure of 0.025 MPa, carbon nitrogen ratio of 5 and HRT of 8 h, and effluent quality could be up to A standard in the national discharge standard of pollutants for municipal wastewater treatment plant (GB 18918-2002) . Furthermore, the system displayed better resistance to shock loads.

[Study on performance characteristics of carbon membrane-aerated biofilm reactor treating municipal wastewater].

Electro-activation of peroxymonosulfate by β-PbO2 partial filling/covering TiO2 nanotube arrays anode for alkaloid berberine degradation: Performance, mechanism and practicability

High ambient temperatures are associated with urban crime risk in Chicago.

Three isomer chlorophenols, o -, m -, p -chlorophenol, were dechlorinated by palladium/iron powder in water through catalytic reduction. The dechlorinated reaction is believed to take place on the surface site of the catalyst in a pseudo-first-order reaction. The reduction product for all the three isomers is phenol. The dechlorination rate increases with increase of bulk loading of palladium due to the increase of both the surface loading of palladium and the total surface area. The molecular structure also has an effect on the dechlorination rate. For conditions with 0.048% Pd/Fe, the rate constants are 0.0215, 0.0155 and 0.0112 min −1 for o -, m -, p -chlorophenol, respectively. Almost complete dechlorination is achieved within 5 h.

/pdf/catalytic-dechlorination-of-chlorophenols-in-water-by-3v8er1zsc3.pdf

Fenglin Yang

Papers

Field study on soil water content variation just after irrigation period in the reed colony of shuangtai wetland, china

[Study on performance characteristics of carbon membrane-aerated biofilm reactor treating municipal wastewater].

Electro-activation of peroxymonosulfate by β-PbO2 partial filling/covering TiO2 nanotube arrays anode for alkaloid berberine degradation: Performance, mechanism and practicability

High ambient temperatures are associated with urban crime risk in Chicago.

Catalytic dechlorination of chlorophenols in water by palladium/iron