Contribution à la dépollution d’un rejet textile par adsorption sur un coagulant à base du mélange fer/aluminium préparé par électrocoagulation

L’industrie textile consomme une grande quantité d’eau, générant ainsi des rejets liquides à charge élevée en divers types de polluants. Ces derniers produisent des effets nocifs sur l’environnement. Ce travail s’intéresse à la dépollution d’un rejet d’une industrie textile, par addition d’un coagulant synthétique à base de fer et d’aluminium, préparé par le procédé d’électrocoagulation. Les résultats ont montré que le traitement de ce rejet par ce coagulant, a permis d’atteindre un rendement d’élimination des matières colorantes de 83.37% en terme de demande chimique en oxygène (DCO).Mots clés: traitement, hydroxyde, coagulation, demande chimique en oxygèn

Electroosmotically generated disinfectant from urine as a by-product of electricity in microbial fuel cell for the inactivation of pathogenic species

This work presents a small scale and low cost ceramic based microbial fuel cell, utilising human urine into electricity, while producing clean catholyte into an initially empty cathode chamber through the process of electro-osmostic drag. It is the first time that the catholyte obtained as a by-product of electricity generation from urine was transparent in colour and reached pH>13 with high ionic conductivity values. The catholyte was collected and used ex situ as a killing agent for the inactivation of a pathogenic species such as Salmonella typhimurium, using a luminometer assay. Results showed that the catholyte solutions were efficacious in the inactivation of the pathogen organism even when diluted up to 1:10, resulting in more than 5 log-fold reduction in 4 min. Long-term impact of the catholyte on the pathogen killing was evaluated by plating Salmonella typhimurium on agar plates and showed that the catholyte possesses a long-term killing efficacy and continued to inhibit pathogen growth for 10 days

Electro-generation of hydrogen peroxide using a graphite cathode from exhausted batteries: study of influential parameters on electro-Fenton process

In this work, the study of hydrogen peroxide (H2O2) electro-generation using graphite from exhausted batteries (Gr-Bat) was conducted. Linear sweep voltammetry and electrolysis experiments were carried out in a single compartment electrochemical cell. Study of the possibility to use this electrode revealed that it presents, as vitreous carbon (VC) electrode, a reduction of oxygen with two successive waves (bi-electronic reduction). The first wave corresponds to the reduction of O2 to H2O2, while the second one corresponds to the reduction of H2O2 to H2O. The cathodic potentials for electro-generation of H2O2 appeared at -600 and -700 mV vs. Ag/AgCl for Gr-Bat and VC electrodes, respectively. Subsequently, electrolysis experiments were conducted by imposing the potentials required for H2O2 formation. The effect of several operating parameters on H2O2 production, such as the nature and concentration of the electrolyte, the pH, the presence of ferrous ions and O2 injection were studied using Gr-Bat and VC electrodes, respectively. For both electrodes, the acidic medium was more favorable for H2O2 electro-generation. The oxygen injection in solution promoted an increase of H2O2 concentration, but its effect was more pronounced in the case of VC electrode. Application for crystal violet degradation by electro-Fenton revealed that Gr-Bat had the best purification performance. A removal rate of 73.18% was obtained with Gr-Bat electrode against 62.27% with VC electrode for an electrolysis time of 120 min. This study has demonstrated the possibility of recycling Gr-Bat by using them as cathode materials in the electro-Fenton process