Combination of an electrochemical pretreatment with a biological oxidation for the mineralization of nonbiodegradable organic dyes: Basic yellow 28 dye

Abstract

International audienceThe aim of this article was to examine the feasibility of combining an electrochemical degradation of wastewater containing Basic Yellow 28 (BY28) dye on Pb/PbO2 electrode and a biological treatment. A central composite design (CCD) was used for the screening of the significant operating parameters and the identification of the most relevant interactions. The model equation obtained led to a classification of these parameters based on their level of significance, namely temperature followed by the initial concentration of BY28, the current density and the agitation speed. A significant interaction occurred between the temperature and the initial dye concentration. The second-order model obtained by CCD led to the following optimal conditions for dye degradation: 50 T 60 C, 8.125 i 25 mA cm22, [BY28]05134 mg L21, and x5720 rpm. Under these conditions, the obtained BY28 dye degradation yield was 96%. The (BOD5/COD) ratio increased from 0.076 initially to 0.30 after pretreatment, showing that the electrochemical pretreatment of BY28 dye generate intermediate products, which are at least partially biodegradable. Microbial degradation was therefore performed for the pretreated solution in an aerobic batch reactor for 30 days using an activated sludge culture. A decrease of the residual amount of intermediate products contained in the electrolyzed solutions was observed which can be related to a biological oxidation, leading to 93% removal of the dissolved organic carbon by the combined process

Electrocatalytic reduction of metronidazole using titanocene/Nafion®-modified graphite felt electrode

“…In recent years, the combined processes, in particular physicochemical and biological combined treatments, have received a growing attention for their efficiency to achieve complete mineralization of biorecalcitrant compounds with the objective to reduce operating costs [1][2][3][4][5][6][7][8][9][10][11][12]. In such systems, a physicochemical pretreatment such as an advanced oxidation process (AOP) or an electrochemical method is used to change the structure of pollutants.…”

“…The aim is to obtain less toxic and more biodegradable intermediates, giving rise to a complete mineralization after a subsequent biological treatment. A lot of studies have highlighted the possibility to use combined processes for the removal of non-biodegradable pollutants such as pesticides [1, 4-6, 9, 11, 13-15], dyes [7,10] and pharmaceuticals [3,8,12,[16][17][18][19].…”

A novel combined electrochemical-biological method for non-biodegradable pollutants degradation

“…It should be noted that the limit of biodegradability (0.4) is just a reference for biodegradation. Yahiaoui and co-workers have reported that the basic yellow 28 dye could be well degraded by the activated sludge with BOD 5 /COD of 0.3 after pretreatment [8]. Moreover, the residual solution treated by the activated sludge could meet the national discharge standard.…”

“…Nowadays, the electrochemical oxidation and combined methods have attracted a great deal of attention for non-biodegradable wastewater treatment, because they are environmentally-friendly and do not add extra chemicals into the system [1][2][3][4][5][6][7][8]. The "electrochemical combustion" and "electrochemical conversion" are the two main applications for the electrochemical oxidation [5].…”

Toxicity Screening after Electrochemical Degradation of Reactive Textile Dyes

“…There are publications addressing the electrochemical treatment of non-biodegradable reactive yellow dye [14][15][16], but reactive green dye RG15 is poorly or not at all documented. Also, there is no assessment of environmental impact for many studies of electrochemical treatments used for water purification.…”