Electrolytic stimulation of denitrification in sand columns

Microbial denitrification by immobilized bacteria Pseudomonas denitrificans stimulated by constant electric field

“…Many authors [15][16][17][18][19][20]24,25] have claimed that the microbial nitrate reduction under electrolytic stimulation in a galvanostatic mode occurs due to water electrolysis and electrolytic hydrogen production. In our case, however, a potentiostatic mode was used and the currents were extremely weak (microamperes).…”

“…There are several approaches in this sphere. The presumption of one of them is to facilitate the microbial activity by cathode production of hydrogen which is itself a strong nitrate reducer [15][16][17][18][19][20][21][22][23][24][25][26]. These studies referred to the galvanostatic performance at relatively high electric currents, i.e.…”

Autotrophic nitrogen removal from ammonium at low applied voltage in a single-compartment microbial electrolysis cell

“…A bio-electrochemical reactor processed by electrolysis of water producing oxygen gas at the anode and hydrogen gas at the cathode for simultaneous nitrification and denitrification (SND) has also been proposed (Goel and Flora, 2005). So far, BER systems that depend on electrolysis of water have been extensively investigated for use in biological nitrogen removal (Feleke and Sakakibara, 2002;Hayes et al, 1998;Islam and Suidan, 1998;Sakakibara and Nakayama, 2001;Szekeres et al, 2001;Wan et al, 2009;Watanabe et al, 2002). However, these electrochemically enhanced nitrogen removals require high applied voltage which is greater than 1.8 V at neutral pH, resulting in increase of electric energy input.…”

Effect of electrokinetic transport on the vulnerability of PAH-degrading bacteria in a model aquifer

“…When DC is applied to living microbial cells, various responses, such as toxic electrode effects, metabolic stimulation due to enhanced substrate mass transfer (Pribyl et al 2001), sublethal injuries (Guillou et al 2003), irreversible dielectric cell membrane breakdown (Zimmermann et al 1974), or changes in the physicochemical surface properties (Luo et al 2005) can be observed depending on the applied current, treatment time, cell type and medium characteristics (Velizarov 1999). Earlier studies using soil have shown that the application of 20 mA cm -2 DC current stimulated the activity of sulphur-oxidising bacteria (Jackman et al 1999) or the biological denitrification of nitrate-contaminated groundwater (Hayes et al 1998) due to the production of H 2 and subsequent pH changes. A study by Lear et al (2005), analysing the effect of DC on the structure of soil microbial communities, has suggested that there is no negative effect of the applied current density (J = 0.31 mA cm -2 ) on soil health in the absence of DC-induced changes in soil pH and temperature.…”