Effect of freeze/thaw conditions, polyelectrolyte addition, and sludge loading on sludge electro-dewatering process

Permanganate/bisulfite (PM/BS) conditioning–horizontal electro-dewatering (HED) of activated sludge: Effect of reactive Mn(III) species

“…As mentioned in section 3.2.3, the water electrolysis, variations of pH, and temperature under the effect of horizontal electric field at HED stage can reduce the liquid density, viscosity, and the surface tension of AS matrix then led to EPS and cell disruption (Mahmoud et al, 2010;Tuan and Sillanp€ a€ a, 2010b). Therefore, the bound water released from the HED treated AS flocs and the free water was driven toward the cathode-side by the electro-osmotic flow, which resulted in the much lower water content in AS at the anode-side than at the cathode-side (Tuan and Sillanp€ a€ a, 2010a). During the whole Mn(III) CeHED process, the reduction rates of TWC, BWC, and FWC for AS flocs were 85.86%, 87.62%, and 51.68% for anode-side; 82.64%, 85.08%, and 36.55% for cathode-side, respectively.…”

“…In addition, the TOC values in EPS of AS flocs at the cathode-side were higher than at anode-side. Under the effect of electroosmosis, the released un-charged intra-cellular materials at anode-side also can migrate to the cathode-side of HED cell along with water (Tuan and Sillanp€ a€ a, 2010a). The more water migration, the more these dissolved organics.…”

Effect of Polyelectrolyte Conditioning and Voltages on Fractionation of Macro and Trace Metals due to Sludge Electro-Dewatering

“…Because of the constant voltage application, the shorter distance between the electrodes relates to an increase in electrical field strength that facilitated electro-osmotic flow. The relationship between increasing electrical field strength and increasing DS content was also shown by comparing the experiments carried out with 10 V and 40 V. The impact of applying higher voltage, resulting in lower water content in the final sludge cake, has been observed by several researchers (3,4,15,16), and it is based on the positive relationship between the electro-osmotic flow rate and electrical field strength (13,17,18).…”

Enhancement of sludge electro-dewaterability during biological conditioning

“…[23][24][25] For realizing the change of sludge properties, conventional sludge pretreatment was achieved by using chemical conditioning agents (e.g., acid, alkali or electrolyte). 3,26,27 Besides, ultrasonication, 28 freeze/thaw conditioning, 21 and magnetic conditioning 29 were also used to damage EPS and change sludge structure.…”