Study on the Degradation of Oilfield Wastewater Treatment by Three-Dimensional Electrode

Abstract

The COD value is the main control index of sewage standard. The method of three-dimensional electrocatalytic oxidation is studied for deep treatment of oilfield sewage. The oxidation mechanism and the structure of the three-dimensional electrode reactor are analyzed and optimized. A series of single factor experimental results show that each control parameter has different influences on COD removal rate in the process of oxidative degradation. Based on the experimental study of electrode materials, electrode filled particles, electrolysis current and resident time of sewage, when the system condition are DSA electrode-F plate, the electrode particles of activated carbons:glass beads:quartz sands = 5:2:2, the electrolysis current of 6 A and the retention time of 50 min, the sewage by oxidized treatment meets the discharge standard of COD ≤ 50 mg·L −1. The SEM result analysis of DSA electrode-F plate before and after using for a period of time shows the electrode material is stable, and no dissolution and corrosion occur. The UV-Vis absorption spectroscopy analysis of water samples in the wavelength range of 200 -600 nm shows pollutants in sewage are degraded into small molecules, and refractory organic pollutants are effectively removed.

Analogous study of cumulative biogas production by anaerobic digestion of sewage treatment plant sludge, the proposal of universal dimensionless models

“…The proposed models (Equations and ) validation is checked by comparing the coefficient of determination with Gelatin product used in Schneider 47 study, the residual organic matter product used in Arras 48 study and Sludge product used in Liu et al 49 study as given in Figure 7. The proposed models (Equations and ) have the highest coefficient of determination.…”

Synthesis and electrochemistry study for La-doped RuO2-TiO2/Ti coatings

“…Many researches have focused on designing new ways and adding various chemical compositions to improve the electro-catalytic activity and chemical stability. Some types of metal oxide electrodes, such as SnO 2 , PbO 2 , Sb 2 O 3 , RuO 2 and composite oxides, have been widely studied, [7][8][9][10][11] and the higher reaction activity is expected all the time.…”

Novel decentralized greywater treatment system based on combined adsorption and electrochemical oxidation

“…It has been previously reported that graphite electrodes can easily react with electrochemically produced oxygen forming CO and CO 2 , resulting in its corrosion (Liu et al 2017). ) (Gamby et al 2001).…”

“…However, the higher conductivity of the GG may favour the occurrence of electrochemical reactions onto its surface when it is polarized, (Brown et al 2004a, Brown et al 2004b. As graphite electrodes have been reported to present a low mechanical strength, the electrochemically produced ROS species can react with the graphite resulting in its corrosion (Liu et al 2017). Therefore, the lower values obtained for the kinetic constant in the 3D system (k 3 ) using GG for the treatment of SGW also suggest that the produced oxidant species may be reacting with the GG rather than oxidising the pollutants.…”

“…The energy efficiency of the electrochemical treatment process may decrease as (1) part of current is used in side reactions for the production of oxygen in the surface of the bed material that that can oxidise it to CO and CO 2 (Liu et al 2017), but also (2) it can be suggested that an enhanced generation of ROS in the surface of the graphite, favoured by its higher electrical conductivity (Brown et al 2004a, Brown et al 2004b, that are distributed in a smaller surface area (700 times lower than GAC) can promote the mass transfer limitation of the pollutants to the surface of the bed material and the oxidation of its surface due to the excess of generated ROS.…”