Pretreatment of Olive Oil Mill Wastewater by Two Different Applications of Fenton Oxidation Processes

Abstract

The removal of chemical oxygen demand (COD) and phenol from olive oil mill wastewaters (OOMW) was investigated experimentally by using conventional Fenton (CFP) and Fenton type processes (FTP) with zero valent iron (ZVI According to the results of kinetic studies, it was observed that COD and phenol were removed by FTP more rapidly, compared to CFP. Consequently, it was determined that both CFP and FTP were effective processes for the pretreatment of OOMW.

COD and color removal from synthetic textile wastewater by ultrasound assisted electro-Fenton oxidation process

“…Therefore, most of COD and RB 5 were removed in the first 2.5 min of the oxidation time in both EF and sono-EF processes. But, the oxidation rate decelerated with decreasing concentrations of H 2 O 2 in the reaction mixture and increasing concentration of catalyst iron which has also a radical scavenging effect [13]. As it was seen from Fig.…”

“…Its oxidation mechanism is based on the production of hydroxyl radicals (OH ) as a result of the reaction of hydrogen peroxide (H 2 O 2 ) with catalyst ferrous ions (Fe 2+ ) under acidic conditions, as shown in Eq. (1) [13]. The OH is known as the second most powerful oxidizing agent and its oxidation capacity is slightly lower than fluorine.…”

Comparative Removal of Rhodamine B from Aqueous Solution by Electro‐Fenton and Electro‐Fenton‐Like Processes

“…Advanced oxidation process using hydroxyl radicals has been found as an alternative and efficient tool for the treatment of various organic pollutants. Among these processes, Fenton processes such as conventional Fenton process [1,[6][7][8][9], photo-Fenton [8,9], sono-Fenton [10,11], electro-Fenton (EF) [12][13][14][15][16][17], helielectro-Fenton [18], sono-photo-Fenton [10], photo-electro-Fenton [19,20], etc., received great attention during recent years. Except EF process, other Fenton processes require the external addition of hydrogen peroxide for the production of hydroxyl radicals.…”

Mineralization of Catechol by Fenton and Photo‐Fenton Processes

“…Approximately 2 Â 10 6 tons of olive are produced annually worldwide, proceeding the majority of them from the Mediterranean basin [1,2]. The average amount of olive mill wastewater generated during the milling process is very high, about 1.5-1.8 m 3 ton À1 olive, but their treatment is still a major problem due to their dark color, high organics content, and toxicity due to the presence of phenolic compounds [3,4]. Catechol is one of the most abundant phenolic components of the wastewaters from olive mills [5][6][7][8], being toxic and persistent under environmental conditions.…”

“…The Fenton process is a rather inexpensive and easy to handle procedure that can be used to efficiently oxidize a wide variety of organics even in industrial wastewaters [3,4,18,[21][22][23]. The chemical attack is normally accelerated in the presence of UVA light in the so-called photo-Fenton process [16,18,19], and two reasons seem to account for such a behavior: (i) the photolysis of the Fe(OH) 2þ complex, the predominant species of Fe(III) in aqueous solution at pH 2.8-3.5, shown in reaction (3) allowing the regeneration of Fe 2þ catalyst and the generation of more OH [18] and (ii) the photo-decarboxylation of complexes of Fe(III) with most generated carboxylic acids by the general reaction (4) [24]:…”