Removal of Olive Mill Wastewater Phenolics with the Use of a Polyphenol Oxidase Homogenate from Potato Peel Waste

Abstract

Olive mill wastewater (OMW) originating from a two-phase olive oil producing plant was treated with a crude polyphenol oxidase (PPO) homogenate, prepared from potato waste peels. The treatments carried out were based on a 2 3-full-factorial, central composite design (CCD) in order to identify optimal operational conditions with regard to polyethylene glycol (PEG) concentration, pH, and treatment duration. The treatment performance was assessed by estimating the % reduction in total polyphenol (TP) concentration. The model obtained produced a satisfactory fitting of the data (2 = 0.96, = 0.0017). The utilisation of the predictive model enabled the theoretical calculation of the optimal set of conditions, which were pH = 4, = 3.57 h, and [PEG] = 900 mg L −1. Under these conditions, the optimal theoretical % removal calculated was 54 ± 9. Examination of the treated samples with high-performance liquid chromatography (HPLC) showed that the potato homogenate afforded changes in the polyphenolic profile. Based on the experimental evidence, oxidation pathways were proposed.

Assessment of phenol compound removal from olive oil mill wastewater by using peroxidases extracted from radish and nettle leaves

“…The OMW toxicity was attributed to the presence of non-degradable compounds such as the phenolic compounds which could be present at high levels (4-15 g•L -1 ) (EL HAJJOUJI et al, 2007). To reduce the OMW toxicity, several treatment methods have been developed: physical (PARASKEVA andDIAMADOPOULOS, 2006), chemical (HODAIFA et al, 2013) and biological (DEMIAN and MAKRIS, 2013;SALMAN et al, 2014;DAÂSSI et al, 2016). Several studies have shown that biological treatment based on enzymatic incubation has more advantages than the physical and chemical treatments (DEMIAN and MAKRIS, 2013).…”

“…To reduce the OMW toxicity, several treatment methods have been developed: physical (PARASKEVA andDIAMADOPOULOS, 2006), chemical (HODAIFA et al, 2013) and biological (DEMIAN and MAKRIS, 2013;SALMAN et al, 2014;DAÂSSI et al, 2016). Several studies have shown that biological treatment based on enzymatic incubation has more advantages than the physical and chemical treatments (DEMIAN and MAKRIS, 2013). Biological treatments implicate, essentially, laccases, polyphenol oxidases or peroxidases provided from fungi and microorganisms (SAAVEDRA et al, 2006;ASGHER et al, 2008).…”

“…Biological treatments implicate, essentially, laccases, polyphenol oxidases or peroxidases provided from fungi and microorganisms (SAAVEDRA et al, 2006;ASGHER et al, 2008). Recent work has demonstrated that plant peroxidases could be used to remove phenolic compounds in OMW (SERGIO et al, 2010;DEMIAN and MAKRIS, 2013). The elimination of phenols using plant peroxidases was described by SERGIO et al (2010).…”

Degradation, dephenolisation and dearomatisation of olive mill wastewater by subcritical water oxidation method using hydrogen peroxide: Application of multi-response central composite design

“…17 The high concentration of polyphenolic content from 1.0 up to 10 g L -1 is considered as the major reason of toxicity of OMWW. 18,19 When the high concentration of other organic compounds is involved along with polyphenolic content which accounts for a 14 % contribution to chemical oxygen demand (COD), 20,21 a wastewater with an extremely high COD value (45-130 g L -1 ) which is several times higher than domestic waste, is encountered. [22][23][24][25] In addition, it is known that the organic content is composed of various aromatic structures such as carcinogenic and toxic aromatic amines.…”

“…Several chemical treatment methods (ozonation, UV irradiation, photocatalysis, hydrogen peroxide/ferrous iron oxidation, electrochemical oxidation, catalytic wet air oxidation, Fenton, supercritical wet air oxidation, subcritical wet air oxidation coupled with Fenton, wet hydrogen peroxide catalytic oxidation and sonication) and biological (anaerobic digestion, aerobic treatment, anaerobic bioremediation) as well as the combination of both of them have been used for treatment of OMWW. [1][2][3][4][5][6][7][8][17][18][19][20][21] Although the biological processes, namely anaerobic processes, are known as the energy and cost saving methods, they may be ineffective in the treatment of highly concentrated OMWW. 3,5 In addition, the biological treatment processes are not able to degrade the persistent compounds such as polyphenols.…”