Modified Fenton Oxidation

Fenton Process, a type of Advanced Oxidation Processes is an efficient method for treating textile
wastewaters. However, excessive use of hydrogen peroxide and catalyst has made this process
economically non-feasible. Besides, industrial grade hydrogen peroxide costs $390 e500 per ton. One of
the means to overcome this problem is the in-situ production of hydrogen peroxide. In this paper, a
detailed review was conducted on the generation methods, degradation potential and optimum operating parameters for in-situ production of hydrogen peroxide/hydroxyl radicals. Additionally the scavenging aspect for hydroxyl radicals was also investigated. From this review, it can be concluded that
hydroxyl radical is highly oxidative and non selective in nature and its in-situ production can be performed through application of catalyst, ozonation, photocatalysis, electro and microbial fuel cells.
Furthermore, optimization of operating parameters can result in an increase in the yield of hydroxyl
radicals/hydrogen peroxide. Sonolysis as an auxiliary tool has potential to induce synergetic effects in
combination with Advanced Oxidation Processes to increase in-situ hydrogen peroxide production.
However, the problem of the scavenging effect is an aspect that needs to be dealt with, as hydroxyl
radicals are prone to deactivation by scavengers. Therefore based on the review, it is concluded that insitu production of hydrogen peroxide/hydroxyl radical for treating textile wastewater is economically
viable and practically feasible if careful selection of process is conducted through selective research

Application of the Fenton process for textile wastewater treatment is limited due to high treatment cost, substantially contributed by the un-availability of cheap hydrogen peroxide. Therefore, alternative methods for hydrogen peroxide production
are in demand. One such option is in situ hydrogen peroxide production using a wastewater based microbial fuel cell (WBMFC).
However, not much have been published regarding in situ production of hydrogen peroxide for textile wastewater treatment in
a WBMFC. Therefore, in this work the concept, advantages, challenges and prospects of using WBMFC to treat textile wastewater by simultaneously producing hydrogen peroxide (hence in situ hydrogen peroxide) and power are reviewed. The concept
of WBMFC is the reduction of oxygen in the presence of electrons and protons from the anode chamber to produce hydrogen
peroxide with simultaneous power production. This review confirms that use of dual chambers, proton exchange membrane,
domestic or municipal wastewater/Geobacter Sulfurreducens or Shewanella species, pure graphite cathode, ammonia and heat
treated carbon-based anode can treat most textile wastewaters. However, single chamber WBMFCs can be used as a low power
source for an electro-Fenton reactor. Power produced can be used to provide energy for aeration required in the WBMFC, thus
providing an integrated and sustainable solution for textile wastewater treatment.

In the present study, a comparison of central composite design (CCD) and Taguchi method was established for Fenton oxidation.
[Dye] ini, Dye : Fe+2, H2O2 : Fe+2, and pH were identifid control variables while COD and decolorization effiency were selected
responses. 𝐿 orthogonal array and face-centered CCD were used for the experimental design. Maximum 99% decolorization and
80% COD removal effiency were obtained under optimum conditions. � squared values of 0.97 and 0.95 for CCD and Taguchi
method, respectively, indicate that both models are statistically signifiant and are in well agreement with each other. Furthermore,
Prob > � less than 0.0500 and ANOVA results indicate the good fiting of selected model with experimental results. Nevertheless,
possibility of ranking of input variables in terms of percent contribution to the response value has made Taguchi method a suitable
approach for scrutinizing the operating parameters. For present case, pH with percent contribution of 87.62% and 66.2% was ranked
as the most contributing and signifiant factor. Ths fiding of Taguchi method was also verifid by 3D contour plots of CCD.
Threfore, from this comparative study, it is concluded that Taguchi method with 9 experimental runs and simple interaction plots
is a suitable alternative to CCD for several chemical engineering applications

Petroleum refinery effluents (PREs) are wastewaters characterised by high values of chemical oxygen demand (COD) and total organic carbon (TOC). Mineralisation of PRE is not commonly reported. For Fenton oxidation, in particular, reported PRE mineralisation is low. In this paper, treatability of a petroleum refinery effluent using a Fenton-like oxidative reaction is described. A statistically designed experimental matrix was used to evaluate the individual and combined effects of process variables based on a five-level central composite design (CCD). Response surface methodology (RSM) was employed to optimise the parameters of interest (COD and TOC), and response surface equations were subsequently developed. These parameters were optimised from studies of the independent variables, for reaction time [t(r)] = 30-240 mm, molar ratio of hydrogen peroxide to the organic wastewater [H2O2]:[PRE] = 2-12 and mass ratio of hydrogen peroxide to catalyst [H2O2]:[Fe3+] = 5-20. The COD and TOC of the PRE at an initial pH of 7 were 1343 mg O-2/L and 398 mg C/L, respectively. Under optimal conditions, maximal TOC and COD reduction achieved within 30 min of oxidation reaction were 70% and 98.1%, respectively. The obtained models had correlation coefficients (R-2 and R-adj(2)) of 0.9984 and 0.9916 for TOC and 0.9636 and 0.8835 for COD. At a pH of 3, corresponding optimal oxidation conditions were found to be [H2O2] = 1008.0 mM and [Fe3+] = 686.0 mg, that is, a molar ratio of [H2O2]:[PRE] = 12 and mass ratio of [H2O2]:[Fe3+] = 5. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

http://www.sciencedirect.com/science/article/pii/S0263876211002346

In the rural regions of Latin America, wastewater treatment systems are based on conventional technologies such as the septic tanks. These treatment systems do not support biodegradability indexes lower than 0,4 measured in the form of BOD 5 /COD, values obtained when refractory contaminants are found in water; which in turn are associated in most cases with the intrusion of industrial wastewater. In these cases, the conventional treatment systems do not meet the regulations for which they were designed; and therefore public investment is lost to build them. This is why in the present investigation the biodegradability index of this type of effluents was increased, for which domestic wastewater mixed with leachate and industrial effluent obtained from the Chasinato creek in the Tungurahua province of Ecuador was used, in which a biodegradability index of 0,22 was obtained in BOD 5 /COD. An advanced oxidation process of modified Fenton was applied to this effluent, which increased the biodegradability index and avoided reducing the pH, since in large volumes this is very expensive. The optimal concentrations of reagents were FeSO 4 /H 2 O 2 = 1 and C 6 H 8 O 7 /H 2 O 2 = 2; with the addition of 10 mg/L of H 2 O 2 , which increased the biodegradabi-lity index to a value of 0,46, which is a satisfactory value to be treated in conventional systems such as septic tanks; in addition to a reduction of BOD 5 and COD in efficiencies of 12.54 %; 44.4 % respectively.

Application of the Fenton process for textile wastewater treatment is limited due to high treatment cost, substantially contributed by the un‐availability of cheap hydrogen peroxide. Therefore, alternative methods for hydrogen peroxide production are in demand. One such option is in situ hydrogen peroxide production using a wastewater based microbial fuel cell (WBMFC). However, not much have been published regarding in situ production of hydrogen peroxide for textile wastewater treatment in a WBMFC. Therefore, in this work the concept, advantages, challenges and prospects of using WBMFC to treat textile wastewater by simultaneously producing hydrogen peroxide (hence in situ hydrogen peroxide) and power are reviewed. The concept of WBMFC is the reduction of oxygen in the presence of electrons and protons from the anode chamber to produce hydrogen peroxide with simultaneous power production. This review confirms that use of dual chambers, proton exchange membrane, domestic or municipa...

In the present study, a comparison of central composite design (CCD) and Taguchi method was established for Fenton oxidation.Dyeini, Dye : Fe+2, H2O2 : Fe+2, and pH were identified control variables while COD and decolorization efficiency were selected responses.L9orthogonal array and face-centered CCD were used for the experimental design. Maximum 99% decolorization and 80% COD removal efficiency were obtained under optimum conditions.Rsquared values of 0.97 and 0.95 for CCD and Taguchi method, respectively, indicate that both models are statistically significant and are in well agreement with each other. Furthermore, Prob >Fless than 0.0500 and ANOVA results indicate the good fitting of selected model with experimental results. Nevertheless, possibility of ranking of input variables in terms of percent contribution to the response value has made Taguchi method a suitable approach for scrutinizing the operating parameters. For present case, pH with percent contribution of 87.62%...

The combination of metal-organic frameworks (MOFs) with nano-carbon materials is an emerging field among the researchers now a days. The addition of carbon materials (CNTs/GO) increases the Physico-chemical characteristics of parent MOFs. In this mini review the photocatalytic and Fenton-like oxidation behavior of these hybrid nanocomposites has been discussed. Additionally, the efficient remediation of a number of pollutants (VOCs, heavy metals and toxic gases) through adsorptive removal from atmospheric environment has been presented. Finally, the recyclability and stability of MOFs-C along with future perspectives are also presented at the end of this review.

Lawrence K. Wang, Mu-Hao Sung Wang, Yung-Tse Hung (2021). Integrated Natural Resources Research, Springer Cham, NY, USA; 651 pages, ISBN:  978-3-030-61001-2; https://doi.org/10.1007/978-3-030-61002-9    ....    ABSTRACT:  The book will be useful to environmental resources engineers, researchers, water treatment plant managers, chemical engineers, industrial plant managers, and environmental conservation agencies. This book includes 12 chapters: (1) Fenton Oxidation and Biological Activated Carbon Treatment for Recycling Biotreated Coking Plant Wastewater; (2) Composting for Food Processing Wastes; (3) Treatment of Wastewaters from Chemical Industries; (4) Agricultural Waste as a Low-Cost Adsorbent; (5) Waste Vegetable Oils, Fats, and Cooking Oils in Biodiesel Production;  (6) Physicochemical Treatment Consisting of Chemical Coagulation, Precipitation, Sedimentation, and Flotation; (7) Water Quality Control of Tidal Rivers and Estuaries; (8) First Wave of Flotation Technology Evolution: Once the World’s Largest DAF-Filtration Plant and Its Hydroelectric Facility;  (9) Cationic Surfactant Analysis with Good Laboratory Practice and Waste Management; (10) Treatment of Laundry Wastewater by Physicochemical and Flotation Processes;  (11) Book Reviews: Natural Resources; and (12) Glossary of Water Quality, Treatment, and Recovery.

The combination of metal-organic frameworks (MOFs) with nano-carbon materials is an emerging field among the researchers now a days. The addition of carbon materials (CNTs/GO) increases the Physico-chemical characteristics of parent MOFs. In this mini review the photocatalytic and Fenton-like oxidation behavior of these hybrid nanocomposites has been discussed. Additionally, the efficient remediation of a number of pollutants (VOCs, heavy metals and toxic gases) through adsorptive removal from atmospheric environment has been presented. Finally, the recyclability and stability of MOFs-C along with future perspectives are also presented at the end of this review.