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The removal of textile azo dye, Reactive Black from the aqueous solutions by catalytic wet air oxidation in the presence of LaNiO 3 perovskite catalyst has been investigated. The most suitable reaction conditions were determined by testing various the catalyst loadings, reaction temperature and pressure values, and the initial pH of the Reactive Black 5 solutions. The most suitable reaction conditions with 0.61 L/min of air flow rate were found to be 1 g/L of LaNiO 3 loading, 50 °C of reaction temperature, 1 atm of reaction pressure, and, pH = 3 for the oxidation of 100 mg/L Reactive Black solutions. Under these conditions the degradation and the decolorization efficiencies were evaluated as 65.4% and 89.6%, respectively. The phytotoxicity analyzes were carried out by using Lepidium sativum . According to the toxicity tests a remarkable decrease in the growth inhibition was achieved by the catalytic wet air oxidation in the presence of LaNiO 3 catalyst. The growth inhibition in the untreated and treated dye solutions were calculated as 49.3% and 23.7%, respectively. [ABSTRACT FROM AUTHOR]

In this study, the degradation of a major pollutant present in terephthalic acid wastewater, benzoic acid, was investigated by several advanced oxidation methods using catalysts derived from walnut shells. The 10% Fe or 10% Fe-TiO 2 (wt/wt, 1:99 as Fe:TiO 2 ) catalysts were loaded on an AC prepared from walnut shells by physical activation or chemical activation methods with different chemical reagents. The effect of the activation method was investigated using catalyst screening tests. The most efficient catalyst for the Fenton-like oxidation and catalytic wet air oxidation was determined as B-FAC and for photocatalytic/photo-Fenton-like oxidation was the N-FTAC from the screening experiments. After the catalyst screening, the effect of operating conditions such as catalyst loading, temperature, initial pH, etc. on the catalytic activity were tested in terms of degradation efficiency by determining their optimum values. Maximum degradation efficiencies from parametric studies for each method were 40% for the Fenton-like oxidation, 70% for the catalytic wet air oxidation, and 90% for photocatalytic oxidation. The highest degradation efficiency was achieved by the photo-Fenton-like oxidation in the presence of the N-FTAC catalyst with a degradation efficiency of 95% at 0.5 g/L catalyst loading, 6 W UV light, 2 mM initial H 2 O 2 concentration, and an initial pH of 3 or 6, with a reaction time of 80 min. [ABSTRACT FROM AUTHOR]

Wastewater management has become crucial for sustaining biological life in the near future. One of the key aspects is integration of treatment processes aiming reuse of treated water for many purposes instead of water discharge. This study focused on combining two different methods, photo-Fenton-like oxidation, and adsorption, for treatment of real textile wastewater to improve water quality to be reused for irrigation. The real textile wastewater was collected from a local plant and subjected to photo-Fenton-like oxidation and adsorption as hybrid process. The operational parameters were optimized for each step by assessing the water quality according to the domestic regulations for irrigation water. The photo-Fenton-like oxidation itself was not successful to achieve the targeted water quality for reuse whereas adsorption as an additional step made the treated water reusable in terms of organic content. But the treated water still contained a certain amount of salinity due to extreme salt usage in textile processing. It was concluded that the treated water at the end of hybrid process could be used for salinity resistant plants such as sugar beet, barley, and cotton which demonstrates a promising contribution to the circular economy for biomass. [Display omitted] • Corncob was valorized for real industrial wastewaters to be reused for irrigation. • Photo-Fenton-like oxidation was effective to satisfy most of the water quality parameters. • Adsorption was the polishing step for removal of organics at low concentrations. • Treated water can be used to irrigate many plants as a part of circular bio-economy. [ABSTRACT FROM AUTHOR]

In this study, the usage of biomass-based materials as co-catalysts was tested for simultaneous sugar industry wastewater treatment/hydrogen production by catalytic wet air oxidation and the final product distribution in gas and liquid effluents were investigated. For this purpose, biochar (BC) and graphene oxide-like biomass derivative (BGO) were synthesized from corncob and coupled with LaCoO 3 (LC). LaCoO 3 -Biochar (LC/BC) catalyst was determined as the most compatible one with pure LC in terms of removal efficiencies which were approximately 100% for total saccharide (TSC), 90% of total organic carbon (TOC) and chemical oxygen demand (COD) removal, respectively. This shows that biochar is a promising alternative to replace metal catalysts. The catalyst reusability was examined and the fresh and used catalysts were characterized by SEM-EDX, XRD, and BET analyses. There were slight decreases in catalytic activities of all catalysts including LC which were associated with the chemical and morphological alterations supported by the characterization analyses as a result of formation of acidic intermediates some of which were identified as formic acid and acetic acid in the liquid effluent. The formation of CO 2 was determined as proportional with TOC reduction but the behaviour for H 2 production was the opposite as a result of total oxidation in which the final products are CO 2 and H 2 O. Although the amount of H 2 produced was relatively lower for the selected catalyst LC/BC with higher treatment performance, the produced H 2 /initial sucrose ratio equal to 0.109 was considered as promising. [Display omitted] • An agricultural waste was successfully utilized as co-catalyst with LaCoO 3. • Hybrid catalysts containing corncob based materials had promising performances. • Biochar was the most viable co-catalyst for high mineralization and H 2 production. • Gas products were consistent with oxidation products including CO 2 , CO, and H 2. • Liquid by-products were identified as simple organic acids. [ABSTRACT FROM AUTHOR]

[Display omitted] • Graphene oxide supported biomimetic CuO catalysts were prepared. • CWAO performances of the biomimetic catalysts were tested. • 52.1% TOC removal and 96.2% acetaminophen degradation efficiencies were achieved. • The degradation kinetics was found to fit Langmuir-Hinshelwood model. • Heat of adsorption and adsorption entropy were calculated. TCuOX-GO (TCuO: Tomato skin inspired copper oxide; GO: Graphene oxide; X, weight percentage of copper oxide: 10, 50, and 90) catalysts were prepared and their performances on acetaminophen removal were tested in catalytic wet air oxidation (CWAO) process. Copper oxide particles were synthesized from tomato skin biotemplates to contribute valorization of food wastes and the development of ecofriendly catalysts. The most effective catalyst was determined as TCuO50-GO. Under the optimum conditions 52.1% TOC removal and 96.2% acetaminophen degradation efficiencies were achieved. The acetaminophen degradation kinetics was found to fit Langmuir-Hinshelwood model. The heat of adsorption and adsorption entropy were calculated as −19148.8 J/mol (for oxygen), −10380.9 J/mol (for acetaminophen), −10.17 J/molK (for oxygen), and −14.5 J/molK (for acetaminophen), respectively. The use of biomimetic catalysts in CWAO process and investigation of treatment cost and reaction kinetics in the presence of the biomimetic catalysts are the main original approaches of this study. [ABSTRACT FROM AUTHOR]

The present study investigates the treatment for textile wastewater through sequential photo Fenton-like oxidation and adsorption processes for reuse in irrigation. The optimum conditions were investigated to reach the minimum irrigation standarts in Turkey. Assessment of the treated wastewater as an irrigation water, evaluation of the agricultural waste as an adsorbent and support material for catalyst are the main significances of this study. Walnut shell and rice husk based adsorbents and catalysts which contain 10% by weight of active site BiBO 3 (B:Fe,Ni) were prepared and used. At the optimum conditions of the photo Fenton-like oxidation; the highest total organic carbon removal, TOC, (20–30%) was achieved with the iron containing walnut shell based catalysts. Adsorption studies were carried out as a consequent step with walnut shell based activated carbon. At the end of adsorption step, approximately 86% TOC and 58% Chemical Oxygen Demand (COD) removals were observed. Irrigation water standards were provided for TOC, color, turbidity, total suspended solids, and pH after the adsorption step. Temkin and Dubinin–Radushkevich isotherm models were found to best fit to the adsorption data. The adsorption rate followed second order kinetic model. As a result, the treated wastewater using photo-Fenton-like oxidation and adsorption process met the quality of irrigation standarts regarding TOC, color, turbidity and TSS. Also irrigation standarts were obtained considering sodium adsorption ratio (SAR). Treated wastewater have been found to be used in cultivation of plants such as barley, cotton, sugar beet, grass, spinach, long wheat grass, date palm tree, asparagus, bermuda grass sorghum. The application of the hybrid process showed that the proposed method can be implemented effectively for the treatment of real textile wastewater. [ABSTRACT FROM AUTHOR]

The photocatalytic performance of copper ferrite graphene oxide catalyst, CFXGO (CF: Copper ferrite, CuFe 2 O 4 ; GO: Graphene oxide; X: GO weight percentage) was tested for photo Fenton-like oxidation of Reactive Black 5 by using UV light irradiation. The effect of the graphene oxide content in the catalyst structure on dye removal efficiency was tested by comparing the performances of the catalysts with different weight ratios of graphene oxide varying between 5 and 90%. The catalysts were characterized by Scanning Electron Microscopy, X-Ray Diffraction, Brunauer–Emmett–Teller method, and, Vibrating Sample Magnetometer. The influences of catalyst loading, initial pH, and, the H 2 O 2 concentration were investigated in the presence of CF90GO catalyst, which has 90% graphene oxide content. According to the parametric studies, 98.2% decolorization and 82.8% TOC removal efficiencies were achieved in 2 h for the treatment of 50 mg/L RB5 solutions when the catalyst loading, the initial pH, and, the initial hydrogen peroxide concentration were 0.275 g/L, 7, and, 5.5 mM, respectively. [ABSTRACT FROM AUTHOR]