Investigation of operational conditions for the removal of methylene blue by Fenton Reaction

Fenton reaction has been concerned by many researchersdue to easy operation and effective degradation of bioresistantorganics. This study aims to investigate the effect ofthe operational conditions on the effectiveness of Fenton’sprocess for the decolorization of methylene blue.The influenceof methylene blue, pH, dose of H2O2 , ferrous sulfateconcentration from the wastewater were studied. Experimentshave shown that highly affect by the value of pH, Laboratoryexperiment conducted in the lab proved that pH should bebetween 3 - 4 to give the best results, It also proved that theincreasing of the dose of both hydrogen peroxide and ferroussulfate enhanced the removal efficiency of MB

Bio-H2 conversion of wastewater via hybrid dark/photo fermentation reactor

Hydrogen energy is a clean source for liveliness betterthan fossil fuel that has hazardous effects on the environmentand atmosphere. Food wastes and organics in the sewage sludgeare a promising sustainable and renewable source for hydrogenproduction where amalgamation of waste treatment and energyproduction would be more than one benefit expressed intreatment of organic pollutants and energy generation.Discovering biohydrogen production from industrialwastewater by dark and photo fermentation was the main aimof this paper. The biogas produced was composed of H2 andCO2, and the maximum H2 content was 25.94%. This ratio wasachieved at batch configuration system and initial pH 6.2 withstarch concentration 15 g/l. Cause of using dark fermentationeffluent (DFE) was used as substrate for A Rhodobactercapsulatus strain and a clostridium culture were cultivated toproduce hydrogen under different light-dark cycles. Acetic andbutyric acids decreased due to first and second photo stages by21.9% and 4.1 % respectively. Maximum hydrogen yield was470.9 ml H2/mol VFAs

Photocatalytic degradation of trimethoprim using S-TiO2 and Ru/WO3/ZrO2 immobilized on reusable fixed plates

In this study, photocatalytic degradation of trimethoprim by synthesized S-TiO2 and Ru/WO3/ZrO2 catalysts was investigated. Both photocatalysts have been immobilized on circular aluminum plates by polysiloxane to investigate their reusability performance. The morphology and structure of the catalysts were studied by high-resolution transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The photocatalytic experiments were carried out using suspended and attached catalysts using a metal halide lamp as a light source. The degradation efficiencies of trimethoprim were 100% and 98.2% at catalyst dose of 0.5 g/L, pH of 7.0 and irradiation time of 240 min using suspended Ru/WO3/ZrO2 and S-TiO2, respectively. After immobilization of the catalysts on the aluminum plates, the removal efficiencies in five repetitive cycles were 98%, 96.9%, 96.8%, 93.2% and 83.4% using Ru/WO3/ZrO2, while they were 88.6%, 86%, 84%, 78% and 75.9% in case of S-TiO2. The irradiation time of each cycle was 240 min, and the initial trimethoprim concentration was 10 mg/L. The degradation rates of trimethoprim were estimated in the case of suspended and immobilized S-TiO2 and Ru/WO3/ZrO2. The radical trapping experiments using various scavengers revealed that superoxide radicals, holes and hydroxyl radicals all participated in the photo-degradation process. Furthermore, the transformation products generated during the trimethoprim oxidation process were detected by liquid chromatography/mass spectroscopy to identify the possible degradation pathways

Toward scaling-up photocatalytic process for multiphase environmental applications

ABSTRACT: Recently, we have witnessed a booming development of composites and multi-dopant metal oxides to be employed as novel photocatalysts. Yet the practical application of photocatalysis for environmental purposes is still elusive. Concerns about the unknown fate and toxicity of nanoparticles, unsatisfactory performance in real conditions, mass transfer limitations and durability issues have so far discouraged investments in full-scale applications of photocatalysis. Herein, we provide a critical overview of the main challenges that are limiting large-scale application of photocatalysis in air and water/wastewater purification. We then discuss the main approaches reported in the literature to tackle these shortcomings, such as the design of photocatalytic reactors that retain the photocatalyst, the study of degradation of micropollutants in different water matrices, and the development of gas-phase reactors with optimized contact time and irradiation. Furthermore, we provide a critical analysis of research–practice gaps such as treatment of real water and air samples, degradation of pollutants with actual environmental concentrations, photocatalyst deactivation, and cost and environmental life-cycle assessment

Toward Scaling-Up Photocatalytic Process for Multiphase Environmental Applications

Recently, we have witnessed a booming development of composites and multi-dopant metal oxides to be employed as novel photocatalysts. Yet the practical application of photocatalysis for environmental purposes is still elusive. Concerns about the unknown fate and toxicity of nanoparticles, unsatisfactory performance in real conditions, mass transfer limitations and durability issues have so far discouraged investments in full-scale applications of photocatalysis. Herein, we provide a critical overview of the main challenges that are limiting large-scale application of photocatalysis in air and water/wastewater purification. We then discuss the main approaches reported in the literature to tackle these shortcomings, such as the design of photocatalytic reactors that retain the photocatalyst, the study of degradation of micropollutants in different water matrices, and the development of gas-phase reactors with optimized contact time and irradiation. Furthermore, we provide a critical analysis of research–practice gaps such as treatment of real water and air samples, degradation of pollutants with actual environmental concentrations, photocatalyst deactivation, and cost and environmental life-cycle assessment

Artificial intelligence, regression model, and cost estimation for removal of chlorothalonil pesticide by activated carbon prepared from casuarina charcoal

Chlorothalonil is a pesticide that can contaminate water bodies, detriment aquatic organisms, and cause cancers of the forestomach and kidney. In this study, a powdered activated carbon prepared from casuarina wood was used for the adsorption of chlorothalonil from aqueous solutions. Based on Scanning Electron microscopy and Fourier Transform Infrared Spectroscopy analyses, the adsorbent material comprised pores and multiple functional groups that favored the entrapment of chlorothalonil onto its surface. At initial chlorothalonil concentration of 480 mg L−1, the equilibrium uptake capacity was 187 mg g−1 at pH: 7, adsorbent dosage: 0.5 g L−1, contact time: 40 min, and room temperature (25 ± 4 °C). The kinetic and isotherm studies indicated that the rate constant of pseudo-second-order model (k2) was 0.003 g mg−1 min−1, and the monolayer adsorption capacity was 192 mg g−1. Results from a quadratic model demonstrated that the plot of adsorption capacity versus pH, chlorothalonil concentration, adsorbent dosage, and contact time caused quadratic-concave, linear-up, flat, and quadratic-linear concave up curves, respectively. An artificial neural network with a structure of 4–5–1 was able to predict the adsorption capacity (R2: 0.982), and the sensitivity analysis using connection weights showed that pH was the most influential factor. An economic estimation using amortization and operating costs revealed that an adsorption unit subjected to 100 m3 d−1 containing chlorothalonil concentration of 250 ± 50 mg L−1 could cost 1.18 $ m−3. Keywords: Activated carbon, Artificial neural network, Chlorothalonil pesticide, Cost estimation, Kinetics and isotherm

Artificial intelligence, regression model, and cost estimation for removal of chlorothalonil pesticide by activated carbon prepared from casuarina charcoal

Chlorothalonil is a pesticide that can contaminate water bodies, detriment aquatic organisms, and cause cancers of the forestomach and kidney. In this study, a powdered activated carbon prepared from casuarina wood was used for the adsorption of chlorothalonil from aqueous solutions. Based on Scanning Electron microscopy and Fourier Transform Infrared Spectroscopy analyses, the adsorbent material comprised pores and multiple functional groups that favored the entrapment of chlorothalonil onto its surface. At initial chlorothalonil concentration of 480 mg L−1, the equilibrium uptake capacity was 187 mg g−1 at pH: 7, adsorbent dosage: 0.5 g L−1, contact time: 40 min, and room temperature (25 ± 4 °C). The kinetic and isotherm studies indicated that the rate constant of pseudo-second-order model (k2) was 0.003 g mg−1 min−1, and the monolayer adsorption capacity was 192 mg g−1. Results from a quadratic model demonstrated that the plot of adsorption capacity versus pH, chlorothalonil concentration, adsorbent dosage, and contact time caused quadratic-concave, linear-up, flat, and quadratic-linear concave up curves, respectively. An artificial neural network with a structure of 4–5–1 was able to predict the adsorption capacity (R2: 0.982), and the sensitivity analysis using connection weights showed that pH was the most influential factor. An economic estimation using amortization and operating costs revealed that an adsorption unit subjected to 100 m3 d−1 containing chlorothalonil concentration of 250 ± 50 mg L−1 could cost 1.18 $ m−3. Keywords: Activated carbon, Artificial neural network, Chlorothalonil pesticide, Cost estimation, Kinetics and isotherm