Removal Yield Research Articles

Biodegradation of tri-butyl phosphate by Trametes versicolor and its application in a trickle bed reactor under non-sterile conditions

Tri-butyl phosphate (TBP) is a widely used organophosphate flame retardant. However, it is also regarded as emerging contaminant due to its various toxic effects and poor removal by conventional wastewater treatment. In present study, we investigated the degradation of TBP (10 mg/L) by the white rot fungus Trametes versicolor in both laboratory conditions and a trickle bed reactor (TBR) under non-sterile conditions. The removal yield reached 98 % after 3 days, during which the intracellular enzymatic system cytochrome P450 was involved. Four transformation products (TPs) were identified, namely dibutyl 3-hydroxybutyl phosphate, dibutyl phosphate, butyl 3-hydroxybutyl phosphate and butyl dihydrogen phosphate, which allowed us to propose a degradation pathway where hydroxylation and hydrolysis made considerable contribution. TBP treatment in the TBR with T. versicolor immobilized on wood chips operating in sequential batch mode with 10 cycles of 3 days reached average removals higher than 93 %, demonstrating the potential for practical application. Despite similar removal rates in heat-killed and abiotic controls (89 % and 97 %, respectively), global mass balance analysis indicated 86 %, 64 %, and 86 % removal by degradation in the fungal, heat-killed, and abiotic controls, respectively. Analysis of the microbial assemblage in solid phase suggested that the established bacterial populations displayed a synergistic effect with immobilized fungus. This study is the first to report on TBP degradation by T. versicolor in a TBR under non-sterile conditions, suggesting that this method could be a viable option for large-scale environmental applications.

Construction and evaluation of electrophotocataltic tubular reactor in phenol degradation

Contamination of the environment is one of the main threats to achieving sustainability. Even though there have been significant legal efforts to regulate parameters for effluent disposal, conventional treatment methods often prove to be ineffective, resulting in the incomplete removal of pollutants. This inefficiency leads to serious environmental issues, such as the toxicity of biomes, which is closely related to the bioaccumulation of harmful substances. In response to this challenge, this study aimed to develop and optimize an electrophotocatalytic reactor for the remediation of a synthetic phenol solution using advanced oxidative processes (AOPs). By applying these processes, we observed that the characteristics of the reaction medium allowed for a maximum pollutant removal yield of 54.73% over a 3-hour operation period in a continuous recirculation regime. Despite the promising results, the study revealed the influence of additional factors that were not considered, which are likely important in further optimizing the reactor's efficiency for real-world applications.

Continuous Fixed Bed Bioreactor for the Degradation of Textile Dyes: Phytotoxicity Assessment

This study explores a novel bioremediation approach using a continuous upflow fixed bed bioreactor with date pedicels as a biosupport material. Date pedicels offer a dual advantage: providing microbial support and potentially acting as a biostimulant due to their inherent nutrients. This research is divided into two phases: with and without microbial introduction. The bioreactor’s efficiency in removing two common textile dyes, RB19 and DR227, was evaluated under various conditions: fixed bed high, the effect of the initial concentration of the pollutant, and recycling the RB19 solution within the bioreactor. Optimization studies revealed an 83% removal yield of RB19 dye with an initial pollutant concentration of 100 mg·L−1 using activated sludge as inoculum. The bioreactor developed its own bacterial consortium without initial inoculation. Microscopic analysis confirmed the presence of a diverse microbial community, including protozoa (Aspidisca and Paramecium), nematodes, and diatoms. The bioreactor exhibited efficient removal of RB19 across a range of initial concentrations (20–100 mg/L) with similar removal efficiencies (around 65%). Interestingly, the removal efficiency for DR227 was concentration-dependent. The bioreactor demonstrated the ability to enhance the biodegradability of treated RB19 solutions. Phytotoxicity tests using watercress and lettuce seeds revealed no negative impacts on plant growth. SEM and FTIR analyses were conducted to examine the biosupport material before and after biotreatment.

Evolution of microbial community structure during biohydrogen production process of palm oil anaerobic sludge

Anaerobic microbial communities and their functions can provide information about waste management practices, as well as reveal novel degradation metabolisms that can be utilized in wastewater treatment. This study was aimed towards sustainable palm oil industry with assessing the microbial evolution during the dark fermentative processing of palm oil anaerobic sludge and palm oil mill effluent (POME) in batch-mode over two-months with a distinct incubation time of 24 h. The process was designed using response surface methodology (RSM) by acclimatization of inoculum using POME with a chemical oxygen demand (COD) of 36 g-COD/l. The effect of mesophilic and thermophilic conditions and pH on COD removal, hydrogen content, and hydrogen yield (HY) were investigated. A potential sample was selected for microbial analysis after the first and second months of operation based on the maximum outputs achieved throughout the experiment. The bacterial community at pH 5.6 and temperature 55 ˚C with maximum hydrogen content of 64.13 %, and HY of 0.93 ml H2/g-COD was dominated by three phyla: Firmicutes, Actinobacteria, and Bacteroidota. The results obtained from high throughput pyrosequencing showed that how acclimatization period affects the microbial community structure towards Firmicutes phylum, which includes the majority of hydrogen-producing microorganisms.

Cellulose / waste Cu2+-activated carbon composite: A sustainable and green material for boosting laccase activity and degradation of bisphenol A in wastewater

Low enzyme activity is one of the disadvantages of immobilized laccase. In this study, waste Cu2+-loaded activated carbon (Cu-AC) was successfully used in preparing a novel composite support，cellulose / Cu2+-loaded activated carbon beads (C / Cu-AC)， and effectively boosted immobilized laccase activity. To achieve optimum conditions for immobilization of laccase, the immobilization time, pH and laccase concentration were examined. The highest immobilized laccase activity (34.21 U/g) was achieved under optimum conditions (T = 4 h, pH = 4, C = 5 g/L), which was increased by 35.86 % compared to control. In addition, the immobilized laccase showed an outstanding performance in thermostability and reusability compared to free laccase. Moreover, the degradation of BPA by immobilized laccase was carried out, and the optimum degradation conditions were explored. Under such conditions: concentration of BPA was 75 mg / L and pH = 4, t = 1 h, T = 50 °C，the removal yield of BPA reached a maximum of 79.88 %. Therefore, the utilization of waste Cu-CA is a powerful method to boost immobilized laccase activity and creating a new way to high value treatment of waste Cu-CA.

Photocatalytic Luminous Textiles for the Treatment of Wastewater Issued from Petroleum Activity: Photocatalytic Process Extrapolation

In this study, the degradation of naphthalene in water was performed via photocatalysis with two different configurations: UV-irradiated TiO2 deposited on cellulosic tissue and photocatalytic luminous textiles. The photocatalytic performance of these configurations was evaluated in terms of pollutant removal and mineralization yield. Moreover, the influence of key operating parameters, such as the initial pollutant concentration, solution turbidity, the number of tissues, and the type of irradiation, was investigated. The results showed a complete removal of 8 mg/L of naphthalene with photocatalytic luminous textiles after 4 h of UV irradiation, with a mineralization yield of 80%. The impact of the turbidity shows that at 90 NTU, reductions in photocatalytic activity of 30% and 10% were recorded for the UV-irradiated TiO2 deposed on cellulosic tissue and photocatalytic luminous textiles, respectively. The reactive oxygen species (ROS) concentrations were monitored during photocatalysis to better understand the contribution of each active species in the mechanism reaction of naphthalene oxidation. The results show that the hydroxyl radical (•OH) is responsible for 70% of pollutant oxidation. A scaling up of the water treatment with photocatalytic luminous textiles was performed. The extrapolation confirmed the same trends observed at the laboratory scale in terms of degradation and mineralization.

In silico and experimental characterization of a new polyextremophilic subtilisin-like protease from Microbacterium metallidurans and its application as a laundry detergent additive.

Considering the current growing interest in new and improved enzymes for use in a variety of applications, the present study aimed to characterize a novel detergent-stable serine alkaline protease from the extremophilic actinobacterium Microbacterium metallidurans TL13 (MmSP) using a combined in silico and experimental approach. The MmSP showed a close phylogenetic relationship with high molecular weight S8 peptidases of Microbacterium species. Moreover, its physical and chemical parameters computed using Expasy's ProtParam tool revealed that MmSP is hydrophilic, halophilic and thermo-alkali stable. 3D structure modelling and functional prediction of TL13 serine protease resulted in the detection of five characteristic domains: [catalytic subtilase domain, fibronectin (Fn) type-III domain, peptidase inhibitor I9, protease-associated (PA) domain and bacterial Ig-like domain (group 3)], as well as the three amino acid residues [aspartate (D182), histidine (H272) and serine (S604)] in the catalytic subtilase domain. The extremophilic strain TL13 was tested for protease production using agricultural wastes/by-products as carbon substrates. Maximum enzyme activity (390U/gds) was obtained at 8th day fermentation on potato peel medium. Extracellular extract was concentrated and partially purified using ammonium sulfate precipitation methodology (1.58 folds purification fold). The optimal pH, temperature and salinity of MmSP were 9, 60°C and 1M NaCl, respectively. The MmSP protease showed broad pH stability, thermal stability, salt tolerance and detergent compatibility. In order to achieve the maximum stain removal efficacy by the TL 13 serine protease, the operation conditions were optimized using a Box-Behnken Design (BBD) with four variables, namely, time (15-75min), temperature (30-60°C), MmSP enzyme concentration (5-10U/mL) and pH (7-11). The maximum stain removal yield (95 ± 4%) obtained under the optimal enzymatic operation conditions (treatment with 7.5U/mL of MmSP during 30min at 32°C and pH9) was in good agreement with the value predicted by the regression model (98 ± %), which prove the validity of the fitted model. In conclusion, MmSP appears to be a good candidate for industrial applications, particularly in laundry detergent formulations, due to its high hydrophilicity, alkali-halo-stability, detergent compatibility and stain removal efficiency.

Continuous Electrocoagulation for a Sustainable Water Treatment: Effects of Electrode Configuration, Electrical Connection Mode, and Polarity Reversal on Fluoride Removal

Water pollution in southern Tunisia, particularly in the mining basin of Gafsa, is primarily due to elevated levels of fluoride ions. This study focuses on removing fluoride from Metlaoui’s tap water through a continuous electrocoagulation (EC) treatment. With a fluoride concentration of 3.5 mg·L−1, this water exhibits the highest fluoride levels in Gafsa’s mining basin. The study investigates the impact of electrode configuration on fluoride removal from tap water through continuous electrocoagulation treatment. Configuring the electrodes perpendicular to the water flow improves the aluminum dissolution by electrocoagulation and the fluoride removal efficiency. Additionally, the study explores the effect of electrical connection modes on electrode performance, showing consistent fluoride removal yield under identical current densities and electrochemical cell numbers. Furthermore, the study examines cathodic deposit removal through polarity reversal, demonstrating its effectiveness in eliminating deposits and achieving high fluoride removal yields, especially with polarity reversal every minute. This method proves to be an efficient approach for a more sustainable fluorinated water treatment, eliminating cathodic deposits without the need for chemical or mechanical interventions, and without producing additional effluents or waste. The optimization of these parameters not only enhances fluoride removal efficiency, but also reduces energy consumption and operational costs, thereby promoting the sustainable management of energy and water resources.

Advanced leachate treatment at Mascara landfill (Algeria): A hybrid pilot approach with activated sludge and ferric chloride

This study investigates a hybrid treatment approach, that combines a Sequencing Batch Reactor (SBR) with a coagulation-flocculation process, to reduce the contaminants in Landfill Leachate (LL), targeting Chemical Oxygen Demand (COD), Turbidity, and Total Suspended Solids (TSS). The experimental set-up incorporated a batch reactor at room temperature and a pH between 7.7 and 8.7, with an Arduino monitoring system for heightened precision. The SBR was operated continuously over a 24-hour cycle, with a Hydraulic Retention Time (HRT) set at 5 days and variable sludge retention times (SRT) of 5, 10, and 15 days. The Aluminum sulfate (Al2 (SO4)3), Ferric Chloride (FeCl3), and Lime (CaO) were assessed for the coagulation-flocculation process. The results indicate a promising removal efficiency of 40 % for COD, 31 % for turbidity, and 47 % for TSS using the SBR process. FeCl3 showed higher findings, achieving removal yields of 87 % for COD and 86 % for turbidity, at an optimized dose of 10 g/L and pH 5.5. Furthermore, adding 0.25 g/L of CaO significantly improved the removal efficiency to 94.14 % for COD, 98.22 % for turbidity and 99.78 % of the TSS. Therefore, this study's results underline the effectiveness of combining SBR with coagulation-flocculation, particularly using FeCl3 and CaO, in treating landfill leachate.

Nutrients removal in overloaded WWTP by intermittently aerated IFAS: Effects of biofilm carrier and intermittent aeration cycle

Updating of the current Urban Waste Water Treatment Directive (91/271/EEC) will demand stricter regulations for nutrients removal. In this frame, wastewater treatment plants (WWTPs) of small-to-medium potential will face new challenges for achieving process intensification. Integrating intermittent aeration (IA) and integrated fixed-film activated sludge (IFAS) technologies could be a promising solution to meet such requirements. This study analyzed how IA cycles affected nutrients removal in IFAS reactors with different biofilm carriers (e.g., plastic and sponge media). The plants responses to different carbon/nitrogen/phosphorous (C/N/P) ratios were evaluated while operating under low sludge retention time (SRT) to simulate overloaded conditions.A short IA cycle (1 h) with an aeration/not aeration ratio of 2:1 enabled high organic carbon and nitrification performances when operating at high C/N/P (11.8/1/1), whereas low denitrification and phosphorous removal yields were obtained because of the short not-aerated phase. Decreasing C/N ratio (8.8/1/1) without changing the IA cycle resulted in nitrification worsening because of the reduced metabolic kinetics of biofilm. Under such load conditions, a higher IA cycle (2 h) was necessary to improve process performance. A longer not-aerated phase was also positive for denitrification and phosphorous removal because of the establishment of anoxic and anaerobic environments within the bulk and inner biofilm layers. Besides, results suggested that sponge carriers offered advantages over plastic ones, enabling a higher biofilm retention capacity, better nutrient removal, as well as robustness and resilience to operating condition changes. This would result in simpler management systems for implementing the IA process, thus reducing process complexity and costs.

Exploratory studies on the use of peanut shell biochar as a promising adsorbent for ivermectin removal from aqueous solutions: impact of biomass treatment, pyrolisis temperature and duration

The contamination of environmental matrices by chemical compounds poses a significant challenge for humanity, demanding focused attention from researchers and governments. Within aquatic environments, the emerging contaminants with potential ecotoxicological effects, even at low concentrations, have earned global interest among researchers. The persistence of these contaminants is exacerbated by specific physicochemical characteristics, hindering their natural degradation and removal through conventional water treatment methods. Biochar, a carbonaceous material produced through biomass pyrolysis at high temperatures, exhibits properties that effectively remove emerging contaminants from water. In this study, we investigated the impact of acidic biomass treatment on the removal efficiency of ivermectin from aqueous solutions. The materials were derived from untreated biomass, as well as basic and acidic-treated peanut shell (PS), subjected to pyrolysis at temperatures of 300, 400, 500, and 600 °C for 2, 3, and 4 hours. Characterization was conducted using TGA, ATR-FT-IR, SEM-EDS, and XRD. Quantification of ivermectin removal was performed using HPLC-DAD. The results showed that the removal was enhanced by temperature and time of pyrolysis, while the chemical treatments had different effects. The most effective removal tendency was observed with acidic biochar calcinated at 600 °C, demonstrating an average removal yield of 84.70%.

Photoremoval of Ibuprophenin and Oxytetracycline and some microorganisms from a pharmaceutical wastewater via Ag-Fe3O4 nanocomposites

In İzmir Turkey, a pharmaceutical industry wastewater produces drugs and antibiotics. The removals of these parameters were not sufficient with the conventional activated sludge process. In order to remove these organics some photocatalysts like Fe3O4 and FeO were solely used with enhanced magnetic properties. However low photodegradation yields (75% - 77%) were detected for the Ibuprophenin drug and Oxytetracycline antibiotic. Although Ag effectively destroys the pharmaceutical chemicals and the pathogenic microorganisms the low photogenerated carrier-separation efficiency limits its application in water treatment. Therefore, it is practically significant to develop a magnetic material to a couple of Ag with Fe3O4 through heterojunctions to separate the nanocomposite magnetically from wastewaters. In order to improve the photocatalytic degradation of Fe3O4, Ag was loaded onto a magnetic nanoparticle to develop Ag-Fe3O4 nanocomposite under laboratory conditions. On the other hand, the toilet wastewater was mixed with the process wastewater due to the dilution purpose of pollutants in the pharmaceutical wastewater. Due to the high working personnel capacity of the industry (10,000 people) the concentrations of Salmonella, Pseudomonas, yeast, fungi, total coliforms, fecal coliforms, and heterotrophic bacteria were found to be high in the raw pharmaceutical industry wastewaters. Therefore, in this study to maximize the removal yields of these pollutants and organisms with Ag-Fe3O4 photodegradation the operational conditions were optimized. The effect of increasing Ag-Fe3O4 nanocomposite concentrations (0.05 - 6.0 mg/l), pollutant concentrations (10 - 500 mg/l), contacting times (5 - 90 mins), pH levels (4.00 - 10.00), power (10 - 100 W/m2), on the photodegradation yields of organisms (Salmonella, Pseudomonas, yeast, fungi, total coliforms, fecal coliforms, heterotrophic bacteria) and ibuprophene, oxytetracycline removal yields were studied. The particle shapes and properties were investigated with field emission scanning electron microscope (FESEM) and fourier transform infrared spectrophotometer (FTIR), X-ray diffraction (XRD). The XRD pattern of Ag-Fe3O4 nanocomposites showed the same diffraction peaks at 26.9°, 33.0°, 38.3°, 55.1°, 65.7°, and 68.7° for Ag and at 28.26°, 34.53°, 44.01°, and 61.88° for Fe3O4, indicating a good coupling of Ag and Fe3O4 with no change in their crystal structure. The maximum organism and pollutant yields were detected at 1 mg/l Ag-Fe3O4 nanocomposite concentration, after 45 mins at a pH 7.00 and 5.00 for Ibuprophenin drug and Oxytetracycline antibiotic, respectively. 99% treatment yields were recorded for ibuprophene, oxytetracycline, and organisms during photocatalysis. The recovery studies with Ag-Fe3O4 NPs showed that all organisms and both pollutants can be used 120 times with the same yields. The photodegradation kinetics was found to be pseudo-first-order and the rate constants (k) for oxytetracycline and ibuprophene were calculated as 5 × 10−2 min−1, and 5.02 × 10−2 min−1, respectively. From 1.5 mg/l Ag- Fe3O4 nanocomposite 0,95 mg/l Fe3+ and 0,39 mg/l Ag +1 was leached during ibuprophene photodegradation. For oxytetracycline from 1.5 mg/l Ag- Fe3O4 nanocomposite 0,89 mg/l Fe3+ and 0,34 mg/l Ag +1 was leached.

Parabolic trough concentrator design, characterization, and application: solar wastewater purification targeting textile industry dyes and pharmaceuticals—techno-economic study

AbstractSolar energy, along with other renewable resources, has the potential to be a major contributor to solving environmental issues in the future, as illustrated by the most recent advancements in solar photocatalytic technology. Indeed, wastewater treatment using a parabolic solar collector for industrial processes is gaining ground owing to improved system performance and economic benefits. The fabricated parabolic trough collector (PTC) incorporates reflective, parabolic panels that focus solar energy onto a transparent tube positioned along the parabolic focal line, where solar-powered photochemical reactions occur. This study investigated the design, implementation, and effectiveness of a concentrated sunlight system for removing industrial dyes and emerging large-use pharmaceutical contaminants in the presence of H2O2 at a small demonstrator scale (10 L/h). A spectrophotometric assessment revealed that subjecting Remazol Brilliant Blue (RBB, 60 ppm) and ciprofloxacin (CIP, 10 ppm) to irradiation in the presence of 0.1 M H2O2 (RBB) or 0.01 M H2O2 (CIP) for 3 h resulted in a degradation rate exceeding 60% and 80%, respectively. Furthermore, the total organic content (TOC) analysis indicates a very high total removal yield for RBB. On these bases, a techno-economic analysis is produced, and economic viability is discussed. The data reveal that the annual costs for water treatment, considering investment, electricity, and catalyst expenses over a 12-month period are significantly lower for our PTC-based prototype than for a comparable artificial UV-based equipment.

Model-based process intensification of deep eutectic solvent treatment of eucalyptus slabs for lignin extraction and pulp production

This work revealed the reaction characteristics in the delignification process of eucalyptus slabs catalyzed by acidic deep eutectic solvent (benzyltriethylammonium chloride/formic acid) from the perspective of heterogeneous reactions. The limitation of internal diffusion on delignification process cannot be ignored. Afterwards, a kinetic model based on cell wall structure was proposed to describe the relationship between the delignification degree and reaction conditions, and it also hold excellent predictive ability for lignin removal, carbohydrate retention and solid residue yield. Compared with other reported kinetic models, this novel model not only took into account all operational parameters of reaction process, but also can be applied to the entire reaction process without the need for segmentation. Besides, an essential requirement based on the developed model was a 44.40 wt% formic acid concentration and a temperature of 130 °C, when the purpose of DES treatment was pulping. Generally, this work could provide guidance on process adjustments and product quality control during the DES processing.

Adsorption of Heavy Metal Ions on Alginate-Based Magnetic Nanocomposite Adsorbent Beads.

Graphene oxide and its magnetic nanoparticle-based composites are a well-known tool to remove heavy metals from wastewater. Unfortunately, one of the major issues in handling such small particles consists of their difficult removal from treated wastewater (even when their magnetic properties are exploited), due to their very small diameter. One possible way to overcome this problem is to embed them in a macroscopic biopolymer matrix, such as alginate or chitosan beads. In this way, the adsorbent becomes easier to handle and can be used to build, for example, a packed column, as in a traditional industrial adsorber. In this work, the removal performances of two different embedded magnetic nanocomposite adsorbents (MNAs) are discussed. The first type of MNA is based on ferrite magnetic nanoparticles (MNPs) generated by coprecipitation using iron(II/III) salts and ammonium hydroxide, while the second is based on a 2D material composed of MNP-decorated graphene oxide. Both MNAs were embedded in cross-linked alginate beads and used to treat artificial water contaminated with chromium(III), nickel(II), and copper(II) in different concentrations. The yield of removal and differences between MNAs and non-embedded magnetic nanomaterials are also discussed. From the results, it was found that the time to reach the adsorption equilibrium is higher when compared to that of the nanomaterials only, due to the lower surface/volume ratio of the beads, but the adsorption capacity is higher, due to the additional interaction with alginate.

Synthesis and photocatalytic properties of zinc-copper bimetallic oxide nanoparticles for removal of reactive blue 19 dye in aqueous suspension

ABSTRACT This research investigates the photocatalytic removal of reactive blue 19 (RB19) dye utilising Zn-Cu (zinc-copper) bimetallic oxide nanocatalysts under UV irradiation. The nanocatalysts were prepared via the co-precipitation technique and thoroughly characterised using different procedures including XRD, FTIR, BET-BJH, FESEM, TEM, and EDX. BET-BJH analysis revealed a specific surface area of 59.774 m2/g for the Zn-Cu bimetallic oxide nanocatalyst. Response surface methodology (RSM) was employed to optimise operational factors such as catalyst amount, pH, H2O2 amount, and UV power, with a quadratic model showing high reliability (R2 = 0.89). Under optimal conditions (4 mg catalyst amount, pH 6.68, 0.42 mL H2O2 dose, 23 W UV power, and 45 min reaction time), the maximum RB19 removal reached 77.14%, increasing to 98.33% after 120 min. The kinetic study revealed a reaction rate constant of 0.884 min−1, indicating efficient removal. Zn-Cu bimetallic oxides demonstrated superior RB19 removal capacity, with only a 5.92% reduction in removal yield after 5 consecutive reuse cycles. This study underscores the potential of Zn-Cu bimetallic oxide nanocatalysts for efficient removal of RB19 dye in suspension media.

Ammonia oxidation by in-situ chloride electrolysis in etching wastewater of semiconductor manufacturing using RuSnOx/Ti electrode: Effect of plating mode and metal ratio

The indirect chloride-mediated ammonia oxidation encounters challenges in maintaining the effectiveness of metal oxide anodes when treating wastewaters with complex compositions. This study aims to develop a highly stable anode with RuO2-SnO2 coatings for treating an etching effluent from semiconductor manufacturing, which majorly contains NH3 and organic compounds. The RuSnOx/Ti electrode was synthesized using wet impregnation and calcination processes. The metal oxide configuration on Ti plate substrate was tuned by varying the step-dipping process in RuCl3 and SnCl4 baths. A 10-day continuous-flow electrolysis was conducted for studying the ammonia removal and chlorine yield under variable conditions, including detention, pH, current density, and initial ammonia and chloride concentrations. In the RuSnOx coatings, the configuration comprising RuO2 nanorods as the surface layer and an intermediate layer of SnO2 crystallites (by plating Ru3+ for three times to cover one Sn4+ layer, denoted as the Ru3Sn/Ti electrode) exhibited the best durability for acid washing, along with relatively high Faradaic efficiency and low energy consumption. To further improve the treatability of real wastewater (NH3-N = 634 mg L−1, chemical oxygen demand (COD) = 6700 mg L−1, Cl- = 2000 mg L−1, pH 11), the duel-cell electrolyzers were constructed in series under a current density of 30 mA cm−2 and 45 min detention. Ultimately, removals of NH3 and COD reached 95.8% and 76.3%, respectively, with successful limitation of chloramine formation.

Zeolite 13X incorporated with Zn-Ce oxide nanocatalyst for removal of Reactive Red 120 dye: RSM-based approach.

In this study, the photocatalytic removal of Reactive Red 120 (RR120) dye was examined using zeolite 13X incorporated with Zn-Ce under UV irradiation. The synthesis of Zn-Ce nanoparticles incorporated with zeolite 13X was conducted through the co-precipitation method, and the features of the prepared nanocatalyst were analyzed using various techniques. The SEM and BET analyses indicated successful incorporation of ZnO-Ce oxides on the surface of zeolite 13X and a specific surface area of 359.39 m2/gm, respectively. Further, the average size of crystal grains was 28 nm. The response surface methodology (RSM) approach was employed to optimize operating parameters. The quadratic model suggested by the RSM approach, characterized by a high regression coefficient (R2 = 0.9632), indicates a high level of reliability. Moreover, under optimal conditions (catalyst loading of 4 mg, pH of 3, H2O2 amount of 0.2 mL, UV power of 25 W, and reaction time of 60 min), the highest RR120 dye removal percentage was 99.97%. Kinetic data indicated an increase in the reaction rate constant from 0.0631 to 0.1796 min-1. The zeolite 13X incorporated with Zn-Ce photocatalyst exhibited excellent stability over 5 cycles, with only a 5.50% decrease in RR120 dye removal yield. This study demonstrates the promising potential of zeolite 13X incorporated with Zn-Ce nanoparticles for the removal of RR120 dye from aqueous suspension.

Cascade fractionation of bamboo shoot shells into high-yield xylose, easily digestible cellulose and high-quality lignin nanoparticles by tailored catalytic hydrothermal–hydrated alkaline deep eutectic solvents pretreatment

The high complexity and compactness of inherent structure in lignocellulosic materials (LCM) leads to the difficulty of fractionation and conversion of its major component, which is the key obstacle limiting the value-added utilization of LCM. In this work, a cascade fractionation strategy, coupling catalytic hydrothermal pretreatment (CHTP, choline chloride: ethylene glycol: AlCl3, ChCl/ EG/ AlCl3) with hydrated alkaline deep eutectic solvent (HADES, triethylbenzyl ammonium chloride/ethanolamine, TEBAC/EM) treatment, was proposed to fractionate dendrocalamus latiftorus munro shoot shells (DLMSS). The results showed that considerably high hemicelluloses removal (94.57 %) and xylose yield (90.73 %) were achieved by the first step (CHTP, 160 °C, 1 h, 2 % of catalyst loading). The cascaded HADES treatment realized 90.25 % delignification ratio under the optimal conditions (120 °C, 3 h, 75 % of ADES loading), and the obtained residue could be easily converted into high-yield (93.35 %) of glucose via enzymatic saccharification. In addition, multiple enrichment cycle strategy (MECS) was performed to facilitate the recyclability of the HADES. The results showed that the enriched lignin recovered by MECS was activated by in-situ demethoxylation reaction. And such lignin fraction could be easily assembled into homogeneous lignin nanoparticles (LNPs, ∼31.51 nm in diameter) by simple sonication. Meanwhile, the MECS signally energized the antioxidant activity of the enriched lignin. Based on the high-efficiency cascade fractionation with the coupled CHTP-HADES fractionation strategy, it will observably boost the effectiveness and scalability of the advanced biorefinery strategy.

A sustainable activated carbon fiber/TiO2 cathode for the photoelectro-Fenton treatment of pharmaceutical pollutant enalapril

In this work, a TiO2-decorated electrode was fabricated by dip coating activated carbon fibers (ACF) with TiO2, which were then used as a cathode for the photoelectro-Fenton (PEF) treatment of the pharmaceutical enalapril, an angiotensin-converting enzyme inhibitor that has been detected in several waterways. The TiO2 coating was found to principally improve the electrocatalytic properties of ACF for H2O2 production via the 2-e- O2 reduction, in turn increasing enalapril degradation by PEF. The effect of the current density on the mineralization of enalapril was evaluated and the highest TOC removal yield (80.5% in 3 h) was obtained at 8.33 mA cm−2, in the presence of 0.5 mmol L−1 of Fe2+ catalyst. Under those conditions, enalapril was totally removed within the first 10 min of treatment with a rate constant k = 0.472 min−1. In contrast, uncoated ACF only achieved 60% of TOC removal in 3 h at 8.33 mA cm−2. A degradation pathway for enalapril mineralization is proposed, based on the degradation by-products identified during treatment. Overall, the results demonstrate the promises of TiO2 cathodes for PEF, a strategy that has often been overlooked in favor of photoelectrocatalysis (PEC) based on TiO2-modified photoanodes.