Degradation Efficiency Research Articles

Efficient degradation of tetracycline in wastewater by novel biochar-based photocatalytic materials: performance, photocatalytic mechanism and degradation pathways

Efficient degradation of tetracycline in wastewater by novel biochar-based photocatalytic materials: performance, photocatalytic mechanism and degradation pathways

Pyroelectrically Driven Charge Transfer and its Advantages on SERS and Self‐Cleaning Property

AbstractThe fabrication of reusable SERS substrates with sensitivity at the single‐molecule level remains challenging but promising. Herein, a composite surface‐enhanced Raman scattering (SERS) substrate is proposed that includes Ag nanoparticle (Ag NPs) /Graphene/BaTiO3 (Ag/G/BTO) from a chemical enhancement perspective. The pyroelectric field generated by BaTiO3 drives the charge transfer between the SERS substrate and molecules, achieving a significant improvement in the SERS performance and self‐cleaning properties. The SERS signals of rhodamine 6G (R6G) molecules are further amplified up to 70‐fold. Thus, the detection limit is reduced by three orders of magnitude in this study, reaching 10−14 m after applying a pyroelectric field. In addition, the substrate exhibits a higher degradation efficiency than previous self‐cleaning SERS substrates because of the outstanding catalytic properties of BaTiO3. Target molecules are degraded effectively after several temperature cycles. A detailed mechanism analysis of pyroelectric SERS is conducted based on theoretical simulations and experimental results. This study is considered to deepen the understanding of SERS mechanisms and boost the application of SERS technology.

Exploring the Mechanism for the Photocatalytic Degradation of Oxytetracycline in Water using TiO2 and Supplementary Oxidants

The persistent presence of antibiotics in wastewater, exemplified by oxytetracycline (OTC), poses environmental risks, necessitating robust removal strategies. This study investigates the effectiveness of photocatalysis utilizing TiO2 (P25) treated at various temperatures, combined with different oxidants such as hydrogen peroxide (H2O2), potassium peroxydisulfate (PDS), potassium peroxomonosulfate (PMS) under diverse experimental conditions. The research systematically explores the impact of temperature, pH, and oxidant concentration on the efficiency of OTC degradation. Our findings reveal that the combination of P25/500, PDS, UV irradiation, and stirring demonstrates superior OTC degradation, surpassing 99% efficiency after 180 min. Optimal pH conditions are identified, emphasizing the importance of balancing acidity for enhanced performance. The study also provides insights into the optimal PDS concentration, indicating a threshold beyond which further increases yield diminishing returns. Mechanistic understanding is enhanced through scavenger experiments, elucidating the pivotal role of reactive oxygen species, particularly O2•−, in the photocatalytic process. This research offers a practical framework for TiO2-based photocatalysis in wastewater treatment, emphasizing tailored conditions for efficient antibiotic removal. The outcomes contribute valuable insights to the development of sustainable wastewater treatment protocols targeting antibiotic pollutants.

Screening, Isolation and Hydrocarbon Degradation Characteristics of Yeasts from Mangrove Sediments of Kerala

The aim of the present work was to examine the hydrocarbon degradation potential of yeasts isolated from the mangrove sediments. Mangrove sediments around the world were considered to be heavily polluted with oil contaminants and the microbes dwelling in them were believed to be highly active in metabolizing and detoxifying the oil fractions. In the present study, 70 yeast isolates were screened for their lipolytic activity qualitatively and 35 of them which showed comparatively higher lipolysis were tested for their crude oil degradation ability. Screening of hydro-carbon utilizing isolates was performed on Bushnell Haas agar media overlaid with 1% crude oil and the appearance of colonies were considered a positive. Three isolates were selected based on this and were sequenced using ITS gene of the 18S region of the rDNA and identified to be Candida tropicalis. The extent of crude oil degradation was assessed by growing the isolates in basal medium supplemented with heavy crude oil as the carbon source for 21 days. The residual crude oil fractions were then analyzed using GC-MS to quantitatively measure the degradation potential of each isolate. Our results showed that the yeast strains under study could actively metabolize the crude oil including the higher chain fractions which make them efficient hydrocarbon degraders that can be used in the bioremediation processes.

Further exploitation of metabolic potential for catechol biodegradation of Klebsiella sp. CD33.

Microbial-mediated degradation of phenolic pollutants (e.g., catechol) has been a critical concern for sewage treatment, while exploiting the strain resources and fully characterizing the metabolic potential of functional microbes for toxic refractory catechol are the key and study-worthy issues. In this study, up to 32 strains originally isolated from phenol-contaminated environments were phylogenetically affiliated with the genus Klebsiella and identified to have the ability of catechol degradation, with strain CD33 as the excellent one. Single-factor experiments determined that strain CD33 exhibited a highly efficient catechol degradation under the conditions of temperature 35°C, initial pH value of 7.0, and inoculum volume of 30.0% (v/v). To preliminarily validate the possible pathway of catechol biodegradation, concentration variation of the initial enzyme (i.e., catechol 1,2 dioxygenase) and the corresponding metabolic intermediate (i.e., cis,cis-muconic acid) were detected, suggesting that strain CD33 can degrade the catechol uniquely via the ortho-cleavage pathway. Furthermore, a combination of genome-wide identification, homologous modeling, and gene expression analysis was employed to elucidate the complete pathway of catechol degradation, especially in which a novel branch mediated by CMBL gene was responsible for the direct conversion of (+)-muconolactone into 3-oxoadipic acid. Collectively, this study extends our understanding of catechol degradation of Klebsiella spp., which may provide an alternative promising avenue for the practical application of pollutant remediation.

Biodegradable cobalt and tin doped chitosan nanocomposites from structure tailoring to solar-driven photocatalytic degradation of toxic organic dyes.

The primary concern is the large amounts of emitted organic dyes through wastewater from numerous sectors. One of the most hazardous dyes commonly used in the industrial sector is methyl violet. It has been known to cause skin, gastric, and respiratory disorders. Therefore, a novel photocatalyst based on cobalt‑tin sulfide (Co3Sn2S2) was prepared using the solvothermal process. The photocatalyst was supplemented with Chitosan to prepare the cobalt tin sulfide-chitosan composite (Co3Sn2S2/Chi) for the photocatalytic degradation of methyl violet dye. Based on EDX analysis, a definite ratio of tin, cobalt, and sulfide was found. The FTIR of Co3Sn2S2/Chi revealed the characteristic bands of chitosan and metal sulfide bonds. SEM results showed that the particle had an irregular shape. The composite's crystalline structure was identified by XRD analysis as being 56 nm in crystalline size. The photocatalyst had a narrow band gap of 1.02 eV. At ideal conditions, the developed photocatalyst demonstrated greater degradation efficiency of methyl violet dye under solar light irradiation. The photocatalyst successfully decomposed 95 % of the methyl violet dye (40 ppm) within 70 min, operating at a pH of 9.0. This remarkable degradation was achieved by employing 0.25 g of the photocatalyst. The photocatalyst is more appealing and can be reused for up to three successive cycles. The photocatalyst is well-suited for "pseudo-first-order kinetics" to decontaminate methyl violet dye. The novel photocatalyst showed the most robust ability to decolorize methyl violet when exposed to sunlight and was a viable substitute for dye detoxification of organic dyes from wastewater.

Enhanced activity of mixed-culture electroactive biofilms and sulfamethoxazole removal efficiency by adding N-acyl-homoserine lactones in bio-electrochemical system

ABSTRACT The addition of exogenous quorum sensing signaling molecules significantly enhanced the degradation efficiency of antibiotics, such as chloramphenicol in bio-electrochemical systems (BESs). However, the effects and mechanisms by which AHLs addition in BES facilitated the removal of sulfamethoxazole (SMX) remained inadequately explored. This study systematically compared the electrochemical performance and SMX removal efficiency in BES under two conditions: with and without the addition of N-acyl-homoserine lactones (AHLs) signaling molecules. In comparison to the control group, the AHL-treated group exhibited an increase in maximum output voltage from 340 to 489.67 mV, alongside a notable enhancement in SMX removal efficiency over 120 h ranging from 14.65% to 15.76%. Analyses of the live and dead cells and extracellular polymeric substances (EPS) composition revealed that following AHLs addition, both the ratio of live to dead cells and protein content within EPS increased by 12.66% and 74.37%, respectively. Furthermore, microbial community structure analysis indicated that after AHLs supplementation, there was a marked increase in the abundance of electroactive microorganisms as well as antibiotic-degrading and nitrogen-removing bacteria. Notably, Klebsiella – characterised by its electroactivity along with antibiotic degradation and nitrogen removal capabilities – exhibited a relative abundance reaching 56.84% in AHL, reflecting an increase of 28.31% compared to Blank; additionally, electroactive bacteria Dysgonomonas showed a relative abundance rise of 2.49%. Collectively, these findings suggested that enhancements in SMX removal efficiency upon AHLs addition were primarily driven by improvements in electrochemical performance coupled with alterations in microbial community structure.

Aeration‐Free Photo‐Fenton‐Like Reaction Mediated by Heterojunction Photocatalyst toward Efficient Degradation of Organic Pollutants

The regulation of peroxymonosulfate (PMS) activation by photo‐assisted heterogeneous catalysis is under in‐depth investigation with potential as a replaceable advanced oxidation process in water purification, yet it remains a significant challenge. Herein, we demonstrate a strategy to construct polyethylene glycol (PEG) well‐coupled dual‐defect VO‐M‐Co3O4@CNx S‐scheme heterojunction to degrade organic pollutants without aeration, which dramatically provides abundant active sites, excellent photo‐thermal property, and distinct charge transport pathway for PMS activation. The degradation rate of VO‐M‐Co3O4@CNx in anaerobic conditions shows a higher efficient rate (4.58 min‐1 g‐2) than in aerobic conditions (1.67 min‐1 g‐2). Experimental evidence reveals that VO‐M‐Co3O4@CNx promotes more rapid redox conversion of photoexcited electrons induced by defects with PMS under anaerobic conditions compared to aerobic conditions. Additionally, in situ experiments and DFT provide mechanistic insights into the regulation pathway of PMS activation via synergistic defect‐induced electron, revealing the competitive effect between O2 and PMS over VO‐M‐Co3O4@CNx during the reaction process. The continuous flow reactor and flow cytometry results demonstrated that the VO‐M‐Co3O4@CNx/PMS/Vis system has remarkably enhanced stability and purification capability for removing organic pollutants. This work provides valuable insights into regulating the heterologous catalysis oxidation process without aeration through the photoexcitation synergistic PMS activation.

Aeration-Free Photo-Fenton-Like Reaction Mediated by Heterojunction Photocatalyst toward Efficient Degradation of Organic Pollutants.

The regulation of peroxymonosulfate (PMS) activation by photo-assisted heterogeneous catalysis is under in-depth investigation with potential as a replaceable advanced oxidation process in water purification, yet it remains a significant challenge. Herein, we demonstrate a strategy to construct polyethylene glycol (PEG) well-coupled dual-defect VO-M-Co3O4@CNx S-scheme heterojunction to degrade organic pollutants without aeration, which dramatically provides abundant active sites, excellent photo-thermal property, and distinct charge transport pathway for PMS activation. The degradation rate of VO-M-Co3O4@CNx in anaerobic conditions shows a higher efficient rate (4.58 min-1 g-2) than in aerobic conditions (1.67 min-1 g-2). Experimental evidence reveals that VO-M-Co3O4@CNx promotes more rapid redox conversion of photoexcited electrons induced by defects with PMS under anaerobic conditions compared to aerobic conditions. Additionally, in situ experiments and DFT provide mechanistic insights into the regulation pathway of PMS activation via synergistic defect-induced electron, revealing the competitive effect between O2 and PMS over VO-M-Co3O4@CNx during the reaction process. The continuous flow reactor and flow cytometry results demonstrated that the VO-M-Co3O4@CNx/PMS/Vis system has remarkably enhanced stability and purification capability for removing organic pollutants. This work provides valuable insights into regulating the heterologous catalysis oxidation process without aeration through the photoexcitation synergistic PMS activation.

Activating Oxygen via the 3‐Electron Pathway to Hydroxyl Radical by La‐O4 Single‐atom on WO3 for Water Purification

Shifting photocatalytic oxygen activation towards 3‐electron (e‐) pathway to hydroxyl radicals, instead of the normal 1 e‐ to superoxide radicals, becomes increasingly important for pollution degradation since hydroxyl radicals possess a high oxidation potential (2.80 V). Here, we demonstrate a selective oxygen activation to hydroxyl radicals via 3 e‐ pathway using single atomically dispersed La based on WO3 fabricated with oxygen vacancies to weaken La‐O coordination strength (denoted as LaO4‐WOv). Unsaturated‐state La overcomes the rate‐limited step of 2 e‐ oxygen reduction reaction towards to hydrogen peroxide via tuning binding free energy of key reaction intermediate *OOH, stepped by easy generation of hydroxyl radicals via 1 e‐. This strategy alters the activation of oxygen process from 1 e‐ to 3 e‐. Hydrogen peroxide and hydroxyl radicals over LaO4‐WOv produces 3.8 and 3.3 mmol L‐1 h‐1, 35 and 8 times that of detected over WO3, respectively. Rapid and complete removal of tetracycline realizes over LaO4‐WOv with 0.077 min‐1 of rate constant, 38 times that of WO3. Degradation efficiencies keep greater than 98% following five repeats, revealing a practical‐utilization‐level robust stability. This work builds an unsaturated‐state transition metal site for manipulating oxygen activation towards an effective water purification as a representative application.

Synthesis and investigation of optical properties and enhancement photocatalytic activity of TiO2-SnO2 semiconductor for degradation of organic compounds.

Industrial wastewater treatment using UV irradiation in combination with oxidants or catalysts (TiO2) has attracted attention as a promising substitute for conventional methods. Studying the preparation and characterization of TiO2-SnO2 nanocomposites with different ratios, as well as their use in the enhanced photocatalytic degradation of acid red 37 dye in aqueous solution under UV irradiation as a model pollutant, are the goals of the research. The crystalline structures of the prepared nanomaterials were confirmed by XRD and the surface morphology of the samples was studied by TEM. The elemental compositions of the catalysts were confirmed by EDAX. The optical properties of the powder samples were analyzed with UV-Vis spectroscopy and their band gaps were estimated. The photocatalytic degradation was investigated using several advanced oxidation techniques using a batch photoreactor. The TiO2-SnO2 (90:10) nanocomposite showed the best degradation efficiency.

Activating Oxygen via the 3-Electron Pathway to Hydroxyl Radical by La-O4 Single-atom on WO3 for Water Purification.

Shifting photocatalytic oxygen activation towards 3-electron (e-) pathway to hydroxyl radicals, instead of the normal 1 e- to superoxide radicals, becomes increasingly important for pollution degradation since hydroxyl radicals possess a high oxidation potential (2.80 V). Here, we demonstrate a selective oxygen activation to hydroxyl radicals via 3 e- pathway using single atomically dispersed La based on WO3 fabricated with oxygen vacancies to weaken La-O coordination strength (denoted as LaO4-WOv). Unsaturated-state La overcomes the rate-limited step of 2 e- oxygen reduction reaction towards to hydrogen peroxide via tuning binding free energy of key reaction intermediate *OOH, stepped by easy generation of hydroxyl radicals via 1 e-. This strategy alters the activation of oxygen process from 1 e- to 3 e-. Hydrogen peroxide and hydroxyl radicals over LaO4-WOv produces 3.8 and 3.3 mmol L-1 h-1, 35 and 8 times that of detected over WO3, respectively. Rapid and complete removal of tetracycline realizes over LaO4-WOv with 0.077 min-1 of rate constant, 38 times that of WO3. Degradation efficiencies keep greater than 98% following five repeats, revealing a practical-utilization-level robust stability. This work builds an unsaturated-state transition metal site for manipulating oxygen activation towards an effective water purification as a representative application.

Exploring the In Vitro Effects of Cassava Diets and Enterococcus Strains on Rumen Fermentation, Gas Production, and Cyanide Concentrations

This study examined the effects of adding CUB alongside HCN sources from fresh cassava diets on HCN reduction, gas production, and in vitro digestibility. A completely randomized design (CRD) with a 2 × 2 × 3 + 1 factorial approach was used, where Factor A was the HCN source [fresh cassava root (FCR) or leaf (FCL)], Factor B was the HCN concentration (300 and 600 mg/kg dry matter (DM)), and Factor C was the bacterial supplement [no-CUB, E. faecium KKU-BF7 (CUB1), and E. gallinarum KKU-BC15 (CUB2)]. Statistical analysis was performed using the PROC GLM procedure in SAS. No interaction was observed among the main factors on gas kinetics and cumulative gas (p > 0.05). The addition of CUB1 or CUB2 enhanced cumulative gas production compared to the no-CUB group (p = 0.04). Cyanide degradation efficiency was high when FCR was included at a high HCN level. At 12 h post-incubation, HCN degradation efficiency was higher in the CUB2 and CUB1 groups, reaching 98.44–99.07% compared to the no-CUB group. The higher HCN level increased in vitro acid detergent fiber digestibility (IVADFD) (p = 0.01) by 7.20% compared to the low HCN level, and CUB2 further improved IVADFD. Compared to the FCL-fed group, FCR supplementation increased total VFA concentration (p = 0.03) and propionic acid (C3) concentration (p = 0.04). The addition of CUB2 further enhanced propionic acid concentration by 8.97% compared to no-CUB supplementation (p = 0.04). These results indicate that supplementing E. gallinarum KKU-BC15 at the highest HCN levels in FCR boosts HCN degradation efficiency, fiber digestibility, total VFA, and C3 concentration.

Adaptive memory reservation strategy for heavy workloads in the Spark environment

The rise of the Internet of Things (IoT) and Industry 2.0 has spurred a growing need for extensive data computing, and Spark emerged as a promising Big Data platform, attributed to its distributed in-memory computing capabilities. However, practical heavy workloads often lead to memory bottleneck issues in the Spark platform. This results in resilient distributed datasets (RDD) eviction and, in extreme cases, violent memory contentions, causing a significant degradation in Spark computational efficiency. To tackle this issue, we propose an adaptive memory reservation (AMR) strategy in this article, specifically designed for heavy workloads in the Spark environment. Specifically, we model optimal task parallelism by minimizing the disparity between the number of tasks completed without blocking and the number completed in regular rounds. Optimal memory for task parallelism is determined to establish an efficient execution memory space for computational parallelism. Subsequently, through adaptive execution memory reservation and dynamic adjustments, such as compression or expansion based on task progress, the strategy ensures dynamic task parallelism in the Spark parallel computing process. Considering the cost of RDD cache location and real-time memory space usage, we select suitable storage locations for different RDD types to alleviate execution memory pressure. Finally, we conduct extensive laboratory experiments to validate the effectiveness of AMR. Results indicate that, compared to existing memory management solutions, AMR reduces the execution time by approximately 46.8%.

Rapid Degradation of Dye Effluents with A SnS Catalyst: A Sustainable Approach Using Natural Light Under Ambient Conditions.

Dye degradation presents a persistent challenge in addressing water pollution. While several methods, including adsorption, biodegradation, and advanced oxidation processes, have been extensively explored, photocatalysis remains one of the most effective techniques. Conventional photocatalytic dye degradation processes often rely on expensive light sources and are time-intensive. Herein, we synthesized a SnS catalyst by the solvated metal atom dispersion (SMAD) method, using Sn foil and sulfur powder. The catalyst exhibited remarkable performance, achieving complete degradation of methylene blue within 2 minutes under ambient room light, without the need for any external light source. Similar degradation efficiency was achieved for methyl orange. To evaluate the role of light for the degradation, control experiments were conducted in the dark using methylene blue as a model dye. Although the degradation rate was slightly reduced, the catalyst still facilitated dye degradation in the absence of light. Additionally, the catalytic performance was tested with four other dyes under natural light, all of which yielded promising results, demonstrating the versatility and effectiveness of the SnS catalyst in dye degradation. This work highlights the potential of the SnS catalyst for efficient and rapid dye degradation under both light and dark conditions, offering an energy-efficient solution for wastewater treatment.

Eco-Friendly TiO2 Nanoparticles: Harnessing Aloe Vera for Superior Photocatalytic Degradation of Methylene Blue

In recent years, the contamination of aquatic environments by organic chemicals, including dyes such as methylene blue (MB), Congo red, and crystal violet, has become an increasing concern, as has their treatment. In this work, titanium dioxide nanoparticles (TiO2 NPs) were studied for their photocatalytic performance by measuring the degradation of MB under UV light. TiO2 NPs were synthesized using two synthetic processes optimized in this study: a green method, namely leveraging the natural properties of Aloe vera leaf extract; and a conventional approach. The resulting NPs were thoroughly characterized using X-rays Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET), UV–Vis and ζ-potential analysis. The TiO2 NPs synthesized by the green method demonstrated a degradation efficiency of (50 ± 3)% after 180 minutes, which was significantly higher than the (16 ± 3)% achieved by NPs synthesized through the conventional route. Moreover, the reaction rate constant for the green-synthesized TiO2 NPs was found to be approximately five times greater than that of the conventionally synthesized NPs. These results open up a new scenario in the pollution removal strategy research, using resources accessible in nature to synthesize NPs with high photocatalytic activity, which could also be useful for other applications, such as hydrogen production.

Study on the parameters of non-thermal plasma degradation process based on the combination of simulation and experiment

The destruction of benzene in a dielectric barrier discharge (DBD) reactor was studied in this work. The effects of specific energy density, initial concentration and oxygen content on benzene degradation efficiency were investigated by experiment and matrix correlation analysis. The results showed that specific energy density was the most important factor on benzene removal with a Pearson's coefficient of 0.7, meanwhile both initial concentration and oxygen content presented the inverse influence. In addition, a model to study the plasma discharge process was developed by COMSOL simulation software and surface reactions were included in the model. The behavior of the plasma was described by the coupled equations of electron density, heavy matter density and electron mean energy, and the drift-diffusion equation was calculated. When the peak voltage is 30 kV, the terminal current obtained by the simulation is 0.03 A, and the corresponding output current measured by the experiment is 0.013 A. Simulated and experimental current change trends are the same, indicating that the method simulation is correct and reasonable.

Synthesis of Nanoparticle ZnO via Chemical Reduction Using Singkil (<i>Premna serratifolia linn</i>) Leaf Extract as Photocatalytic

Nanoparticles are one of the widely studied research topics. ZnO nanoparticles have numerous benefits, such as photocatalysts and antibacterial applications. Methylene blue, which a highly dangerous and pollutes the environment and human health, is mostly used as a coloring dye in the textile industry. The use of biodegradation to treat textile waste is time-consuming and less effective. Applying photocatalysts using semiconductor materials is a more efficient method than conventional approaches for decomposing organic waste. One environmentally friendly method is green synthesis, which involves the use of microorganisms, enzymes, and plant extracts in the fabrication process. In this study, the green synthesis using chemical reduction of Premna serratifolia linn leaf extract was used to produce ZnO nanoparticles. The objective of this study is to investigate the effect of temperature on the fabrication of ZnO nanoparticles and their photocatalytic performance. Zinc nitrate tetrahydrate was used as a precursor, and the furnace temperature was varied at 400, 500, and 600 °C. The obtained ZnO was then tested using scanning electron microscopy (SEM), X-ray diffractometry (XRD), and Fourier transforms infrared spectrophotometry (FTIR). Moreover, the photocatalytic test was evaluated by examining the degradation efficiency of methylene blue using UV light. The XRD analysis indicated that the ZnO nanoparticles had crystallite sizes ranging between 44-60 nm. The SEM morphological test showed that the ZnO particles had a nano-sized spherical shape. The FTIR test results demonstrated the presence of ZnO peaks around 520 cm‑1. The performance of photocatalytic activity under UV light irradiation was significantly affected by tuning the temperatures. It was observed that the photocatalytic activity increased with increasing temperature, and methylene blue degradation efficiency reached 50% at a temperature of 600 °C. The ability of ZnO as a photocatalyst material was also evaluated by recycling the used material two times, where there was no significant change in photocatalytic performance.

The Degradation of Furfural from Petroleum Refinery Wastewater Employing a Packed Bubble Column Reactor Using O3 and a CuO Nanocatalyst

Furfural is one of the main pollutant materials in petroleum refinery wastewater. This work used an ozonized bubble column reactor to remove furfural from wastewater. The reactor applied two shapes of packing materials and two dosages of CuO nanocatalyst (0.05 and 0.1 ppm) to enhance the degradation process. The results indicated that adding 0.1 ppm of nanocatalyst provided an efficient rate of furfural degradation compared to that of 0.05 ppm. Also, the packing materials enhanced the furfural degradation significantly. As a result, the contact area between the gas and liquid phases increased, and a high furfural removal efficiency was achieved. It was found that the CuO nanocatalyst generated more (OH•) radicals. At a treatment time of 120 min and an ozone flow of 40 L/h, the furfural degradation recorded values of 80.66 and 78.6% at 10 and 20 ppm of initial concentration, respectively. At 60 ppm, the degradation efficiency did not exceed 74.16%. Furthermore, the kinetic study indicated that the first-order mechanism is more favorable than the second-order mechanism, representing the furfural degradation with a correlation factor of 0.9837. Finally, the furfural reaction can be achieved successfully in a shorter time and at low cost.

Biosynthesis of gold and silver nanoparticle using water hyacinth (Eichhornia crassipes) extract for photocatalytic degradation of organophosphate and organochlorine pesticide

The study aimed to assess the efficiency of synthesized gold (Au) and silver (Ag) nanoparticles in the degradation of organochlorine and organophosphate pesticides through photocatalysis. The synthesis of gold and silver nanoparticles was achieved using Eichhornia crassipes (water hyacinth extract). Photocatalytic degradation tests were conducted on organochlorine and organophosphate pesticides using gold and silver nanoparticles, with the absorbance of the samples measured by a UV spectrophotometer. The photocatalytic degradation rates of organochlorine and organophosphate were determined, with varied concentrations of the synthesized nanoparticles. The results showed high degradation rates at lower concentrations (10–20 ppm), with degradations of 51.789%, 47.954%, 47.983%, 44.088%, 41.565%, and 36.749% for 25/75, 50/50, and 75/25 Au nanoparticle ratios, respectively. The results also revealed that higher degradation rates were observed at longer reaction times (70–80 minutes), with percentage degradations of 44.344% and 49.987%, 41.754% and 45.937%, 36.773% and 40.458% for 25/75, 50/50, and 75/25 Au nanoparticle ratios, respectively. Lower degradation efficiencies were observed at shorter reaction times (10–20 minutes), with percentage degradations of 15.356% and 19.982%, 13.746% and 17.082%, and 10.976% and 15.167% for 25/75, 50/50, and 75/25 ratios, respectively. Additionally, the results showed high degradation rates at lower concentrations (10–20 ppm) for Ag nanoparticles, with percentage degradations ranging from 40.814% to 44.822% across AgNP ratios (25/75, 50/50, 75/25), indicating efficient degradation at lower concentrations. Conversely, at higher concentrations (60–80 ppm), the degradation efficiency was notably lower, with percentage degradations ranging from 7.004% to 13.539% across different AgNP ratios. In conclusion, Au nanoparticles exhibited higher photocatalytic efficiency than Ag nanoparticles, particularly in degrading organophosphate (Sniper) pesticides. It is recommended that these synthesized nanoparticles be considered as environmentally friendly and cost-effective options for pesticide degradation.