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Arsenic (As), a highly toxic and carcinogenic heavy metal, poses significant risks to soil and water quality, while oxytetracycline (OTC), a widely used antibiotic, contributes to environmental pollution due to excessive human usage. Addressing the coexistence of multiple pollutants in the environment, this study investigates the simultaneous adsorption of As(III) and OTC using a novel bimetallic zinc-iron-modified biochar (1Zn-1Fe-1SBC). The developed adsorbent demonstrates enhanced recovery, improved adsorption efficiency, and cost-effective operation. Characterization results revealed a high carbon-to-hydrogen ratio (C/H) and a specific surface area of 1137 m2 g−1 for 1Zn-1Fe-1SBC. Isotherm modeling indicated maximum adsorption capacities of 34.7 mg g−1 for As(III) and 172.4 mg g−1 for OTC. Thermodynamic analysis confirmed that the adsorption processes for both pollutants were spontaneous (ΔG < 0), endothermic (ΔH > 0), and driven by chemical adsorption (ΔH > 80 kJ mol−1), with increased system disorder (ΔS > 0). The adsorption mechanisms involved multiple interactions, including pore filling, hydrogen bonding, electrostatic attraction, complexation, and π-π interactions. These findings underscore the potential of 1Zn-1Fe-1SBC as a promising adsorbent for the remediation of wastewater containing coexisting pollutants. [ABSTRACT FROM AUTHOR]

Arsenic contamination in groundwater poses serious health risks, as exemplified by the Blackfoot disease epidemic in Taiwan, which was caused by prolonged arsenic exposure. This study investigates the use of biochar derived from the wastewater treatment sludge of the Far Eastern Memorial Hospital (New Taipei City, Taiwan) as an efficient adsorbent for arsenic removal. A novel iron-doped sludge biochar (Fe-SBC) was developed to enhance arsenic adsorption efficiency, facilitate adsorbent recovery, and reduce operational costs. The adsorption mechanism of arsenic on Fe-SBC, modified with iron hydroxide complexes, was examined through Density Functional Theory (DFT) simulations. The results demonstrate a high arsenic removal efficiency of approximately 90% using continuous adsorption systems. The DFT calculations revealed strong chemical interactions between arsenic and the biochar, evidenced by high adsorption energy (−156.8 kJ mol−1) and a short bond distance (1.48 Å), correlating with the high adsorption performance observed experimentally. Additionally, arsenic byproducts desorbed from the adsorbent were repurposed into antibacterial agents and pigments. Four distinct pigment colors—green, blue, gray, and orange—were produced through different preparation methods, with the antibacterial agents showing effective antimicrobial properties. This study highlights the potential of Fe-SBC for sustainable arsenic remediation and resource recovery. [ABSTRACT FROM AUTHOR]

Gac fruit (Momordica cochinchinensis Spreng.) is a prominent source of carotenoids, renowned for its exceptional concentration of these compounds. This study focuses on optimizing the extraction of active components from the aril of gac fruit by evaluating the effects of extraction temperature, solid–liquid ratio, and extraction time. The primary objective is to maximize the yield of gac oil while assessing its antioxidant capacity. To analyze the kinetics of the solid–liquid extraction process, both first-order and second-order kinetic models were employed, with the second-order model providing the best fit for the experimental data. In addition, the potential of gac fruit peel as a precursor for biochar production was investigated through carbonization. The resultant biochars were evaluated for their efficacy in adsorbing crystal violet (CV) dye from aqueous solutions. The adsorption efficiency of the biochars was found to be dependent on the carbonization temperature, with the highest efficiency observed for BCMC550 (91.72%), followed by BCM450 (81.35%), BCMC350 (78.35%), and BCMC250 (54.43%). The adsorption isotherm data conformed well to the Langmuir isotherm model, indicating monolayer adsorption behavior. Moreover, the adsorption kinetics were best described by the pseudo-second-order model. These findings underscore the potential of gac fruit and its byproducts for diverse industrial and environmental applications, highlighting the dual benefits of optimizing gac oil extraction and utilizing the peel for effective dye removal. [ABSTRACT FROM AUTHOR]

Acetone is solvent widely used in laboratories and factories. Serious problems will occur when it is exposed to the environment. Therefore, a new design for a bimetallic metal functional group catalyst that can convert acetone into carbon dioxide and water within 250 °C was prepared, in order to effectively treat acetone and reduce the required energy. Hydrophobic Y type zeolite adsorption and low-temperature catalytic combustion were used to continuously treat acetone, and the effect of different operating parameters (including different metal loads, metal content, transformation temperature, pollutant concentration, and space velocity) on the efficiency of acetone treatment was discussed in this study. The isothermal adsorption model, kinetics, and thermodynamic model analysis were also used to establish the reaction mechanism, and to explore the factors affecting the catalyst reaction rate. The results show that the acetone conversion rate of 10-Fe1Mn1-USY reaches 90% at 400 ppm, 20,000 h−1 space velocity, and 227 °C. The kinetic behavior of the reaction between 10-Fe1Mn1-USY and acetone is more suited to the Power-rate Law model. Arrhenius equation analysis results show that the required activation energy for the reaction between 10-Fe1Mn1-USY and acetone is 70.2 kJ mol−1, and the collision frequency factor is 2.81 × 105 s−1. This reaction is an endothermic reaction, and the main reaction mechanism is surface metal oxidation. A new design for a bimetallic metal functional group catalyst that can convert acetone into carbon dioxide and water within 250 ℃ was prepared, in order to effectively treat acetone and reduce the required energy. Hydrophobic Y type zeolite adsorption and low-temperature catalytic combustion were used to continuously treat acetone, and the effect of different operating parameters on the efficiency of acetone treatment was discussed in this study. Result shown that the redox reaction between the adsorbed acetone and the active oxygen on the surface of the catalyst to generate CO2 and H2O. [ABSTRACT FROM AUTHOR]

According to statistics, the number of patients with kidney dialysis is increasing every year, especially in Taiwan. The high content of antibiotics in kidney dialysis wastewater can create an environmental burden if not properly treated. Therefore, in this study, a new design for a flower-like ZnO catalyst that can effectively treat norfloxacin (NF) in dialysis wastewater is presented and its NF treatment efficiency is investigated under different operating parameters (including different dosages, pH, ambient temperatures, and pollutant concentrations). Scanning electron microscope results indicate that the ZnO sample consists of flower-like nanostructures with diameters of about 4.97 μm. The surface area, pore volume, and pore size of the flower-like ZnO were estimated to be 46.45 m2g−1, 0.132 cm3g−1, and 19.50 nm, respectively. The total removal efficiency increased with the increase in the initial pH value of NF, when the initial pH value of NF increased from 3.5 (38.1%) to 7.5 (82.5%). However, the total removal efficiency decreased with an increase in the initial pH value of NF, when the initial pH value of NF increased from 9.5 (79.5%) to 11.5 (32.9%). The second-order kinetic simulation results show that the linear relationship is better than that of the first-order kinetic, and the Rc2 values are all above 0.9. [ABSTRACT FROM AUTHOR]

Acetone is a solvent used in many laboratories and factories. Serious problems will occur when it is exposed to the environment. Therefore, a new design hydrophobicity bimetallic metal material (10-Fe1Mn1-USY) was prepared for acetone adsorption under conditions of high humidity. Hydrophobic Y type zeolite was used to prepare bimetallic metal materials and the effect of different operating parameters (including different material, humidity, temperature, pollutant concentration, residence time, and regeneration) on the efficiency of acetone treatment was examined. Isothermal adsorption model, kinetics and thermodynamic model analysis were also used to establish the reaction mechanism. The 10-Fe1Mn1-USY material has good adsorption capacity (133 mg g−1) for acetone under a relative humidity of 50%. The main factors affecting the adsorption capacity are the contact angle, hydrophobicity, specific surface area, and Si/Al of the material. The isothermal adsorption and the kinetic adsorption behavior of 10-Fe1Mn1-USY material for acetone are more suitable for the Temkin isotherm adsorption model and the pseudo-first-order kinetic model. The adsorption of acetone by 10-Fe1Mn1-USY material is dominated by intra-particle diffusion. According to the thermodynamic analysis results, the adsorption behavior of 10-Fe1Mn1-USY material for acetone is a type of physical adsorption, and a spontaneous and non-sequential reaction. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons are a class of chemicals that occur naturally. They generally demonstrate a high degree of critical toxicity towards humans. Acenaphthene and naphthalene contain compounds that are commonly found in the environment as compared to other PAHs. Consequently, a reliable method of detecting PAHs is crucial for the monitoring of water quality. A colorimetric method based on sodium nitrite-functionalized gold nanoparticles was developed in this study for acenaphthene and naphthalene detection. Different functionalized parameters are determined for the optimization of assay conditions. A linear relationship was found in the analyte concentration range of 0.1–10 ppm with the limit of detection for acenaphthene and naphthalene being 0.046 ppm and 0.0015 ppm, respectively, under the optimized assay conditions. The method's recovery rate for actual samples falls within the range of 98.4–103.0%. In selective and anti-interference tests, the presence of cations and anions has minimal impact on the detection of the analyte. The colorimetric detection method proposed in this study effectively determines the presence of the analyte in real water samples and has a high recovery rate. [ABSTRACT FROM AUTHOR]

Given the high toxicity and carcinogenic properties of pesticides, reducing pesticide residues is crucial for mitigating water pollution and promoting sustainable development. In the present study, a novel colorimetric method using gold nanoparticles (AuNPs) was designed for the detection of target analytes. The Turkevich-Frens method was used to synthesize AuNPs, which were then modified with sodium nitrite and L-cysteine for the detection of 1-naphthol and glyphosate, respectively. Different assay conditions strongly influenced the detection performance of the modified AuNPs, so the assay conditions were optimized for further investigation. In the presence of the target analytes (1-naphthol and glyphosate) under the optimum assay conditions, the absorption peak at 520 nm shifted and a corresponding color change was observed. The limits of detection of 1-naphthol and glyphosate were determined to be 0.15 and 0.27 ppm, respectively. In addition, the modified AuNPs had high selectivity for the target analytes and did not exhibit interference in the presence of other substances. This novel colorimetric method was then applied to detect the target analytes in mineral water and tap water with acceptable results. [ABSTRACT FROM AUTHOR]

Glossogyne tenuifolia is a high economic value crop cultivated on Penghu Island, Taiwan. However, there is no extraction optimization of G. tenuifolia reported in the literature. Simplex lattice and central composite design of response surface methodology (RSM) were used in this study to investigate the extraction variables (solvent proportion, extraction temperature, the ratio of liquid to solid and pH) in the extraction of solvent from G. tenuifolia. The total phenolic content (TPC), total flavonoid content (TFC), total triterpenoid content (TTC) and antioxidant capacity of G. tenuifolia were considered as the response variables, while the solvent proportion, extraction temperature, the ratio of liquid to solid (L/S) and the pH effect were considered for determining the optimal conditions. Quadratic models were used by the RSM optimization approach to obtain the optimal conditions and to predict the relative response variables. ANOVA analysis results exhibited a high coefficient of determination (R2) and adjusted-R2, which indicated that the quadratic models were adequate for the response variables. The results demonstrated that the extract of G. tenuifolia is a good source of antioxidant and has the potential to be applied in various industries. [ABSTRACT FROM AUTHOR]

One of the most energy-intensive industries in Taiwan is the cement industry. With the increasing awareness of the need to reduce carbon emissions, the cement industry in Taiwan is under huge pressure to reduce its greenhouse gas emissions. The use of alternative fuels (AFs) is an option to reduce the use of fossil fuels and reduce greenhouse gas emissions. The objectives of this study are to review and analyze the experiences of using AFs in the cement industry in Germany and Japan. The contribution of AFs to total thermal energy demand in the cement industry of Germany reached 64.6% in 2015. In Japan, the contribution of AFs to total thermal energy demand reached 16.4% in 2014. The analysis of specific alternative fuels shows that the level of usage of AFs in one cement plant in Taiwan is less than that of Japan and much lower than that of Germany. This paper provides a comparison, barriers and recommendations for the use of AFs in the cement industry, particularly in Taiwan. [ABSTRACT FROM AUTHOR]

Response surface methodology (RSM) was applied to evaluate the extraction of active compounds from Litsea cubeba fruits. A central composite design (CCD) with five levels and three process parameters (extraction temperature, extraction time and ethanol concentration) was used to investigate the influence of the extraction temperature, extraction time and ethanol concentration on the multiple response variables (TPC, DPPH and ABTS assays). The results of the ANOVA analysis show that the quadratic term of the ethanol concentration was significant for all the response variables. The quadratic model was highly significant ( P<0.05) for all the response variables. After optimizing for multi-response, the optimal conditions were determined as an extraction temperature of 42.3 ºC, extraction time of 126.4min and ethanol concentration of 51%. Moreover, the extract of Litsea cubeba fruit attested possessing tyrosinase inhibitory activity, with an IC value of 5,720 μg mL. The second-order kinetic model represented the kinetic data very well. In addition, the obtained values of the effective diffusivities were in the range of 2.28-5.83×10ms. [ABSTRACT FROM AUTHOR]

This work determined the moisture sorption isotherm of rice bran and investigated the effects of the pre-treatment method, solvent type, solid-liquid ratio and soaping temperature on extract yield, total phenolic content, 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity assay and 2,2′-azino-bis antioxidant capacity assay of rice bran extract. The Taguchi method and L9 (34) orthogonal array were employed in this study. The sorption isotherms of rice bran showed a sigmoidal pattern and displayed type II of van der Waals adsorption. Adsorption and desorption data on rice bran were best fitted using the Henderson model among the six models tested at three temperatures. The net isosteric heat of desorption was higher than the net isosteric heat of adsorption. Based on the analysis of the signal-to-noise ratio, solvent selection effected the largest contribution to the overall performance. Confirmation experiments showed that the optimal combination that contained the four quality attributes was appropriate (error margin <5%) and reproducible. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The moisture sorption isotherms of Hemerocallis Fulva and Cymbopogon are measured by the static gravimetric method at 25, 35, and 45 °C over a water activity range of 0.09 to 0.95 using standard saturated salt solutions. The sorption isotherms of H. fulva and Cymbopogon display type III ( J-shaped) and type II (nearly sigmoid shapes) isotherms. In addition, the adsorption and desorption data of H. fulva and Cymbopogon fit well with the White & Eiring model and the Oswin model, respectively. The Brunauer-Emmett-Teller equation is applied to determine the monolayer moisture content, and the surface area of a monolayer was calculated. The values of the net isosteric heat of sorption are found to increase with decreases in the equilibrium moisture content. Moreover, the net isosteric heat of desorption is higher than that of the adsorption heat. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Artificial lightweight aggregate (LWA) is produced using water reservoir sediment, spent glass, and diatomaceous earth in various compositions and sintering temperatures between 1020°C and 1110°C. This study prepared aggregate samples whose physical properties included bloating index (BI), water absorption capacity (WAC), apparent density, and compressive strength. Results showed that the morphology of the external aggregated samples, the number of pores increased as the sintering temperature rose, while the water adsorption capacity decreased with the increasing sintering temperature. Apparent density generally decreased with an increasing fraction of waste glass (WG) because average particle size of the WG was larger than spent diatomaceous earth, and water reservoir sediment. Furthermore, LWA with lower apparent density corresponded to a higher BI. According to analysis results, formulations of water reservoir sediment 50%, WG 40%, and spent diatomaceous earth 10% and water reservoir sediment 40%, WG 40%, and spent diatomaceous earth 20% aggregated samples can be used to produce artificial LWA for use as structural concrete. [ABSTRACT FROM AUTHOR]

The cement industry is the most energy intensive of Taiwan's manufacturing industries. This paper presents a case study of the greenhouse gas (GHG) inventory in Taiwan's cement industry, which includes an analysis of GHG emission intensity (EI) and the testing of raw meal calcination. The GHG inventory analysis results show that direct GHG emissions (Scope 1) are the largest emission source of the study subject, the H plant. As regards the EI analysis results of Taiwan's cement plants, only one cement plant (H plant) meets the EI limit announced by the Environmental Protection Administration (EPA) of Taiwan. According to the calcination test, the major calcination reaction occurs in the 700–900°C temperature range and accounts for nearly 87% of total CO2emissions. Finally, a modified and feasible process is proposed as a base case for simulating options for GHG reductions in the cement industry. The modified process can reduce coal consumption and pipeline corrosion, and increase the efficiency of waste heat recovery and the calcination rate; these procedures require low investment and operating cost. [ABSTRACT FROM PUBLISHER]

Mesoporous MCM-41 was synthesized using cetyltrimethyl ammonium bromide (CTAB) as a cationic surfactant and spent quartz sand as the silica source. Modification of the mesoporous structure to create an absorbent was then completed using 3-aminopropyltrimethoxysilane. Amine-Quartz-MCM (The A-Q-MCM) adsorbents were then characterized by N2adsorption/desorption, elemental analysis (EA), X-ray fluorescence (XRF), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), as well as the carbon dioxide (CO2) adsorption/desorption performance. In this study, spent quartz sand was utilized to synthesize Quartz-MCM (Q-MCM) and the amine functionalized material, A-Q-MCM, which exhibited a higher uptake of CO2at room temperature compared with the nongrafted material. The results showed that Q-MCM is similar to MCM-41 synthesized using commercial methods. The surface area, pore volume, and pore diameter were found to be as high as 1028 m2/g, 0.907 cm3/g, and 3.04 nm, respectively. Under the condition of CO2concentration of 5000 ppm, retention time of 50 cc/min, and the dosage of 1 g/cm3, the mean adsorption capacity of CO2onto A-Q-MCM was about 89 mg/g, and the nitrogen content of A-Q-MCM was 2.74%. The adsorption equilibrium was modeled well using a Freundlich isotherm.Implications:In this study, spent quartz sand was utilized to synthesize Q-MCM. The amine functionalized material exhibited a higher uptake of CO2 at room temperature compared with the nongrafted material. The results showed that Q-MCM is similar to MCM-41 synthesized using commercial methods. The adsorption equilibrium was modeled well using a Freundlich isotherm. [ABSTRACT FROM AUTHOR]

In this study, polyvinyl alcohol (PVA) and titania (TiO2) Degussa P-25 were mixed to generate TiO2nonwoven filters using electrospinning. The wires of titanium dioxide and the nonwoven binding titania nanofibers were formed using 14 kV voltage and a distance of 15 cm. A single-factor experimental method was used to investigate the effects of parameters such as initial concentration, retention time, and light source on acetone removal by nonwoven binding titania nanofibers. Furthermore, the effects of parameters such as gas pressure, particle size, initial concentration, and retention time on the removal of particulates were also assessed. The results showed that the degradation efficiency increased with decreasing initial concentrations and increasing retention time. The best operational conditions during this study for the removal of acetone using the TiO2nonwoven filters were a retention time of 100 sec, initial acetone concentration of 250 ppm, and ultraviolet (UV) light source of 254 nm. Under those conditions, 99% acetone removal efficiency was obtained. In addition, 90% particulate matter removal efficiency was reached when the particulate size was greater than 200 nm and the reaction time was longer than 5 minutes. The prepared TiO2/nanofiber has good performance for volatile organic compounds (VOCs) and particulate removal at the same time. Implications:In this study, polyvinyl alcohol (PVA) and titania (TiO2) Degussa P-25 were mixed to generate TiO2 nonwoven filters using electrospinning. The results showed that the optimum operating conditions for the removal of acetone using the TiO2 nonwoven filters were a retention time of 100 sec, initial acetone concentration of 250 ppm, and UV light source of 254 nm. Under those conditions, 99% acetone removal efficiency was obtained. [ABSTRACT FROM AUTHOR]

This study is to optimize the multi-quality performance of magnetic catalyst/ozone process by combining a technique for order performance by similarity to ideal solution (TOPSIS) with the Taguchi method, which simultaneously has the best decomposition rate constant of benzoic acid and removal rate constant of total organic carbon (TOC). The optimal experimental parameters were pH of 7, initial concentration of 75 ppm and catalyst loading of 0.05 g/L. More than 93% of the magnetic catalyst was easily separated and redispersed for reuse by the magnetic force due to the paramagnetic behaviours of the prepared SiO2/Fe3O4. It is believed that through the joint efforts improvement, design and manufacturing, new separation and recycling technologies will be available and more easily recyclable magnetic catalysts will be developed in the future. [ABSTRACT FROM PUBLISHER]

Thin films of pure TiO2, silver-deposited TiO2, and platinum-deposited TiO2 were prepared on quartz substrates by a dip-coating process for the photodecomposition of o-cresol under light emitting diodes (LEDs) irradiation instead of a traditional lamp. In this work, effects of noble metal doping, periodic illumination, and LEDs wavelength on the photoactivity, electrical energy consumption, and quantum yield were explored in an effort to better understand the roles of noble metal and LEDs characterization in photocatalytic reactions. Degradation of o-cresol under LED irradiation increased with the decreased wavelength of LEDs, due to the higher power energy of a photon. Pt/TiO2 films on quartz substrates prepared by a photodeposition method exhibited excellent optical characteristics, energy savings, and visible light-induced photocatalytic properties compared with Ag/TiO2 and pure TiO2 (P25). EEO increased from 22 to 31 kWh/m3/order indicating that energy consumption for periodic illumination was significantly lower than continuous illumination under similar experimental conditions. This study showed the feasible and potential use of LEDs in photocatalysis. [ABSTRACT FROM AUTHOR]

Nanotechnology is used in a wide range of fields, including medicine, cosmetics, and new material development, and is one of the most popular technologies in the field of flexible electronic products. For the present work, the chemical reduction method with environmentally friendly reducing agents was used to synthesize copper nanoparticles (CuNPs) with good dispersibility. The CuNPs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and ultraviolet–visible spectrophotometry (UV–vis). After the CuNPs were formed, the solvent, polymers, and additives were added to form copper ink. Finally, the prepared copper inks were applied to flexible polyethylene terephthalate (PET) substrate under low sintering temperature and the effects of sintering time and different concentrations of sintering agent on resistivity were investigated. The results show that the copper nanoparticles synthesized by secondary reduction were smaller, more uniform, and better dispersed than those formed by primary reduction. Ethylene glycol has reducing effects under high temperatures; therefore, the CuNPs formed using the mixed solvent were small and well dispersed. The copper ink was applied on the PET substrate, treated with a formic acid aqueous solution, and sintered at 130 °C for 60 min, and its resistivity was about 1.67 × 10−3 Ω cm. The proposed synthesizing method is expected to have potential applications in the flexible electronic products field. [ABSTRACT FROM AUTHOR]

In the scientific industry, sustainable nanotechnology has attracted great attention and has been successful in facilitating solutions to challenges presented in various fields. For the present work, silver nanoparticles (AgNPs) were prepared using a chemical reduction synthesis method. Then, a low-temperature sintering process was deployed to obtain an Ag-conductive ink preparation which could be applied to a flexible substrate. The size and shape of the AgNPs were characterized by ultraviolet–visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). The experiments indicated that the size and agglomeration of the AgNPs could be well controlled by varying the reaction time, reaction temperature, and pH value. The rate of nanoparticle generation was the highest when the reaction temperature was 100 °C within the 40 min reaction time, achieving the most satisfactorily dispersed nanoparticles and nanoballs with an average size of 60.25 nm at a pH value of 8. Moreover, the electrical resistivity of the obtained Ag-conductive ink is controllable, under the optimal sintering temperature and time (85 °C for 5 min), leading to an optimal electrical resistivity of 9.9 × 10−6 Ω cm. The results obtained in this study, considering AgNPs and Ag-conductive ink, may also be extended to other metals in future research. [ABSTRACT FROM AUTHOR]

Appropriately disposing of and reusing waste is a major step in promoting environmentally sustainable development. Following the rise in environmental awareness, agricultural waste has been applied as a reusable organic resource and as a cost-efficient material for preparing hydrogel adsorbents. The present study combined rice bran with sodium alginate and chitosan to prepare two new types of hydrogel beads. The beads were then modified using simple methods, and their material characteristics were analyzed using a Fourier transform infrared spectroscope, a scanning electron microscope, and thermogravimetric analysis. Specifically, the effects of pH, adsorbent dosage, adsorption time, and adsorption temperature on the performance of the hydrogel beads in the adsorption of dyes with various properties were examined. The results revealed that the optimal conditions for the rice bran/alginate hydrogel beads to adsorb crystal violet were pH 5, a dosage of 30 mg, at 30 °C, for 6 h of adsorption; furthermore, the kinetic and isothermal adsorption data were found to be consistent with the pseudo-second-order model and the Freundlich isotherm model, respectively. The optimal conditions for the rice bran/chitosan hydrogel beads to adsorb reactive blue 4 were pH 3, a dosage of 40 mg, at 50 °C, for 7 h of adsorption, and the kinetic and isothermal adsorption data were consistent with the pseudo-first-order model and the Langmuir isotherm model, respectively. This study applied natural polymers and agricultural waste to prepare cost-efficient and environmentally friendly adsorbents, which satisfy today's environmental protection trends and economic values because of their low environmental impact and favorable adsorptive and regenerative properties. They can be prepared without high-temperature and high-pressure processing, and can be recycled through the separation of water bodies using simple filter methods, thus substantially reducing energy and monetary costs. [ABSTRACT FROM AUTHOR]

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions. [ABSTRACT FROM AUTHOR]

This research work reports an approach used to prepare a SnO2 photocatalyst by precipitation and calcination pathways and describes an investigation of the effects of preparation parameters on SnO2 yield. The SnO2 photocatalyst was further used for the photocatalytic degradation of Congo red (CR) dye, and the removal efficiency was optimized using response surface methodology. The results indicate that the SnO2 photocatalyst yield was the highest in 0.05 M of the precursor, stannous chloride and 28 wt % ammonia as the precipitant, pH 10, at 30 °C. The transmission electron microscopy results of the SnO2 photocatalyst illustrate that the average particle size was mainly around 30–50 nm and had a solid spherical shape. The X-ray diffraction results reveal that the prepared sample had a highly crystalline SnO2 rutile crystal structure. The prediction and experimental results of the Response surface methodology (RSM) indicate that, when the reaction time was 97 min, the operating temperature was 47 °C, the photocatalyst dosage was 751 mg/L, and the optimal degradation rate of the CR dye was 100%. After five consecutive photodegradation reactions, the degradation rate remained at 100%. The results demonstrated that the SnO2 photocatalyst prepared in this study possesses excellent reusability. [ABSTRACT FROM AUTHOR]

Although several studies have explored green adsorbent synthesized from many types of agriculture waste, this study represents the first attempt to prepare an environmentally friendly rice bran/SnO2/Fe3O4-based absorbent with economic viability and material reusability, for the promotion of sustainable development. Here, rice bran/SnO2/Fe3O4 composites were successfully synthesized and applied for adsorption of reactive blue 4 (RB4) and crystal violet (CV) dyes in aqueous solutions. The adsorption data were well-fitted by the Langmuir isotherm model and the pseudo-second-order kinetic model. The maximum adsorption capacities of the RB4 and CV dyes as indicated by the Langmuir isotherm model were 218.82 and 159.24 mg/g, respectively. As results of response surface methodology (RSM) showed, the quadratic model was appropriate to predict the performance of RB4 dye removal. The findings exhibited that an optimum removal rate of 98% was achieved at 60 °C for pH 2.93 and adsorption time of 360 min. Comparative evaluation of different agricultural wastes indicated that the rice bran/SnO2/Fe3O4 composite appeared to be a highly promising material in terms of regeneration and reusability, and showed that the composite is a potential adsorbent for dye removal from aqueous solutions. Overall, the study results clearly suggest that an adsorbent synthesized from rice bran/SnO2/Fe3O4 magnetic particle composites provides encouraging adsorption capacity for practical applications for environmental prevention. [ABSTRACT FROM AUTHOR]

To maximize the extraction of antioxidants from Chenopodium formosanum seeds, the process factors, such as the ethanol concentration (0–100%), extraction time (30–180 min) and temperature (30–70 °C), for the extraction of the bioactive contents as well as the antioxidant capacity are evaluated using response surface methodology (RSM). The experimental results fit well with quadratic models. The extract was identified by GC/MS, and it was found that some active compounds had antioxidant, repellency and insecticidal activities. Various concentrations of the extract were prepared for the evaluation of the insecticidal activity against Tribolium castaneum, and the toxicity test results indicated that the extract was toxic to Tribolium castaneum, with an LC50 value of 354.61 ppm. The oxidative stability of the olive oil determined according to the radical scavenging activity and p-anisidine test demonstrates that the extract obtained from the Chenopodium formosanum seeds can retard lipid oxidation. [ABSTRACT FROM AUTHOR]