Organic pollutants, such as rhodamine B (RhB), methylene blue (MB), and 1,2-dihydroxybenzene (catechol) used in dyes, textile industries, cosmetics, plasticizers, pesticides, and pharmaceuticals are difficult to be degraded and have important influence on the ecosystems and human beings. The removal of organic contaminants and sensitive detection of catechol are still important challenges. Rice husk biochar (RHBC) was successfully prepared via a simple sintering technology under Ar atmosphere.
RESULTS
The morphological and structural characterizations show that the proposed RHBC consists of irregular particles with the size of less than 10 μm and amorphous structure. The adsorption performance for the removal of organic pollutants including RhB and MB using the RHBC was investigated. The optimal RHBC dose is 1.25 mg·mL−1 dyes (RhB or MB) solution. 10 mg·L−1 RhB or MB can be totally removed with the adsorption time of 140 min and 70 min, respectively. The RHBC can be used as electrode materials and has an essential effect in the electro-catalytic sensing performance for catechol detection by square wave voltammetry (SWV) method.
The RHBC-modified electrode indicates a determination range of 0.001–1000 μM, low limit of detection of 0.57 nM, oxidation potential of + 0.35 V, good selectivity, reproducibility, stability, and applicability in real water environment for catechol detection.
Charu Agarwal, Gladys Sara Saji, Anurag Singh Rathore
BACKGROUND
Utilization of sustainable plant proteins is limited by low yield of the existing extraction and processing methods. The study aims to present a comparative assessment of three extraction techniques – ultrasound, microwave and high-pressure homogenization – against conventional alkaline extraction as control on the structural and functional properties of Vigna radiata L. (mung bean) proteins.
RESULTS
Homogenization resulted in the highest extraction yield (20.1%). Infrared and circular dichroism spectroscopic analyses revealed changes in the secondary structure of proteins due to extraction treatments compared to alkaline extraction. All concentrates showed X-ray diffraction amorphous halos typically seen in legume proteins. Compared to the control, microstructural analysis revealed the porous structure of homogenization-derived proteins, roughness of microwave-derived proteins, and dense and aggregated morphology of ultrasound-derived proteins. The electrophoresis profiles and size-exclusion chromatograms were similar for all concentrates. Microwave treatment resulted in the highest water absorption (5.20 g g−1), oil binding (3.32 g g−1), foam stability (100%) and surface hydrophobicity (1250). Homogenization treatment resulted in the lowest particle size (142 nm), as confirmed by dynamic light scattering.
Graphene oxide (GO) is a derivative of graphene with hydrophilic properties and the ability to form stable aqueous suspensions. Titanium dioxide (TiO2), a semiconductor with photocatalytic activity, is often used as a matrix for GO in nanocomposites. Hydrothermal methods are the most commonly used for production nanocomposites by controlling their properties by changing the pressure, temperature, and component ratio.
RESULTS
Various hydrothermal procedures have been utilized for the synthesis of GO/TiO2 nanocomposites at different ratios. Gravitational field-flow fractionation and dynamic light scattering were applied to measure the particle size and determine the influence of different hydrothermal methods on the particle size distribution. The reflux method produced the smallest particles and a favorable size distribution. Ultraviolet–visible spectroscopy was used to determine the energy gap of the produced materials, and a shift from 3.3 eV for pure TiO2 to 2.1 eV for the composites was determined, a fact that suggests enhanced photocatalytic potential. The presence of strong chemical bonding between TiO2 and GO was confirmed by utilizing Raman spectroscopy.
This study was conducted to develop and characterize Pickering emulsions stabilized by basil seed mucilage powder (BSMP), incorporating orange peel essential oil at two concentrations (2% and 4%), with the aim of determining their physicochemical properties, stability, and antimicrobial activity against foodborne pathogens.
RESULTS
The recovery yield of BSMP from basil seeds was 8.55 g 100 g−1 and BSMP showed flake-like structure with thin layers, high crystallinity, and glass transition temperature of 192.8 °C. Meanwhile, orange peel essential oil contained 93.247% d-limonene and demonstrated bacteriostatic effects against different Gram-positive and Gram-negative bacteria despite being incapable of destroying them. The resulting Pickering emulsions, particularly at 4% oil concentration, showed excellent stability over 3 weeks with maintained nano-sized particles (d10 of 138.87 nm) and highly negative zeta potential (−52.0 mV) while exhibiting enhanced antimicrobial efficacy against various pathogenic bacteria at lower concentrations compared to pure essential oils.
Textile dyes, used for coloring fabrics, cause environmental challenges because approximately 30% of the applied dye may enter the wastewater without being treated. This wastewater has intense color, variable pH, and salt content. Limited biodegradability of dyes due to their complex polymer structures necessitates advanced treatment. This study investigated the decolorization of dyeing wastewater by electrocoagulation (EC) and electrooxidation (EO) methods, which are common techniques of electrochemical advanced oxidation processes. Box–Behnken design was applied to experimental design in the determination of the maximum removal efficiency. Initial pH, current density (CD), and reaction time (RT) were chosen as independent variables, and the removal efficiency of Acid Black 172 (AB172) and Basic Red 46 (BR46) dyestuffs was selected as model responses.
RESULTS
Higher BR46 dyestuff removal efficiency was obtained by the EO process using a Ti:RuO2:IrO2 electrode, and higher AB172 dyestuff removal efficiency was obtained by the EC process using an Al electrode. Under optimum conditions, the highest removal efficiencies based on dyestuff were 93.4% with the EC process for AB172 dyestuff (initial pH 5.63; CD 0.07 mA cm−2; RT 13.1 min) and 94.0% for BR46 dyestuff with the EO process (initial pH 4.61; CD 2.89 mA cm−2; RT 72.6 min).
The catalytic conversion of biomass-derived feedstocks into valuable chemicals is a key focus in sustainable chemistry. This study explores the zinc chloride (ZnCl2)-catalyzed synthesis of 2-furyl methanol from Acacia auriculiformis leaves. The influence of reaction parameters, including catalyst concentration, temperature, and time, on product yield was systematically investigated.
RESULTS
Gas chromatographic–mass spectrometric results confirmed the formation of 2-furyl methanol, with a maximum yield of 9.35%, equivalent to 458.04 mg g−1 of feed, obtained at 40 °C using 1.0% ZnCl2 catalyst. The reaction pathway involves ZnCl2-assisted thermal hydrolysis, dehydration, and mild hydrogenation of hemicellulose-derived pentose sugars. Comparative catalyst studies (using BaCl2, NaOH, ZnO, CaO, and MgO) revealed that ZnCl2 exhibited superior selectivity and efficiency in the conversion process.
Shefaa Omar Abu-Nassar, Nurul Hana Mokhtar Kamal, Herni Halim, Mohd Suffian Yusoff, Mohammed JK Bashir, Mahmoud Zuhier Aldrabseh, Amani Abdallah Assolie
BACKGROUND
Landfill leachate contains high levels of refractory organic matter, particularly humic acid (HA) and fulvic acid (FA), which are difficult to degrade due to their complex structures and molecular weight. This study evaluates the effectiveness of a combined ultrasonic–electrocoagulation (US-EC) process for degrading these substances. Key treatment parameters such as total organic carbon (TOC), color, 254 nm ultraviolet light (UV₂₅₄), and UV–visible were used to assess performance. Fourier transform infrared (FTIR) and UV–visible spectroscopy were employed to analyze structural changes in organic matter, while energy-dispersive X-ray (EDX) analysis provided insights into elemental composition and pollutant transformation.
RESULTS
Optimal conditions were identified as a surface area-to-volume ratio of 7 m−1, electrode spacing of 3 cm, current density of 50 mA m−2, stirring speed of 200 rpm, and 30 min of electrolysis. The US-EC process improved TOC removal from 41% (EC alone) to 47%, and color removal from 83.5% to 88.2%. The UV254 absorbance of raw landfill leachate was 14.78, decreasing to 7.18 and 6.23 after EC and US-EC, respectively. This reduction indicates lower aromaticity and molecular weight, as confirmed by spectral analysis. Additionally, by-products contained high concentrations of oxygen, carbon, and nitrogen, according to EDX results. FTIR analysis showed significant peaks at 3450 cm−1 (OH), 1530 cm−1 and 1400 cm−1 (CC), and 570 cm−1 (CH), supporting the effective removal of organic matter by both EC and US-EC.
Among various CO2 capture technologies, solid adsorption has become the most widely used method. In addition, organic amine modified solid adsorbents can further improve their CO2 adsorption performance and have broad application prospects.
Result
CuAl-LDH/HNT composite material was synthesized via the co-precipitation method by using acid-treated halloysite (HNT) as one of the substrates. Further, the xAPTES CuAl-LDH/HNT composite adsorbent was successful synthesized by using 3-aminopropyltriethoxysilane (APTES) as modifier. It was found that adjusting the composite ratio of CuAl-LDH, HNT, and APTES can fully utilize the synergistic effect between materials, thereby affecting their CO2 adsorption performance. Especially, when the ratio of CuAl-LDH to HNT was 2:1 and the loading amount of APTES was 30 wt%, the performance of the composite material was optimal. The adsorption performance and regenerability test results of the material showed that the adsorption capacity of 30APTES-LDH/HNT was 4.38 mmol/g after static adsorption for 24 h, and maintained over 92% regeneration efficiency after 6 cycles. By fitting the adsorption process of the material with a kinetic model, it was found that chemical adsorption was the main process, and the comparison of infrared spectra before and after adsorption also clearly showed the improved performance of the modified material.
Muhammad Bilal, Amir Hossein Behroozi, Rifat Jahan, Javed Ali, Vahid Vatanpour
Background
The widespread occurrence of antibiotics in aquatic environments has emerged as a serious environmental concern due to their persistence, bioaccumulation, and role in promoting antimicrobial resistance. Conventional treatment methods are often inadequate for complete antibiotic removal. Thus, developing multifunctional, sustainable materials capable of both adsorption and degradation is essential for effective water treatment.
Results
This study introduces a novel titanium dioxide (TiO2)/activated carbon (AC) composite synthesized from Diospyros texana seed biomass for efficient removal of oxytetracycline (OTC) and amoxycillin (AMX). The optimized 10 wt% TiO2/AC composite, prepared via an impregnation method, exhibited enhanced visible-light photocatalytic activity and adsorption capacity. Structural characterization confirmed well-dispersed TiO2 nanoparticles within the macroporous AC framework, promoting effective light harvesting, charge separation, and contaminant binding. The composite demonstrated thermal stability and a point of zero charge of 7.8, facilitating pH-dependent interactions with AMX and OTC. Under optimal conditions (pH 3 for AMX, pH 7 for OTC, 0.1 g/L composite), the system achieved rapid removal (> 90%), equilibrium within 3 min for AMX and 5 min for OTC. Performance remained stable for over 180 min and showed no significant decline even after five reuse cycles. However, increasing TiO2 beyond 10% reduced efficiency due to pore blockage and loss of active surface area.
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