This study investigates the synthesis and characterization of polylactic acid (PLA) derived from water hyacinth as a sustainable alternative to conventional plastics. Biomass characterization through proximate analysis, chemical composition analysis, and Fourier transform infrared radiation (FTIR) revealed cellulose (34.82%), hemicellulose (42.44%), lignin (12.11%), and extractives (10.63%), confirming the biomass as a carbohydrate-rich feedstock suitable for biopolymer production. Fermentable sugars were obtained via sulfuric acid hydrolysis and converted to lactic acid through fermentation, followed by recovery using reactive distillation. Optimal fermentation conditions were identified at 40 degrees C, pH 6.5, and 48 h incubation, yielding 15.04 wt% lactic acid (LA). Optimization using Response Surface Methodology with a Box-Behnken Design predicted a yield of 15.19 wt%, closely matching the experimental value of 15.12 wt%, validating the predictive model. The produced LA and synthesized PLA were characterized using FTIR, rheometry, Differential Scanning Calorimetry (DSC), and mechanical analysis. Thermal analysis indicated a glass transition temperature (Tg) of 62.9 degrees C, crystallization temperature (Tc) of 106.5 degrees C, and melting temperature (Tm) of 183.15 degrees C. Mechanical properties showed tensile strength of 29.4 MPa, elongation at break of 35.6%, and Young's modulus of 82.6 MPa. The biodegradability of the synthesized PLA is influenced by thermal properties, mechanical performance, and water absorption. Biodegradability testing demonstrated 12.5% degradation after 30 days of soil burial, while water absorption reached 4.7% after 16 h immersion. The results confirm that a good PLA sheet was produced from water hyacinth with interesting mechanical properties through environmentally friendly strategy to reduce dependence on petroleum-based plastics.

The global energy crisis has increased the need for sustainable renewable fuels. This study focused on synthesizing, characterizing, and optimizing biodiesel from Jatropha curcas seed oil using novel heterogeneous catalysts derived from waste banana peel and animal bone. Catalyst preparation involved calcination in a muffle furnace, with banana peel treated at 600-1000 degrees C and animal bone at 700-1000 degrees C for 2-6 h. The calcined materials were then mixed in ratios ranging from 0:100 to 100:0, immersed in distilled water, stirred, and heated at 80 degrees C for 3 h. They were dried at 120 degrees C for 12 h, followed by a final calcination at 800 degrees C for 2 h. Characterization using XRD confirmed the crystalline structure, while FT-IR identified functional groups and chemical compounds. Optimal catalyst synthesis was achieved at 900 degrees C for 3 h for banana peel, 1100 degrees C for 5 h for animal bone, and with a 50:50 wt% mixture of both materials. This catalyst was used in the transesterification of Jatropha curcas seed oil under conditions of 5 wt% catalyst loading, 65 degrees C, and a methanol-to-oil ratio of 12:1 for 3 h, producing a biodiesel yield of 92.87 wt%. Optimization using Response Surface Methodology (RSM) predicted a maximum yield of 96.14 %, which was experimentally validated with a yield of 93.02 %. Biodiesel composition analyzed by FT-IR and GC-MS confirmed the formation of fatty acid methyl esters. Catalyst reusability tests showed promising performance over multiple cycles. The physicochemical properties of the biodiesel met established biofuel standards. Overall, this study demonstrates the potential of waste-derived catalysts for efficient biodiesel production and contributes to the advancement of renewable energy solutions.

This study compared the efficacy of combined adsorption–photocatalytic process using biosynthesized TiO2 nanoparticles with the Fenton process in removing profenofos. Characterization techniques such as BET, XRD, and SEM were employed to characterize the biosynthesized nanoparticles. Batch tests were conducted to analyze the effects of different parameters on the adsorption process. The characterization of the TiO2 nanoparticles derived from guava leaves showed an increased BET surface area of 13.002 m2 g–1 compared to commercially available TiO2. Under optimal conditions of pH 6, 110 min contact time, 1.5 g L–1 adsorbent dosage, and 9 mL L–1 H2O2 concentration, nanoparticles exhibited high initial removal efficiency of 98.6 ± 0.65% for pesticide from wastewater. The reusability study showed that TiO2 nanoparticles can retain more than 81% of pesticides over the five cycles, and this decline in removal capacity may be due to the saturation of adsorption sites. The TiO2 nanoparticles had a point of zero charge at 6.7, facilitating efficient pesticide removal below this pH value. Adsorption isotherm studies favored the Freundlich model (R2= 0.993), indicating multilayer adsorption of profenofos on TiO2 nanoparticles. A strong agreement with a pseudo-second-order (PSO) kinetic model (R2= 0.996), as well as similar fits to the Dubinin-Radushkevich isotherm and Elovich kinetic models, suggested chemisorption mechanisms in the adsorption processes. Guava leaf-based biosynthesized TiO2 nanoparticles exhibited superior performance in removing profenofos compared to the Fenton process, indicating a more environmentally friendly and efficient method for OPPs remediation.

The present research focused on the synthesis and characterization of fatty acid methyl ester (FAME) derived from cottonseed oil using a nickel-doped chicken eggshell (Ni-CaO) catalyst, and evaluated the biodiesel's engine performance and emission characteristics. The Ni-CaO catalyst was prepared via calcination and characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM), showing improved catalytic activity and higher FAME yields compared to un-doped CaO. The maximum oil yield obtained from cottonseeds was 44.75 wt %, achieved using 100 g of seeds under extraction conditions of 65 degrees C, 5 h, a 6:1 solvent-to-solid ratio, and atmospheric pressure using solvent extraction method. Similarly, the maximum FAME yield reached 96 wt% at 60 degrees C, 120 min reaction time, 5 wt% catalyst loading, and a 12:1 methanol-to-oil ratio via transesterification reaction. The produced cottonseed methyl ester (COME) complied with ASTM D6751 and EN 14214 standards, satisfying critical fuel quality parameters such as cetane number, viscosity, acid value, flash point, and moisture content. Engine performance tests demonstrated that COME exhibited a slight decrease in brake thermal efficiency (2-4 %) and a 6-10 % increase in brake specific fuel consumption compared to diesel, while significantly reducing CO, hydrocarbons (HC), and particulate emissions, indicating improved combustion characteristics and environmental performance.

The surging demand for ecofriendly and sustainable energy sources has propelled the exploration of innovative solutions. This study comprehensively investigates the production and characterizations of bioethanol derived from the waste lignocellulose sugarcane top and leave. The biomass composition, including hemicellulose, cellulose, and lignin, was thoroughly analyzed. The hydrolysis uses diluted sulfuric acid at a temperature ranging from 110 degrees C to 122 degrees C, with a time of 20-30 min, and acid concentrations of 2%-3%. To understand the effect of hydrolysis during fermentation, the untreated and acid-treated biomass samples underwent various characterization techniques, including FTIR and SME-EDX. The anaerobic fermentation transformed the hydrolyzed biomass into bioethanol using the yeast strain Saccharomyces cerevisiae. Fermentation occurred at a temperature of 30 degrees C and a pH of 4.86, with a fixed biomass concentration of 10 v/v yeast strain and a final fermentation time of 72 h. The resulting ethanol-water mixture was separated through distillation, and its characteristics were determined, revealing a density of 807 kg/m3 and a viscosity of 1.55 & times; 106 m2s-1. The observed ethanol yield from sugarcane leaves and tops reached 28.24%. To optimize the process parameters, response surface methodology was employed. The optimal conditions were a temperature of 121.95 degrees C, time of 26.36 min, and an acid concentration of 2.99%. These conditions yielded a total reduced sugar content of 69.63%, thereby maximizing the bioethanol yield. Under these optimal conditions, chromatography-coupled mass spectrometry (GC-MS) confirmed the presence of 18.65 g/L of bioethanol in the broth.

A sustainable waste-to-energy strategy has been developed for the production of fatty acid ethyl esters (FAEE) from waste cooking oil using a heterogeneous CaO catalyst derived from discarded chicken eggshells. The process combines dual waste valorization with enhanced renewable energy production by employing ethanol instead of methanol. Catalyst characterization revealed that a hydration–dehydration treatment generated a highly porous CaO structure, with Ca–O vibrational bands observed at 598 and 545 cm⁻¹, and a maximum basicity of 4.23 mmol g⁻¹ achieved after calcination at 900 °C for 3 h. Optimization using response surface methodology resulted in a maximum FAEE yield of 94.86% at 77 °C, with an ethanol-to-oil molar ratio of 14.65:1 and a catalyst loading of 7.42 wt%. The activation energy was determined to be 94.73 kJ mol⁻¹. The produced FAEE met ASTM D6751 and EN 14,214 specifications, reducing free fatty acid content from 1.07% to 0.11% and exhibiting improved oxidative stability with 500 ppm of tert-butylhydroquinone (TBHQ). Furthermore, engine performance testing of FAEE-diesel blends (B5–B20) demonstrated comparable performance to conventional diesel fuel. At 40% load, brake power increased from 1.95 kW (B0) to 2.00 kW (B20), while brake thermal efficiency decreased slightly from 19.2% to 18.2%, and brake-specific fuel consumption rose from 0.51 to 0.59 kg/kWh. At full load, B20 reduced emissions of CO₂, CO, and particulate matter by 6.7%, 19.0%, and 40.9%, respectively, with a modest increase in NOx emissions. These findings confirm the strong potential of eggshell-derived CaO catalysts for sustainable biodiesel production.

Excess fluoride in industrial wastewater poses serious environmental and health risks due to its toxicity and persistence in aquatic environments. This study developed a low-cost ZnCl₂-modified biochar from waste banana peels and corn cobs for fluoride removal. The prepared adsorbent was characterized using TGA, XRD, FTIR, and SEM analyses. Batch adsorption experiments were conducted to evaluate the influence of pH (2–12), contact time (20–120 min), adsorbent dosage (0.1–2.0 g), and initial fluoride concentration (5–60 mg/L). The results confirmed that the treated biochar exhibited enhanced surface roughness, improved porosity, and abundant active functional groups that facilitate fluoride adsorption. Under optimal conditions (pH 4, 80 min contact time, 2 g dosage, and 30 mg/L fluoride concentration), the removal efficiency of 95.5 ± 1.10

The rapid growth of industrialization and urbanization has led to significant water contamination by toxic heavy metals, notably hexavalent chromium (Cr(VI)). This study investigates the potential of an eco-friendly bio-composite adsorbent synthesized from agricultural waste for the efficient removal of Cr(VI) from aqueous solutions. Characterization using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of key functional groups (CO, C-O, -OH) and a favorable surface morphology, respectively. Batch adsorption experiments were conducted by varying Cr(VI) concentration (20-100 mg/L), contact time (15-95 min), pH (2-10), and adsorbent dosage (0.1-1.3 g). A removal efficiency of 90 +/- 0.64 % was achieved using 0.7 g of adsorbent at 20 mg/L Cr(VI), pH 2, and 45 min of contact time, resulting in a maximum adsorption capacity (Qm) of 18.944 mg/g. The nonlinear Temkin model (RMSE = 0.238, chi(2) = 0.009, R-2 = 0.999) provided the best fit to the adsorption data, while the pseudo-first-order kinetic model (RMSE= 0.173, chi(2) = 0.02946, R-2 = 0.925) most accurately described the adsorption kinetics. Thermodynamic analysis indicated that a positive value of Delta H degrees (+0.0854 kJ/mol) suggests that the adsorption of Cr(VI) ions onto the adsorbent is endothermic. This implies that increasing the temperature enhances adsorption efficiency by providing the energy required for interactions. A negative entropy value (Delta S degrees = -0.27 J/mol K-circle) indicates decreased randomness at the solid-solution interface, while Delta G < 0 across the entire temperature range signifies that the adsorption process is spontaneous. Overall, the bio-composite exhibited high adsorption potential and presents a sustainable approach for the removal of Cr(VI) from wastewater.

Agricultural wastewater, which contains nitrates, phosphates, pesticides, and biochemical oxygen demand (BOD), along with industrial discharges that include heavy metals, volatile organic compounds (VOCs), chemical oxygen demand (COD), suspended particulates, and phenolic compounds, poses a risk of water contamination even at minimal levels. Therefore, it is essential to manage this wastewater through integrated treatment methods before releasing it into aquatic environments. The combination of traditional systems with Advanced Oxidation Processes (AOPs) specifically for treating industrial and agricultural wastewater is a crucial area of research aimed at improving the effectiveness of treatment methods to facilitate the reuse of treated water across various sectors. These integrated approaches offer advantages but also introduce challenges that need addressing for broader application. Additionally, this review focused on the removal of harmful contaminants from agricultural and industrial wastewater. It covered a variety of advanced treatment techniques, including combined coagulation-flocculation-decantation and the Fenton method, as well as integrated coagulation with photo-Fenton oxidation, electrocoagulation paired with photo-Fenton, and coagulation alongside UV/H2O2/ferrioxalate complexes. It also examined Fenton-adsorption, Fenton-nanofiltration methods, and microelectrolysis integrated with Fenton oxidation and coagulation. Moreover, the combination of UV/Fe2+ and photo-Fenton was discussed, along with hybrid moving bed bioreactors utilizing advanced oxidation processes such as Fenton, photo-Fenton, and UV-C/H2O2. The integration of air stripping with Fenton oxidation and enhanced coagulation was also considered, alongside O3/H2O2/peroxymonosulfate processes, catalytic wet air oxidation, and photocatalytic oxidation involving activated carbon doping, among others. These methodologies aim to address the complex nature of pollutants found in industrial discharges. Furthermore, a comprehensive discussion was provided on the use of combined traditional systems with AOPs for wastewater treatment in both agricultural and industrial contexts, emphasizing the importance of these processes in achieving significant treatment results.

Model predictive control is a powerful advanced process control technique for controlling dynamic systems with complex interconnections. It is a control strategy that forecasts future behavior using a dynamic model and then optimizes control actions to fulfill objectives while accounting for constraints. Heating, ventilation, and air conditioning (HVAC) is the process of regulating temperature, humidity, and air quality in a compact space using a range of technologies. Due to their significant energy consumption, HVAC systems require sophisticated control techniques and multi-objective optimization to maximize system efficiency and minimize costs. Building HVAC performance can be optimized with the help of model predictive control, which provides a strong framework that lowers energy expenditures, increases comfort, and improves overall system performance. The main focus of the paper is a detailed review of the model predictive control technique for heating, ventilation, and air conditioning systems. The fundamental concept, the basic principles, and the ongoing state of model predictive control research in heating, ventilation, and air conditioning are explained in this review. The difficulties with heating, ventilation, and air conditioning systems and control strategies are outlined, along with a modern comparison of several heating, ventilation, and air conditioning control strategies using model predictive control. The review examines and briefly discusses some of the key elements that influence model predictive control performance in the heating, ventilation, and air conditioning system. The review identifies several promising research areas and model predictive control implementation gaps in heating, ventilation, and air conditioning technology that warrant additional investigation. This review compiles important developments in the field and offers scholars and researchers insightful information.