Chemical and Natural Resources Engineering Journal
Not a member yet
86 research outputs found
Sort by
OPTIMIZATION AND ADSORPTION STUDIES OF LEAD REMOVAL USING MODIFIED MACROPHYTE BIO-ADSORBENT
No full textLead contamination in wastewater presents a major environmental and public health concern due to its toxicity, persistence, and non-biodegradable nature. Although conventional treatment methods such as chemical precipitation and membrane filtration are commonly used, they often come with drawbacks including high operational costs, energy demands, and secondary pollution. As a sustainable alternative, this study investigates the potential of Azolla, an aquatic macrophyte, as a low-cost and eco-friendly bio-adsorbent for lead removal from contaminated water. The Azolla biomass was pre-treated with hydrochloric acid for five hours to improve its surface area and activate functional groups. Its lignocellulosic structure, rich in hydroxyl and carboxyl groups, supports effective lead adsorption via complexation and ion exchange mechanisms. A 2-Level Factorial Design was used to optimize key adsorption parameters including pH, contact time, and initial lead concentration. The highest removal efficiency of 93.69% was achieved at pH 10, a lead concentration of 250 ppm, and a contact time of 10 minutes. Adsorption isotherm analysis indicated that the process followed the Freundlich isotherm model, suggesting multilayer adsorption on a heterogeneous surface with multiple binding sites. These findings demonstrate the effectiveness of Azolla as a promising bio-adsorbent for lead removal. Further research is recommended to explore its long-term performance and scalability for industrial wastewater treatment applications
OPTIMIZING FORMULATION AND SYNTHESIS CONDITIONS OF RED PALM OIL (RPO)-BASED NANOEMULSIONS STABILIZED BY TWEEN 80
Get PDFNanoemulsion is an important class of nanomaterial that offers several advantages due to its improved stability and dispersibility in aqueous systems. In this preliminary study, oil-in-water nanoemulsions were synthesized using red palm oil (RPO). RPO was chosen for its high insoluble vitamin E content, a potent antioxidant that can reduce oxidative stress by neutralizing free radicals. The most suitable emulsifier, optimal formulation, and synthesis conditions to produce stable nanoemulsions were evaluated. A laser beam penetration test based on the Tyndall effect and light-scattering principles was used to confirm the presence of nanoemulsions qualitatively. The results indicate that Tween-80 produced the most stable and translucent nanoemulsion. The optimal formulation was found to have a weight ratio of 10:15:74:1 for RPO: Tween 80: water: glycerin. The optimal synthesis conditions were using the high-speed homogenizer at 15000 rpm for 40-minute synthesis time. The resulting nanoemulsions demonstrated stability suitable for further studies (e.g., physicochemical characterization, scale-up, and additional functionalization) for food and beverage applications
CARBON NANOTUBE-CHITOSAN THIN FILM ON QCM (QUARTZ CRYSTAL MICROBALANCE) FOR DETECTION OF IPA (ISOPROPYL ALCOHOL)
Get PDFThis study presents the development of a quartz crystal microbalance (QCM) sensor coated with a multi-walled carbon nanotube–chitosan (MWCNT-COOH/CS) composite for the detection of isopropyl (IPA) vapor, a common volatile organic compound (VOC). The composite was synthesized via glutaraldehyde crosslinking to enhance bonding between carboxyl-functionalized MWCNTs and chitosan, followed by sonication and stirring to ensure uniform dispersion. Material characterization was carried out using Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FESEM), confirming successful integration and interaction between MWCNTs and CS. Static QCM analysis showed that the MWCNT-COOH/CS composite achieved a balanced frequency shift of approximately 106 Hz with a response time of ~40 seconds, outperforming standalone CS and MWCNT layers in terms of response speed and signal stability. Dynamic measurements across IPA concentrations from 300 to 700 ppm revealed a linear frequency shift trend with a correlation coefficient (R²) of 0.9713. Compared with similar sensors reported in the literature, the developed composite exhibits promising sensitivity, faster response time, and ease of fabrication, suggesting strong potential for real-time VOC monitoring applications
OPTIMISATION OF BIOGAS YIELD THROUGH ENZYMATIC PRETREATMENT OF WASTEWATER
Get PDFAnaerobic digestion is commonly used to produce biogas from organic wastes, which are considered renewable energy sources. However, the slow degradation of complex organic compounds available in organic wastes poses difficulties for this process. Lower biogas yields and longer hydraulic retention times (HRT) are caused mainly due to the complex nature of the substrate. This study considers the possibility of applying enzymatic pretreatment to improve biogas production in anaerobic digestion systems. Enzymatic pretreatment is the process of breaking down complex organic molecules into simpler, more readily biodegradable compounds in hydrolysis steps utilising enzymes, such as cellulases, proteases, and lipases. The rise in biogas production measures the efficiency of the enzymatic pretreatment. According to preliminary findings, enzymatic pretreatment significantly increases the biodegradability of organic waste compared to untreated controls, producing higher biogas yields and shorter HRTs. However, the improvement varies depending on the type of waste and the process parameters used. The enzymatic pretreatment of municipal sludge, pulp and paper sludge, and POME has been reported to improve biogas yield by 23.1%, 26%, and 52.17%, respectively. The HRTs of the above-mentioned anaerobic processes are recorded as 11 days, 62 days, and 38 days, respectively. These results highlight the potential of enzymatic pretreatment as an effective way to maximise biogas production in anaerobic digestion operations. By improving biogas production efficiency, this strategy can support more environmentally friendly methods of managing waste and producing energy. To enhance economic and environmental sustainability, future research will expand the enzymatic pretreatment process and assess its useful applications in industrial anaerobic digestion systems. In addition, more research will look at the best enzyme combinations and dosages to maximise effectiveness and economy in practical applications
INFLUENCE OF THE PROCESS PARAMETER ON CHLORELLA VULGARIS CULTIVATION FOR CO2 SEQUESTRATION AND PROTEIN PRODUCTION
No full textMicroalgae, known for their high photosynthetic efficiency, offer a promising approach for CO? sequestration and the production of high-value products such as single-cell proteins (SCP). However, low CO? solubility in water and strain-specific tolerance limit CO2 fixation efficiency. This study aimed to optimise CO? fixation and SCP production in freshwater Chlorella vulgaris using the Taguchi Orthogonal Array method. Key parameters, namely light (5-15 kLx), CO? concentration (1–5%), and nitrogen content (0–1 g/L), were investigated in a 2-L Schott glass bottle. Process validation was performed within the same system, and a comparative assessment was subsequently conducted against a 2-L flat-panel photobioreactor (FPPBR) to determine any differences in cultivation performance. Results showed that biomass productivity had a greater influence on CO? fixation (9.049%) and protein yield (45.78%) than CO? concentration or nitrogen content. Notably, the flat-panel PBR achieved superior growth performance (47.67%), highlighting the importance of reactor design. Logistic growth modelling with the Taguchi growth rate equation provided the best fit for the experimental data (R2 between 0.6-0.93). These findings provide valuable insights for enhancing microalgae CO? capture and SCP production, although further refinement of cultivation systems and kinetic models is necessary
INVESTIGATING ADSORPTION ISOTHERMS AND KINETICS, AND ECOTOXICITY OF ACTIVATED CARBON FROM CARBON-FIBER REINFORCED POLYMER (CFRP)
Get PDFThis study presents the synthesis of activated carbon (AC) from carbon fiber reinforced polymer (CFRP) waste as a sustainable adsorbent for wastewater treatment. Characterization by FTIR, SEM, and XRD confirmed the development of functional groups, a porous morphology, and a predominantly amorphous carbon structure in AC, with minor graphitic domains in CFRP. Adsorption tests using the methylene blue (MB) dye showed good performance, with the Langmuir isotherm resulting in the best-fitted model (adjusted R² = 0.88), indicating monolayer adsorption and pseudo-first-order kinetics (adjusted R² = 0.96). Thus, confirming concentration-dependent adsorption of MB by AC, produced from CFRP. Ecotoxicity evaluation using brine shrimp assay revealed an LC50 of 33.11 mg (or 3311 mg/L), suggesting moderate toxicity. These findings demonstrate that AC derived from CFRP exhibits strong adsorption efficiency with acceptable ecological risk, providing a viable pathway to convert CFRP waste into valuable materials for environmental remediation
EVALUATION OF STABILITY, TANNIN CONTENT, ANTIOXIDANT ACTIVITY, AND ANTIMICROBIAL PROPERTIES OF Melastoma Malabathricum Linn. LEAF EXTRACT IN A WATER-BASED EMULSION
Get PDFMelastoma malabathricum (Linn.) (MML) is a small tree native to Southeast Asia, traditionally used in folk medicine to treat a variety of ailments, including hemorrhoids and wounds from childbirth. The leaves of MML contain several phytochemical constituents, including tannins, which are known for their antimicrobial and antioxidant properties. These properties position MML as a promising alternative to traditional antibiotics, especially in combating drug-resistant pathogens like Staphylococcus aureus. Traditionally, MML leaves are applied as a paste to wounds to serve as a topical antibiotic. However, this approach has proven to be impractical, prompting interest in more conventional formulations such as lotions and emulsions. To keep pace with the increasing reliance on herbal medicine, this study evaluates the potential of MML leaf extract in water-based emulsions, focusing on tannin content, antimicrobial and antioxidant activities, and emulsion stability. The crude extract was obtained using two methods—Soxhlet Extraction Method (SEM) and Cold Extraction Method (CEM)—to determine which method has the higher potential to produce the most effective antimicrobial agent. Both methods used a solvent mixture of ethanol, methanol, and water in a 70:20:10 ratio. After rotary evaporation, the yields of crude extract were 4.98 grams (SEM) and 3.62 grams (CEM), respectively. The extraction efficiency of CEM was higher in terms of tannin yield (31.63% more than SEM), while SEM exhibited superior antioxidant activity (66.94% higher than CEM). In addition, the stability tests indicated that the emulsions should be stored at 30ºC to prevent dissociation, suggesting a temperature-dependent stability factor. For antimicrobial activity, the study tested emulsions containing 3%, 5%, and 7% crude leaf extract, with the 7% concentration exhibiting the most promising antimicrobial properties. Based on the results of both the extraction methods and emulsion testing, the 7% emulsion could serve as an effective formulation for developing alternative topical treatments
EVALUATION OF FTA CARD PREPARATION FOR SSR MARKER AMPLIFICATION OF mEgCIR3607 FROM MATURE OIL PALM LEAVES
Get PDFABSTRACT: The oil palm (Elaeis guineensis) leaves are characterized by high levels of polysaccharides and secondary metabolites, which present significant challenges for effective DNA extraction and Polymerase Chain Reaction (PCR) analysis. The objective of this study is to investigate the applicability of Flinders Technology Associates (FTA) cards to preserve oil palm tissue from mature oil palm leaf for direct PCR. A total of 50 mature oil palm leaf samples were collected from independent smallholder plantations and deposited onto the FTA card. An attempt was made to compare between direct use of FTA card disc and FTA elute as DNA templates for PCR amplification using primer mEgCIR3607. Evaluation of FTA elutes as DNA template on 50 oil palm samples demonstrated successful PCR amplification with high intensity of PCR product. The findings showed that FTA cards effectively preserve DNA from mature oil palm leaves, enabling successful PCR amplification using FTA elute as a DNA template, which demonstrates their suitability for overcoming challenges associated with DNA extraction in Elaeis guineensis
IN SILICO CHARACTERIZATIONS OF DEGRADATIVE ENZYME FROM LANDFILL LEACHATE METAGENOME FOR POTENTIAL POLYCHLORINATED BIPHENYL (PCB) BIOREMEDIATION
Get PDFThe characterization of enzyme structure and function was essential for understanding biochemical pathways and developing effective biotechnological applications, particularly in environmental bioremediation. Traditional experimental methods for protein analysis were often labor-intensive and limited by the inability to culture certain microorganisms. In this study, an in silico approach was employed to predict the structure and function of a putative degradative enzyme identified from metagenomic analysis of landfill leachate. Using a combination of bioinformatics tools, including sequence alignment, domain annotation, secondary structure prediction and three-dimensional (3D) structural modeling, the target enzyme was analyzed for its catalytic potential and stability. Conserved motifs and active sites were identified, suggesting its involvement in the degradation of xenobiotic compounds such as polychlorinated biphenyls (PCBs). The 3D structure model revealed a typical fold associated with oxygenase or dehydrogenase activities, with predicted metal-binding sites critical for catalyses. These findings demonstrate the power of computational methods to accelerate the discovery and characterization of novel enzymes, especially from unculturable microbial communities. This approach provides a valuable foundation for future functional validation, protein engineering and the development of environmentally sustainable biocatalysts
POLYVINYL ALCOHOL-POLYETHYLENE GLYCOL/GLYCERIN HYDROGEL ENHANCED PHYSICOCHEMICAL CHARACTERISTICS: STATISTICAL COMPOSITION: Composition of PEG-Glycerin Hydrogel
No full textThis study addresses the weaknesses of polyvinyl alcohol (PVA) hydrogels by modifying their compositions through cross-linking with other polymers and adjusting the composition. PVA-polyethylene glycol (PVA-PEG) hydrogels, incorporating glycerin, were synthesized for wound dressings using the freeze-thaw method. Central composite design (CCD) and response surface methodology (RSM) assessed the impact of PEG and glycerin concentrations on moisture retention capability (MRC). The optimized composition, with 6% (w/v) PEG and 4% (w/v) glycerin, achieved the highest MRC at 46.82 ± 0.54%. The hydrogel exhibited a swelling capacity of 143.24 ± 1.66%, a gel fraction of 58.06 ± 1.65%, and a porosity of 42.17 ± 0.94%. Field emission scanning electron microscopy (FESEM) confirmed surface features and porosity, while Fourier transform infrared (FTIR) spectra analysis verified cross-linking within the PVA-PEG matrix with glycerin. These findings highlight the hydrogel's potential for wound dressings due to its favorable attribute