Zurina Zainal Abidin

Concerns on the environment, health and safety issues posed by synthetic resins has amplified numerous efforts of producing resin from various renewable sources. The use of plant oil as potential source of resin has attracted interest from various researchers. Jatropha Oil is a competitive source to petroleum counterparts due to its availability, biodegradability, low eco-toxicity but exhibit poor mechanical properties among many. The objective of this study is to study the effect of adding nanoparticles as reinforcing fillers to bio-based resin from Epoxidized crude Jatropha Oil (ECJO) to improve its mechanical performance. Various loadings of 0% to 4% of Al2O3 nanoparticles was tested on epoxy bio-resin. Later the specimens fabricated were cured and characterized for its mechanical properties. Addition of 1 wt% of Al2O3 nanoparticles improved the tensile strength of a bio-based epoxy resin to tensile stress of 29.37±2.00 MPa, elastic with an elastic modulus of 840.80±124.53 MPa. Further characterization at optimum addition of nano-Al2O3 resulted a glass transition temperature of 37.95˚C. In overall, the inclusion of nano-Al2O3 has definitely improved the mechanical properties of the material which will be useful for further application material engineering.

This study aimed to optimize the removal of Cu(II) ions from an aqueous solution using a Jatropha oil bio-based membrane blended with 0.50 wt% graphene oxide (JPU/GO 0.50 wt%) using a central composite model (CCD) design using response surface methodology. The input factors were the feed concentration (60–140) ppm, pressure (1.5–2.5) bar, and solution pH value (3–5). An optimum Cu(II) ions removal of 87% was predicted at 116 ppm feed concentration, 1.5 bar pressure, and pH 3.7, while the validated experimental result recorded 80% Cu(II) ions removal, with 95% of prediction intervals. A statistically non-significant term was removed from the analysis by the backward elimination method to improve the model’s accuracy. Using the reduction method, the predicted R² value was increased from −0.16 (−16%) to 0.88 (88%), suggesting that the reduced model had a good predictive ability. The quadratic regression model was significant (R² = 0.98) for the optimization prediction. Therefore, the results from the reduction model implied acceptable membrane performance, offering a better process optimization for Cu(II) ions removal.

This paper studies the mechanical properties of bio-epoxy resins blended with synthetic epoxy resins (epoxamite). The bio-epoxy resins were derived from Jatropha methyl esters through epoxidation method. They were formulated with epoxamite and hardener at different compositions and then cured at different temperature and time settings. The cured blends were subjected to tensile and flexural tests using Instron machine. Tensile and flexural strength of the mixtures were compared with the 100% epoxamite in order to evaluate the suitability of bio-epoxy resins as an alternative to synthetic epoxy resins with respect to mechanical properties. Tensile strength of 100% epoxamite is 38.32 MPa and flexural strength is 63.32 MPa. The mixtures of bio-resins and epoxamite demonstrated very low mechanical strengths compared to the 100% epoxamite. Therefore, they are not suitable to be used as an alternative to synthetic epoxy resins in industrial applications. However, they may find other usage due to high reactivity of the bio-epoxy resins.

New ways of synthesizing organic-based fluorescent carbon dots (CDs) are required in environmental application. This is crucial for mitigation and control of pollutants without increasing the risk of releasing byproduct pollutants as the case with non-organic (metallic) quantum based substrate. Notably, this study provides current research on sustainable synthesis of CDs and their applications through analytical concept of recent and advance techniques for efficient and optimized processes. New scrutinized methods of synthesis and applications of CDs are beneficial and essential to optimize the state-of-art practices. The value distilled in this study adds to the field of sustainable production and application of CDs.

In this study, a techno-economic assessment of an on-farm biogas system using an anaerobic biofilm reactor utilizing cow manure as a fermentation substrate was evaluated. A projection model was developed using Microsoft Excel software with three outputs, the size and dimension of a bioreactor, experimental microbial kinetic studies, and the economic studies based on the experimental results. Characterization analysis of cow manure wastewater showed the total solid (TS), total volatile solid (TVS), total carbohydrate (TC), chemical oxygen demand (COD), and pH values which were 10.95 g/L, 8.65 g/L, 6.65 g/L, 57.80 g/L, and 7, respectively. Using the modified Gompertz equation for the microbial studies, it was found that, at 37 °C and 20 days hydraulic retention time (HRT), the biogas yield was 934.54 mL/gVS, the volume of biogas produced was 11.28 m³/d, and 22.56 kWh of electricity was generated. The Gompertz prediction helps to determine the optimal HRT for the system so that the microorganisms are at their optimum stage to produce biogas. The economic analysis was done, and the results illustrated that, when the rate of cow manure produced was at 55 L/day.cow, the net present value (NPV) was RM 611,936.09, with a 13% internal rate of return (IRR), 0.14 return on investment (ROI), and 7.02 years of payback period (PP). By developing a techno-economic assessment that included all the necessary parameters such as sizing of the bioreactor, microbial kinetic studies, and economics of the plant, farmers could easily implement the system into their farms. This model showed that the anaerobic digestion system utilizing an attached biofilm with cow manure as a fermentation inoculum and substrate was applicable on an industrial scale to generate electricity and reutilize to the farm, at the same time generating additional income from the production of fertilizer.