Abstract Palm oil (PO) is a potential alternative to mineral oil for electrical insulation and has previously been studied with rice husk (RH) powder as a filler. Research has shown that RH powder enhances the breakdown voltage (BDV) and hence the dielectric, and physical properties of PO. Additionally, the effect of different preparation methods has been explored, showing further improvements in these properties. In this study, we modified the preparation method by scaling up the sample volume from 500 ml to 800 ml, leading to a positive impact on the properties of PO. To determine the optimal RH concentration for achieving the highest BDV, various concentrations of RH in PO were tested according to the IEC 60156 standard. The results demonstrate that the BDV improved significantly with the 800 ml sample volume compared to previous studies. Moreover, the data revealed a maximum curve trendline in the graph of BDV versus RH concentration. Overall, the modified preparation method yielded better BDV results, with the optimal RH concentration found to be 0.20 g/L, providing the highest BDV value.

Abstract Heavy metal pollution in aquatic environment usually happened at low concentration. Current heavy metal removal technologies have high operational cost. Subsurface flow constructed wetland is a potential solution as it is a low-cost ecotechnology. The high production of underutilised oil palm shell in Malaysia poses a potential as an alternative media for constructed wetland in heavy metal removal. This study aimed to compare the feasibility of oil palm shell as alternative media to gravel in mesocosm-scale constructed wetland for the removal of copper, zinc and lead. All oil palm shell- and gravel-based mesocosm units, unplanted and planted with Typha angustifolia, were spiked with synthetic wastewater under batch drain-and-fill mode and operated at three days hydraulic retention time for 180 days. The removal of lead in both oil palm shell- and gravel-based mesocosms were consistently near 100%. Copper and zinc removals in the oil palm shell-based mesocosms were ranging at 93.11 – 100% and 97.75 – 100%, respectively. Whereas copper removal in the gravel-based mesocosms ranged at 92.13 – 99.98%. Although pH in the planted gravel-based mesocosm was near neutral (pH 6.47 – 7.43), plant presence reduced zinc removal from 99.93% (Day 228) to 66.37% (Day 405) in the gravel-based mesocosm. Higher removal of sulphate in the oil palm shell-based mesocosms suggested the occurrence of metal sulphide precipitation. Oil palm shell-based mesocosms performed better than gravel-based mesocosms, both in unplanted and planted conditions. Further studies need to be done on the changes of media’s physicochemical properties after experiment as well as copper, zinc and lead mass balance to understand better the removal pathway of copper, zinc and lead in all the mesocosms.

Abstract The study aims to assess the knowledge of plastic and microplastic pollution as well as the issues, determine students' attitudes and perceptions about the best practices for reducing plastic and microplastic pollution, and analyze the correlation between awareness, attitude, and opinion on the current efforts to decrease plastic pollution among UTHM students. An online survey was distributed over social media platforms like WhatsApp and Telegram. Four sections were utilized to collect data: demographic information; knowledge, attitudes, and perceptions about plastic and microplastic pollution. The 120 students who responded were 60 from each diploma and degree program. UTHM students showed a great awareness of plastic and microplastics, and as a result, they had a favorable attitude toward pollution reduction. Consequently, participants also had a positive opinion of current initiatives to reduce plastic and microplastic contamination. Besides, a moderate positive correlation exists between attitude and opinion on current efforts with a Pearson correlation of 0.574, implying that students should be taught plastic reduction and encouraged to participate in current initiatives. Plastic or microplastic pollution education via organized education, mass media, and substituting non-biodegradable plastics with eco-friendly alternatives may assist in alleviating the existing problem of plastic or microplastic pollution.

Abstract An unknown leaf spot disease was reported in the nursery of an oil palm estate. A study was conducted to isolate and identify the potential causal agents and to screen the efficacy of different fungicides in suppressing the isolated fungal genera under in vitro condition. Disease symptoms were recorded, and healthy and diseased leaflets were collected from the estate’s nursery for microbe community analysis. The leaflets were subjected to genomic DNA extraction for Illumina MiSeq sequencing to determine the fungal community in the samples. Additionally, sterilised leaflets were cut and placed on Rose-Bengal chloramphenicol (RBCA) agar for isolating fungal cultures. The DNA of fungal isolates were then extracted, sequenced, and compared with the database using BLAST program. MiSeq sequencing revealed that there were significantly higher relative abundances of Curvularia sp. (38.53 %), Colletotrichum sp. (14.19 %), and Thermoascus sp. (4.79 %) in diseased leaflets compared to healthy leaflets. Different fungicides were screened at the recommended rates using poison food agar assay to test their efficacy in suppressing the potential causal agents. Mancozeb 80% WP (0.188%), propineb 70% WP (0.300%), difenoconazole 23% + propiconazole 23% EC (0.100%), difenoconazole 23% (EC) (0.050%), and prochloraz manganese chloride 50% WP (0.100%) gave 100% mycelial growth inhibitions of Curvularia oryzae isolate and two Colletotrichum sp. isolates. This study provides insights into the effective fungicides for controlling leaf spot diseases in oil palm nurseries.