Palm Oil Mill Effluent for Lipid Production by the Diatom Thalassiosira pseudonana

Biomass and lipid production by the marine centric diatom Thalassiosira pseudonana were characterized in media based on palm oil mill effluent (POME) as a source of key nutrients. The optimal medium comprised 20% by volume POME, 80 µM Na2SiO3, and 35 g NaCl L−1 in water at pH ~7.7. In 15-day batch cultures (16:8 h/h light–dark cycle; 200 µmol photons m−2 s−1, 26 ± 1 °C) bubbled continuously with air mixed with CO2 (2.5% by vol), the peak concentration of dry biomass was 869 ± 14 mg L−1 corresponding to a productivity of ~58 mg L−1 day−1. The neutral lipid content of the biomass was 46.2 ± 1.1% by dry weight. The main components of the esterified lipids were palmitoleic acid methyl ester (31.6% w/w) and myristic acid methyl ester (16.8% w/w). The final biomass concentration and the lipid content were affected by the light–dark cycle. Continuous (24 h light) illumination at the above-specified irradiance reduced biomass productivity to ~54 mg L−1 day−1 and lipid content to 38.1%.

Pollution and Potential Ecological Risk Assessment of Heavy Metals Around the Active Bukit Mendi Palm Oil Mill Area, Bera Pahang, Malaysia

The study on the impact of palm oil mill processing activities on the environment of Bukit Mendi Palm Oil Mill was conducted by determining the distribution of six heavy metal concentrations Cadmium (Cd), Copper (Cu), Manganese (Mn), Lead (Pb), Iron (Fe) and Zinc (Zn) and the selected pollution indices. This study provided some information on the accumulation of heavy metals in the selected area and served to identify the potential sources contributing to these heavy metals. Soil samples were collected from eight sampling sites around the palm oil mill and analysed for the selected metals using ICP-OES. Three types of pollution indices were used to observe the pollution level of the area, namely Enrichment Factor (EF), potential ecological risk index (PERI), and Contamination Factor (CF) of heavy metal content. The average total concentration of the selected metals was found to increase in the order of Fe, Mn, Zn, Cd, Pb, and Cu. The metal Fe showed the highest metal content, followed by Mn at 1573.00 mg/kg and 154.00 mg/kg, respectively. The values of EF showed that the metal was unevenly distributed throughout the sampling areas, where heavy metal content ranged from minimal to extremely high enrichment. The potential ecological risk ranging from low to severe was observed in this study. The CF values revealed that the area was heavily contaminated with Cd and only slightly contaminated with Pb. The pollution indices determined in this study suggested that the study area was moderately contaminated with metals, and the metal Cd was found to be the only metal potentially posing an ecological risk to the area.Keywords: ICP-OES, palm oil mill, heavy metals, soil pollution, pollution indices

Screening for Noise-Induced Hearing Loss among Palm Oil Mill Workers in Peninsular Malaysia: A Comparison across Noise Exposure Levels

Background: Palm oil mill workers in Malaysia are exposed to hazardous levels of noise in the workplace, and thus are at risk of developing noise-induced hearing loss (NIHL). In 2019, Malaysia introduced a new noise regulation, which reduced the level of permissible noise exposure. Objectives: This study aims to determine the prevalence of NIHL among palm oil mill workers based on screening data and assess the effects of different noise exposure levels on NIHL. Methods: A cross-sectional study was conducted by analyzing data from noise risk assessment reports of selected mills and screening audiometric data from workers. NIHL was defined as bilateral high-frequency hearing loss. Results: The overall NIHL prevalence was 50.8%. Noise exposure level and age were significant predictors of NIHL among the workers. The risk of developing NIHL was high even for workers who were not categorized in the high-risk group. Conclusions: In view of the findings, a precautionary approach is needed when evaluating the risk of NIHL in the study population. Vulnerable groups of workers must be protected from occupational noise hazards through the implementation of effective hearing conservation programs in the workplace.

Frond Base Fracture and Dynamics of Palm Oil Inflorescence Applied With Different Nutrient Sources

Frond base fracture is an increasingly common phenomenon in oil palm plantations caused by various stress factors. This study aimed to determine the incidence of frond base fracture in the plantation where different nutrient sources were applied (palm oil mill effluent, oil palm EFB, and organic fertilizers) in relation to the dynamics of oil palm inflorescence. The incidence of frond base fracture and the production of male and female inflorescences were observed in 30 sample trees for each nutrient source. Observations were made three times with an interval monthly. To reveal the research objectives, it used descriptive analysis. The results showed that the routine application of POME increased the susceptibility of oil palms to fractured fronds and the sex ratio was higher other than that of EFB; the lowest incidence was found in the palm that was given inorganic fertilizers. frond base fracture trees produced fewer female inflorescence, although the number of male ones did not differ between frond base fracture palm and healthy ones.

Esterification of Free Fatty Acid in Palm Oil Mill Effluent using Sulfated Carbon-Zeolite Composite Catalyst

Free fatty acid esterification (FFA) in palm oil mill waste (POME) was carried out using a sulfonated carbon-zeolite composite catalyst. The catalyst is synthesized with carbon precursor obtained from molasses, which is adsorbed on the surface of the zeolite and then carbonized and sulfonated with concentrated H2SO4 to form a sulfonated carbon-zeolite catalyst composite, which will be used for the esterification catalyst and the optimization process for the esterification reaction is carried out using the response surface methodology (RSM) and experimental central composite design (CCD). Importantly, the observed independent variables were temperature, catalyst weight, and reaction time to produce fatty acid methyl ester (FAME) products. The catalyst was successfully synthesized, which was shown from the SEM characterization strengthened by the presence of a sulfate group in the FTIR results and the calculation results of high acidity properties. Optimization of FFA esterification with SCZ catalyst obtained optimal conditions with a temperature of 79oC, a catalyst weight of 3.00 g, and a reaction time of 134 minutes with a FAME product of 93.75%, considering that the viscosity of biodiesel is below that required by the API.