This research paper introduces an innovative methodology to produce biodegradable composite films by combining kaolin, polyvinyl alcohol (PVA), and potato starch (PS) using a solvent casting technique. The novelty of this study resides in the identification and implementation of optimal synthesis conditions, which were achieved by utilizing the Response Surface Methodology—Central Composite Design. The study defines starch, polyvinyl alcohol (PVA), and kaolin as independent variables and examines their influence on important mechanical qualities, water absorption capacity, moisture content, and degradability as primary outcomes. The study establishes the ideal parameters as 5.5 weight percent Kaolin, 2.5 g of starch, and 3.5 g of PVA. These settings yield notable outcomes, including a tensile strength of 26.5 MPa, an elongation at break of 96%, a water absorption capacity of 21%, a moisture content of 3%, and a remarkable degradability of 48%. The study emphasizes that the augmentation of kaolin content has a substantial impact on many properties, including degradability, tensile strength, and elongation at break. Simultaneously, it leads to a reduction in the water absorption capacity and moisture content. The study’s novelty is reinforced by conducting an additional examination on the ideal composite film, which includes investigations using FTIR, TGA, and SEM-EDX techniques. The consistency between the predicted and experimental results is noteworthy, as it provides further validation for the prediction accuracy of Design Expert software’s quadratic equations. These equations effectively capture the complex interactions that exist between process parameters and selected responses. This study presents novel opportunities for the extensive utilization of PVA/PS composite films, including kaolin in various packaging scenarios, thereby significantly advancing sustainable packaging alternatives. The statistical analysis provides strong evidence supporting the relevance of the models, hence increasing our level of trust in the software’s prediction skills. This conclusion is based on a 95% confidence level and p-values that are below a threshold of 0.05.

The rapid increase in demand for renewable energy has led to a need for more efficient and effective ways to produce biogas from palm oil mill effluent (POME), which is rich in biological and chemical oxygen demand (BOD and COD). Despite its potential as a source of biogas, POME is not always effectively utilized in biogas production due to a lack of optimization of the treatment process. This study aims to address this issue by identifying the critical parameters affecting biogas production from POME and optimizing the process for maximum biogas yield and COD removal. This study employed comparative analysis and response surface methodology to optimize the performance of palm oil mill effluent (POME)-based biogas plants in Malaysia. Historical data from three commercial POME-based biogas plants in Malaysia were analyzed to identify the most critical parameters for biogas yield and COD removal. Response surface methodology, using Box–Behnken design and Design-Expert software, was then used to optimize these parameters. Sensitivity analysis was performed to interpret the impact of parameters on biogas production, with Organic Loading Rate (OLR) found to be the most critical factor for methane yield. The results showed that the optimum conditions for maximum methane production were OLR of 1.23 kg/m³·day, inlet Total Solids (TS) of 46,370 mg/L, pH of 4.5, and temperature of 45.4 °C, resulting in a 39.6% increase in methane yield (0.335 m³ CH₄/kgCOD_removed) and a 1.1% increase in COD removal (93.4%).

Shampoo prepares surfactants to remove dirt, surface grease, and skin debris from hair, shaft, and scalp without harming the user. This study aimed to formulate herbal shampoo using Ethiopian plant extracts and evaluate their quality parameters. Herbal shampoos were formulated using seed oil extracts of Lepidium sativum L. and Ricinus communis L., and essential oil extracts of Lippia adeonsis Hochst ex. Walp koseret, along with other ingredients. The formulated herbal shampoos were evaluated for their organoleptic and physicochemical properties such as pH, surface tension, viscosity, dirt dispersion, antimicrobial activities, and stability. When the investigation data were assessed, the formulations were pleasant and attractive, produced sufficient foam, and showed suitable cleansing activities. The pH values were in a range 5.90 ± 0.22–7.45 ± 0.19, and lower surface tension (23.39 ± 0.20–31.89 ± 1.04 dyne/cm) together with acceptable viscosity with good shearing properties were obtained. The formulated products exhibited good antimicrobial activities against Escherichia coli, Staphylococcus aureus, and Aspergillus niger. When the surface morphologies of hair samples were examined using a scanning electron microscope (SEM), a clean and smooth surface was observed for treated samples, comparable to that of the marketed shampoo. This result indicated that the formulated herbal shampoo is good, having acceptable properties at par with commercially available shampoos. However, further investigation, research, and development are required to improve its quality and safety.