Abstract Illicium verum Hook essential oil (EO) is composed mainly of trans-anethole (TA), which has therapeutic potential. The extraction is usually by hydrodistillation, taking long hours, leaving the process costly and product with lower quality. Thus, the present study sought to optimize dehydrated fruit fragmentation by Box-Wilson central composite design and EO extraction and EO quality using a 24-1 fractional factorial design. It is concluded that the fruits must be fragmented to sizes smaller than 425 μm using a knife mill. For hydrodistillation, the condition reported as ideal was granulometry < 0.425 mm, 8% mass, 1 hour and water volume of 200 mL. This process provided an EO yield of 10.2% and high-grade TA (96.6%), requiring shorter time of extraction.

ABSTRACT: This study aimed to evaluate the effect of variations in organic load (hydraulic retention times - HRTs: from 2 to 0.5 day) and in alkalinity (NaHCO3 from 4,000 to 1,000 mg.L−1) on methane production. Biomass of sewage sludge was inoculated and stabilized on 1" polypropylene rings. The rings were immersed in the liquid phase (8.41 L) of an upflow anaerobic filter reactor (12.22 L). A solution of 5 g of whole milk powder per liter was used to simulate effluent from the dairy industry. Process effectiveness was measured by chemical oxygen demand reduction, biogas production, and biogas methane content. Biogas production started at a 2-day HRT and synthetic effluent alkalinization with 4,000 mg.L−1 NaHCO3. The best operation condition was at 1-day HRT and with the addition of 4,000 mg.L−1 NaHCO3. Biogas production reached 1.5 NL of biogas per L of reactor liquid phase, with 68% of methane and a concomitant reduction in COD of 57%.