Component optimization of dairy manure vermicompost, straw, and peat in seedling compressed substrates using simplex-centroid design

Adding an appropriate proportion of phosphogypsum ensured rice husk and urea composting to promote the compost as substrate utilization

To explore the effectiveness of urea replacing poultry manure as the nitrogen source in the rice husk composting system, and to promote the utilization of compost products as substrates, 0%, 10%, 20%, and 30% of phosphogypsum were added respectively in the urea composting system, and were compared with the chicken manure composting (RCP0). Finally, the fermentation and maturation of RCP0 were achieved, but high EC value limited the utilization of compost products as the substrate. Urea, as an N source, could lower the EC value, but the C/N ratio was uncoordinated during the initial stage of composting. Adding an appropriate proportion of phosphogypsum could ensure a proper C/N ratio to promote smooth fermentation and enable the products to be ideal substrates. When the added proportion was 30%, the thermophilic stage was shortened significantly but this may increase heavy metals. 10%-20% were concluded to be the recommended proportion.

Effects of different fermentation assisted enzyme treatments on the composition, microstructure and physicochemical properties of wheat straw used as a substitute for peat in nursery substrates

To solve the central problems caused by traditional composting treatments, such as long-time consumption and poor regulation effects, this study used three fermentation methods and four enzymes to develop rapid and directional regulation methods to convert wheat straw into a suitable substrate. The results showed that the mixed anaerobic method led to better pH (4.39-5.75) and EC values (1.27-1.89 mS/cm) in the straw substrates, while the aerobic method retained more nutrients and increased lignin and cellulose contents by 5.07-8.04% and 1.52-3.32%. The cellulase mixed with hemicellulase or laccase treatments all increased the crystallinity by 0.45-7.23%. The TG/DTG results showed that all treatments decreased the initial straw glass transition temperature, particularly when using the mixed anaerobic method, with decreases of 10.63-25.48 °C. Overall, mixed anaerobic fermentation and multiple enzymes, including cellulase, have been suggested as alternative biological modification methods for straw substrates.

Recent Applications of Mixture Designs in Beverages, Foods, and Pharmaceutical Health: A Systematic Review and Meta-Analysis

Design of Experiments (DoE) is a statistical tool used to plan and optimize experiments and is seen as a quality technology to achieve products excellence. Among the experimental designs (EDs), the mixture designs (MDs) stand out, being widely applied to improve conditions for processing, developing, or formulating novel products. This review aims to provide useful updated information on the capacity and diversity of MDs applications for the industry and scientific community in the areas of food, beverage, and pharmaceutical health. Recent works were selected following the Preferred Reporting Items for Systematic Review and Meta-Analyses statement (PRISMA) flow diagram. Data analysis was performed by self-organizing map (SOM) to check and understand which fields of application/countries/continents are using MDs. Overall, the SOM indicated that Brazil presented the largest number of works using MDs. Among the continents, America and Asia showed a predominance in applications with the same amount of work. Comparing the MDs application areas, the analysis indicated that works are prevalent in food and beverage science in the American continent, while in Asia, health science prevails. MDs were more used to develop functional/nutraceutical products and the formulation of drugs for several diseases. However, we briefly describe some promising research fields in that MDs can still be employed.

A novel technology for separating live earthworm from vermicompost: Experiment, mechanism analysis, and simulation

The vermicomposting is widely acknowledged as an effective and sustainable biological technology to dispose large scale organic solid waste such as livestock manure, crop residues and municipal sludge. The scale of vermicomposting has constantly increased over recent years due to high market demand for live earthworms. Rapid and efficient extraction and harvesting earthworm from large-scale vermicompost has become a bottle-neck problem at the end of vermicomposting. Currently, most earthworm separation is done manually or relies on simple tools, and is therefore low efficient, time consuming and labor intensive. In this study, to explore earthworm separation technology and underlying mechanisms, three major studies were conducted based on the developed separator: Earthworm separation experiment, mechanism analysis of separation, and separation process simulation. The result indicated that under a 45% moisture content of vermicompost, earthworm can be separated centrifugally with approximately 83.79% worm separation rate. The treatment capacity of separator is 21.2 kg of total vermicompost mixture per minute. The critical factor in earthworm-vermicompost separation is frictional force and liquid membrane adhesion at the contact interface of conical separator. The final separated X velocity of earthworms is higher, whereas the Y and Z velocities are less than those of vermicompost. The earthworms are centrifugally thrown to a specific area called the earthworm harvest position. The outcome of this study provides a valuable reference for improvement of earthworm harvest efficiency and for shortening the recycling period of vermicomposting products in practice.