Microalgae Harvesting by Self-Driven 3D Microfiltration with Rationally Designed Porous Superabsorbent Polymer (PSAP) Beads

Carboxymethyl chitosan-capped nanoparticles for the preparation of epoxidized rubber dipped products with chemical resistance, barrier and antibacterial properties

Epoxidized natural rubber (ENR), a kind of bio-elastomer, exhibits favorable elasticity, gas tightness and solvent resistance, thereby demonstrating considerable potential for utilization in the rubber industry. However, producing ENR latex products poses significant challenges due to the low dry rubber content and high surfactant concentration in ENR latex. This study addresses these challenges by employing superabsorbent polymer beads as concentration agents to prepare concentrated ENR latex. Additionally, carboxymethyl chitosan is utilized as a bridging agent to securely bind ENR with manganese silicate nanoparticles through the formation of hydrogen bonds. The resulting composite material-based dipped film retains the inherent properties of ENR while exhibiting stable mechanical performance, even exposure to various disinfectants. Notably, the composites exhibit remarkable barrier capabilities and antibacterial properties, effectively disrupting the cellular structures of diverse bacterial species and promoting the healing of infected wounds. Furthermore, this research provides a set of standardized testing methods for rubber-based antibacterial products. These advancements underscore the distinct advantages of the ENR latex production process, highlighting its simplicity, cost-effectiveness, and potential for commercialization due to the affordability of the raw materials.

Construction and transcriptomic analysis of salinity-induced lipid-rich flocculent microalgae

The lack of cost-effective nutrient sources and harvesting methods is currently a major obstacle to the production of sustainable biofuels from microalgae. In this study, Chlorella pyrenoidosa was cultured with saline wastewater in a stirred photobioreactor, and lipid-rich flocculent microalgae particles were successfully constructed. As the influent salinity of the photobioreactor increased from 0% to 3%, the particle size and sedimentation rate of flocculent microalgae particles gradually increased, and the lipid accumulation of microalgae also increased gradually. Transcriptome analysis showed that the number of differentially expressed genes (DEGs) in microalgae increased as the salinity of wastewater increased from 1% to 3%, and the number of up-expressed genes was greater than that of down-expressed genes in microalgae at different salinity levels. The enrichment analysis of DEGs showed that the up-expressed genes under salt stress mainly involved in fatty acid biosynthesis and other metabolic processes, which initially revealed the mechanism of the lipid accumulation of microalgal particles in saline wastewater. In addition, the expression and functions of genes involved in lipid and EPS synthesis pathway in microalgae were analyzed, and the key genes involved in salinity affecting lipid and EPS synthesis in microalgae were preliminarily identified. The results could provide novel insight for genetic engineering to regulate the construction of lipid-rich flocculent microalgae particles.

Sustainability and carbon neutrality trends for microalgae-based wastewater treatment: A review

As the global economy develops and the population increases, greenhouse gas emissions and wastewater discharge have become inevitable global problems. Conventional wastewater treatment processes produce direct or indirect greenhouse gas, which can intensify global warming. Microalgae-based wastewater treatment technology can not only purify wastewater and use the nutrients in wastewater to produce microalgae biomass, but it can also absorb CO₂ in the atmosphere or flue gas through photosynthesis, which demonstrates great potential as a sustainable and economical wastewater treatment technology. This review highlights the multifaceted roles of microalgae in different types of wastewater treatment processes in terms of the extent of their bioremediation function and microalgae biomass production. In addition, various newly developed microalgae cultivation systems, especially biofilm cultivation systems, were further characterized systematically. The performance of different microalgae cultivation systems was studied and summarized. Current research on the technical approaches for the modification of the CO₂ capture by microalgae and the maximization of CO₂ transfer and conversion efficiency were also reviewed. This review serves as a useful and informative reference for the application of wastewater treatment and CO₂ capture by microalgae, aiming to provide a reference for the realization of carbon neutrality in wastewater treatment systems.