Ashiwin Vadiveloo

Food processing wastewater is characterized by high concentrations of biodegradable organic carbon that are typically lost through mineralization in conventional treatment systems. This review presents carbon chain rearrangement as a conceptual framework for converting wastewater carbon into value‐added products via microalgae‐driven bioconversion processes. The heterogeneous nature of wastewater carbon, consisting of significant variations in chain length, molecular structure, and functional groups, directly impacts its usability and transformation efficiency by microorganisms. Algal–bacterial consortia offer a promising platform for carbon upgrading by coupling bacterial degradation of complex substrates with photosynthetically driven biosynthesis. Carbon conversion at the cellular level is determined by metabolic pathway distribution and limited by energy and nutrient availability, while microbial interactions enhance stability and substrate use. In contrast to conventional aerobic and anaerobic treatments, which predominantly mineralize carbon, these systems promote carbon retention in biomass, thereby improving resource recovery potential. However, large‐scale implementation remains limited by challenges including light attenuation, nutrient imbalance, and process instability. Future progress will require integrating metabolic insights with process engineering and predictive control strategies. Overall, carbon chain rearrangement provides a unified framework for transitioning wastewater treatment from pollutant removal to resource‐oriented biomanufacturing.

Electronic waste (e-waste) has emerged as one of the most critical environmental challenges of the twenty-first century. It encompasses a wide range of discarded electrical and electronic equipment, including information and communication technologies, household appliances, entertainment systems, and related components. While e-waste contains valuable recoverable materials, it also harbours hazardous substances such as toxic heavy metals, flame retardants, and persistent organic pollutants. Inadequate disposal practices, particularly open dumping and landfilling, result in the generation of toxic leachates that contaminate soil as well as surface and groundwater, posing severe threats to environmental integrity and public health. Evidence indicates that landfill leachates can infiltrate groundwater at considerable depths, exceeding permissible limits of heavy metals and metalloids and contributing to serious health disorders. Consequently, the implementation of effective e-waste management strategies and environmentally sound disposal practices is imperative to minimize its detrimental environmental and human health impacts. Microalgae systems can achieve up to 98% removal efficiency and up to five cycles reusability. In this paper, the drawbacks of the traditional methods for metal recovery from e-waste and the potential of microalgae were discussed. The downstream processing and metal extraction from microalgal biomass is critically discussed as well as strategies to support the circular economy.

This article explores the impact of nano-silica on the properties of woven flax fibre/epoxy composites. Using compression moulding, epoxy/flax/silica hybrid nanocomposites were produced. The nano-silica was dispersed in the epoxy matrix via ultrasonication at various weight ratios. A series of tests, including crack durability, dynamic mechanical analysis, and scanning electron microscopy, were conducted to evaluate the modified materials. Notably, a 3% nano-silica filler load resulted in a 54% and 57% improvement in initiation and transmission interfacial fracture toughness, respectively. Scanning electron microscope imaging confirmed that fibres pull out at the crack tip during initial debonding, accounting for the increased toughness. Dynamic mechanical analysis further revealed enhancements in mechanical properties. Moreover, the 3% nano-silica content led to less fibre pull-out, suggesting higher heat resistance than standard flax/epoxy composites. The material also demonstrated promising antimicrobial efficacy against gram-positive and gram-negative bacteria, offering a potential alternative to conventional antibiotics.

Microalgae possess high oil content, exhibit rapid growth rates and biomass productivity, and leave a minimal environmental footprint, making them highly attractive for biofuel applications. Consequently, this present study is aimed at evaluating the impact of nitrogen starvation on the marine microalgae Nannochloropsis sp. to enhance lipid accumulation. The microalga culture was grown under an irradiance of 120 μmol photon m^-2 s^-1, temperature °C, continuous air-CO₂, and with different concentrations of sodium nitrites over a 14-day cultivation period. From the results, it was found that the growth of the strain decreased under limited nitrogen conditions. After harvesting, the cells in the supernatant were regenerated by cultivating in double concentration of media. The results showed that on the 12^th day, the highest lipid content was achieved, reaching wt.% of the dry weight under nitrogen limitation. The composition of the obtained lipid consisted of 18.0 wt.% saturated fatty acids, 72.38 wt.% monounsaturated fatty acids, and 8.95 wt.% polyunsaturated fatty acids. The lipid composition was dominated by monounsaturated oleic acid ( wt.%), saturated palmitic acid ( wt.%), and polyunsaturated linoleic acid ( wt.%). The findings of this study demonstrated that limiting nitrogen availability enhanced lipid accumulation in Nannochloropsis sp. Despite experiencing inhibited growth, this microalga species shows great potential for the large-scale cultivation of lipids and essential fatty acids. These results contribute to understanding the relationship between nitrogen availability and lipid metabolism in microalgae, providing valuable insights for optimizing lipid production in the context of biofuel and biotechnology applications.