A comprehensive review on carbon source effect of microalgae lipid accumulation for biofuel production.

Energy is a major driving force for the economic development. Due to the scarcity of fossil fuels and negative impact on the environment, it is important to develop renewable and sustainable energy sources for humankind. Microalgae as the primary feedstock for biodiesel has shown great application potential. However, lipid yield from microalgae is limited by the upstream cost, which restrain the realization of large-scale biofuel production. The modification of lipid-rich microalgae cell has become the focus over the last few decades to improve the lipid content and productivity of microalgae. Carbon is a vital nutrient that regulates the growth and metabolism of microalgae. Different carbon sources are assimilated by microalgae cells via different pathways. Inorganic carbon sources are mainly used through the CO2-concentrating mechanisms (CCMs), while organic carbon sources are absorbed by microalgae mainly through the Pentose Phosphate (PPP) Pathway and the Embden-Meyerhof-Pranas (EMP) pathway. Therefore, the addition of carbon source has a significant impact on the production of microalgae biomass and lipid accumulation. In this paper, mechanisms of lipid synthesis and carbon uptake of microalgae were introduced, and the effects of different carbon conditions (types, concentrations, and addition methods) on lipid accumulation in microalgal biomass production and biodiesel production were comprehensively discussed. This review also highlights the recent advances in microalgae lipid cultivation with large-scale commercialization and the development prospects of biodiesel production. Current challenges and constructive suggestions are proposed on cost-benefit concerns in large-scale production of microalgae biodiesel.

Emerging pollutants in water environment: Occurrence, monitoring, fate, and risk assessment.

The occurrence of emerging pollutants (EPs) is continuously reported worldwide. Nevertheless, only few of these compounds are toxicologically evaluated due to their vast numbers. Reliable analytical methods and toxicity assessment methods are the basis of either the management or the elimination of EPs. In this paper, literature published in 2018 on EPs were reviewed with special regard to their occurrence, detection methods, fate in the environment, and ecological toxicity assessment. Particular focus was placed on practical considerations, novel processes, and new solution strategies. PRACTITIONER POINTS: Literature published in 2018 on emerging pollutants were reviewed. This review article is with special regard to the occurrence, detection methods, fate and toxicity assessment of emerging pollutants. Particular focus was placed on practical considerations, novel processes and new solution strategies.