A review on microalgae and cyanobacteria in biofuel production

Today, fossil fuel shortages and climate change impacts have led mankind to the search for an alternative energy. With many advantages, bioenergy is a promising source to replace conventional energy. However, biofuel productions in the first and second generation are likely to add more concerns to the problems in water scarcity and threats to food security. Meanwhile, third generation biofuels obtained from microalgae and cyanobacteria are able to overcome existing challenges thanks to their rapid growth rates, abilities to fix CO 2 , high yields in lipid extraction and capabilities to be grown in non-arable lands. Microalgae and cyanobacteria appear to be the only ones among renewable sources that are capable of producing a wide range of biofuels including biohydrogen, biomethane, bioethanol and biodiesel.In this study, we present an overview about microalgae and cyanobacteria use for the production of biofuels in fundamentals, including their biology, cultivation systems taking into account the hydrodynamic conditions, harvesting, and processing. The review also provides a general picture at the current status of this renewable energy industry

Zooplankton from Can Giuoc River in Southern Vietnam

In this study, the variables of zooplankton and water quality were investigated in the Can Giuoc River, Southern Vietnam. Zooplankton was monitored in April and September 2015 at 5 sampling sites in the river. Some basic water quality parameters were also tested, including pH, total suspended solid (TSS), dissolved oxygen (DO), biological oxygen demand (BOD5), inorganic nitrogen (NH4+), dissolved phosphorus (PO43-), and coliform. The zooplankton biodiversity indices were applied for the water quality assessment. The results showed that pH ranged from 6.7 to 7.6 during the monitoring. The TSSs were between 34–117 mg/L. The DO and BOD5 were from 0.6 to 3.8 mg/L and from 6.3 to 13.2 mg/L, respectively. The NH4+ and PO43- concentrations ranged from 0.44 to 3.23 and from 0.08 to 1.85 mg/L, respectively. The coliform number was between 9.3x103–9.3x104 MPN/100 mL. The zooplankton analyses showed that there were 31 species of coelenterates, rotatoria, oligochaetes, cladocerans, copepods, ostracods, mysidacea, and 8 larval types. Thereof, the species of copepods were dominant in the species number. The zooplankton density ranged from 9 500 to 23 600 individuals/m3 with the main dominant species of Moina dubia (Cladocera), Thermocyclops hyalinus, Acartia clausi, Oithona similis (Copepoda), and nauplius copepods. The biodiversity index values during the monitoring were from 1.47 to 1.79 characteristic of mesotrophic conditions of the aquatic environment. Besides, the species richness positively correlated with pH, TSS, DO, BOD5, NH4+, PO43-, and coliform, while the zooplankton densities got a positive correlation with DO, BOD5, NH4+, PO43-, and coliform. The results confirmed the advantage of using zooplankton and its indices for water quality assessment