Microalgae production in fresh market wastewater and its utilization as a protein substitute in formulated fish feed for oreochromis spp.

Rapid growing of human population has led to increasing demand of aquaculture production. Oreochromis niloticus or known as tilapia is one of the most globally cultured freshwater fish due to its great adaptation towards extreme environment. Besides, farming of tilapia not only involves small scales farming for local consumption but also larger scales for international market which contributes to a foreign currency earning. Extensive use of fishmeal as feed for fish and for other animals indirectly caused an increasing depletion of the natural resource and may consequently cause economic and environmental unstable. Microalgae biomass seems to be a promising feedstock in aquaculture industry. It can be used for many purposes such as live food for fish larvae and dried microalgae to substitute protein material in fish feed. The microalgae replacement in fish feed formulation as protein alternative seem potentially beneficial for long term aqua-business sustainability. The present chapter discussed the potential of microalgae as an alternative nutrition in fish feed formulations, specifically Tilapia

Chromium(III) removal by Spirulina platensis biomass

Dried and 48 h re-hydrated biomass of Spirulina platensis was employed as a biosorbent in tests of chromium(III) removal from water. Various concentrations of biomass (from 1 to 3 g l 121) and metal (from 25 to 200 mg l 121) were tested. Increasing and re-hydrating biomass allowed removing almost entirely up to Cro = 100 mg l 121 of Cr3+ (95% of removal with X0 = 3 g l 121 of re-hydrated biomass), whereas, lower percentages were obtained at higher concentrations of pollutant (56% of removal at Cro = 200 mg l 121). Kinetics of the biosorption was generally better at low Cr(III) concentrations (kads = 1.41 and 1.44 h 121 at Cro = 35 mg l 121 and Xo = 1 g l 121 of dry and re-hydrated biomass, respectively). The kinetics of the process and the adsorption capacity of biomass were finally put into relationship, highlighting that, at low concentrations of pollutant (Cro = 25, 35 and 50 mg l 121), re-hydrated biomass did not lead to noticeable improvement, whereas, as the concentration of Cr(III) was increased from 75 to 200 mg l 121, re-hydratated biomass ensured remarkably higher removal

Cadmium biosorption on Spirulina platensis biomass

Dry biomass of Spirulina platensis re-hydrated for 48 h was employed as a biosorbent in tests of cadmium(II) removal from water. Various concentrations of biomass (from 1 to 4 g l 121) and metal (from 100 to 800 mg l 121) were tested. Low biomass levels (Xo 64 2 g l 121) ensured metal removal up to 98% only at Cdo = 100 and 200 mg l 121, while Xo 65 2.0 g l 121 were needed at Cdo = 400 mg l 121 to achieve satisfactory results. Whereas Xo = 4.0 g l 121 was effective to remove up to Cdo = 500 mg l 121, a further increase in metal concentration (Cdo = 600 and 800 mg l 121) led to progressive worsening of the system performance. At a given biomass levels, the kinetics of the process was better at low Cd2+ concentrations, while, raising the adsorbent level from 1.0 to 2.0 g l 121 and then to 4.0 g l 121, the rate constant of biosorption increased by about one order of magnitude in both cases and the adsorption capacity of the system progressively decreased from 357 to 149 mg g 121

Batch and fed-batch cultivations of Spirulina platensis using ammonium sulphate and urea as nitrogen sources

In this work, the replacement of potassium nitrate with ammonium sulphate (A) and urea (U) as cheaper nitrogen sources has been investigated

Spirulina platensis biomass as adsorbent for copper removal

Dry biomass of Spirulina platensis was used as biosorbent for copper removal from water

Carbon dioxide removal for the photoautotrophic cultivation of the microalga Arthrospira (Spirulina) platensis

The present work aimed at evaluating the ability of the cyanobacterium Arthrospira (Spirulina) platensis (Nordstedt) Gomont to grow on carbon dioxide, to identify the optimal growth conditions and to estimate the photosynthetic and carbon utilization efficiencies