http://fac.ksu.edu.sa/sites/default/files/Abdel-Raouf%20et%20al%2C2012.pdf

Microalgae and wastewater treatment.

Immobilized microalgae for removing pollutants: review of practical aspects.

This presentation comprises a review on the use of immobilized algae for wastewater nitrogen, phosphorus and metal removal purposes. Details of the use of immobilized algae, the techniques of immobilization and the effects of immobilization on cell function are included. Particularly relevant in their use for heavy metal removal from wastewaters; upon enriching the biomass in metal, can be recoverd, thereby providing economic advantages. The use of immobilized microalgae in these processes is very adequate and offers significant advantages in bioreactors. The future of this area of algal cell biotechnology is considered.

Biotechnological potential of immobilized algae for wastewater N, P and metal removal: A review

Microalgae immobilization: current techniques and uses.

Phycoremediation: key issues for cost-effective nutrient removal processes

Cells of the non-N2-fixing cyanobacteriumPhormidium laminosum were immobilized in polyurethane (PU) foams either by absorption or by entrapment in the PU prepolymer followed by polymerisation and by adsorption onto polyvinyl (PV) foams. Although entrapment caused toxicity problems which lead to rapid death of the immobilized cells, they were immobilized successfully by adsorption onto PU or PV foams and maintained their photosynthetic electron transport activities (PS I, II, I + II) for at least 7 weeks. Changes in the morphology resulting from immobilization, as revealed by scanning electron microscopy (SEM) and low temperature-SEM, were investigated. Batch cultures and a continuous-flow packed bed photobioreactor were used to study nitrate removal from water. The effects of light intensity and CO2 concentration on bioreactor performance were studied with respect to the nitrate uptake efficiency of the system. It was concluded thatP. laminosum immobilized on polymer foams is of potential value for biological nitrate removal in a continuous-flow system.

Removal of nitrate from water by foam-immobilized Phormidium laminosum in batch and continuous-flow bioreactors

Cells of the non-N2-fixing cyanobacterium Phormidium uncinatum were immobilized by adsorption into polyvinyl (PV-50) foam pieces. The effect of inoculum size as well as the initial inoculum/support ratio on the cell immobilization process was investigated. After 2 months of immobilization similar net O2-exchange activity was measured in immobilized and free-living cells. Polyvinyl-adsorbed cells also showed similar nitrate uptake capacity to free-living cells. Nitrogen starvation promoted a remarkable increase in nitrate uptake rate of both free-living and immobilized cells. A lab-scale photobioreactor packed with polyvinyl foam pieces colonized in situ by cells was used for nitrate removal in a continuous mode. In the best working conditions found, nearly 90% of nitrate supplied in the influent (50 mg l−1) was removed by cells having a residence time of 3–4 h.

Jone M. Gil

Papers

Removal of nitrate from water by foam-immobilized Phormidium laminosum in batch and continuous-flow bioreactors

Nitrate removal by immobilized cells of Phormidium uncinatum in batch culture and a continuous-flow photobioreactor