REMOVAL OF INORGANIC-IONS FROM WASTEWATERS BY IMMOBILIZED MICROALGAE

Anabaena doliolum and Chlorella vulgaris immobilized on chitosan were more efficient at removing NO3-, NO2-, PO43- and Cr2O72- from wastewaters than cells immobilized on agar, alginate, carrageenan or even free cells. Carrageenan-immobilized cells, however, were better at removing NH4+ and Ni2+. The PO43--uptake capacity was significantly increased in cells starved of PO43- for 24 h. Agar-immobilized cells, though having good metal and nutrient uptake efficiency, had only a slow growth rate. Chitosan is recommended as an algal support for wastewater detoxification.