Algal growth as a means of evaluation of nutrient status of the effluent of a fertilizer factory near Shahupuri, Varanasi

Abstract

The nutrient status of the effluent of a fertilizer factory has been assayed by growing the unicellular green alga Chlorella sp. and the filamentous blue-green alga Anabaena doliolum as the test organisms. Nitrogen content was estimated by (a) growing Chlorella in different proportions of effluent and culture medium; (b) estimating the rate of NH4-N absorption in the dark by Chlorella cells previously grown in either surplus or limiting nitrogen conditions; and (c) comparing the heterocyst frequencies of Anabaena in nitrogen-free medium and in nitrogen free medium supplemented with effluent. The nutrient status as evaluated by algal assay agrees well with that determined by actual physico-chemical analysis of the effluent.