Utilisation of rural wastes for algal biomass production with Scenedesmus Acutus and Spirulina Platensis in India

Abstract

A technology for the production of the green alga, Scenedesmus acutus, and blue-green alga, Spirulina platensis, in clean water has been developed at our Institute to suit Indian conditions. Experience gained on algal production technology in India indicates the scope for applying this at the rural level for use in the production of animal feed. Spirulina is the most promising alga in view of its amenability to low level technology. Nutrient input to the cultures is one of the expensive steps. It is shown that agricultural and domestic wastes can be effectively recycled for algal biomass production by replacing, at least partly, the nutrient inputs. Urine and bonemeal reduce the inputs of nitrate, calcium and phosphate salts into the culture medium. Sheep's blood has a growth promoting effect on algal cultures and a good potential for application. Carbon dioxide enriched air—‘aerobic biogas’—produced by composting cow dung, can be used as a carbon source for algal cultivation. Several experiments carried out in India indicate the possibility of developing an integrated algal production system in rural areas by means of which wastes can be effectively recycled. The use of algae in poultry and fish feeds is a distinct possibility for the future.