13.2.1 Internal and External Factors Required for Growth of Algal Biomass

13.2.1.1 Water

Being photosynthetic organisms, algae have comparatively simple requirements for growth. Water, containing the accurate amounts of salts and minerals, is a particu­larly essential component needed for algal cultivation. Based on the need for water, algae are basically categorized into aquatic or semiaquatic species. The standard quantity of water required for effective farming of aquatic algae is approximately 1.5 L/ha. This figure is valid considering the fact that growth occurs in an open pond and roughly 7-11 million liters of water is evaporated from that region annually. Algal production can be linked to the remediation of wastewater from both domes­tic and industrial sources. The wastewater, containing the essential elements, can be directly supplied to the algal culture. This allows nourishment of algae while simul­taneously treating wastewater.

13.2.1.2 Carbon

Algae require very high amount of carbon for efficient growth. Procuring carbon for algal growth costs up to 60 % of the total nutrients budget. Carbon can be obtained from multiple sources, which include (1) CO2 from the atmosphere (2) CO2 con­tained within industrial smoke (3) CO2 from soluble carbonates. For each kilogram of algae that is grown, approximately 1.65 kg of CO2 is used.