ABSTRACT
This chapter examines the important biochemical pathways which make algae useful in the reclamation of agricultural wastewaters, with particular reference to dissolved inorganic and organic nitrogen and phosphorus and dissolved organic materials, including a wide variety of xenobiotic compounds and trace metals. The uptake and assimilation of inorganic N compounds by algae is affected by several environmental parameters, principally ammonium concentration and light. The cell wall polysaccharides of several species of algae affect ion-exchange reactions with polyvalent metals. In general, agricultural drainage waters contain lower concentrations of dissolved organic matter than urban waste effluents. Microalgae have often been considered ideal waste removers for sewage effluents because of their requirements for dissolved forms of both nitrogen and phosphorus, which are major components of wastewaters. The biochemical pathways responsible for the uptake and assimilation of these elements are obviously interrelated, making it difficult to distinguish pathways which are specific for any one element.
