As mentioned earlier, one of the advantage of cultivation of microalgae for biodiesel production is their ability to grow on wastewater—either domestic or agricultural or industrial wastewaters. The cultivation of microalgae on wastewater to obtain biodiesel can be an economically feasible strategy with minimal environmental impacts [116]. The cultivation of microalgae species, such as Chlamydomonas mexicana, Chlorella vulgaris, Scenedesmus obliquus, and Micractinium reisseri, in wastewaters has been demonstrated previously [117,118]. Abou-Shanab et al. [119] isolated the microalgal species M. reisseri and S. obliquus from municipal wastewater mixed with agricultural drainage. M. reisseri was proved to grow well in municipal wastewater (influent, secondary, and tertiary effluents) which varied in nutrient concentration. M. reisseri showed growth rate (μ_opt) of 1.15, 1.04, and 1.01 1/day for the influent and the secondary and tertiary effluents, respectively. One of the advantages of algae cultivation in wastewater is their effective ability to assimilate both organic carbons and inorganic nutrients from wastewater to produce maximum algal biomass, efficient nutrient removal, and lipid accumulation which can then be converted into biodiesel [120]. In this connection, [119] found that the microalga M. reisseri removed 94% of phosphorus from secondary effluent of municipal wastewater and supported 40% saturated fatty oil content. The microalgae when grown on tertiary effluent supported 40% lipid content, unsaturated fatty acid content, including monounsaturated and polyunsaturated fatty acids (66%), and nitrogen removal (80%). The fatty acids of M. reisseri were mainly composed of palmitic, oleic, linoleic, and α-linolenic acids.