Abstract: The disclosure encompasses, among other aspects, mixed algal populations able to survive and proliferate on culture media that have a high proportion of carpet industry wastewater. Embodiments further encompass methods of cultivating mixed populations of freshwater and marine alga comprising a plurality of genera and species to provide a biomass from which may be extracted lipids, or converted into biodiesel by such procedures as pyrolysis. Lipid material extracted from the algae may be converted to biodiesel or other organic products. A combined stream of carpet industry untreated wastewater with 10-15% sewage was found to be a good growth medium for cultivation of microalgae and biodiesel production. Native algal strains were isolated from carpet wastewater inoculated with mixed populations derived from environments exposed to such wastewater. Both fresh water and marine algae showed good growth in wastewaters.