Abstract: An exemplary method of treating nitrogen-contaminated wastewaters, especially those with high ammonia concentrations, according to the invention includes the steps of ammonia degassing and recapture, and of nutrient assimilation with microalgae. Organic nitrogen, organic carbon, phosphorus, heavy metals and other compounds may also be removed in different embodiments of the invention. Examples of applicable wastewaters include landfill leachate, municipal solid waste anaerobic digester effluent, agricultural anaerobic digester effluent, municipal wastewaters, agricultural wastewaters, and other similarly contaminated wastewaters.

Abstract: Rapidly settling algal strains are selectively developed through a method that is based on manipulating the velocity of a host liquid. In one embodiment, the method includes the steps of providing a uniform flow velocity to the liquid, thereby promoting development of one or more algal strains; stopping or at least reducing the uniform flow velocity; removing the upper portion of the water, including any suspended algal strains; providing a second uniform flow velocity to the liquid, which may be the same as the flow velocity that was applied during the first step; stopping or at least reducing the second uniform flow velocity; and removing the upper portion of the remaining liquid, leaving a residual liquid amount that includes one or more rapidly settling algal strains in the form of a rapidly settling algal floc or of a precursor thereof.