Skip to Main Content
Skip Nav Destination
*Corresponding author: [email protected]

Nitrogen-rich wastewaters (10–400 mg N/L) are produced by municipal, industrial and agricultural wastes, including effluents from anaerobic treatment processes. These represent a risk to the environment due to the high nutrient concentrations (nitrogen and phosphorous), which can cause eutrophication of water bodies, deteriorating the quality of the ecosystems. As a solution, the nitrogen removal capacity of a novel bio-treatment system, the photo-activated sludge (PAS), composed of microalgae and bacteria consortia can be applied. Photobioreactors used for the simultaneous cultivation of microalgae and bacteria under sequencing batch conditions showed that microalgal–bacterial consortia can remove ammonium 50% faster than solely microalgal consortia. The increase in ammonium removal rates is due to the action of nitrifying bacteria, supplied with oxygen produced by the algae. The microalgal–bacterial system offers the possibility of reducing the hydraulic retention time, which can decrease the large area requirements often demanded by algal systems. The SRT is the main parameter to control the efficiency of the technology. The control of the suspended solids concentration, by adjusting the SRT, influences the light penetration within the reactor, which can limit or enhance the oxygen production of the algae. The photo-activated sludge system using microalgal–bacterial consortia is a sustainable treatment option for ammonium-rich wastewaters, providing clean effluents and opening reuse options for the biomass.

This content is only available as PDF.

or Create an Account

Close Modal
Close Modal