Fractional Sliding Mode Nonlinear Procedure for Robust Control of an Eutrophying Microalgae Photobioreactor

Abstract

Water contamination due to human activity is increasing significantly, hampering our future development; hence, we should take immediate action and look for sustainable technologies to treat this vital resource. It is well known that some microorganisms are useful to remediate contaminatedwater; for example, microalgae are capable of eliminating organic nitrogen, the normal limiting substrate in wastewater [1]. Eutrophication refers to a significant increase in the concentration of nutrients of a given aquatic ecosystem due to human industrial activities. High nutrients availabilityleads to considerable proliferation of certain species of algae and higher aquatic plants. Proper control of microalgae growth either in photobioreactors or in the natural ambient (basins, rivers, and lakes) can reduce the concentration of pollutants generated by human activities. In Mexico, especially in the state of Sinaloa, eutrophication is critical. Hence, local authorities are looking for technologies, such as cultivation of microalgae in open photobioreactors, that can simultaneously aid the reduction of eutrophication and can be useful in producing biofuels [2].