Bioremediation of Industrial and Municipal Wastewater Using Microalgae

Abstract

The present scenario of increased population and industrial development leads to deterioration of freshwater and decreases the quality of water all over the world. This causes freshwater shortage in most of the area. Moreover, organic and inorganic substances released from various sources into the existing natural water bodies or environment lead to pollution. The primary and secondary treatment of wastewater had been introduced in many numbers of places to extinguish the easily settled material and to oxidize the organic matter in wastewater. But these methods were not found to be efficient because the effluent from secondary treatment is loaded with increased amount of inorganic nitrogen and phosphorus, and so, it leads to eutrophication and much more long-standing problems because of discharged heavy metals and refractory organics. On the other side, wastewater contains numerous ingredients, and interestingly, some of the compounds in the wastewater, like nitrogen and phosphorus, are identified as beneficial ingredients for microalgae cultures. Therefore, algal bioremediation can be considered as a feasible alternate technology for treating the wastewater in a cost-effective and assertable way compared to conventional water treatment process. These microalgal cultures are autotrophs, and they play a notable role in remediation of wastewater by their photosynthetic ability. A win–win situation of using microalgae in the bioremediation of industrial or municipal wastewater provides tertiary biotreatment of wastewater coupled with the production of potentially valuable biomass as bioresource for biofuel or high-value by-products. There is a mutual advantage in this method in which using wastewater for microalgal culture will minimize the use of freshwater, reduce the cost of nutrient addition, and also removal of nitrogen and phosphorous, and reduce CO2 emission. This chapter covered the overview of the role of microalgae in treatment of industrial as well as municipal wastewater.