Abstract
Unplanned and unmonitored growth of civilization and industries recorded in the previous decades have resulted in the introduction of several pollutants of emerging concern like pharmaceuticals and antibiotic drugs, endocrine disrupters, personal care products, etc. in adjacent aquatic environments. Moreover, the primary considerations of recent wastewater treatment strategies include energy neutrality and efficient recovery of valuable products as end/byproducts of the concerned process. The present study reviews such recent advances in designs, development, and implementation of algae based photobioreactors for simultaneous CO2 capture and treatment of effluents containing various types of emerging contaminants with negligible energy input. It also discusses the subsequent usage of algal biomass for production of value-added products like bioethanol, alginate, etc. This study has primarily addressed the potential and limitations of such photobioreactors for simultaneous achievement of wastewater remediation, CO2 sequestration, and bioenergy production with a zero-discharge concept.
TopTypes Of Pbr
Sufficient availability of light, selection of viable species of microalgae, appropriate environmental conditions, minimum usage of land and microalgae production over the entire year are considered as significant parameters for designing and development of PBRs (Ting et al., 2017). Successful cultivation of microalgae on commercial scale requires maximum possible reduction of cost incurred, enhancement of biomass productivity and prevention of contamination of microalgal cultures from bacteria or fungi (Ting et al., 2017). According to previous reports, PBRs are usually classified into two systems: open and closed. Open systems are usually installed outdoor and make maximum utilization of sunlight. Closed systems may be installed both outdoor and indoor and are supported by natural or artificially controlled environment respectively. Both systems have been described as follows.
Key Terms in this Chapter
Upscaling: Raising or upgrading a process for improved benefits.
Wastewater: Wastewater is contaminated water produced as a result of anthropogenic activities in agricultural, commercial, domestic, and industrial sectors.
Pharmaceuticals: Compounds used for diagnosis, treatment or prevention of diseases and restoration, correction or modification of organic functions.
Antioxidants: Compounds preventing damage of cellular components by inhibiting oxidation and preventing formation of free radicals.
Biodiesel: Biodiesel is a form of fuel containing long-chain fatty acid esters that is usually synthesized from reaction of lipids like animal fats or vegetable oils with an alcohol.
Photobioreactors: Photobioreactors are open, closed or partially closed containers prepared from transparent and water-resistant materials and are capable of facilitating ideal environment for growth of photosynthetic microorganisms.
Bioremediation: Bioremediation refers to the application of indigenous or purposely introduced microorganisms for degradation of toxic compounds present at a polluted site.
Flue Gas: Exhaust gas produced as a result of combustion by power plants containing reaction products of fuel and combustion air as well as residual substances like particulate matter, SO x , NO x , and CO.