Growth and Heavy Metals Accumulation Potential of Microalgae Grown in Sewage Wastewater and Petrochemical Effluents

Abstract

Microalgae exhibit a number of heavy metal uptake process by different metabolism. In this study, the ability of microalgae for removal of heavy metal from wastewater was studied. Growth and biochemical contents of microalgae were determined by spectrophotometer. Heavy metal analysis of wastewater effluents were performed by atomic absorption spectrophotometer before and after treatment at laboratory scale. The growth of Scenedesmus bijuga and Oscillatoria quadripunctulata in sewage wastewater was higher than those grown in synthetic medium. Whereas, the growth of S. bijuga and O. quadripunctulata in sterilized petrochemical effluents was slightly lower than that grown in the standard synthetic medium. The chlorophyll, carotenoid and protein content of S. bijuga and O. quadripunctulata grown in sterilized sewage wastewater were higher than those grown in the standard medium. Similarly S. bijuga and O. quadripunctulata grown in sterilized petrochemical effluents showed lower contents of pigments and protein than those grown in sewage and synthetic medium. Heavy metals copper, cobalt, lead and zinc were removed by 37-50, 20.3-33.3, 34.6-100 and 32.1-100%, respectively from sewage wastewater and petrochemical effluent using Ocillatoria culture. The metal absorption by S. bijuga were (Cu, Co, Pb, Zn) 60-50, 29.6-66, 15.4-25 and 42.9-50%, respectively from sewage and petrochemical effluents. Both species showed high level of heavy metal removal efficiency and metal sorption efficiency of both microalgae depended on the type of biosorbent, the physiological status of the cells, availability of heavy metal, concentration of heavy metal and chemical composition of wastewater.

Influence of lead salts on some morphological and physiological parameters of filamentous cyanobacteria

“…It could be caused by change in the functional structure of the thylakoids: increase in the space between the thylakoids and accumulation of particles of the metals there, formation of membrane vesicles. Intense decrease in concentration of both chlorophyll a and carotenoids can indicate the irreversible degradation effect of the toxicant (Heng et al, 2004;Ajayan et al, 2011;Wong et al, 2014;Deep et al, 2016).…”

Integration of Microalgae‐Based Wastewater Bioremediation–Biorefinery Process to Promote Circular Bioeconomy and Sustainability: A Review

“…[ 55 ] Scenedesmus bijuga and Oscillatoria quadripunctulata bioaccumulated Pb, Co, Cu, and Zn from sewage wastewater and petrochemical effluents. [ 56 ]…”

“…[55] Scenedesmus bijuga and Oscillatoria quadripunctulata bioaccumulated Pb, Co, Cu, and Zn from sewage wastewater and petrochemical effluents. [56] It is necessary for the success of integrated application of microalgae that suitable algal diversity is selected that is stress tolerant, able to grow in the toxic environment of wastewater, bioremediate diverse pollutants efficiently, and also produce high yields of biomass, lipids, and other products. Microalgal diversity in HRAPs exhibited collective adaptability toward adverse environmental conditions and was reported to be beneficial for enhanced and stable biomass productivity that could be used as a biodiesel feedstock after wastewater treatment.…”

Phycoremediation: Use of Algae to Sequester Heavy Metals

“…Advantages of using phytoremediation include: economic feasibilityphytoremediation is an autotrophic system driven by solar energy, hence their management is easy, and the maintenance and installation cost is low; eco-friendly-it can decrease the exposure of the contaminants to the ecosystem; applicability-it may be used over a vast field and may be disposed easily; it checks leaching and erosion of metal by stabilizing HMs, decreasing the risk of proliferation of contaminants; it may also improve the fertility of soil by releasing several organic matters into the soil [31][32][33]. Advantages of phycoremediation (Figure 1) include economic viability [34]; algal biomass may be used over a period of years [35]; algae have the potential to sequester diverse contaminants (e.g., HMs, pesticides, inorganic and organic toxins) [36]; in dilute effluents, they are quite effective, due to their high surface area-to-volume ratio [37]; they are highly efficient at sequestering HMs [36]; they are suitable even in wastewater containing higher metal concentrations [37]; algae are appropriate for aerobic and anaerobic effluent treatment units [38]; and cultures of microalgae may be cultivated in large-scale reservoirs, open ponds, and also in the laboratory [38].…”