Microalgae in aquatic environs: A sustainable approach for remediation of heavy metals and emerging contaminants

https://doi.org/10.1016/j.eti.2020.101340Get rights and content

Highlights

  • Emerging Concerned Contaminants (ECCs) has grown to be a grave concern globally.

  • Microalgae is a doable approach for remediation of ECCs and toxic metals.

  • Microalgae stabilizes physicochemical quality in disturbed aquatic environs.

  • Microalgae biomass cultivation could be a potent stock for biofuel production.

Abstract

Water pollution has grown to be a grave concern in the world. Direct discharge of wastewater poses risks to the aquatic ecosystems by causing eutrophication and degrades their physico-chemical characteristics. Moreover, wastewater is mainly enriched with recalcitrant toxic substances that pose detrimental impacts on the receiving environments. Conventional treatment approaches are mostly applied to remove nuisance pollutants from aquatic systems but are expensive and inefficient. Exploring microalgae has been found to be an efficient and ecofriendly technique for purification of aquatic environs. Furthermore, microalgae can effectively remove N (90–98.4%), P (66%–98%), Pb (75%–100%), Zn (15.6–99.7%), Cr (52.54%–96%), Hg (77%–97%), Cu (45%–98%) and Cd (2–93.06%)from contaminated aquatic systems. Microalgae play a pivotal role in degrading the complex pesticides (α-endosulfan, lindane, isoproturon and glyphosate) and emerging concerned contaminants (triclosan, bisphenol A, 17α-ethinylestradiol, tramadol and diclofenac) in elegant manner from disturbed environs. Apart from toxic pollutant removal, microalgae produce biomass, thereby acts as the efficient source of additional products like biofuel, carbohydrates, lipids and proteins which can make phycoremediation more frugal and sustainable.

Introduction

Water is one of the most vital natural resource necessary for the sustenance of life on the earth (Gleick, 2000, Mushtaq et al., 2020). However, unplanned establishment of industries and industrialization (Kollmuss and Agyeman, 2002, Walker et al., 2019), urbanization (Chan, 2006), higher living standards and population explosion deteriorate the quality as well as quantity of water (Goel, 2006). Pollution of freshwater resource is currently the burning issue worldwide (Abdel-Raouf et al., 2012). Discharge of untreated wastewater into fresh water environs from different point and non-point sources viz., cities, industries and agricultural units etc., degrade the quality of concerned water bodies (Lim et al., 2010, Bhat et al., 2018, Mushtaq et al., 2020). Due to improper discharge of wastewater, the available sources of water are shrinking in the major part of the world (Edokpayi et al., 2017). Generally, wastewater is rich in nitrogen and phosphorus (Bhat et al., 2017, Solovchenko, 2019), heavy metals, pesticides, endocrine disruptors and pathogens (Ahmad et al., 2019, Sarkar et al., 2019). Besides, it contains some emerging concerned contaminants (ECC) and organic contaminants (polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAHs)). These contaminants have detrimental effects on recipient aquatic environs (Okoh et al., 2007) viz., high nutrient load (eutrophication), hyphoxia (Al-Gheethi et al., 2013) and loss of aquatic biota (Paerl et al., 2018, Nagarajan et al., 2019). Therefore, treatment of wastewater prior to discharge into aquatic environs is crucial for the safeguard of precious life on earth (Oh et al., 2018, Khattiyavong and Lee, 2019). With the advancement, various conventional and new techniques have been employed but still have certain drawbacks like low efficiency, high maintenance and operational cost. Nowadays, microalgae are gaining rapid interest owing to dual role of wastewater remediation and useful biomass production (Kadir et al., 2018). Growing microalgae in wastewater can play an important role in reducing the production cost of biofuel by using wastewater as a source of nutrients (Abinandan et al., 2018). Biofuel extracted from microalgal biomass could be valuable substitute of energy in lieu of fossil fuels (Randolph and Masters, 2018).

Microalgae are the oxygen evolving organisms that can assimilate large amount of nutrients (carbon, nitrogen and phosphorus) from wastewater for their growth and development (Supeng et al., 2012). They are also capable to grow in varied climatic and environmental conditions (Vernes et al., 2019), thus providing an alternative option for wastewater treatment (Kadir et al., 2018). Remediation of wastewater with the help of algae is economically efficient and environmentally proficient for wastewater treatment (Cheah et al., 2016). Phycoremediation approach of wastewater treatment can enhance the availability of dissolved oxygen, promote extraction of nutrients as well as toxic pollutants (Tibbetts et al., 2015). Micro-organisms (microalgae) are known as “biological purifiers” because of their intrinsic phenomenon of not only extracting and accumulating nutrient but also sorption of various toxic and persistent pollutants from the wastewater (De-Bashan and Bashan, 2010). Microalgae can also easily fix carbon dioxide from the atmosphere thus help in the sequestration of carbon dioxide (Qiu, 2019) with simultaneous remediation of wastewater and biofuel production (Bhatia et al., 2019).

The aim of an effective and sustainable wastewater treatment can be fulfilled by not only focusing on removal of macronutrients and heavy metals from the contaminated environment (Bilal et al., 2018; Wang et al., 2017) but also the remediation of several other toxic pollutants like pesticides, emerging contaminants which even in minute quantity can have serious impacts on human health and freshwater ecosystems (Shahid et al., 2019). Thus, holistic approach is the necessity of current time in order to enhance the freshwater availability for the swiftly growing global population. The main of this review is to focus on effective role of microalgae not only in stabilizing the physico-chemical characteristics of wastewater but also on the exclusion of myriad of pollutants (heavy metals, pesticides and emerging contaminants) which are commonly discharged from several industries. Exploiting microalgae for the treatment of wastewater of different origin is beneficial paradigm in each way that can boost the effectiveness of treatment plants through tapping nutrient load by microalgae and biomass obtained after culturing can become the feedstock for multiple products have multifarious roles in diverse industries.

Section snippets

Wonders of microalgae

Microalgae are microscopic, photosynthetic, fast growing aquatic organisms (Suthers et al., 2019). These organisms inhibit wide range of habitats; freshwater, brackish and saline water (Neto and Pinto, 2019) and can be cultured without competing with arable land resources (Bhagea et al., 2019). The most important feature of microalgae is to produce oxygen by the process of photosynthesis and is known to be responsible for more than 50% of the total oxygen production on the biosphere (Chew et

Colour

Wastewater generated from various industries contain the toxic colouring agents (Benit and Roslin, 2015, Libralato et al., 2012). Release of such kind of pollutants has significant impact on the physico-chemical and biological properties of the recipient water environs (Amin et al., 2008). Effluents containing high organic load and dark coloured water shield the sunlight necessary for phytoplankton and other photosynthetic organisms. Microalgae have great ability to detoxify phenolic and

Advantages of microalgae based wastewater treatment over other techniques

Ultraviolet disinfection (Gibson et al., 2017), flocculation(Wang and Chen, 2009), ultrafiltration(Te Poele and Van der Graaf, 2005), chemical precipitation (Rajasulochana and Preethy, 2016a, Rajasulochana and Preethy, 2016b), electro-coagulation(Tahreen et al., 2020), activated charcoal (Wang and Chen, 2009), ion exchange (Rajasulochana and Preethy, 2016a, Rajasulochana and Preethy, 2016b), reverse osmosis (Vinardell et al., 2020) are the major techniques employed for the treatment of

Challenges and future prospects

Although, several benefits ranging from stabilization of physico-chemical attributes to biofuel production are associated with microalgal cultivation in wastewater but numerous risks in the form of pathogenic contamination, highly coloured water, exposure to heavy metals and emerging contaminants and high variable nutrient concentration linked with wastewater condition can obliterate the functioning of microalgae. The essential attributes of microalgae must be able to effectively adapt under

Conclusion

Wastewater contains abundant nutrients, heavy metals and recalcitrant persistent pollutants. Conventional treatment approaches are not capable of eliminating the contaminants effectively in wastewater. The complexity and composition of wastewater are putting more pressure in conservation of aquatic systems. Thus causing imbalance in the functioning of concerned aquatic ecosystems. Therefore, need of an hour is to stabilize the perturbed aquatic ecosystems by employing the techniques based on

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References (252)

  • BestM.A. et al.

    Dissolved oxygen as a physico-chemical supporting element in the water framework directive

    Mar. Pollut. Bull.

    (2007)
  • BhatiaS.K. et al.

    Carbon dioxide capture and bioenergy production using biological system–a review

    Renew. Sustain. Energy Rev.

    (2019)
  • BhatnagarA. et al.

    Renewable biomass production by mixotrophic algae in the presence of various carbon sources and wastewaters

    Appl. Energy

    (2011)
  • BhattacharyaT. et al.

    Eco-restoration potential of vegetation for contaminated water bodies

  • BilalM. et al.

    Emerging contaminants of high concern and their enzyme-assisted biodegradation–a review

    Environ. Int.

    (2019)
  • BilottaG.S. et al.

    Understanding the influence of suspended solids on water quality and aquatic biota

    Water Res.

    (2008)
  • BrusseauM.L. et al.

    Chemical contaminants

  • CheahW.Y. et al.

    Cultivation in wastewaters for energy: a microalgae platform

    Appl. Energy

    (2016)
  • CheahW.Y. et al.

    Biosequestration of atmospheric CO2 and flue gas-containing CO2 by microalgae

    Bioresour. Technol.

    (2015)
  • ChewK.W. et al.

    Effects of water culture medium, cultivation systems and growth modes for microalgae cultivation: a review

    J. Taiwan Inst. Chem. Eng.

    (2018)
  • ChoS. et al.

    Reuse of effluent water from a municipal wastewater treatment plant in microalgae cultivation for biofuel production

    Bioresour. Technol.

    (2011)
  • ChojnackaK. et al.

    Trace metal removal by Spirulina sp. from copper smelter and refinery effluent

    Hydrometallurgy

    (2004)
  • ChoudharyP. et al.

    Screening native microalgal consortia for biomass production and nutrient removal from rural wastewaters for bioenergy applications

    Ecol. Eng.

    (2016)
  • CollaL.M. et al.

    Production of biomass and nutraceutical compounds by spirulina platensis under different temperature and nitrogen regimes

    Bioresour. Technol.

    (2007)
  • De-BashanL.E. et al.

    Immobilized microalgae for removing pollutants: review of practical aspects

    Bioresour. Technol.

    (2010)
  • De GodosI. et al.

    Tetracycline removal during wastewater treatment in high-rate algal ponds

    J. Hazard. Mater.

    (2012)
  • De WiltA.

    Micropollutant removal in an algal treatment system fed with source separated wastewater streams

    J. Hazard. Mater.

    (2016)
  • DellamatriceP.M. et al.

    Degradation of textile dyes by cyanobacteria

    Braz. J. Microbiol.

    (2017)
  • DemirbasA.

    Heavy metal adsorption onto agro-based waste materials: a review

    J. Hard Mater.

    (2008)
  • DesmetN.J.S. et al.

    Quantification of the impact of macrophytes on oxygen dynamics and nitrogen retention in a vegetated lowland river

    Phys. Chem. Earth

    (2011)
  • El-KassasH.Y. et al.

    Bioremediation of the textile waste effluent by Chlorella vulgaris

    Egypt. J. Aquat. Res.

    (2014)
  • El-SheekhM.M. et al.

    Growth and heavy metals removal affinity of Nostoc muscorum and Anabaena subcylindrica in sewage and industrial wastewater effluent

    Environ. Toxicol. Pharmacol.

    (2005)
  • El-SheekhM.M. et al.

    Biodegradation of dyes by some green algae and cyanobacteria

    Int. Biodeterior. Biodegrad.

    (2009)
  • El-SheekhM.M. et al.

    Biodegradation of crude oil by Scenedesmus obliquus and Chlorella vulgaris growing under heterotrophic conditions

    Int. Biodeterior. Biodegrad.

    (2013)
  • El-SikailyA. et al.

    Removal of toxic chromium from wastewater using green alga Ulva lactuca and its activated carbon

    J. Hard Mater.

    (2007)
  • EscapaC. et al.

    Nutrients and pharmaceuticals removal from wastewater by culture and harvesting of Chlorella sorokiniana

    Bioresour. Technol.

    (2015)
  • EscapaC. et al.

    Comparative assessment of diclofenac removal from water by different microalgae strains

    Algal Res.

    (2016)
  • EscapaC. et al.

    Paracetamol and salicylic acid removal from contaminated water by microalgae

    J. Environ. Manag.

    (2017)
  • EzeV.C. et al.

    Kinetic modelling of microalgae cultivation for wastewater treatment and carbon dioxide sequestration

    Algal Res.

    (2018)
  • ForgacsE. et al.

    Removal of synthetic dyes from waste waters: a review

    Environ. Int.

    (2004)
  • FranchinoM. et al.

    Growth of three microalgae strains and nutrient removal from an agro- zootechnicaldigestate

    Chemosphere

    (2013)
  • GattulloC.E. et al.

    Removal of bisphenol a by the freshwater green alga Monoraphidium braunii and the role of natural organic matter

    Sci. Total Environ.

    (2012)
  • AbinandanS. et al.

    Nutrient removal and biomass production: advances in microalgal biotechnology for wastewater treatment

    Crit. Rev. Biotechnol.

    (2018)
  • AdhikariS. et al.

    Effects of climate change on the use of wastewater for aquaculture practices

  • AjayanK.V. et al.

    Phycoremediation of tannery wastewater using microalgae Scenedesmus species

    Int. J. Phytoremediation

    (2015)
  • AL-AhmadiM.S.

    Pesticides, anthropogenic activities, and the health of our environment safety

  • Al-DahhanM.H. et al.

    Biodegradation of phenolic components in wastewater by micro algae: a review

    (2018)
  • Al-GheethiA.A. et al.

    Reduction of faecal indicators and elimination of pathogens from sewage treated effluents by heat treatment

    Cas. J. Appl. Sci. Res.

    (2013)
  • AliH. et al.

    Environmental chemistry and ecotoxicology of hazardous heavy metals: environmental persistence, toxicity, and bioaccumulation

    J. Chem.

    (2019)
  • AminH. et al.

    Treatment of textile waste water using H2O2/UV system

    Physicochem. Probl. Miner. Process.

    (2008)
  • Cited by (57)

    View all citing articles on Scopus
    View full text