The Utilization of Algae and Seaweed Biomass for Bioremediation of Heavy Metal-Contaminated Wastewater

Abstract

The presence of heavy metals in water bodies is linked to the increasing number of industries and populations. This has serious consequences for the quality of human health and the environment. In accordance with this issue, water and wastewater treatment technologies including ion exchange, chemical extraction, and hydrolysis should be conducted as a first water purification stage. However, the sequestration of these toxic substances tends to be expensive, especially for large scale treatment methods that require tedious control and have limited efficiency. Therefore, adsorption methods using adsorbents derived from biomass represent a promising alternative due to their great efficiency and abundance. Algal and seaweed biomass has appeared as a sustainable solution for environmentally friendly adsorbent production. This review further discusses recent developments in the use of algal and seaweed biomass as potential sorbent for heavy metal bioremediation. In addition, relevant aspects like metal toxicity, adsorption mechanism, and parameters affecting the completion of adsorption process are also highlighted. Overall, the critical conclusion drawn is that algae and seaweed biomass can be used to sustainably eliminate heavy metals from wastewater.

Pharmaceuticals in the Aquatic Environment: A Review on Eco-Toxicology and the Remediation Potential of Algae

“…Most of the microalgae of commercial interest are microscopic in size and are evolutionally adapted to remain suspended in the water column. Due to their unicellular forms and low population density, commercial biomass harvesting of microalgae is difficult, and the cost of biomass recovery is usually significant [315,316] Moreover, the harvesting process strictly depends on microalgae characteristics, such as cell size and population density [317][318][319]. Harvesting technologies may involve one or more steps and incorporate different biological (bioflocculation and microalgae immobilization), physical (centrifugation, gravity sedimentation, filtration and dissolved air flotation) and chemical (chemoflocculation) processes, which have been extensively described in the literature [318,320,321], but most of them are energy-consuming, making phycoremediation less attractive compared to other remediation methods [322].…”

“…Due to their unicellular forms and low population density, commercial biomass harvesting of microalgae is difficult, and the cost of biomass recovery is usually significant [315,316] Moreover, the harvesting process strictly depends on microalgae characteristics, such as cell size and population density [317][318][319]. Harvesting technologies may involve one or more steps and incorporate different biological (bioflocculation and microalgae immobilization), physical (centrifugation, gravity sedimentation, filtration and dissolved air flotation) and chemical (chemoflocculation) processes, which have been extensively described in the literature [318,320,321], but most of them are energy-consuming, making phycoremediation less attractive compared to other remediation methods [322]. Thus, reducing the costs of biomass harvesting is a problem that is currently widely investigated using single-and multiple-step harvesting systems; however, none of those systems are ideal because numerous factors (algal species, culture system, culture volume, total biomass yield, etc.)…”

Modified Polymeric Biosorbents from Rumex acetosella for the Removal of Heavy Metals in Wastewater

“…Among the most economical methods for the treatment of water contaminated with heavy metals is biosorption; this technique has advantages in its applicability, easy obtaining, simple design, and wide use [ 13 , 14 , 15 , 16 , 17 , 18 ]; the physicochemical characteristics of biosorbents rich in lignocellulose allow us to understand the different adsorption mechanisms and their potential application in the removal of metal cations; Characterizations such as proximal, thermal, chemical groups, surface, geometry, and porosity analysis are important for this purpose. It is also known that lignocellulose is present in different plant fibers and also has functional groups such as hydroxyl, carboxyl, and silanol, which contribute to its high biosorption capacity [ 19 , 20 ].…”

Determination of Antioxidant, Antimicrobial Activity, Heavy Metals and Elements Content of Seaweed Extracts

“…Their detection is also used as a biomonitor for heavy metal pollution in rivers, seas, and oceans worldwide. Overall, algae and seaweed biomass can be used to sustainably remove heavy metals from wastewater [ 14 ]. The presence of heavy metals is dependent on environmental parameters and on the area (salinity, temperature, pH, light, nutrient concentrations, oxygen, etc.…”