Comparative Utilization of Dead and Live Fungal Biomass for the Removal of Heavy Metal: A Concise Review

Abstract

Human and industrial activities produce and discharge wastes containing heavy metals into the water resources making them polluted, threatening human health and the ecosystem. Biosorption, the process of passive cation binding by dead or living biomass, represents a potentially cost-effective way of eliminating toxic heavy metals from industrial wastewater. The abilities of microorganisms to remove metal ions in solution have been extensively studied; in particular, live and dead fungi have been recognized as a promising class of low-cost adsorbents for the removal of heavy metal ions. The biosorption behavior of fungal biomass is getting attention due to its several advantages; hence, it needs to be explored further to take its maximum advantage on wastewater treatment. This review discusses the live and dead fungi characteristics of sorption, factors influencing heavy metal removal, and the biosorption capacities for heavy metal ions removal and also discusses the biosorption mechanisms.

Mycelium-Based Composite: The Future Sustainable Biomaterial

“…It has been used as the production of dietary supplements or nutraceuticals such as antitumor, antimetastatic, antioxidant, anti-inflammatory, insecticidal, and antimicrobial. Gradually, utilization of mycelium was translated into mycoremediation since the 1980s [ 52 – 54 ]. Beyond bioremediation and medicinal application, nowadays mycelium is applied in biomaterial production such as biocement, bioblock, and bioenzyme.…”

“…The length of the incubation period affects the quality of the composite materials. The density of fungal-based composites increased as the incubation period increased from 195 kg/m 3 to 280 kg/m 3 [ 52 ]. That might be due to the fact that the voids between the fibers are filled as the mycelium continues to grow and the substrate is bonded more strongly together which in turn increases the density [ 28 ].…”

Polysaccharides as Support for Microbial Biomass-Based Adsorbents with Applications in Removal of Heavy Metals and Dyes

“…The biomass (algae, bacteria, yeast, and fungi) can be used as living cells, offering the possibility of removing larger amounts of pollutants, since it has the enzymatic facility that allows it to either transform or degrade the pollutant (considered as food source for living cells/microorganism), but the biosorption process depends on the cell metabolism and requires specific conditions compatible with living cells (nutrient supply, temperature and pH in a certain domain, oxygen supply for aerobic cells, etc.) and can be stored for very limited periods of time [20,22,23]. The non-living biomass is used in the simpler and less expensive treatment processes, thus the biosorbent can be utilized for more than one cycle (taking into account the pollutant concentration), and no cell disruption occurs as long as the working conditions are not extreme.…”

“…There are different immobilization techniques that can be applied for biosorbents, with microbial cells being bonded either on the surface or within a polymer matrix: adsorption, covalent bonding, cross-linking, encapsulation, and entrapment in a matrix (Figure 2) [6,22,[24][25][26]. [23,27].…”

“…An extremely important step in the immobilization process is the selection of a suitable support (it can be natural-gelatin, agar, gum, sodium alginate, calcium alginate, dextran, fats and fatty acids, starch, chitosan, sucrose, and wax, or synthetic-acrylic polymer and copolymers, and semi-synthetic-cellulose acetate, cellulose nitrate, ethylcellulose and hydroxypropylcellulose, methylcellulose, sodium carboxymethylcellulose, hydrogenated fat, and myristic alcohol), since it needs to fulfill several characteristics, presented in Table 2 [6,[22][23][24][25]. The choice of a support is very important for the efficiency of immobilization and the stability of final biosorbent.…”