Biosorption of nickel(II) and copper(II) ions from synthetic and real effluents by alginate-based biosorbent produced from seaweed Sargassum sp

Microbial strategies for copper pollution remediation: Mechanistic insights and recent advances

Environmental contamination is aninsistent concern affecting human health and the ecosystem. Wastewater, containing heavy metals from industrial activities, significantly contributes to escalating water pollution. These metals can bioaccumulate in food chains, posing health risks even at low concentrations. Copper (Cu), an essential micronutrient, becomes toxic at high levels. Activities like mining and fungicide use have led to Copper contamination in soil, water, and sediment beyond safe levels. Copper widely used in industries, demands restraint of heavy metal ion release into wastewater for ecosystem ultrafiltration, membrane filtration, nanofiltration, and reverse osmosis, combat heavy metal pollution, with emphasis on copper.Physical and chemical approaches are efficient, large-scale feasibility may have drawbackssuch as they are costly, result in the production of sludge. In contrast, bioremediation, microbial intervention offers eco-friendly solutions for copper-contaminated soil. Bacteria and fungi facilitate these bioremediation avenues as cost-effective alternatives. This review article emphasizes on physical, chemical, and biological methods for removal of copper from the wastewater as well asdetailing microorganism's mechanisms to mobilize or immobilize copper in wastewater and soil.

Biosorption of chromium (VI), iron (II), copper (II), and nickel (II) ions onto alkaline modified Chlorella vulgaris and Spirulina platensis in binary systems

The simultaneous biosorption of chromium (VI), copper (II), iron (II), and nickel (II) was investigated by alkaline-modified Chlorella vulgaris and Spirulina platensis in binary systems. The alkaline modified biosorbents were CV-KCl, SP-KCl, CV-Na2CO3, and SP-Na2CO3. The maximum removal efficiency recorded in this study was 99.7% with a biosorbent dosage of 0.3 g within a pH range of 2 to 6. The highest biosorption capacities obtained were 14.1, 13.5, 21.6, and 15.8 mg/g for Cr (VI), Cu (II), Fe (II), and Ni (II), respectively. The pseudo-second-order best described the biosorption rate, while the Langmuir isotherm model best described the biosorption equilibrium interaction. The values for Gibbs free energy (ΔG°) were in the range of 0.5 to 6.5 kJ/mol (Cr-Fe), 1.3 to 8.4 kJ/mol (Cr-Ni), and 3.9 to 11.3 kJ/mol (Cr-Cu) binary systems. This showed that the biosorption processes were characterized by physisorption reactions. The Temkin constant B values were in the range of 0.339 to 1.485 kcal/mol and the biosorption processes were largely exothermic reactions. The values for the Freundlich constant KF were between 1.4 and 10.4 (L/g), which indicated favourable biosorption. The Temkin isotherm model confirmed a strong binding affinity for Fe (II) and Ni (II). The results suggest that potassium chloride and sodium carbonate modification are very suitable for green algae and cyanobacteria for the efficient removal of heavy metals.

Effective biosorption of Cu(II) using hybrid biocomposite based on N-maleated chitosan/calcium alginate/titania: Equilibrium sorption, kinetic and thermodynamic studies

In this research work, a hybrid biocomposite based on N-maleated chitosan, amino-thiocarbamate functionalised calcium alginate and anhydrous Titania nanoparticles (NMC-MCA-TiO₂) was fabricated. The study involves the one pot facile synthesis of N-maleated chitosan and amino-thiocarbamate functionalised alginate under moderate conditions. Sorbent was conditioned in the form of hydrogel beads and characterized through FT-IR and SEM analysis. Newly grafted functional groups could act as potential chelating sites for enhanced Cu(II) sorption. Modified biopolymers were organo-functionalised which provided excellent support for immobilization of Titania nanoparticles (TiO₂) as inorganic filler. Kinetic data illustrated the manifestation of intrinsic chemisorption instead of simple bulk/film diffusion. Equilibrium sorption data fitted well with Freundlich adsorption model (R² ≈ 0.99) which designated the heterogeneous nature of sorbent. Maximum sorption capacity of biosorbent was found 192 mg/g at 298 K and pH = 6.0. Standard Gibbs free energy change ∆G^o (-21.53, -21.97, and - 22.42 kJ/mol), standard enthalpy change ∆H^o (5.12 kJ/mol) and standard entropy change ∆S^o (0.09 kJ/mol K^-1) values suggested that the sorption process to be spontaneous and endothermic. The sorbent 3NMC-MCA-TiO₂ could be competitive candidate for economical and rapid adsorptive removal of Cu(II) from dilute contaminated liquids.

Biosorption: A Review of the Latest Advances

Biosorption is a variant of sorption techniques in which the sorbent is a material of biological origin. This technique is considered to be low cost and environmentally friendly, and it can be used to remove pollutants from aqueous solutions. The objective of this review is to report on the most significant recent works and most recent advances that have occurred in the last couple of years (2019–2020) in the field of biosorption. Biosorption of metals and organic compounds (dyes, antibiotics and other emerging contaminants) is considered in this review. In addition, the use and possibilities of different forms of biomass (live or dead, modified or immobilized) are also considered.

Simultaneous biosorption of Cd(II), Ni(II) and Pb(II) onto a brown macroalgae Fucus vesiculosus: Mono- and multi-component isotherms, kinetics and thermodynamics

Due to the anthropic activities, several heavy metal ions are introduced into the environment, impacting ecosystems and local activities. In this context, the biosorption process using algae represents an alternative form for these compounds remediation due to the advantages derived from the biosorbent and process efficiency. Thus, the present study evaluated Cadmium (Cd(II)), Nickel (Ni(II)) and Lead (Pb(II)) remediation from aqueous media in mono- and multi-component systems. The biosorbent was characterized in terms of its morphology and composition and parameters involving equilibrium, kinetics, and thermodynamics were investigated. Lastly, the sample was considered in a real surface water sample remediation impacted by a mining dam rupture. Except for Freundlich, all isotherm models tested satisfactorily adjusted to the experimental data for a mono-component system. The maximum biosorption capacities (qm) were 143.2 ± 7.5, 70.1 ± 1.9, 516.3 ± 12.5 mg g-1 for Cd(II), Ni(II) and Pb(II) ions, respectively. When binary systems were considered, an antagonism effect was observed. The biosorption of Cd(II) was drastically affected by the presence of Ni(II), while Pb(II) biosorption in general was less affected by other metals presence. As observed for the binary system, the worst effect in the ternary system was observed for Cd(II) biosorption, being significantly affected by Ni(II) and Pb(II) presence. Overall, the biosorption order in mono- and multi-component systems was found to be Pb(II) ≫ Cd(II) > Ni(II). The affinity for the metals ions was also observed by Elovich's desorption constant, in which aPb(II)≪aCd(II)aCd(II), achieving an equilibrium passed 49 min. From the stages involved in biosorption process, film diffusion presented the greatest contribution as control-stage obtaining a lower diffusion coefficient in all cases. The process was spontaneous in all temperature range evaluated, considered exothermic for all metal ions evaluated. Iron, manganese and nickel concentrations in real surface water samples were higher than the allowed by the Brazilian National Environment Council (CONAMA). Comparing the hazard index values before and after the biosorption process, a reduction superior to 8 × was observed (HIbefore: 3.36, HIafter: 0.40), in which there was no non-carcinogenic risk imposed to the surrounding population after the treatment applied.

Assessment of Pb2+ removal capacity of lichen (Evernia prunastri): application of adsorption kinetic, isotherm models, and thermodynamics

Biological materials play a significant role in the treatment of heavy metal-contaminated soil and wastewater. In this study, the Pb²⁺ biosorption potential of lichen Evernia prunastri, extensively available at a forest in Bilecik-Turkey, was investigated at batch-scale level. The optimal conditions were determined and the adsorption isotherms, kinetics, and thermodynamic calculations were also done. In order to have detailed knowledge about metal biosorption, SEM, FTIR, and BET analyses were carried out before and after the biosorption process. The optimal pH was found pH 4 and the maximum metal uptake capacity was found as 0.067 mol kg^-1. The results of this study indicate that the lichen was effectively applied to the removal of Pb²⁺ process as an inexpensive biosorbent from industrial wastewater.