Papers by Keyword: Biosorption

Abstract: This study evaluates the potential of hemp shives (HS) as candidate for two basic dyes removal, namely Azure B (AB) and Malachite Green (MG), from aqueous solutions. The biosorption tests were conducted in batch mode. The influence of experimental variables, including pH, dye concentration, adsorbent dosage, and contact time, was evaluated. Under optimal biosorption conditions, equilibrium and kinetic studies were conducted in order to gain further insight into the process. Hemp shives, without any additional treatment, exhibited the highest value of the maximum Langmuir adsorption capacity reported in the literature for AB (q_max = 364.4 mg/g). Furthermore, HS has demonstrated superior MG removal efficiency compared to other biosorbents previously reported, reaching a value of q_max = 91.0 mg/g. The biosorption of both dyes can be described by a pseudo-second-order kinetic model. The formation of chemical bonds between the dye molecules and the active sites of the biosorbent represents the rate-limiting step in the process. Moreover, it has been demonstrated that the spent hemp shives can be partially regenerated. The AB biosorption capacity of the recycled material (q₂ = 23.60 mg/g), which had been washed with HCl, was approximately half that of the adsorption capacity of the fresh HS (q₁ = 44.80 mg/g). Following the washing of spent hemp shives with acetic acid, it was observed that the recycled material retained in excess of 40% of its original biosorption capacity for AB (q₂ = 18.72 mg/g). The desorption of MG from HS is a more challenging process than that of AB.

Abstract: Arsenic in the water bodies being a serious menace for human and living organisms. To tackle this arsenic contaminant, a series experiments were conducted on biosorption of arsenic using isolated from soil and water sample of Taptapani Hotspring of Odisha, India. Out of the various collected microorganisms three isolates viz. Exiguobacterium sp.(SSB11), Alcaligenesfaecalis DZ2(SSB17) and Lysinibacillussphaericus SI-3(SSB58) possess better affinity towards heavy metals. By exploring this, the consortium of these microorganisms was chosen for bioremediation of As(III) from waste water. As revealed from experiments, the maximum adsorption capacity of the consortium isolates were observed to be 51 g/g. Further, the biosorption kinetics were tested with two robust isotherms viz. Freundlich and Langmuir, thereby revealing better agreement with the Freundlich isotherm.

Abstract: Heavy metal contamination has been one of the primary environmental concerns for many years in most developing countries. As the industries continue to search for low-cost and efficient adsorbents to treat their effluents contaminated with these toxic metal ions, biomass-based adsorbents have gained much attention. This work exploits such ten different biomass-based adsorbents (namely, Karanja de-oiled cake, Neem de-oiled cake, Neem leaves, Moringa Leaves, Bagasse, Mango Kernel, Wheat Bran, Eucalyptus, Fly ash, and Corn cob) for adsorption of copper ions in particular. Further, selected adsorbents (namely Karanja de-oiled cake, Neem de-oiled cake, Bagasse, Wheat Bran and Mango Kernel) were taken to the next stage and modified to biochar and tested again for copper removal. Among the biomass-based adsorbents, the highest adsorption capacity was observed for Neem de-oiled cake (equal to 9.6 mg/g). While for biochar-based adsorbents, Bagasse showed the highest adsorption capacity for copper (equivalent to 13.0 mg/g).

Abstract: This review article presents the usage of various animal bones such as chicken bone, fish bone, pig bone, camel bone, and cow bone as reliable biosorbent materials to remove heavy metals contained in contaminated water and wastewater. The sources and toxicity effects of heavy metal ions are also discussed properly. Then specific insights related to adsorption process and its influential factors along with the proven potentiality of selected biosorbents especially derived from animal bone are also explained. As the biosorbents are rich in particular organic and inorganic compounds and functional groups in nature, they play an important role in heavy metal removal from contaminated solutions. Overall, after conducting study reports on the literature, a brief conclusion can be drawn that animal bone waste has satisfactory efficacy as effective, efficient, and environmentally friendly sorbent material.

Abstract: In this chapter the adsorption fundamentals using biomass as adsorbents in the removal of metallic ions are presented. The research as shows the importance of many factors that affects the adsorption, such as the biomass superficial area, system temperature, pH, initial concentration of the metal, biomass amount and status (living or dead). The study was directed at the approach of two applications using Saccharomyces cerevisiae yeast in the adsorption of Cd²⁺ metal ions. In the first application it is discussed the influence of the pH of the medium and the biomass status (living or dead) in the adsorption of Cd²⁺, in batch. In the second application, it was studied the adsorption of Cd²⁺metallic ions through the Saccharomyces cerevisiae yeast immobilized in chitosan, in fixed bed, where the influence inlet mass flow rate and the initial effluent concentration on the adsorption capacity and percentage of Cd²⁺ ions removal are evaluated.The studies realized are supported by statistical analysis with 95% confidence intervals.

Abstract: The objective of this study was the synthesis of various activated carbons from grape marc issued from oenological by-product as a biosorbent. The biosolid was then applied to remove an industrial dye (red bemacid ETL) in aqueous solution. Activation of the synthesized charcoal was carried out using a solution of zinc chloride induced by two physical methods (microwaves and heating at 300°C). The obtained materials are characterized by FTIR and SEM methods. Results from batch adsorption tests have shown that pH solution, initial dye concentration and contact time affect the adsorption mechanism. Removal of the industrial dye revealed second order kinetics, exothermic adsorption and isothermal adsorption of BET type.

Abstract: The aim of this paper was to study of biosorption by use waste material as a biosorbent. Waste material used in this work was activated industrial hemp shives (Cannabis sativa), which occurs during the processing of hemp shives grown as the waste biomass in the processing process. The sorbent was utilized to reduce the content of Cu(II) ions from aqueous solutions. Sorption experiments of the cannabis hemp shives were conducted in a batch mode by use the model solutions of Cu(II). The impact of pH, contact time and initial concentration on the pollutant removal efficiency was observed. The sorption kinetics were evaluated with pseudo-first and pseudo-second order kinetic models. Adsorption process has been modeled by the Langmuir, Freundlich, Temkin and Dubinin‑Radushkevich isotherms using linear regression. The results of this study indicated that the application of hemp shives of Cannabis sativa waste material as a biosorbent is highly effective for the removal copper ions from wastewater.

Abstract: In the present study, the efficiency of biosorbent derived form Pongamia pinata to remove a basic textile dye Methylene Blue from an aqueous solution was evaluated in batch system. The influence of adsorption parameters such as biosorbent dosage (0.2-1.0g/L), P^H (2-10) and initial dye concentration (30-110 mg/L) on the biosorption process was studied. It was noticed that adsorbent dosage has negative effect on dye uptake, could be due to reduced mass transfer rate of dye on to adsorbent. High equilibrium uptake was observed at P^H 8. However, initial dye concentration has shown linear relationship with dye uptake. As the dye concentration increases, the number of dye molecules available to be adsorbed on to adsorbent surface increases. Equilibrium isotherms for the adsorption of methylene blue was analyzed through Langmuir and Freundlich isotherm models. The data best fit with Freundlich model than Langmuir isotherm model, suggesting the adsorption was by multilayer mechanism. Maximum adsorption capacity (Q ̊) was found to be 40.49mg/g. It can be concluded from the study that the adsorbent derived from P. pinnata can be a potential low cost competent of activated carbon for textile dyes removal.

Abstract: We have focused on the metal-reducing bacterium, Shewanella algae that are able to reduce and deposit platinum group metals (Pt (IV), Pd (II) and Rh (III)) and gold (Au (III)) in neutral solutions at room temperature under anaerobic conditions. When processing the aqua regia solution of spent automotive catalysts, the solution pH was adjusted to the optimal range for S. algae activity between pH 4 and 7. After this pH adjustment, the S. algae cells were able to rapidly and selectively reduce and accumulate the platinum group metal ions from the leaching solution into the bacterial cells as metallic nanoparticles. The biotechnological procedure also has the potential to allow the recovery of Au (III) ions from the leaching solution of electronic waste. We also found that the S. algae cells were also applicable to the adsorption of rare metal ions from acidic solutions. We achieved selective adsorption of indium (In (III)) ions on the bacterial cells from the leaching solution of waste liquid crystal displays by adjusting its pH, because the pH range necessary for S. algae to act as an effective adsorbent differs for different metal ions. Our proposed microbial methods enable the rapid and highly efficient recovery of precious and rare metals sourced from post-consumer products.

Abstract: The development of effective and ecofriendly processes for the recovery of critical elements poses a challenge for scientists all over the world. A novel approach is the generation of highly specific peptides that bind with high affinity to individual elements of interest. The peptides are selected by phage surface display (PSD) technology. In this study, PSD technology has been applied in two different approaches. The focus of the first approach was the identification of peptides that bind specifically to special particles of interest that are part of electronic scrap aiming towards the development of new recycling processes. In the second approach, metal ion binding peptides were isolated via PSD to use them for the targeted removal and enrichment of these elements from complex leaching solutions or from industrial waters. To address the economic production of peptides, the development of a new expression system is also part of this study.