Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system

Olive industry liquid waste from trash to metal adsorbent for wastewater purification

The development of biobased polymeric materials for wastewater purification has become a demand due to the growing need for water free of hazardous metal ions for safe purposes. The organic components of the OLLW including carbohydrates, phenolics, aromatic acids and others are cost-effective and sustainable choices for this application. This work focuses on a method for turning the organic components of liquid waste from the olive industry (OILW) into a foam-based value-added polymer that has several metal ion binding sites. The process of making the target polymers involved reacting the components of the OILW with hexamethylene diisocyante and 1,4-phnyelene diisocynate to create the polymeric materials LHMIDIC and LPDIC that are in foam forms with urethane linkages, respectively. The adsorption competence of the polymeric foams toward Pb(II) was evaluated as a function of various parameters including adsorbent dose, pH, temperature, initial ion concentration and time. The optimum parameters values that led to a quantitative removal of Pb(II) were identified. The obtained thermodynamic parameters showed that the adsorption by the two foams was spontaneous at room temperature. The isothermal and kinetic values showed that the adsorption by synthesized foams follows a second order kinetic and obeys the Langmuir isothermal model. The foams showed a high tendency for removing multi metal ions present in a real sample of wastewater. The original nature of the starting material used in making the foam, cost and the obtained results showed the potential of using the foam in a large-scale plants of wastewater purification.

Cellulose based polyurethane with amino acid functionality: Design, synthesis, computational study and application in wastewater purification

Contamination in water is due to various environmental pollutants from natural and anthropogen activities. To remove toxic metals from contaminated water, we developed a novel adsorbent in foam form based on an olive industry waste material. The foam synthesis involved oxidation of cellulose extracted from the waste to dialdehyde, functionalization of the cellulose dialdehyde with an amino acid group, reacting the functionalized cellulose with hexamethylene diisocyanate and p-phenylene diisocyanate to produce the target polyurethanes Cell-F-HMDIC and Cell-F-PDIC, respectively. The optimum condition for lead(II) adsorption by Cell-F-HMDIC and Cell-F-PDIC were determined. The foams show the ability to quantitatively remove most of metal ions present in a real sample of sewage. The kinetic and thermodynamic studies confirmed a spontaneous metal ion binding to the foams with a second pseudo-order adsorption rate. The adsorption study revealed it obeys the Langmuir isotherm model. The experimental Qe values of both foams Cell-F-PDIC and Cell-F-HMDIC were 2.1929 and 2.0345 mg/g, respectively. Monte Carlo (MC) and Dynamic (MD) and simulations showed excellent affinity of both foams for lead ions with high adsorption negative energy value indicating vigorous interactions of Pb(II) with the adsorbent surface. The results indicate the usefulness of the developed foam in commercial applications. ENVIRONMENTAL IMPLICATION: Elimination of metal ions from contaminated environments is important for a number of reasons. They are toxic to humans via interaction with biomolecules, resulting in disruption of the metabolism and biological activities of many proteins. They are toxic to plants. Industrial effluents and/or wastewater discharged from production processes, contain a considerable amount of metal ions. In this work, the use of naturally produced materials, such as olive waste biomass, as adsorbents for environmental remediation has received great attention. This biomass represents unused resources and presents serious disposal problems. We demonstrated that such materials are capable of selectively adsorbing metal ions.

Olive Industry Solid Waste-Based Biosorbent: Synthesis and Application in Wastewater Purification

In this work, we present a process for converting olive industry solid waste (OISW) into a value-added material with ionic receptors for use in the removal of toxic metal ions from wastewater. This 3D polymer is a promising adsorbent for large-scale application, since it is a low-cost material made from agricultural waste and showed exceptional performance. The synthesis of the network polymer involved the carboxymethylation of OISW and curing of the carboxymethylated OISW at an elevated temperature to promote the formation of ester linkages between OISW's components. FT-IR, atomic force microscopy, and thermal analysis were performed on the crosslinked product. The adsorption efficiency of the crosslinked carboxymethylated OISW toward Pb(II), Cu(II), and other toxic metal ions present in sewage was evaluated as a function of adsorbent dose, temperature, pH, time, and initial metal ion. The percentage removal of about 20 metal ions present in a sewage sample collected from a sewer plant located in the Palestinian Territories was determined. The adsorption efficiency did not drop even after six cycles of use. The kinetic study showed that the adsorption process follows the Langmuir isotherm model and the second-order adsorption rate. The experimental Qe values of 13.91 and 13.71 mg/g were obtained for Pb(II) and Cu(II) removal, respectively. The thermodynamic results confirm the spontaneous metal bonding to the receptor sites of the crosslinked carboxymethylated OISW.

Cellulose polymers with β-amino ester pendant group: design, synthesis, molecular docking and application in adsorption of toxic metals from wastewater

BACKGROUND

Cellulose polymers with multidentate chelating functionalities that have high efficiency for toxic metal ions present in water were designed, synthesized, and analyzed. The synthesis was carried out by reacting microcrystalline cellulose extracted from the solid waste of the olive industry with tert-Butyl acetoacetate (Cell-AA), produced cellulose with β-ketoester functionality was then reacted with aniline and the amino acid glycine to produce Cell-β-AN and Cell-β-GL, respectively.

RESULTS

The adsorption efficiency of the three polymers toward Pb(II) and various toxic metal ions present in sewage was evaluated as a function of adsorbent dose, time, temperature, pH value, and initial ion concentration to determine optimum adsorption conditions. The three polymers showed excellent efficiency toward about 20 metal ions present in a sewage sample collected from the sewer. The adsorption process follows the Langmuir adsorption isotherm model with a second-order of adsorption rate, the calculated qe values (2.675, 15.252, 20.856 mg/g) were close to the experimental qe values (2.133, 13.91, 18.786 mg/g) for the three polymers Cell-AA, Cell-β-AG and Cell-β-AN, respectively. Molecular Dynamic (MD) and Monte Carlo (MC) simulations were performed on the three polymers complexed with Pb(II).

CONCLUSION

The waste material of the olive industry was used as a precursor for making the target cellulose polymers with β-Amino Ester Pendant Group. The polymer was characterized by SEM, proton NMR, TGA, and FT-IR spectroscopy. The efficacy of adsorption was quantitative for metal ions present in a real sample of wastewater and the efficiency didn't drop even after 7 cycles of use. The results indicate the existence of strong complexation. The thermodynamic study results showed a spontaneous bonding between of Pb(II) and the polymers pendant groups expressed by the negative value of the Gibbs free energy.

A comprehensive review on the decontamination of lead(ii) from water and wastewater by low-cost biosorbents

The disadvantages of conventional methods in water and wastewater management including the demand for high energy consumption, the creation of secondary toxic sludge, and operation cost are much too high for developing countries. However, adsorption using low-cost biosorbents is the most efficient non-conventional technique for heavy metals removal. The high adsorption capacities, cost-effectiveness, and the abundance of agricultural waste materials in nature are the important parameters that explain why these biosorbents are economical for heavy metals removal. The present investigation sought to review the biosorption of lead [Pb(ii)] onto low-cost biosorbents to understand their adsorption mechanism. The review shows that biosorption using low-cost biosorbents is eco-friendly, cost-effective, and is a simple technique for water and wastewater treatment containing lead(ii) ions. The batch biosorption tests carried out in most studies show that Pb(ii) biosorption by the low-cost biosorbents is dependent on biosorption variables such as pH of the aqueous solution, contact time, biosorbent dose, Pb(ii) initial concentration, and temperature. Furthermore, batch equilibrium data have been explored in many studies by evaluating the kinetics, isothermal and thermodynamic variables. Most of the studies on the adsorptive removal of Pb(ii) were found to follow the pseudo-second kinetic and Langmuir isotherm models with the thermodynamics variables suggesting the feasibility and spontaneous nature of Pb(ii) sequestration. However, gaps exist to increase biosorption ability, economic feasibility, optimization of the biosorption system, and desorption and regeneration of the used agricultural biosorbents.

Phlebia gigantea cells immobilized on renewable biomass matrix as potential ecofriendly scavenger for lead contamination

A novel biomaterial was prepared by the immobilization of Phlebia gigantea cells in the medium containing lignocellulosic waste and used for the first time in the bioremediation purpose. The developed new biocomposite possesses higher Pb(II) retention potential when compared with the free microbial cells. It could remove Pb(II) up to 74.11% at a biosorbent dosage of 4.0 g L^-1. Surface characterization was carried out through zeta potential, EDX, SEM, and IR studies to understand the metal-biocomposite interactions. The biosorption amount at equilibrium slightly decreased with the increase of the solution temperature. Kinetic data indicated Pb(II) biosorption onto suggested biocomposite fits well with the pseudo-first-order model. Biosorption equilibrium data suited Langmuir model with the highest coefficient of determination values. The immobilized material reached to maximum monolayer Pb(II) retention capacity (1.449 × 10^-4 mol g^-1) within the short equilibrium time (10 min). The designed biocomposite was also adapted to continuous flow mode sorption process. Regeneration tests by dynamic flow mode confirmed reutilization potential of biocomposite.

Synthesis of a cross-linked cellulose-based amine polymer and its application in wastewater purification

A cross-linked cellulose-amine polymer composed of nanocrystalline cellulose and 1,4-pheneylnediamine was synthesized, and its application as an adsorbent of metal ions from wastewater was dementated. The nanocrystalline cellulose was generated from an olive industry solid waste. The cross-linked polymer analysis results of FTIR, NMR, TEM, SEM, and XRD were generated. The adsorption efficiency of the cellulose-amine polymer toward Cu(II) and Pb(II) was investigated as a function of adsorbent dose, temperature, pH, and time. The adsorption parameters that lead to an excellent adsorption efficiency were determined. The polymer also showed an excellent extraction efficiency toward 20 metal ions present in a sewage sample. The various functional groups present on polymer surface such as amino, hydroxyl, and aryl played a crucial role on metal adsorption. Thermodynamic analysis results support the high efficiency of the polymer toward the metal ions. Kinetic study results reveal that the adsorption process fits well with the pseudo-second-order model and the adsorption isotherm follows a Langmuir isotherm model.

Removal of Cu(II), Pb(II) and Cr(VI) ions from aqueous solution using amidoximated non-woven polyethylene-g-acrylonitrile fabric

Pre-irradiation method was applied to graft acrylonitrile (AN) onto non-woven polyethylene film. Graft yield reached 130% at 70 kGy radiation dose, 60% monomer concentration and 4 h reaction time when H₂SO₄ was used as an additive. The modification of AN grafted films with hydroxyl amine hydrochloride was done for the preparation of amidoxime adsorbent. The constructed adsorbent was characterized using FTIR, DMA and SEM. The amidoxime adsorbent was used for adsorption of Cu(II), Pb(II) and Cr(VI). Adsorption capacity was investigated under different conditions: contact time, pH and initial metal ion concentration. The optimum condition for maximum adsorption was found to be contact time 72 h and initial metal concentration 500 ppm for all the metal ions studied and pH 5.2 for Cu(II), 5.4 for Pb(II), 1.5 for Cr(VI). Kinetic adsorption data was elucidated using pseudo-first-order and pseudo-second-order equations. The equilibrium experimental data of metal adsorption matched Langmuir isotherm model. From the Langmuir equation, the monolayer saturation adsorption capacity (highest adsorption capacity) of the adsorbent was found to be 74.62 mg/g for Cu(II), 107 mg/g for Pb(II) and 156.25 mg/g for Cr(VI). The thermodynamics of metal adsorption was also investigated. Furthermore, desorption and reuse of the adsorbent film was studied. The results suggest that the adsorbent can be effective for adsorption of Cu(II), Pb(II) and Cr(VI).

Nitrilotriacetic acid functionalized Adansonia digitata biosorbent: Preparation, characterization and sorption of Pb (II) and Cu (II) pollutants from aqueous solution

Nitrilotriacetic acid functionalized Adansonia digitata (NFAD) biosorbent has been synthesized using a simple and novel method. NFAD was characterized by X-ray Diffraction analysis technique (XRD), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier Transform Infrared spectrometer (FTIR), particle size dispersion, zeta potential, elemental analysis (CHNS/O analyzer), thermogravimetric analysis (TGA), differential thermal analysis (DTA), derivative thermogravimetric analysis (DTG) and energy dispersive spectroscopy (EDS). The ability of NFAD as biosorbent was evaluated for the removal of Pb (II) and Cu (II) ions from aqueous solutions. The particle distribution of NFAD was found to be monomodal while SEM revealed the surface to be heterogeneous. The adsorption capacity of NFAD toward Pb (II) ions was 54.417 mg/g while that of Cu (II) ions was found to be 9.349 mg/g. The adsorption of these metals was found to be monolayer, second-order-kinetic, and controlled by both intra-particle diffusion and liquid film diffusion. The results of this study were compared better than some reported biosorbents in the literature. The current study has revealed NFAD to be an effective biosorbent for the removal of Pb (II) and Cu (II) from aqueous solution.

Evaluation of Pb (II) biosorption utilizing sugarcane bagasse colonized by Basidiomycetes

The contamination of water resources by metallic ions is a serious risk to public health and the environment. Therefore, a great emphasis has been given to alternative biosorption methods that are based on the retention of aqueous-solution pollutants; in the last decades, several agricultural residues have been explored as low-cost adsorbent. In this study, the ability of Pb (II) biosorption using sugarcane bagasse modified by different fungal species was evaluated. The presence of carbonyl, hydroxyl, and carboxyl groups in the biosorbent was observed by spectroscopy in the infrared region. By scanning electron microscopy, changes in the morphology of modified material surfaces were observed. The highest adsorption capacity occurred at pH 5.0, while the shorter adsorbate-adsorbent equilibrium was at 20 min, and the system followed the pseudo-second-order model. The maximum biosorption in isotherms was found at 58.34 mg g(-1) for modified residue by Pleurotus ostreatus U2-11, and the system followed the Langmuir isotherm. The biosorption process was energetically spontaneous with low desorption values. This modification showed great potential for filters to remove Pb (II) and provide the preservation of water resources and animal health.

Nitrogen-functionalised carbon nanotubes as a novel adsorbent for the removal of Cu(ii) from aqueous solution

Nitrogen-functionalized multiwalled carbon nanotubes synthesized were effective and efficient for the removal of Cu²⁺ from aqueous solutions.