Adsorption Capacity of Silica SBA-15 and Titanosilicate ETS-10 toward Indium Ions.

Indium is an extremely important element for industry that is distributed in the Earth's crust at very low concentrations. The recovery of indium by silica SBA-15 and titanosilicate ETS-10 was investigated at different pH levels, temperatures, times of contact and indium concentrations. A maximum removal of indium by ETS-10 was achieved at pH 3.

Ion-Imprinted Polymeric Materials for Selective Adsorption of Heavy Metal Ions from Aqueous Solution.

The introduction of selective recognition sites toward certain heavy metal ions (HMIs) is a great challenge, which has a major role when the separation of species with similar physicochemical features is considered. In this context, ion-imprinted polymers (IIPs) developed based on the principle of molecular imprinting methodology, have emerged as an innovative solution. Recent advances in IIPs have shown that they exhibit higher selectivity coefficients than non-imprinted ones, which could support a large range of environmental applications starting from extraction and monitoring of HMIs to their detection and quantification.

Feather-weight cryostructured thiourea-chitosan aerogels for highly efficient removal of heavy metal ions and bacterial pathogens.

Designing of economically feasible and recyclable polysaccharide-based materials with thiourea functional groups for removal of specific metal ions such as Ag(I), Au(I), Pb(II) or Hg(II) remains a major challenge for environmental applications. Here, we introduce ultra-lightweight thiourea-chitosan (CSTU) aerogels engineered by combining successive freeze-thawing cycles with covalent formaldehyde-mediated cross-linking and lyophilization. All aerogels exhibited outstanding low densities (0.

Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions.

It is still a challenge to develop advanced materials able to simultaneously remove more than one pollutant. Exclusive cationic composite double- and triple-network cryogels, with adequate sustainability in the removal of CrO and HPO oxyanions, were developed in this work starting from single-network (SN) sponges. Chitosan (CS), as the only polycation originating from renewable resources, and poly(N,N-dimethylaminoethylmethacrylate) (PDMAEMA) and polyethyleneimine (PEI), as synthetic polycations, were employed to construct multi-network cationic composite cryogels.

Optimization of Arsenic Removal from Aqueous Solutions Using Amidoxime Resin Hosted by Mesoporous Silica.

The paper reports on the performances of cross-linked amidoxime hosted into mesoporous silica (AMOX) in the removal of As(III) and As(V). The optimum pH for sorption of As(III) and As(V) was pH 8 and pH 5, respectively. The PFO kinetic model and the Sips isotherm fitted the best the experimental data.

Experimental Studies on the Removal of Aluminium Ions from Synthetic Aqueous Solution by Hydroxyapatites.

In this work we have presented the results obtained in the adsorption behavior of hydroxyapatite with different treatment towards aluminium ions from synthetic wastewaters. Experiments were performed in batch technique at different pH values, temperatures, sorbent dosage, contact time and initial aluminium concentration. The thermodynamic studies on the adsorption process of aluminium onto hydroxyapatite indicated that the process is spontaneous and endothermic.

Analysis of Copper(II), Cobalt(II) and Iron(III) Sorption in Binary and Ternary Systems by Chitosan-Based Composite Sponges Obtained by Ice-Segregation Approach.

With the intensive industrial activity worldwide, water pollution by heavy metal ions (HMIs) has become a serious issue that requires strict and careful monitoring, as they are extremely toxic and can cause serious hazards to the environment and human health. Thus, the effective and efficient removal of HMIs still remains a challenge that needs to be solved. In this context, copper(II), cobalt(II) and iron(III) sorption by chitosan (CS)-based composite sponges was systematically investigated in binary and ternary systems.

Evaluation of phosphate adsorption by porous strong base anion exchangers having hydroxyethyl substituents: kinetics, equilibrium, and thermodynamics.

Phosphate anions are recognized as the main responsible for the eutrophication of surface waters. In this work, two strong base anion exchangers having either N,N-dimethyl 2-hydroxyethylammonium (SBAEx.2M) or N,N-diethyl 2-hydroxyethylammonium (SBAEx.

Superadsorbents for Strontium and Cesium Removal Enriched in Amidoxime by a Homo-IPN Strategy Connected with Porous Silica Texture.

In light of the fact that two with good compatibility are better than one, the homo-interpenetrating polymer network (IPN) strategy was used in this work to design novel amidoxime (AOX)-interpenetrating networks into porous silica (PSi) with the final aim to enhance the sorption performances of composite sorbents toward Cs and Sr. To achieve this goal, first, a homo-IPN of poly(acrylonitrile) (PAN) was constructed inside the channels of two kinds of porous silica, one mesoporous (PSi1) and one macroporous (PSi2), the textural properties of silica being exploited in controlling the sorption performances of the composites. The novel composites were fully characterized by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and the nitrogen sorption/desorption isotherms (Brunauer-Emmett-Teller (BET) analysis).

Erratum: Dragan, E.S., et al., Contribution of Cross-Linker and Silica Morphology on Cr(VI) Sorption Performances of Organic Anion Exchangers Embedded into Silica Pores. 2020, , 1249.

The authors wish to make a change to the published paper [...

Contribution of Cross-Linker and Silica Morphology on Cr(VI) Sorption Performances of Organic Anion Exchangers Embedded into Silica Pores.

Removal of Cr(VI) from the environment represents a stringent issue because of its tremendous effects on living organisms. In this context, design of sorbents with high sorption capacity for Cr(VI) is getting a strong need. For this purpose, poly(vinylbenzyl chloride), impregnated into porous silica (PSi), was cross-linked with either ,,','-tetramethyl-1,2-ethylenediamine (TEMED) or ,,','-tetramethyl-1,3-propanediamine, followed by the reaction of the free -CHCl groups with ,-diethyl-2-hydroxyethylamine to generate strong base anion exchangers (ANEX) inside the pores.

Removal of heavy metal ions from multi-component aqueous solutions by eco-friendly and low-cost composite sorbents with anisotropic pores.

Copper, nickel, zinc, chromium, and iron ions are the prevailing contaminants in the aqueous effluents resulting from the photo-etching industry. In this context, we investigate here the metal ion sorption performance of an ion-imprinted cryogel (IIC), consisting of low-cost materials coming from renewable resources, towards multi-component metal ion solutions. The IIC sorbent, which is based on a chitosan matrix embedding a natural zeolite, was synthesized using a straightforward strategy by coupling copper-imprinting and unidirectional ice-templating methods.

Adsorptive Performance of Soy Bran and Mustard Husk Towards Arsenic (V) Ions from Synthetic Aqueous Solutions.

Recently, there is growing attention on the use of low-cost sorbents in the depollution of contaminated waters. As a consequence, the present work investigates the potential of soy bran and mustard husk as possible sorbent for the removal of arsenic(V) from residual water. Effects of various operating parameters such as: contact time, pH, initial arsenic concentration, pH, sorbent dose, temperature were investigated to determine the removal efficiency of arsenic(V).

Development of chitosan-poly(ethyleneimine) based double network cryogels and their application as superadsorbents for phosphate.

The fabrication of novel chemically cross-linked double network cryogels (DNC), with an abundant number of amine groups, based on chitosan (CS) cross-linked with glutaraldehyde (GA), as the first network, and poly(ethyleneimine) (PEI), with a concentration up to 15% cross-linked with ethyleneglycol diglycidyl ether (EGDGE), as the second network, and their enhanced sorption capacity for phosphate ions are presented here. The phosphate sorption was fast (equilibrium in three hours) and well modeled by the pseudo-second-order kinetic model. The experimental sorption isotherms were fitted with Langmuir, Freundlich, Sips and Dubinin-Radushkevich isotherm models.

Evaluation of Adsorption Capacity of Montmorillonite and Aluminium-pillared Clay for Pb2+, Cu2+ and Zn2.

Adsorption capacity of the two adsorbents was investigated as a function of contact time between adsorbent and heavy metal ions solutions, the initial heavy metals concentration of the synthetic wastewater, pH value, temperature and adsorbent mass. Preliminary experiments at different pH values between 2.0 and 7.

Uptake of uranyl ions from uranium ores and sludges by means of Spirulina platensis, Porphyridium cruentum and Nostok linckia alga.

In this paper was studied the uranyl ions biosorption on three types of alga: Nostok linckia, Porphyridium cruentum and Spirulina platensis. These ions were supplied either from a pure solution of uranyl nitrate, or after leaching process of uranium ore, or from the sludge resulting in the output of pure UO(2) technology. It was investigated the retention degree versus contact time and afterwards the Langmuir and Freundlich biosorption isotherms of uranyl ions on the three alga types.

Adsorption characteristics of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto chitosan/clinoptilolite sorbents.

Adsorption features of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto a novel chitosan/clinoptilolite (CS/CPL) composite as beads have been investigated compared with chitosan cross-linked with epichlorohydrin. The effects of contact time, the initial metal ion concentration, sorbent mass and temperature on the adsorption capacity of the CS-based sorbents were investigated. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Sips model.

On the retention of uranyl and thorium ions from radioactive solution on peat moss.

The efficiency of the radioactive uranyl and thorium ions on the peat moss from aqueous solutions has been investigated under different experimental conditions. The sorption and desorption of uranyl and thorium ions on three types (unmodified peat moss, peat moss treated with HNO(3) and peat moss treated with NaOH) of peat moss were studied by the static method. Peat moss was selected as it is available in nature, in any amount, as a cheap and accessible sorbent.

A fluorescence emission, FT-IR and UV-VIS absorption study of the some uranium (VI) Schiff bases complexes.

The capacity of metallic ions to form complexes depends on the electric charge and its mass and on the ligands nature. In this study we followed the coordination capacity of the uranyl ion (UO2(2+)) with a series of Schiff bases. The Schiff bases have been obtained through the condensation of some salicylic aldehyde derivates with a series of diamines.

Laboratory analyses of 60Co2+, 65Zn2+ and (55+59)Fe3+ radiocations uptake by Lemna minor.

The living Lemna minor vascular plant and two different sorbents obtained by chemical treatment of this plant were tested to study the removal process of 60Co2+, 65Zn2+ and (55+59)Fe3+ from low radioactive wastewaters. The most effective sorbent was the protonated biomass, indicating the decisive contribution of the complexation process in the assembly of the uptake mechanisms. The uptake performance of the biosorbent obtained from the L.