Modified Exfoliated Carbon Nanoplatelets as Sorbents for Ammonium from Natural Mineral Waters

In this manuscript an improved sorbent based on modified exfoliated carbon nanoplatelets, applied in the removal of ammonium from aqueous samples, is presented. This sorbent showed better efficiency in comparison with the previous one obtained in our group for ammonium removal, the values of the maximum sorption capacity being improved from 10 to 12.04 mg/g. In terms of kinetics and sorption characteristic parameters, their values were also improved. Based on these results, a sorption mechanism was proposed, taking into account ion-exchange and chemisorption processes at the surface of the oxidized exfoliated carbon nanoplatelets. Future applications for simultaneous removal of other positive charged contaminants from natural waters might be possible.

Sorption characteristic of starch-based film

Moisture sorption characteristic is important in determining the stability of bio-based plastic during packaging and storage condition. This study was carried out to investigate the moisture sorption characteristic of starch-based film. Moisture sorption test was conducted at different temperatures (5, 30 and 50°C) and relative humidity (23-75%). The experimental data was fitted using several models. Based on the Peleg model, the maximum rate of absorption and absorption capacity occurred at higher relative humidity. Guggenheim Anderson de Boer (GAB) model was the most suitable model to fit the experimental isotherm data and it is useful to predict the water sorption properties of the film which relate to different relative humidity conditions. In addition, the shelf life of film was reduced when placed under lower temperature due to the higher sorption capacity of moisture. The sorption properties of the starch-based film are important and worth investigation as it will be useful for the final application in food packaging due to its dependency on this behaviour.

Preparation of novel nano composite materials from biomass waste and their sorptive characteristics for certain radionuclides

The aim of this work is directed to prepare nanoparticles of egg shell hydroxyapatite-humic acid (ESHAP-HA) as a novel composite material. FTIR, EDX, TEM, XRD, and SEM identified it. Sorption characteristic studies on ESHAP-HA at different pH of solutions, shaking time, initial ion concentration and complexing agent were performed at 152,154Eu, 99Mo and 63Ni. The results were demonstrated that selectivity removal of 152,154Eu (~96 %) rather than 99Mo (8.5 %) and 63Ni (26.7 %). The sorption capacity of 152,154Eu(III), 63Ni(II) and 99Mo(VI) are 80.1, 12.5 and 2.3 mg/g, respectively, onto the ESHAP-HA nanoparticles. Application on the eclectic removal of 152,154Eu from mixed radionuclides (152,154Eu, 60Co, and 137Cs) solution has been evaluated. It concluded that the prepared ESHAP-HA composite material is a promising and recommended for separation of radio lanthanides and/or actinides (such as Am) from nuclear liquid waste and/or contaminated aquatic environmental.

Effects of Dissolved Organic Matter on Sorption of Oxytetracycline to Sediments

The effects of two representative dissolved organic matters (DOMs) (derived from corrupt plants (PDOM) and chicken manure (MDOM)) on sorption characteristic of oxytetracycline to three typical sediments (first terrace (FT), river floodplain (RF), and riverbed (RB) sediments collected from the Weihe River) were investigated. Results showed that both DOMs can make the adsorption equilibrium time advance about 6 hours. The presence of DOMs changed the sorption kinetics model and the spontaneous degree of the reaction but did not change the sorption isotherm models. The adsorption of oxytetracycline (OTC) could be promoted by adding PDOM, and its maximum adsorption amount increased by 23.8% for FT, 38.0% for RB, and 28.3% for RF, respectively, whereas MDOM could inhibit the adsorption and maximum adsorption amount decreased by 23.3% for FT, 11.6% for RB, and 16.1% for RF, respectively. In addition, the DOM concentration also affected the adsorption. Overall, this study suggests that the humus-like DOM can promote the adsorption of OTC while the protein-like DOM can inhibit the adsorption of OTC to sediments, which is determined by the aromaticity, hydrophilicity, and polarity of the DOMs.