In this paper, we report the synthesis of metal organic framework of uranium
1,2,4,5-benzene tetracarboxylic acid (U-H4btec MOF) by solvothermal method.
The obtained MOF was characterized by Fourier transform infrared spectroscopy
(FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy
(TEM), X-ray diffraction spectroscopy (XRD), Energy dispersive spectroscopy
(EDS), thermogravimetric and differential thermogravimetric analysis
(TGA/DTA). The morphology of the uranium 1,2,4,5-benzene tetracarboxylic acid
MOF observed by SEM, revealed the presence of flaky porous structure.
Adsorption of Cr3+ from aqueous solution onto the uranium 1,2,4,5-benzene
tetracarboxylic acid MOF was systematically studied. Langmuir and Freundlich
adsorption isotherms were applied to determine the adsorption capacity of the
MOF to form a monolayer. Kinetic determination of the adsorption of Cr3+
suggested both chemisorption and physisorption probably due to the presence
of carbonyl groups within the MOF and its porous structure.
The present study investigated the use of local and affordable clinoptilolite for the removal of persistent dyes from water. To improve its adsorption capacity, Na-clinoptilolite was modified chemically with two N-terminated siloxanes (molar mass: 2600 and 11000 g/mol) and used to adsorb the dye phenol red. The results of Fourier-transform infrared spectroscopy (FTIR) showed that N-terminated siloxanes were grafted successfully onto clinoptilolite. Examination by X-ray diffraction and scanning electron microscopy supported the suggestion of modifications observed by FTIR. The modified clinoptilolite showed improved adsorption properties for phenol red: up to 0.32 mg of phenol red were removed per g of clinoptilolite modified with N-terminated siloxanes from water, while HCl-treated clinoptilolite removed only 0.15 mg after 4 h. Langmuir and Freundlich models were used to obtain isotherm parameters. Results (with R2 > 0.84) from pseudo-first and pseudo-second order equations suggested that adsorption could have involved chemisorption and physisorption, probably because of the mineral-organic nature of the materials prepared.
In many developing countries, the scarcity of potable water is an ongoing challenge. Even when water is plentiful, its quality may be unsuitable for household use such as in the city of Kinshasa in the Democratic Republic of Congo (DRC) which is the study area for this investigation. Shortage of potable water has forced inhabitants in the city to rely on water wells dug without adherence to regulations or specifications within perimeters of their homesteads. The water from such wells is often polluted with household waste being generally disposed by burning and burying in shallow pits, thrown in pit toilets or into rivers. Such practices have led to contamination of ground water. This study examines the water quality of drinking water drawn from wells in Fer-bois, which falls under the Kimbanseke municipality in the South East of Kinshasa. The dynamics of well design/location, sources of possible contamination with respect to water treatment and water quality as well as its possible impact on health are examined. The area was shown to have poor groundwater quality with significant amounts of pollutants such as NO3, Pb and Cd leading to environmental and health concerns.
This study reports the chemical modification of lignocellulose (from Kikuyu grass) with N-terminated siloxanes and its utilisation as adsorbent for the removal of phenol red from aqueous media. The stability of the bond between lignocellulose and siloxane was assessed after Soxhlet extraction of unreacted siloxanes in tetrahydrofuran for 5 h, as well as soaking the materials in water for 24 h. Adsorption tests showed the prepared materials to be good candidate for the removal of phenol red (dye) from water, with adsorption capacity from 1.454 to 3.312 mg of phenol red adsorbed per gram of adsorbent. The kinetics of adsorption was found to follow a pseudo-second-order equation indicating chemisorption rather than simple forces of association. The linearised form of adsorption isotherms matched with the Langmuir model.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.