Abstract: Contamination of aromatic compounds in water can
cause severe long-lasting effects not only for biotic organism but also
on human health. Several alternative technologies for remediation of
polluted water have been attempted. One of these is adsorption
process of aromatic compounds by using organic modified clay
mineral. Porous structure of clay is potential properties for molecular
adsorptivity and it can be increased by immobilizing hydrophobic
structure to attract organic compounds. In this work natural
montmorillonite were modified with cetyltrimethylammonium
(CTMA+) and was evaluated for use as adsorbents of aromatic
compounds: benzene, toluene, and 2-chloro phenol in its single and
multicomponent solution by ethanol:water solvent. Preparation of
CTMA-montmorillonite was conducted by simple ion exchange
procedure and characterization was conducted by using x-day
diffraction (XRD), Fourier-transform infra red (FTIR) and gas
sorption analysis. The influence of structural modification of
montmorillonite on its adsorption capacity and adsorption affinity of
organic compound were studied. It was shown that adsorptivity of
montmorillonite was increased by modification associated with
arrangements of CTMA+ in the structure even the specific surface
area of modified montmorillonite was lower than raw
montmorillonite. Adsorption rate indicated that material has affinity
to adsorb compound by following order: benzene> toluene > 2-chloro
phenol. The adsorption isotherms of benzene and toluene showed 1st
order adsorption kinetic indicating a partition phenomenon of
compounds between the aqueous and organophilic CTMAmontmorillonite.
Abstract: A piston cylinder based high pressure differential
thermal analyzer system is developed to investigate phase
transformations, melting, glass transitions, crystallization behavior of
inorganic materials, glassy systems etc., at ambient to 4 GPa and at
room temperature to 1073 K. The pressure is calibrated by the phase
transition of bismuth and ytterbium and temperature is calibrated
by using thermocouple data chart. The system developed is
calibrated using benzoic acid, ammonium nitrate and it has a
pressure and temperature control of ± 8.9 x 10 -4 GPa , ± 2 K
respectively. The phase transition of Asx Te100-x chalcogenides,
ferrous oxide and strontium boride are studied using the
indigenously developed system.
Abstract: Biological Ammonia removal (nitrification), the
oxidation of ammonia to nitrate catalyzed by bacteria, is a key part of
global nitrogen cycling. In the first step of nitrification,
chemolithoautotrophic ammonia oxidizer transform ammonia to
nitrite, this subsequently oxidized to nitrate by nitrite oxidizing
bacteria. This process can be affected by several factors. In this study
the effect of influent COD on biological ammonia removal in a
bench-scale biological reactor was investigated. Experiments were
carried out using synthetic wastewater. The initial ammonium
concentration was 25mgNH4
+-N L-1. The effect of COD between
247.55±1.8 and 601.08±3.24mgL-1 on biological ammonia removal
was investigated by varying the COD loading supplied to reactor.
From the results obtained in this study it could be concluded in the
range of 247.55±1.8 to 351.35±2.05mgL-1, there is a direct
relationship between amount of COD and ammonia removal.
However more than 351.35±2.05 up to 601.08±3.24mgL-1 were
found an indirect relationship between them.