10 research outputs found
A Study on Synthesis of Zeolite and Removal of Amido Black dye by adsorption with Zeolite
Investigations have been undertaken to determine whether cheap, commercially available materials (natural zeolite and bentonite) hold promise in the treatment of wastewaters from the textile industry. The initial findings indicate that zeolite synthesized from fly ash has high adsorptive capacity for dyes and it is relatively cheap. The adsorption of two basic dyes (Amido Black and Thionine) onto granular activated carbon as well as zeolite from fly ash and bentonite has to be studied as single equilibrium isotherms. The effectiveness of each adsorbent has to be measured in terms of its adsorption capacity towards individual constituents of the effluent. The adsorption isotherm would be described by the Langmuir and Freundlich isotherm equations. The parameters in the adsorption isotherms will be estimated from the experimental equilibrium data using non-linear regression analysis. Using these data, the selection of the best adsorbent can be done for design purposes. Keywords: Natural Zeolite, bentonite, Amido Black, Thionine, Langmuir, Freundlich, granular activated carbo
NADPH oxidases: key modulators in aging and age-related cardiovascular diseases?
Reactive oxygen species (ROS) and oxidative stress have long been linked to aging and diseases prominent in the elderly such as hypertension, atherosclerosis, diabetes and atrial fibrillation (AF). NADPH oxidases (Nox) are a major source of ROS in the vasculature and are key players in mediating redox signalling under physiological and pathophysiological conditions. In this review, we focus on the Nox-mediated ROS signalling pathways involved in the regulation of 'longevity genes' and recapitulate their role in age-associated vascular changes and in the development of age-related cardiovascular diseases (CVDs). This review is predicated on burgeoning knowledge that Nox-derived ROS propagate tightly regulated yet varied signalling pathways, which, at the cellular level, may lead to diminished repair, the aging process and predisposition to CVDs. In addition, we briefly describe emerging Nox therapies and their potential in improving the health of the elderly population
Synthesis of xylene over cerium modified large pore zeolite: A kinetic study
379-385<span style="font-size:11.0pt;font-family:
" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;color:black;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi;mso-bidi-font-weight:bold"="" lang="EN-GB">Synthesis of xylene by
transalkylation of 1, 2, 4 trimethylbenzene with toluene over cerium modified
beta zeolite has been investigated in the present study. The reaction has been
carried out in a fixed bed down-flow reactor<span style="font-size:11.0pt;
font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">. The effect of various process parameters: temperature
(623-723K), reactant ratio (0.5-4) and space time (0.88-2.9 kg h/kmol), on the
toluene conversion and xylene selectivity are investigated. Zeolites with
different amount of cerium loading (4.12 wt%,
6<span style="font-size:9.0pt;
font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-bidi-language:hi"="" lang="EN-GB">.54 wt%,
8.1 wt% and 10.34 wt%) have been prepared and characterized. Zeolite having
8.1wt% cerium loading is proved to be the most active catalyst. Maximum toluene
conversion of 58.77% is achieved at a temperature-698K, reactant
ratio–3:1, space time-2.9 kg h/kmol.
The kinetic runs have been carried out to choose the zone in which the mass
transfer effects are negligible. Based on product distribution, a mechanism for
the formation of xylene over the modified catalyst is proposed along with a
rate expres<span style="font-size:
9.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-bidi-language:hi"="" lang="EN-GB">sion. The kinetic and
adsorption co<span style="font-size:11.0pt;font-family:
" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">nstants of the rate equations are estimated by
non-linear regression. The activation energy is found to be 122.41 kJ/mol which
compares well with those reported in
the literature for transalkylation reaction over similar catal<span style="font-size:
11.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">ysts.</span
Low-cost removal of basic red 9 using cow dung ash
In the present study, basic red 9 had been removed from synthetic waste water using animal waste. Cow dung ash had been prepared and characterized by scanning electron microscope. Morphology analysis shows very fine particles of less than 1 μm. The pH analysis study favours a pH of 8.5 for maximum dye removal. The removal of basic red 9 was very fast on cow dung ash. Percentage dye removal was 80.24% and 95.24 in 5 minutes and 90 minutes, respectively at initial dye concentration of 10 ppm