scholarly journals Point Zero Charge Determination and Fluoride Adsorption on Natural Red Ash (Metal Oxide)

Author(s):  
Lejalem Abeble Dagnaw ◽  
Dessie Almaw Cherie

The PZC is essential parameter for the characterization of certain materials used for the treatment of organic or inorganic wastes in the environment, particularly from waste water and industrial sludge. Potentiometric titration and batch experimentation method was used to determine PZC value and type of adsorption isotherm behavior observed.  Red ash is the natural metal oxides collected from the rift valley of Ethiopia which have PZC values of 3.35 for 0.5g, 1g and 1.5g adsorbent dose studied. On the adsorbent surface, monolayer and homogeneous adsorption process of fluoride observed. Therefore, based on the interest of the researcher and the adjustment of the pH of red ash solution might used for the treatment of ionic wastes.

2019 ◽  
Vol 11 (2) ◽  
pp. 67
Author(s):  
Muhammad Naswir ◽  
Susila Arita ◽  
Widi Hartati ◽  
Lusi Septiarini ◽  
Desfaournatalia Desfaournatalia ◽  
...  

The Palm Oil Factory produces wastewater containing high enough Phosphor (P). High levels of Phosphor can cause pollution load for the environment, so it needs to be lowered. The decrease of this content can be done by adsorption process using bentonite as adsorbent. The purpose of this research is to determine the absorption of activated bentonite to the absorption of Phosphor contained in waste water. Phosphor measurements were performed using the UV-vis Spectrophotometric Instrument. Bentonite was activated using HCl 1.6 M. Characterization of bentonite using X-ray diffraction (XRD) and Scanning Electron Microscopy with Energy Divertive Spectroscopy (SEM-EDS). The results showed that bentonite was able to adsorb Phosphor contained in the waste water of Palm Oil Factory, with adsorption capacity> 90%. Activated Bentonite has greater power capability than natural bentonite.


Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuxuan Gong ◽  
Chengquan Qiao ◽  
Bochao Zhong ◽  
Jiarang Zhong ◽  
Decai Gong

2012 ◽  
Vol 23 (5) ◽  
pp. 539-546 ◽  
Author(s):  
Carlos Estrela ◽  
Manoel Damião Sousa-Neto ◽  
Orlando Aguirre Guedes ◽  
Ana Helena Gonçalves Alencar ◽  
Marco Antonio Hungaro Duarte ◽  
...  

Root perforation represents an undesirable complication that may lead to an unfavorable prognosis. The aims of this study were to characterize and to compare the presence of calcium oxide (CaO) on the chemical composition of materials used for root perforation therapy: gray and white mineral trioxide aggregate (MTA) and Portland cement (PC), gray MTA+5%CaO and gray MTA+10%CaO. The last two materials were analyzed to evaluate the increase of CaO in the final sample. CaO alone was used as a standard. Eighteen polyethylene tubes with an internal diameter of 3 mm and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37ºC. The chemical compounds (particularly CaO) and the main components were analyzed by energy-dispersive X-ray microanalysis (EDX). EDX revealed the following concentrations of CaO: gray MTA: 59.28%, white MTA: 63.09%; PC: 72.51%; gray MTA+5%CaO: 63.48% and gray MTA+10%CaO: 67.55%. The tested materials presented different concentrations of CaO. Even with an increase of 5 and 10% CaO in gray MTA, the CaO levels found in the MTA samples were lower than those found in PC.


2012 ◽  
Vol 9 (3) ◽  
pp. 1457-1480 ◽  
Author(s):  
R. Bhaumik ◽  
N. K. Mondal ◽  
B. Das ◽  
P. Roy ◽  
K. C. Pal ◽  
...  

A new medium, eggshell powder has been developed for fluoride removal from aqueous solution. Fluoride adsorption was studied in a batch system where adsorption was found to be pH dependent with maximum removal efficiency at 6.0. The experimental data was more satisfactorily fitted with Langmuir isotherm model. The kinetics and the factor controlling adsorption process fully accepted by pseudo-second-order model were also discussed. Eawas found to be 45.98 kJmol-1by using Arrhenius equation, indicating chemisorption nature of fluoride onto eggshell powder. Thermodynamic study showed spontaneous nature and feasibility of the adsorption process with negative enthalpy (∆H0) value also supported the exothermic nature. Batch experiments were performed to study the applicability of the adsorbent by using fluoride contaminated water collected from affected areas. These results indicate that eggshell powder can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution as well as groundwater.


2009 ◽  
Vol 6 (s1) ◽  
pp. S153-S158 ◽  
Author(s):  
Tariq S. Najim ◽  
Suhad A. Yassin

Modified pomegranate peel (MPGP) and formaldehyde modified pomegranate peel (FMPGP) were prepared and used as adsorbent for removal of Cr(VI) ions from aqueous solution using batch process. The temperature variation study of adsorption on both adsorbents revealed that the adsorption process is endothermic, from the positive values of ∆H˚. These values lie in the range of physisorption. The negative values of ∆G˚ show the adsorption is favorable and spontaneous. On the other hand, these negative values increases with increase in temperature on both adsorbents, which indicate that the adsorption is preferable at higher temperatures. ∆S˚ values showed that the process is accompanied by increase in disorder and randomness at the solid solution interface due to the reorientation of water molecules and Cr(VI) ions around the adsorbent surface. The endothermic nature of the adsorption was also confirmed from the positive values of activation energy, Ea, the low values of Ea confirm the physisorption mechanism of adsorption. The sticking probability, S*, of Cr(VI) ion on surface of both adsorbents showed that the adsorption is preferable due to low values of S*(0< S*< 1 ), but S*values are lower for FMPGP indicating that the adsorption on FMPGP is more preferable .


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