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conferenceseries.com
Volume 3, Issue 2 (Suppl) Ind Chem
ISSN: 2469-9764, ICO an open access journa Industrial Chemistry 2017
May 22-23, 2017
May 22-23, 2017 Las Vegas, USA
2nd World Conference on
Industrial Chemistry and Water Treatment
Ind Chem 2017, 3:2 (Suppl)
Application of FeCl3 and Fe(OH)3 compounds for comprehensive silica removal facilitating zero liquid
discharge in RO and IC waste water reuse
Ehren D Baca1, Jr L Lin2 and Kerry J Howe1
1University of New Mexico, USA
2Chung Yuan Christian University, China
C hemical mechanical planarization (CMP), used heavily in integrated circuit (IC) manufacture, generates copious amounts
of waste water high in colloidal and reactive silica, which inhibits on-site reuse in cooling operations and ultra-pure water
(UPW) production. Silica, when present in cooling water, can reach solubility limits via evaporation and form impervious scale
on heat transfer surfaces that decreases efficiency. Silica in reverse osmosis feed-water inhibits aspirations for high rejection
and zero liquid discharge (ZLD) due to scale formation. When subjected to RO at high rejection, silica forms difficult-to-
remove scale on the membrane concentrate side in the form of glassy patches and communities of aggregate particles. Current
methods for silica scale mitigation in industry include dosing with chemical anti scalents or complex operating schemes
including ion exchange and large pH swings. This work evaluates the implementation of the common chemical coagulant,
FeCl3 and highly insoluble Fe (OH)3 in the removal of silica by coagulation and adsorption mechanisms, respectively. FeCl3
was shown to be optimizable for silica colloid coagulation in CMP waste water via charge neutralization resulting in turbidity
<10NTU. Adsorption of reactive silica on Fe (OH)3 using a sequencing batch reactor approach exhibited >90% silica removal
for the first adsorption cycle, and increased utilization of adsorbent material for subsequent runs in both CMP waste water and
RO concentrate.
Allium cepa L. as an acid-base indicator
Gan Lui Nam, Koo Thai Hau and Ling Jia Yi
Form 6 Centre of SMK Taman Johor Jaya 1,China
In this study, a facile and environmentally friendly method was reported for manufacturing of natural acid-base indicator
by preparing Allium cepa L. juice, which provided the anthocyanins pigment. The anthocyanins pigment was extracted via
boiling process. In detailed, the Allium cepa L. was cut into small fragments. Then the small fragments of Allium cepa L. was
boiled in distilled water in order to extract the anthocyanin pigment. This process was followed by the addition of different
solutions of acidic solutions; base solution as well as neutral solution was added into separate test tubes filled with extraction of
Allium cepa L. juice. The obtained Allium cepa L. juice was then used as the pigment for the acid-base indicator. The pH of the
solution can be determined by observing the color change in the Allium cepa L. juice. The light purple color of the Allium cepa
L. juice turned into red color when added with hydrochloric acid, its purplish color of the juice turned into yellow when added
with sodium hydroxide, the original color of Allium cepa L. did not undergo any observable color change when distilled water
is added into it. The Allium cepa L. exhibited excellent color change property with chemical solutions. These color changes
make the Allium cepa L. be attractive for applications in acid-base indicators.