Technology and Technique Demonstration Day
Engineering Division (Environment
After reading this section and attending
this demonstration, the attendee will have an increased knowledge of:
Oxidation processes and equipment |
Separation processes and equipment|
Stripping processes and equipment|
following section presents an overview of the technologies.
oxidation is a destructive process which takes place at ambient temperatures.
It utilizes hydroxyl radicals to oxidize organic compounds into carbon dioxide,
water and in the presence of chlorinated organic compounds, salt. A proprietary
ultra-violet light source is used to generate these highly reactive hydroxyl radicals
from titanium dioxide, ozone, and/or hydrogen peroxide.
processes involve the use of pressure to drive water through a semi-permeable
membrane while leaving the bulk of the contaminant behind. Reverse osmosis involves
this process using specialized equipment operating at high pressure levels (700
- 1000 psi). Since the water crosses the membrane more easily than does the contaminant,
it is possible through successive passes to concentrate the contaminant in the
reject stream. The effectiveness of the process against a particular contaminant
is determined by the interaction of the molecule with the membrane surface and
substrate. In general, inorganic compounds are easily removed as are organic compounds
with molecular weights over 100. This latter number is being reduced as better
membranes are being developed.
stripping is a separation process which utilizes the differences in thermodynamic
properties of liquids. In this process, organic-contaminated water and steam are
fed counter-currently to a packed column, causing the transfer of the contaminant(s)
from the water phase to the vapour phase. The driving force for the separation
is the concentration differential of the organic components(s) between the liquid
and vapour phases. Two streams are generated in this process, namely: the treated
effluent (bottoms) and the concentrated contaminant (tops). The bottoms are sent
to a holding tank prior to their re-injection so as to ensure that the remediated
water discharged is in accordance with regulations. The tops are temporarily stored
then either recovered or disposed of in an appropriate manner (e.g. destruction
in an advanced oxidation unit).