Environmental Engineering Reference
In-Depth Information
6.7.1 Water Remediation
By using cavitation, solids and other substances can be separated from water molecules,
as can unwanted gases as well. Many forms of mining, including coal, produce highly
contaminated wastewater containing high concentrations of heavy metals. These heavy
metals include aluminum (Al), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), manganese
(Mn), and zinc (Zn). Results show that with addition of cavitation treatment, a noticeable
improvement of removal could be achieved; >90% of the dissolved heavy metal concentra-
tions could be removed from the residual water by “exit porting” a spatial region of the
chamber. Both laboratory testing and real-life applications of the Vortex VPT indicate that
it is also effective in removing various organics from inluent water. Cavitation from the
Vortex VPT has been shown to produce the very reactive hydroxyl radical, just like in het-
erogeneous photocatalysis. Adding other oxidants such as peroxide or ozone can increase
its eficiencies even further [30-32].
6.7.2 Fuel Emulsification and Mixing
Fascinatingly, the Vortex VPT can also be used to achieve optimization where mixing
tasks are required, such as in the manufacturing of nanomaterials, or on the oil to keep
water emulsiied in the mixture to produce fuel/water, fuel/ethanol, or other emulsions.
For such applications, water and air can be introduced simultaneously, producing a stable
emulsion even at room temperature and without emulsiiers. These applications are of
special importance to the food and drug industries, and particularly the cosmetic indus-
try, because using emulsiiers can cause undesired effects [33].
6.7.3 Cooling Water Treatment
The cooling tower applications of Watreco's Vortex VPT are currently in use worldwide for
calcium carbonate removal from the inluent. Water treatment results from samples con-
taining a high concentration of CaCO 3 indicate that a relatively stable, low-level calcium
concentration in the efluent is obtained even if the inluent calcium concentration is very
high. This process is ideal for the enhanced removal of calcium with the advantages of the
reducing chemical usage and preventing scale formation in the wastewater treatment facil-
ity. Normally, the excess of CaCO 3 is usually removed through precipitation and iltration.
Scale-forming calcium carbonate is removed from the cooling water through the mecha-
nism of gas stripping of CO 2 , resulting in a buffered pH of 8.8-9.0. However, with the VPT
and the localized high temperatures, there is a shift in the equilibrium, calcium carbonite
to aragonite, aiding in its precipitation. In addition, the treatment of cooling water without
the use of any additional chemicals by the Vortex VPT includes bacterial eradication effects,
providing a consistent control of bacteria, such as Legionella , which can develop in the warm
oxygen-rich environment of recirculation cooling water.
6.7.4 Wastewater/Digester
A low-cost, environmentally friendly technology that can improve digester eficiency,
increase methane production and throughput, and lower sludge generation demonstrated
that VPT will result in cell lysis, or the breaking down of a cell, often by viral, enzymatic,
or osmotic mechanisms that compromise its integrity, resulting in an increase in soluble
Chemical Oxygen Demand (COD). This has been shown to accelerate the overall degradation
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