This paper builds on a prior paper by this author, McGrane (1991). In that paper, ozone is used as the sole means of cooling tower water treatment. The paper discusses water conservation by increased cycles of concentration, greatly increased efficiency through extremely low biological populations, and corrosion data which is compared to ozonated and chemically treated towers.
New in this paper are the results from the combination of a low pressure reverse osmosis system with ozone treatment for cooling tower water. Scale formation has continued to plague cooling towers with high concentrations of calcium in the make-up water. The use of a mineral removal system in cases of extremely hard water has made ozone an attractive alternative to traditional chemicals in many areas. 相似文献
Regioisomerically pure 1(3)-rac-monoacylglycerols are conveniently prepared in high yields (>75%) and in multigram quantities by enzymatic esterification
of glycerol in the presence of various lipases(Chromobacterium viscosum, Rhizopus delemar, Rhizomucor miehei) with a variety of different acyl donors, such as free fatty acids, fatty acid alkyl esters, vinyl esters and triacylglycerols,
as well as natural fats and oils. All reactions are carried out in aprotic organic solvents with low water content, namelyn-hexane, diethyl ether, tBuOMe or mixtures of these solvents. Essential for the success of these transformations were the
following two factors. First, the creation of an artificial interphase between the solvent-immiscible hydrophilic glycerol
and the hydrophobic reaction medium by its adsorption onto a solid support. Second, a facile system for the separation of
the desired monoacylglycerol from the reaction mixture, coupled with the continuous recycling of acyl donor and undesirable
by-products. 相似文献
Luminescent yttrium aluminum garnet (YAG, Y3Al5O12) nanoparticles doped with Eu (10 at%) were synthesized in batch-type and continuous-type supercritical water (SCW) reactors.
In the case of the continuous-type SCW method, the particles of YAG: Eu phosphors were much smaller and demonstrated a uniform
spherical-like shape. Inversely, in the case of the batch-type SCW method, a needle-like or elliptical-like shape was formed
because a finite amount of time was required to reach SCW conditions from ambient conditions. However, the emission intensity
of YAG: Eu phosphors synthesized by using the batch-type SCW method was stronger. Therefore, it is concluded that the continuous-type
SCW method is superior to the batch-type SCW method from the viewpoint of the particle size and shape, but the luminescence
property of phosphors in the continuous-type SCW method needs to be improved. In addition, a calcination process slightly
improved the luminescence intensities of YAG: Eu phosphors generated by using either the batch-type or continuous-type SCW
methods. 相似文献
Ozone treatment for preventing the biofouling in cooling water systems is investigated.
In the fresh water system, the separating effect of the ozonated water on the microorganisms such as the sphaerotilus and the zoogloea which adhere to the piping and form the slime is recognized. When the ozonated water is supplied intermittently to the piping without stopping the flow of the cooling water, a constant volume of cooling water can be maintained. At the velocity of 1 m/sec, the amount of metal corrosion produced by the ozonated water is reduced on the mild steel, increased on the copper and does not change on the cast iron, when compared with that produced by the water containing no ozone.
In the seawater system, since many substances are oxidized by the ozone, the same treatment as that in the fresh water system cannot be applied. However, if the seawater in the cooling system can be replaced with ozone-containing air intermittently once a week, the adhesion of organisms such as barnacles and mussels to the piping can be prevented without having a bad influence on the other living oceanic organisms. 相似文献
Chemostat and total cell retention cultures with internal filter system ofSaecharomyc.es cerevisiae H1-7 were carried out to produce ethanol from wood hydrolysate. Maximum ethanol productivity obtained in a chemostat with
the aeration rate of 1 vvm was 3.79 g/(L·h). This was 20% higher than that in a chemostat without aeration. However, the substrate
was not completely consumed at the dilution rate with the maximum productivity. The realistic productivity, which has higher
than 99% conversion rate of substrate, was. 2.95 g/(L·h). The maximum productivity in the total cell retention culture was
6.65 g/(L·h) at the dilution rate of 0.19 h1 and the residual glucose concentration was negligible. 相似文献