INDUSTRIAL AND ENGINEERING CHEMISTRY
September, 1944
kively, before regeneration was begun. After regeneration the corresponding concentrations were 6, 3, 1, and O.l%, a t which time the first was sent out of the system for precipitation. Regeneration was followed by downflow water wash to phenolphthalein neutrality, after which the beds were upwashed and drained for the next cycle.
PERCENT EFFICIENCY
857
upon the length of useful life of the expensive exchange materials when contacted with the complex grape solution-suspension. One anion exchange column has been through 80 cycles in this laboratory during which it has been contacted with winery materials from a number of sources. It has dropped in capacity approximately 25%. From the results presented here, it may be assumed that recovery from slop of average composition should be at least 5 pounds per cubic foot of anion exchanger per cycle when the material is fresh. If the process is carried out substantially as described, the volume requirement of cation exchanger will be three t o four times that of the anion exchanger (in the case of the materials studied). Capital investment in the plant itself may be nominal. The necessary equipment can be built largely of noncritical materials. Labor will be a n item of greater or lesser consequence in inverse ratio t o the magnitude of the operation. One man with some technical supervision should be able to handle a well designed plant. The chemicals are all inexpensive. Results of experiments involving a chloride-tartrate ion-exchange cycle on the anion exchanger bed thus far indicate that in this cycle the exchanger retains its efficiency longer in contact with the complex grape substance; in addition the process would require only about half the plant setup demanded by the procedure outlined here. The cation exchanger would not be required. I n either cycle, thorough defecation and decolorization of the influent solutions appear certain to prolong effectively the useful life of exchangers. ACKNOWLEDGMENT
4 8 12 16 MILLIEQUIVALENTS N A ~ C O S
20
PER MILLIEQUIVALENT HeT
