Pickling, treatment system

One technique used in a number of facilities that utilize molten salt for metal surface treatment prior to pickling is to take advantage of the alkaline values generated in the molten salt bath in treating other wastes generated in the plant. When the bath is determined to be spent, it is in many instances manifested, hauled off-site, and land disposed. One technique is to take the solidified spent molten salt (molten salt is sold at ambient temperatures) and circulate acidic wastes generated in the facility over the material prior to entry into the waste treatment system. This in effect neutralizes the acid wastes and eliminates the requirements of manifesting and land disposal. 

FIGURE 28.1 Typical treatment system for pickling. (From Eroglu, V. and Erturk, F., in Handbook of Industrial Waste Treatment, Wang, L.K. and Wang, M.E1.S., Eds, Marcel Dekker, New York, 1991, pp. 293-306 Eroglu, V., Topacik, D., and Ozturk, I., Wastewater Treatment Plant for Cayirova Pipe Factory, Environmental Engineering Department, Istanbul Technical University, Turkey, 1989. With permission.)... 

Waste pickle liquors from these operations can often be of use to sanitary waste treatment systems for phosphate control and sludge conditioning. Some industrial firms can use spent process waste from pickling operation. Iron in the waste is used as a coagulant in wastewater treatment systems.1415... 

Sa.lts Salting out metal chlorides from aqueous solutions by the common ion effect upon addition of HCl is utilized in many practical apphcations. Typical data for ferrous chloride [13478-10-9] FeCl2, potassium chloride [7447-40-7] KCl, and NaCl are shown in Table 9. The properties of the FeCl2-HCL-H2 0 system are important to the steel-pickling industry (see Metal SURFACE TREATMENTS Steel). Other metal chlorides that are salted out by the addition of hydrogen chloride to aqueous solutions include those of magnesium, strontium, and barium. 

The dry powder process has several additional advantages over the wet process. For example, much less waste of enamel occurs because the dry over-spray is airborne and recycled in a closed system. No-pidde ground coats have broadened the apphcation of both wet-process and dry-process systems. These enamels are appHed over cleaned-only metal. Thus the problems of disposing of pickling acid wastes containing iron sulfates and nickel wastes are eliminated (see Metal surface treatments) (7). 

The two water desalination applications described above represent the majority of the market for electrodialysis separation systems. A small application exists in softening water, and recently a market has grown in the food industry to desalt whey and to remove tannic acid from wine and citric acid from fruit juice. A number of other applications exist in wastewater treatment, particularly regeneration of waste acids used in metal pickling operations and removal of heavy metals from electroplating rinse waters [11]. These applications rely on the ability of electrodialysis membranes to separate electrolytes from nonelectrolytes and to separate multivalent from univalent ions. 

Concord grapes, peas, seed alfalfa, and seed clover as a result of damin-oxide treatments or the 50% increases in yield of pickling cucumbers because of ethephon. In addition, there are many crops where 10-15% increases have been consistently noted, but because of normal crop variability, these increases are not considered to be of economic importance. It would seem that it is only a matter of time before more active compounds are found or systems devised whereby available products can be utilized to provide the desired yield responses. 

The leaves of perilla are well known for use in traditional medicine as an herbal treatment for several different diseases, such as asthma, influenza, bronchitis, and digestive system dysfunction (Yu et al., 1997). The leaves contain an essential oil enriched in monoterpenes, aldehydes, and ketones, which are potentially applicable as antimicrobials, fungicides, antioxidants, and insecticide (Yu et al., 1997 Seo and Baek, 2009 Tian et al., 2014 Tabanca et al., 2015). Seeds also contain volatile oil. The pomace residue resulting from oil extraction of the seeds is rich in phenolic compounds such asrosmarinic acid that are potentially valuable as antioxidants (Guan et al., 2014). Typically, the pomace is used as animal and bird feed (Asif, 2012). In Korea, leaves are used for wrapping meats and raw fish, and other food products (Nitta et al., 2003). In Japan, Perilla leaves are a common ingredient in the popular dish tempura and are frequently added to pickled fruit known as umeboshi in rice balls (Sawabe et al., 2006). 

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