Waste inorganic salts

Reverse osmosis is a high-pressure membrane separation process (20 to 100 bar) which can be used to reject dissolved inorganic salt or heavy metals. The concentrated waste material produced by membrane process should be recycled if possible but might require further treatment or disposal. 

Tyj)e of dryer Applicable with dry-product recirculation True and colloidal solutions emulsions. Examples inorganic salt solutions, extracts, milk, blood, waste liquors, rubber latex, etc. Pumpable suspensions. Examples pigment slurries, soap and detergents, calcium carbonate, bentonite, clay sbp, lead concentrates, etc. does not dust. Recirculation of product may prevent sticking Examples filter-press cakes, sedimentation sludges, centrifuged sobds, starch, etc. 

Residuals Produced The resulting effluent may contain dissolved inorganic salts at concentrations which may be unacceptable for discharge. Based on the chemical composition of the waste stream, a precipitate may be formed which may require removal and disposal. 

Applicability/Limitations Most t qjes of solid, liquid, and gaseous organic waste or a mixture of these wastes can be treated with this technology. Explosive wastes and wastes with high inorganic salt content and/or heavy metals require special evaluation. This operation can create high particulate emissions which require post-combustion control. 

The concentration of a compound in water is controlled by its equilibrium solubility or solubility constant (the maximum amount of a compound that will dissolve in a solution at a specified temperature and pressure). Equilibrium solubility will change with environmental parameters such as temperature, pressure, and pH for example, the solubility of most organic compounds triples when temperature rises from 0°C to 30°C. Each type of waste has a specific equilibrium solubility at a given temperature and pressure. The solubility of toxic organic compounds is generally much lower than that of inorganic salts. This characteristic is particularly true of nonpolar compounds because of their hydrophobic character. 

The manufacture of fine chemicals and pharmaceuticals generates in the order of 25-100 times more waste than product [52], Inorganic salts account for the bulk of the waste and are most often produced by neutralization of acidic or basic solutions [53]. Salts can pollute soil and ground water, lower the pH of atmospheric moisture and they may contribute to acid dew or acid rain [6]. For cleaner production, their minimization is essential and hence our concentration on new processes, such as the etherification (discussed in Sect. 2.6.3.1) and hydrogen transfer reduction (Sect. 2.6.3.2), that avoid salt formation and the use of salts. 

One of the most difficult wastes for industry to dispose of is that of solutions of inorganic salts [270]. Unlike organic salts which can be treated by various methods to convert the organic species into carbon dioxide and water, inorganic salts can rarely be broken down. 

NO. However, ferrous sulfamate adds some undesirable inorganic salts to the aqueous high-level waste. 

The unique characteristic of the HAZCON process is the use of the proprietary ingredient Chloranan. The wastes most effectively solidified by the process are aqueous solutions, suspensions, or solids containing appreciable amounts of heavy metals and inorganic salts. The claimed characteristic of the Chloranan to inhibit the effects of organics on the crystallization of the cement is unique to the HAZCON process. 

Based on observations from the RMA cleanup project, downtime and reduced production may be experienced during initial periods of operation due to plugging of packed-bed scrubbers by precipitates from inorganic salts generated from the waste material. 

The use of alkylhalides, or dimethylsulphate or acylhalides as co-reactants, with co-production of waste effluents containing inorganic salts, which have to be disposed. 

Aqueous systems have been used in separations, coatings, and synthesis. Aqueous biphasic systems have been developed for hquid-liquid extractions using water-soluble polymers such as polyethylene glycol, and inorganic salts such as ammonium chloride or potassium phosphate (Rogers et al., 1998), (Sherman et al., 1998). These systems have been investigated for use in the separation and recovery of heavy metals from mixed wastes and in the recovery of colored impurities from textile waste streams (Sherman et al., 1998). 

The advantages of this industry scale synthesis are the use of non-halogenated solvents, formation of inert inorganic salts as waste products, recycling of valuable side products, ambient temperatures, relinquishment of protecting groups and purification by crystallization or filtration. 

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