Posttreatment

The chemical nature of the surface of carbon black is crucial to its applications-related behavior and in the first instance is a function of the manufacturing process. In addition to physically adsorbed organic substances, chemically combined surface oxygen is present on the surface, which is formed upon pyrolysis in the presence of sufficient oxygen and accounts for the acidity of gas blacks. Furnace blacks produced in oxygen-poor conditions with feedstocks with low sulfur contents have an excess of basic metal oxides on their surfaces and have neutral to alkaline properties. The content of physically and chemically bonded species is known as the volatile content, since it can be removed by heating to 950°C in the absence of air. 

In many cases it is desirable to augment the content of volatile components. This is accomplished by oxidative posttreatment in which acidic surface groups are formed. This oxidation can be carried out at high temperatures both in the liquid phase and in the gas phase with e.g.  

Oxidative posttreatment can increase the surface-content of acid groups and thereby make the carbon black more hydrophilic 

This posttreatment is mainly carried out on gas blacks for pigment manufacture. Strongly oxidized gas blacks can contain more than 20% by weight of volatile components. 

As the surface concentration of oxygen-containing groups increases the initially hydrophobic carbon black surface becomes increasingly hydrophilic. Such posttreated carbon blacks are preferred for use in aqueous and polar organic media. 

---

Chemical Oxidation. Chemical oxidation can be appHed ia iadustrial wastewater pretreatment for reduction of toxicity, to oxidize metal complexes to enhance heavy metals removal from wastewaters, or as a posttreatment for toxicity reduction or priority pollutant removal. 

Solidification/Stabilization technologies are techniques designed to be used as final waste treatment. A major role of these processes is posttreatment of residuals produced by other processes such as incineration or chemical treatment. In some cases, solidification/ stabilization processes can serve as the principal treatment of hazardous wastes for which other detoxification techniques are not appropriate. High volume, low toxicity wastes (such as contaminated soils) are an example of this application. 

To enhance the purification process and increase the degree of purification, powdered activated carbon (PAC) may be added directly to the aeration tank, or the biologically treated wastewater may be filtered through granulated activated carbon (GAC) for posttreatment. 

Similarly, posttreatment refers to similar process equipment after the boiler section (such as condensate polishing). 

Pretreatment (e.g., filters, softeners, or antiscalents) and posttreatment (permeate flush and clean-in-place systems)... 

Anton RF, Moak DH, Latham PK, et al Posttreatment results of combining naltrexone and cognitive-behavior therapy for the treatment of alcoholism. J Clin Psycho-pharmacol 21 72—77, 2000... 

Project MATCH Research Group Matching alcoholism treatments to client heterogeneity Project MATCH posttreatment drinking outcomes. J Stud Alcohol 58 7— 29, 1997... 

Posttreatment of the permeate for potable water use can include dissolved CO2 removal to prevent corrosion (by aeration, lime treatment), chlorination for microbial control, and oxygenation to improve taste. 

Histologic response is defined as improving inflammation and fibrosis as noted by pretreatment and posttreatment biopsy scores. 

Although many clinical studies have been performed evaluating antibiotics for ABRS, no randomized, double-blind, placebo-controlled studies have used pre- and posttreatment sinus aspirate cultures as an outcome measure. Despite this, antibiotics appear to resolve symptoms more quickly and reduce failure rates and complications compared with no treatment.35-37 Since diagnosis usually is based on clinical presentation and not sinus aspirate cultures, clinicians must attempt to differentiate ABRS from viral rhinosinusitis. Therefore, it is important to limit antibiotic use to cases where infection is unlikely to resolve without causing prolonged disease patients with mild to moderate symptoms that persist for 10 days or worsen over 5 to 7 days and patients with severe symptoms,31,34... 

Values are mean SE 5 plants/replicate 3 replicates/treatment. b 11 Days posttreatment, plants were washed and transferred to fresh... 

Technical Compound , Ounces/100 Applica- Interval, Fresh Weight, Entire Fruit, P.P.M. Pretreat- Posttreat- Interval, Fresh Weight, Entire Fruit, P.P.M. ... 

Table VI. Attenuation of Posttreatment Surface Residues of DDT on Citrus Following...

Table I. Immediate Posttreatment Residues of DDT in Peel of Citrus Fruits...

Consistent with the definition of terms adopted for the discussion in this series of papers of integral phases of the residue studies being conducted by the Division of Entomology, University of California Citrus Experiment Station (2, 13-15), the following distinctions are noted Residues may be specified as pretreatment, posttreatment, harvest, or ultimate. The latter refers to the residue on or in foodstuffs, whether fresh or processed, at the time of consumption (2, 13). The location of residues with reference to fruit parts may be extra-surface (external to the cuticle) or subsurface. Subsurface residues may be differentiated with reference to actual location as cuticular residues or specified intracarp residues. Residues in the cuticular layers or in any of the cellular structures or matrices are herein indicated as subsurface (penetrated) residues (2, 13). 

Table VII. Posttreatment and Harvest Residues of Parathion in Peel of Citrus Fruits— Effect of Seasonal and Multiple Applications...

Unlike other methods, it is necessary to posttreat the product, either through vacuum purging or by allowing... 

The major waste sources during normal nickel-chromium plating operations are alkaline cleaners, acid cleaners, plating baths, posttreatment baths, and auxiliary operation units. 

---