Activated carbon adsorption, treatment

Activated carbon adsorption, treatment of wastewater, 125-50,155 Activated coconut charcoal, effect, degradation In soil, 168... 

IV. Experiment Protocol for Activated carbon adsorption treatment 65... 

Adsorption. Adsorption (qv) is an effective means of lowering the concentration of dissolved organics in effluent. Activated carbon is the most widely used and effective adsorbent for dyes (4) and, it has been extensively studied in the waste treatment of the different classes of dyes, ie, acid, direct, basic, reactive, disperse, etc (5—22). Commercial activated carbon can be prepared from lignite and bituminous coal, wood, pulp mill residue, coconut shell, and blood and have a surface area ranging from 500—1400 m /g (23). The feasibiUty of adsorption on carbon for the removal of dissolved organic pollutants has been demonstrated by adsorption isotherms (24) (see Carbon, activated carbon). Several pilot-plant and commercial-scale systems using activated carbon adsorption columns have been developed (25—27). 

Adsorption This is the most widely used of the physical-chemical treatment processes. It is used primarily for the removal of soluble organics with activated carbon serving as the adsorbent. Most liquid-phase-activated carbon adsorption reactions follow a Freundlich Isotherm [Eq. (25-21)]. 

Adsorption — An important physico-chemical phenomenon used in treatment of hazardous wastes or in predicting the behavior of hazardous materials in natural systems is adsorption. Adsorption is the concentration or accumulation of substances at a surface or interface between media. Hazardous materials are often removed from water or air by adsorption onto activated carbon. Adsorption of organic hazardous materials onto soils or sediments is an important factor affecting their mobility in the environment. Adsorption may be predicted by use of a number of equations most commonly relating the concentration of a chemical at the surface or interface to the concentration in air or in solution, at equilibrium. These equations may be solved graphically using laboratory data to plot "isotherms." The most common application of adsorption is for the removal of organic compounds from water by activated carbon. 

Perrich, J. R. (1981). Activated Carbon Adsorption for Wastewater Treatment. CRC Press, Boca Raton, FL. 

There are several potential treatment technologies that may be applicable, but are more expensive than the methods currently used. These potential treatments include sulfide precipitation, ultrafiltration, reverse osmosis, deep-well disposal, activated carbon adsorption or activated alumina adsorption, solidification, or ion exchange.19-21... 

Oil-Water Separation, Biological Treatment, Powdered Activated Carbon Adsorption, and Clarification... 

Activated carbon has high specific surface area with respect to its volume, and thus has high adsorption capacity. Activated carbon adsorption is considered to be one of the most versatile treatment technologies and can remove classical pollutants such as COD, TOC, BOD, and nitrogen, as well as toxic pollutants such as phenol, refractory organic compounds, VOCs, and soluble heavy metals.38 Activated alumina and peat have also demonstrated similar abilities. 

Several methods are available to remove gasoline constituents from water, such as air stripping, biorestoration, activated carbon adsorption, reverse osmosis, ozonation, oxidation, resin adsorption, oxidation with hydrogen peroxide, ultraviolet irradiation, flotation, and land treatment. 

The competitive physical/chemical system that is being installed at Rosemount, Minn., consists of primary treatment followed by coagulation, sand filtration, activated carbon adsorption, another filtration step, ion exchange, and oxidation. This can produce a highly purified water at less cost than a system involving primary, secondary, and tertiary treatment.30... 

U.S. producers of, 4 748t Activated carbon adsorption, as advanced wastewater treatment, 25 909 Activated catalyst layer, 70 40-42 Activated charcoal, 73 461 Activated coke, for SO and NO removal, 77 720... 

Alternative 3 consists of preliminary treatment followed by filtration and activated carbon adsorption (Figure 8.5). The preliminary treatment step and filtration requirements and costs would be the same as specified for Alternative 2 (air stripping). 

FIGURE 8.5 Preliminary treatment, filtration, and granular-activated carbon adsorption (Alternative 3). 

There are six primary in-plant control methods for removal of priority pollutants and pesticides in pesticide manufacturing plants. These methods include steam-stripping, activated carbon adsorption, chemical oxidation, resin adsorption, hydrolysis, and heavy metals separation. Steam-stripping can remove volatile organic compounds (VOCs) activated carbon can remove semi volatile organic compounds and many pesticides and resin adsorption, chemical oxidation, and hydrolysis can treat selected pesticides [7]. Heavy metals separation can reduce toxicity to downstream biological treatment systems. Discussion of each of these methods follows. 

Activated carbon adsorption is a well-established process for adsorption of organics in wastewater, water, and air streams. Granular activated carbon (GAG) packed in a filter bed or of powdered activated carbon (PAG) added to clarifiers or aeration basins is used for wastewater treatment. In the pesticide industry, GAG is much more widely used than PAG. Figure 10 shows the process flow diagram of a GAG system with two columns in series, which is common in the pesticide industry [11]. 

The treatment methods for ruber wastewaters consist of various biological processes, and physico-chemical processes including coagulation, ozonation, activated carbon adsorption, aeration, sulfonation, chlorination, and aeration, and biological nutrient removal processes. The purpose of the treatment is to meet USEPA effluent limitations [4]. 

Recently investigated methods of treating waste waters contaminated with 1,3-DNB or 1,3,5-TNB and related products include biological treatment, stripping, solvent extraction, and activated carbon adsorption (HSDB 1994). 

Adachi A., M. Kamide, R. Kawafume, N. Miki, and T. Kobuyashi (1990). Removal-efficiency of anionic and nonionic surfactants from chemical wastewater by a treatment plant using activated carbon adsorption and coagulation precipitation processes. Environmental Technology 11 133-141. 

Table 1 shows treatment costs for the technology (based on a processing rate of 20 gpm) in comparison to other groundwater treatment technologies (i.e., chemical reduction and precipitation, chemical precipitation with sedimentation or filtration, activated carbon adsorption, ion exchange, reverse osmosis, and electrodialysis) (D168869, Table 13). 

Suffet coedited with M. J. McGuire ADVANCES IN CHEMISTRY SERIES No. 202, Treatment of Water by Granular Activated Carbon, as well as a two-volume set, Activated Carbon Adsorption of Organics from the Aqueous Phase. He also edited a two-volume treatise, The Fate of Pollutants in the Air and Water Environments he was a journal editor for a special issue of the Journal of Environmental Science and Health, Part A—Environmental Science and Engineering and he served on the editorial board of the companion journal, Journal of Environ-mental Science and Health, Part B—Pesticides, Food Contaminants, and Agricultural Wastes. He serves on the editorial boards of the journals Chemosphere and CHEMTECH. He is now completing a 4-year term as treasurer of the ACS Division of Environmental Chemistry. 

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