Common Pollutants

Generally, under NPDES program, the following pollutants are required to be monitored and reported. 

Total Suspended Solids Total dissolved Solids 

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Table 5.53 Common pollutants that may be found in buildings...

Strict control is necessary over pollutant levels, acidity, temperature, turbidity, etc. because of their impact upon aquatic environments. Common pollutants in aqueous effluents are identified in Table 16.11. 

Estimate some typical emission factors and make a comparison between industry sectors. One way to express an emission factor is in terms of the tons of pollution produced per year per unit capita of production. Develop a table for several common pollutants (e.g., SO, NO, HCs, others) for each industry sector you select. What conclusions can you draw from these comparisons. 

The nitrogen oxides are common pollutants generated by internal combustion engines and power plants. They not only contribute to the respiratory distress caused by smog, but if they reach the stratosphere can also threaten the ozone layer that protects Earth from harmful radiation. 

Table 13.8 identifies common pollutants in aqueous effluents. Of the metals, the most toxic are salts of the heavy metals beryllium, cadmium, chromium, copper, lead, mercury, nickel and zinc. 

Common pollutants in a titanium dioxide plant include heavy metals, titanium dioxide, sulfur trioxide, sulfur dioxide, sodium sulfate, sulfuric acid, and unreacted iron. Most of the metals are removed by alkaline precipitation as metallic hydroxides, carbonates, and sulfides. The resulting solution is subjected to flotation, settling, filtration, and centrifugation to treat the wastewater to acceptable standards. In the sulfate process, the wastewater is sent to the treatment pond, where most of the heavy metals are precipitated. The precipitate is washed and filtered to produce pure gypsum crystals. All other streams of wastewater are treated in similar ponds with calcium sulfate before being neutralized with calcium carbonate in a reactor. The effluent from the reactor is sent to clarifiers and the solid in the underflow is filtered and concentrated. The clarifier overflow is mixed with other process wastewaters and is then neutralized before discharge. 

Another critical part of the incinerator design is the pollution control system.11 Pollution control systems directly influence the levels and kinds of pollutants that are released and that can potentially reach the public. Most modern hazardous waste incinerators are designed with extensive air pollution removal systems. For example, a common pollution control system might include a system that cools or quenches gases produced by burning waste, followed by a system that reduces acid gas emissions, and ultimately followed by a particulate removal system such as fabric filters (bag-houses), electrostatic precipitators, venturi scrubbers, and others.10... 

Common Pollutants and Sources John Cairns, Jr. (1923- ) Oxygen-depleting Substances Nutrients... 

Criteria pollutants six common pollutants—ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), lead (Pb), and particulate matter less than 10 microns (10 pm) in size—regulated since 1970 in the United States and presenting relatively well quantified risks... 

Halo-alkenes are common pollutants. Therefore, there is an ongoing study on plausible approaches to the dehalogenation of halo-alkanes. One of these approaches involves their electrocatalytic reduction. NinL2 + (L = a tetraaza macrocyclic ligand) complexes were proposed as plausible electrocatalysts (150). A pulse radiolytic study on the mechanism and kinetics of the reaction ... 

The field of study that encompasses this technology is called bioremediation. From a practical view, the degradation of a wide variety of organic molecules is an accepted method. Microorganisms have developed to handle most common pollutants. Thus, municipal waste treatment plants operate without special needs for particular organisms. 

The effect of nitrate on the photochemical degradation kinetics of hydrophilic was studied by Sorensen and Frimmel (1997). A number of common pollutants were examined, including amino-polycarboxylates and aromatic sulfonates. Kinetic experiments were performed with or without H202. Quantum yield was used as a tool for examining whether a substance acts as an inner filter. Under the assumption that water compounds do not take part in the chemical reaction but exert influence only in a physical way by the absorption of light, the true integral quantum yield (Oaj ) is independent of the concentration of the inner filter. 0.a , is expressed as ... 

Zero-valent iron is a promising in situ remediation technology for the degradation of many common pollutants, as it is comparatively inexpensive, does not restrict land use, and requires no energy for operating. Zero-valent iron has been successfully utilized to destroy trichloroethenes, chromate, chlorinated organics, and mixed wastes. It is capable of reducing and... 

The principle was applied to some common pollutants obtaining delay time values. The slope is the pH variation after the delay time can be assumed as proportional to the ability to be degraded, as rate of degradation [1-9]. 

Table 1.7.1 lists some common pollutants and their characteristic wavelengths (at which their absorbance or transmittance should be measured). 

Sulfur dioxide is a common pollutant found in coal-fired facilities. Various membrane permeation schemes have been proposed but few are competitive with wet scrubbing. More recently, however, bipolar membrane technology (q.v.) has been successfully used to recycle the scrubbing effluent and convert the sulfur into sulfuric acid. 

The laboratory-scale experimental setups are designed typically to conduct chemical reaction studies under a range of pressures, temperatures, densities, oxidant and organic concentrations, and residence times in several reactor configurations. In general, model compounds for simulating common pollutants in industrial waste streams are used in laboratory-scale experiments. 

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