Pollutionprevention Hierarchy

As discussed in the introduction, the hierarchy set forth by the USEPA in the Pollution Prevention Act establishes an order to which waste-management activities should be employed to reduce the quantity of waste generated. The preferred method is source reduction, as indicated in Fig. 25-1. This approach actually precedes traditional waste management by addressing the source of the problem prior to its occurrence. Although the EPA's policy does not consider recycling or treatment as actual...

Primary Treatment

Wastewater treatment is directed toward removal of pollutants with the least effort. Suspended solids are removed by either physical or chemical separation techniques and handled as concentrated solids. Screens Fine screens such as hydroscreens are used to remove moderate-size particles that are not easily compressed under fluid flow. Fine screens are normally used when the quantities of screened particles are large enough to justify the additional units. Mechanically cleaned fine screens have...

Introduction

The amount of waste generated in the United States has reached staggering proportions according to the United States Environmental Protection Agency (EPA), 250 million tons of solid waste alone are generated annually. Although both the Resource Conservation and Recovery Act (RCRA) and the Hazardous and Solid Waste Act (HSWA) encourage businesses to minimize the wastes they generate, the majority of the environmental protection efforts are still centered around treatment and pollution clean-up....

Dispersion From Stacks

Stacks discharging to the atmosphere have long been the most common industrial method of disposing of waste gases. The concentrations to which humans, plants, animals, and structures are exposed at ground level can be reduced significantly by emitting the waste gases from a process at great heights. Although tall stacks may be effective in lowering the ground-level concentration of pollutants, they do not in themselves reduce the amount of pollutants released into the atmosphere. However, in...

Barriers And Incentives To Pollution Prevention

As discussed previously, industry is beginning to realize that there are profound benefits associated with pollution prevention including cost effectiveness, reduced liability, enhanced public image, and regulatory compliance. Nevertheless, there are barriers or disincentives identified with pollution prevention. This section will briefly outline both barriers and incentives that may need to be confronted or considered during the evaluation of a pollution prevention program. Barriers to...

Source Control Of Particulate Emissions

There are four conventional types of equipment used for the control of particulate emissions Each is discussed in Sec. 17 of this handbook under Gas-Solids Separations. The effectiveness of conventional air-pollution-control equipment for particulate removal is compared in Fig. 25-23. These fractional efficiency curves indicate that the equipment is least efficient in removing particulates in the 0.1- to 1.0- m range. For wet FIG. 25-23 Fractional efficiency curves for conventional...

Sludge Processing

Objectives Sludges consist primarily of the solids removed from liquid wastes during their processing. Thus, sludges could contain a wide variety of pollutants and residuals from the application of treatment chemicals i.e., large organic solids, colloidal organic solids, metal sulfides, heavy-metal hydroxides and carbonates, heavy-metal organic complexes, calcium and magnesium hydroxides, calcium carbonate, precipitated soaps and detergents, and biomass and precipitated phosphates. As sludge...

97209

Source EPA-454 R-94-027, National Air Pollutant Emission Trends, 1900-1993. source EPA-454 R-94-027, National Air Pollutant Emission Trends, 1900-1993. d. Alcohols. Methanol, ethanol, isopropanol e. Organic halides. Cyanogen chloride bromobenzyl cyanide f. Organic sulfides. Dimethyl sulfide g. Organic hydroperoxides. Peroxyacetyl nitrite or nitrate The most common gaseous pollutants and their major sources and significance are presented in Table 25-11. Particulate Pollutants Particulates may be...