Wastewater treatment and disposal

A significant reason for conservation in both arid and nonarid regions is the cost of wastewater disposal. Decreasing domestic use of water results in decreased hydraulic loading on wastewater treatment plants. The cost of wastewater treatment and disposal is very closely linked to the flow being treated. Thus coimnunities with an abundant supply of water can also benefit from water conservation. 

The surviving U.S. plants have embraced all types of waste treatment processes (see Wastes treatment, hazardous waste Wastes, industrial). The most desired poUution prevention processes are those which reduce the total amount of waste discharged. Treatment and disposal are less strongly emphasized options. Zero wastewater discharge faciHties and water recycling processes are becoming more common (55,56). 

RO, primarily used ia the dairy iadustry, is expanding iato other areas of food processiag. RO can be used for a variety of operations, ranging from wastewater treatment and material recovery to clarification and concentration. Material recovery is advantageous for two reasons. By recovering valuable products, eg, proteias, from waste streams, profits can be iacreased while costs for waste disposal decreased. An excellent review of the different apphcations ofRO ia food processiag is available (9). 

Metcalf, Eddy, Inc., Wastewater Engineering Collection, Treatment, and Disposal, McGraw-HiU Book Company, New York, 1972. 

P. A. Vesilind, Treatment and Disposal of Wastewater Sludges, Ann Arbor Science PubHshers, Ann Arbor, Mich., 1974, Chapt. 6. 

Environmental Factors These inchrde (I) eqrripment location, (2) available space, (3) ambient conditions, (4) availabuity of adeqrrate rrtilities (i.e., power, water, etc.) and ancillary-system facilities (i.e., waste treatment and disposal, etc.), (5) maximrrm aUowable emission (air polhrtion codes), (6) aesthetic considerations (i.e., visible steam or water-vapor phrme, etc.), (7) contribrrtions of the air-poUrrtion-control system to wastewater and land poUrrtion, and (8) contribrrtion of the air-poUrrtion-control system to plant noise levels. 

The cost of storing wastewater for subsequent reuse may be far less than the treatment and disposal costs. 

For PM applications, wet scrubbers generate waste in the form of a slurry or wet sludge. This creates the need for both wastewater treatment and solid waste disposal. Initially, the slurry is treated to separate the solid waste from the water. The treated water can then be reused or discharged. Once the water is removed, the remaining waste will be in the form of a solid or sludge. 

Tier 0 and Tier 1 costs are direct and indirect costs. They include the engineering, materials, labor, construction, contingency, etc., as well as waste-collection and transportation services (in many cases we simply transform an air pollution problem into a solid waste or wastewater problem that requires final treatment and disposal), raw-material consumption (increase or decrease), and production costs. Tier 2 and... 

P. Aarne Vesilind. Treatment and Disposal Of Wastewater Sludges. Michigan Ann Arbor Science, 1979. 

Wastewater treatment and water purification applications employ UF in a TFF or NFF mode to produce permeate product with reduced colloids, pyrogens, and viruses. Oil droplets in wastewater are retained by UF for recycle or disposal at a significantly reduced vol-... 

Treatment technologies used in the porcelain enameling industry are generally chosen to remove the major wastewater components, such as suspended solids and toxic metals. Table 8.15 presents a summary of the treatment and disposal techniques used by this industry. Usually more than one treatment methods will be used at each facility.3 610... 

In this treatment process, unit operations such as chemical coagulation, flocculation, and sedimentation followed by filtration, activated carbon, ion exchange, and reverse osmosis are employed to remove significant amounts of nitrogen, phosphorus, heavy metals, organic matters, bacteria, and viruses present in wastewater.2 It is always the last process step in the wastewater treatment plant that finally renders the treated wastewater reusable and disposable into the environment without any adverse effect (Figure 22.1). 

For PM applications, wet scrubbers generate waste in the form of a slurry or wet sludge. This creates the need for both wastewater treatment and solid waste disposal. Initially,... 

The flows of wastewater originating from the water supply of a community and runoff from precipitation on urban surfaces are typically collected and conveyed for treatment and disposal. The system used for this purpose is called a sewer network or a collection system that consists of individual pipes (sewer lines) and a number of installations, such as inlet structures and pumps, to facilitate collection and transport. The efficient, safe and cost-effective collection and transport of wastewater and urban runoff have been identified as key criteria to be observed. In this context, the word safe means that public health, welfare and environmental protection have high priority. The demand for solutions toward more sustainable water management in the cities is a new challenge. 

Against this background, a sustainable and integrated dimension of wastewater management in sewer networks is needed. The safe and efficient collection and conveyance of wastewater to treatment and disposal are still main concerns. The consideration of sewer processes as an element in the design and operation of sewers will give anew dimension to the overall objective of sewer management and contribute to improved sustainability. Therefore, the technical systems must be considered holistically ... 

Verlicchi P, Galletti A, Al Aukidy M (2011) Hospital wastewaters quali-quantitative characterization and strategies for their treatment and disposal. In Sharma SK, Sanghi R (eds) Water treatment and pollution prevention advances in research. Springer (in press)... 

Significant parameters to be considered in designing a treatment and disposal facility for pharmaceutical wastewater are given in Table 12. Biochemical oxygen demand measurements of the waste have been reported to increase greatly with dilution, indicating the presence of toxic or inhibitory substances in some pharmaceutical effluents. The toxicity impact upon various biological treatments by various antibiotics, bactericidal-type compounds, and other pharmaceuticals has been described in the literature [21-24]. 

The above-cited studies demonstrate the performance of a particular unit system for the treatment of specific type of waste stream. A particular unit system alone may not be able to treat the wastewater to a level of effluent standard prescribed for its safe disposal. Hence a number of pretreatments, such as screening, sedimentation, equalization, and neutralization, and post-treatment units such as secondary sedimentation, sludge thickening, digestion and disposal, disinfection, and so on, are extremely important for complete treatment. The effluent treatment and disposal facilities adopted by various types of pharmaceutical industries are described in the following sections. 

Lawson, J.R. Woldman, M.L. Eggerman, P.P. Squibb solves its pharmaceutical wastewater problems in Puerto Rico. Chem. Engng. Progress Symposium Series No. 107, 1971, Water-1970 , 1970,401 -404. Murthy, Y.S. Subbiah, V. Rao, D.S. Reddy, R.C. Kumar, L.S. Elyas, S.I. Rama Rao, K.G. Gadgill, J.S. Deshmukh, S.B. Treatment and disposal of wastewater from synthetic drugs plant (I.D.P.L.), Hyderabad, Part I - Wastewater characteristics. Indian J. Environ. Health 1984, 26 (1), 7-19. 

Deshmukh, S.B. Gadgil, J.S. Subrahmanyanm, P.V.R. Treatment and disposal of wastewater from synthetic drugs plant (I.D.P.L.), Hyderabad, Part II - Biological treatabiUty. Indian J. Environ. Health 1984, 26, 20-28. 

Nemerow [23] summarized the major characteristics of wastes from phosphate and phosphorus compounds production (i.e., clays, slimes and tall oils, low pH, high suspended solids, phosphorus, silica, and fluoride) and suggested the major treatment and disposal methods such as lagooning, mechanical clarification, coagulation, and settling of refined wastewaters. The... 

---