Water Conservation, Reuse, and Recycling Proceedings of an Iranian-American Workshop (2005) / Chapter Skim
Currently Skimming:
Pages 35-53
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 37... ...
37 Large Scale Systems Stephen M Lacy ABSTRACT The arid Southwest of the United States has a very similar climate to portions of Iran.
|
From page 38... ...
38 WATER CONSERVATION, REUSE, AND RECYCLING Wastewater reuse provides a drought-proof resource for a community that automatically increases as population growth occurs. Reuse also provides for some immediate reductions in water diversions by replacing existing demands (such as turf irrigation at parks)
|
From page 39... ...
LARGE SCALE SYSTEMS 39 COMPARISON OF WATER QUALITY STANDARDS FOR NONPOTABLE REUSE Water quality standards for nonpotable uses have been established by many states within the United States and continue to be revised as a result of developing technologies in wastewater treatment and a better understanding of the health effects. The focus of these standards is to provide policy direction and regulation of reuse applications that are protective of public health.
|
From page 40... ...
40 WATER CONSERVATION, REUSE, AND RECYCLING Restricted Reuse for Non-Commercial Food Crops This category describes how reclaimed water may be used for surface or spray irrigation of food crops that can be consumed raw or that are not commercially processed. California requires that reclaimed water receive secondary and tertiary treatment followed by high-level disinfection.
|
From page 41... ...
LARGE SCALE SYSTEMS 41 The organic content must be reduced to less than 10 mg/l of BOD and the solids to less than 2 NTU (5 mg/l TSS)
|
From page 42... ...
42 WATER CONSERVATION, REUSE, AND RECYCLING FIGURE 2 Typical large water reclamation plant configuration. Tertiary Treatment With the advancements in membrane technology into the wastewater area, there are now two viable media that can be used effectively to filter secondary effluent: traditional sand (or similar media)
|
From page 43... ...
LARGE SCALE SYSTEMS 43 Filtration Filters come in many forms, but the basic concept by which they work is the same. It is a physical straining process where the solid particles pass through a bed of sand or other media.
|
From page 44... ...
44 WATER CONSERVATION, REUSE, AND RECYCLING • Continuous Backwash. This type of filter also requires a low operating head (450mm to 600mm)
|
From page 45... ...
LARGE SCALE SYSTEMS 45 ent to the high level required for unrestricted reuse of reclaimed water. Chlorine has been used for many years in water and wastewater applications.
|
From page 46... ...
46 WATER CONSERVATION, REUSE, AND RECYCLING USE OF MICROFILTRATION IN THE MEMBRANE BIOREACTOR PROCESS The increased need for reclaimed water in arid environments has resulted in the emergence of new wastewater reclamation technologies. One of the most promising and innovative technologies in water reclamation today is the membrane bioreactor (MBR)
|
From page 47... ...
LARGE SCALE SYSTEMS 47 FIGURE 3 Treatment plant process comparison. INDIRECT POTABLE REUSE DEFINITIONS, WATER QUALITY REQUIREMENTS, AND TREATMENT TECHNOLOGIES Due to the seasonal nature of demands for nonpotable water reuse, it is likely that the supply of reuse water in a community can exceed the demand for turf irrigation and other nonpotable applications.
|
From page 48... ...
48 WATER CONSERVATION, REUSE, AND RECYCLING water body, or wetland. This provides additional time and treatment by naturally occurring processes.
|
From page 49... ...
LARGE SCALE SYSTEMS 49 rized in Table 1. It should be noted that very stringent treatment and monitoring requirements are expected in the permitting process and that as more indirect reuse applications are proposed, the policies, water quality standards, and regulations are likely to change.
|
From page 50... ...
50 WATER CONSERVATION, REUSE, AND RECYCLING TABLE 1 Sample Criteria for Aquifer Recharge with Treated Effluent Depth to Groundwater Maximum Retention Percent Perc.
|
From page 51... ...
LARGE SCALE SYSTEMS 51 FIGURE 4 Summary of effectiveness of advance treatment process. FIGURE 5 Summary of effectiveness and limitations of membrane process.
|
From page 52... ...
52 WATER CONSERVATION, REUSE, AND RECYCLING Table 2 compares conventional treatment removal mechanisms with removal mechanisms found in soil-aquifer treatment. An advanced water treatment facility (AWTF)
|
From page 53... ...
LARGE SCALE SYSTEMS 53 the reclaimed water storage tank at the head of the AWTF if the treated water is determined not to meet the water quality requirements for aquifer injection. A pilot study is necessary to develop design criteria prior to finalizing the AWTF process design.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.