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FIGURE 2.5 Conventional rapid sand filter plant flow diagram. Possible chemical combinations: A: Chlorine. A\ Eliminate if THMs formed. B: Coagulant: aluminum sulfate (pH 5.5-8.0). 10 to 50mg/l; ferric sulfate (pH 5.0-11.0). 10 to 50mg/l; ferrous sulfate (pH 8.5-11.0). 5 to 25mg/l; ferric chloride (pH 5.0-11.0): sodium aluminate, 5 to 20mg/l; activated silica, organic chemicals (polyelectrolytes). C: Alkalinity adjustment: lime, soda ash. or polyphosphate. D : Activated carbon, potassium permanganate. E: Dechlorination: sulfur dioxide, sodium sulfite, sodium bisulfite, activated carbon. F: Fluoridation treatment. X: Chlorine dioxide, ozone, chlorine-ammonia. Note that the chlorinator should be selected to postchlorinate at 3 mg/1. Provide for a dose of 3 mg/1 plus chlorine demand for groundwater. Additional treatment processes may include softening (ion exchange, lime-soda, excess lime and recarbonation), iron and manganese removal (ion exchange, chemical oxidation and filtration, ozone oxidation, sequestering), organics removal (activated carbon, superchlorination, ozone oxidation), and demineralization (distillation, electrodialysis, reverse osmosis, chemical oxidation and filtration, freezing).

Lime Carbon Dosing

FIGURE 2.6 Flow diagram of typical treatment plant. This plant is compactly arranged and adaptable within a capacity range of 0.25 to 1.0 mgd. Operation is simple as the emphasis is on manual operation with only the essentials in mechanical equipment provided. Design data are described in the text. (Source: Water Treatment Plant Design, American Water Works Association, New York, 1969. Copyright 1969 by the American Water Works Association. Reprinted with permission.)

FIGURE 2.6 Flow diagram of typical treatment plant. This plant is compactly arranged and adaptable within a capacity range of 0.25 to 1.0 mgd. Operation is simple as the emphasis is on manual operation with only the essentials in mechanical equipment provided. Design data are described in the text. (Source: Water Treatment Plant Design, American Water Works Association, New York, 1969. Copyright 1969 by the American Water Works Association. Reprinted with permission.)

The presence of paper fiber or of diatoms in excess of 1,000 areal standard units per milliliter (asu/ml) requires that settling (or microscreening) be included in the treatment process chain. Diatom levels in excess of 200 asu/ml may require the use of special coarse coal on top of the bed in order to extend filter runs. Coliform MPNs should be low. Filter rates of 4 to 5 gpm/ft2 and as high as 15 gpm/ft2 may produce satisfactory results with some waters, but caution is advised. Decreased chemical dosage, and hence sludge production but increased filter washwater, will usually result in reduced net cost as compared to conventional treatment.59 Surface wash, subsurface wash, or air scour is required. Good pretreatment and operation control are essential.

Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

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