1 / 11

Overview of Water Treatment

Overview of Water Treatment. Physical, chemical, and biological processes are used for treating water. Unit operation: physical treatment. Unit process: chemical or biological treatment.

koen
Télécharger la présentation

Overview of Water Treatment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Overview of Water Treatment • Physical, chemical, and biological processes are used for treating water. • Unit operation: physical treatment. • Unit process: chemical or biological treatment. • A series of unit operations and unit processes are selected by the process engineer based on influent characteristics to achieve the desired effluent quality.

  2. Water Treatment Problem A water treatment plant is to be designed to treat water with the following characteristics: High turbidity High bacteriological concentrations No carbon dioxide Medium color Low hardness What is the source of the water? Prepare schematic of treatment train.

  3. Items to Consider Source: River– variable flow and quality High turbidity: removed by sedimentation and filtration; suggest presedimentation. High bacteriological concentrations: removed by disinfection; some microbes removed by coagulation, flocculation and settling; suggest predisinfection. Carbon dioxide: aerate or add lime if present. Medium color: ozonation and chlorination will reduce, may be necessary to use activated carbon Low hardness : would soften if moderately hard.

  4. Screens Flow Meter Disinfectant Low Lift Pumps Plain Sedimentation Screening: unit operation, removes large debris and tree limbs. Low Lift Pumps: unit operation, provides energy to lift water up to the treatment plant Flow Meter: unit operation, measures flow. Pre-disinfection: unit process, disinfectant added to lower bacterial and pathogen levels. Plain sedimentation: unit operation, removes suspended solids lowering turbidity.

  5. Focculation Disinfectant Mixing Sedimentation Coagulant Mixing: unit operation, dispersion of coagulant. Flocculation: unit process, destabilization of colloidal particles and promotion of floc growth. Sedimentation: unit operation, removal of suspended solids, lowers turbidity. Disinfection: unit process, addition of disinfectant to kill pathogens.

  6. Disinfectant Disinfectant To Distribution System Filtration Clear Well High Service Pumps Filtration: unit operation, removes remaining turbidity and microbial cysts. Disinfection: unit process, disinfectant added to ensure pathogens are destroyed. Clear well provides necessary contact time with disinfectant. High Service Pumps: unit operation, energy provided to pump water throughout distribution system.

  7. Water Treatment Problem A water treatment plant is to be designed to treat water with the following characteristics: Low turbidity Low bacteriological concentrations Moderate carbon dioxide Low color High hardness What is the source of the water? Prepare schematic of treatment train.

  8. Items to Consider Source: Well– relatively constant flow and high quality. Low turbidity: removed by coagulation, flocculation, sedimentation and filtration; may need to add turbidity in the form of clay to provide nuclei for coagulation. Low bacteriological concentrations: removed by disinfection; some microbes removed by coagulation, flocculation and settling; lime-soda ash treatment followed by sedimentation and filtration should remove microbes . Carbon dioxide: aerate or add lime if present. Low color: ozonation and chlorination will reduce. High hardness : soften if moderately hard using lime-soda ash; alternative treatment would be to used membranes rather than conventional treatment.

  9. Low Lift Pumps Trasy Aeration Wells Flow Meter Disinfectant Wells: unit operation, source of groundwater. Low Lift Pumps: unit operation, provides energy to lift water up to the treatment plant Flow Meter: unit operation, measures flow. Pre-disinfection: unit process, disinfectant added to reduce pathogen levels and oxidize H2S, Fe & Mg. Tray Aeration: unit operation, removes CO2, H2S, and other gases.

  10. Focculation Disinfectant Mixing Sedimentation Lime & Soda Mixing: unit operation, dispersion of lime & soda-ash for hardness removal. Flocculation: unit process, destabilization of colloidal particles and promotion of floc growth. Sedimentation: unit operation, removal of suspended solids, lowers turbidity. Disinfection: unit process, addition of disinfectant to kill pathogens.

  11. Disinfectant Disinfectant To Distribution System Filtration Clear Well High Service Pumps Filtration: unit operation, removes remaining turbidity and microbial cysts. Disinfection: unit process, disinfectant added to ensure pathogens are destroyed. Clear well provides necessary contact time with disinfectant. High Service Pumps: unit operation, energy provided to pump water throughout distribution system.

More Related