Skip to main content

Location

Technologies Decision Tool

This list of technologies is intended to be representative but not comprehensive. There are technologies that may be appropriate to a given application that are not listed here. Before applying a technology to any real-life situation, it is critical to test the potential water supply source for contaminants and to consult a professional water scientist or engineer.

Additionally, countries have different laws and regulations. These technologies are not warranted to be legal and appropriate in a given country.

Finally, many non-technological factors are important to consider, including community needs and preferences, mechanisms to prevent recontamination of the treated water, personal hygiene such as handwashing, and financial and other mechanisms to provide sustained and uninterrupted availability.

Coagulation-Flocculation

Conventional Coagulation-
Flocculation-
Sedimentation
Dissolved Air Flotation Flocculation-
Chlorination
Lime Softening
System/Process Coagulation-
Flocculation associated with sedimentation and/or filtration
Coagulation-
Flocculation associated with sedimentation and/or filtration
Coagulation-
Flocculation associated with sedimentation and/or filtration
Coagulation-
Flocculation associated with sedimentation and/or filtration
Contaminant Types Turbidity; Color; Disinfection byproduct precursor; Algae; Protozoa; Bacteria; Viruses; Iron; Calcium and magnesium; Phosphate; Selenium Turbidity; Color; Disinfection byproduct precursor; Algae; Protozoa; Bacteria; & Viruses Viruses; Bacteria; Parasites; Protozoa; Arsenic; and Pesticides Turbidity; Protozoa; Bacteria; Viruses; Hardness (calcium and magnesium); Iron; Manganese; Arsenic; Selenium; Radium
Usage Type - centralized/ household Centralized Centralized Household Centralized
State of Technology Conventional in most countries including developed ones Accepted but rare Emerging Conventional
Relative Capital Cost-Centralized Medium Medium N/A High
Relative Capital Cost - Household N/A N/A Low N/A
Water Source Surface water sources Surface water sources Surface water sources All water sources
Raw Water Quality Range Can treat wide range of water quality Very high algae okay; high color okay; moderate turbidity Can treat wide range of water quality All hard waters
Operator Skill Level Required Basic Advanced Basic Advanced
Monitoring Requirements Low High N/A High
Relative Operating Cost - Centralized Medium Medium/High N/A High
Relative Operating Cost - Household N/A N/A Low N/A
Requires Electricity Yes Yes No Yes
to top

Filtration Systems

Bag/Cartridge Filters Biosand Ceramic Filtration Conventional Filtration Diatomaceous Earth Filtration Direct Filtration Slow Sand Filtration
System/Process Filtration Systems Filtration Systems Filtration Systems Filtration Systems Filtration Systems Filtration Systems Filtration Systems
Contaminant Types Protozoa Turbidity; Taste and odor; Protozoa; Bacteria Turbidity; Bacteria; Protozoa Turbidity; Color; Disinfection byproduct precursor; Algae; Protozoa; Bacteria; Viruses; & Arsenic
Iron & Manganese if used with chlorine
Ammonia & Biodegradable organic matter if used without chlorine
Turbidity; Algae; Protozoa; Bacteria; & Viruses Turbidity; Color; Disinfection byproduct precursor (limited); Protozoa; Bacteria; Viruses; Ammonia;
Iron & Manganese if used with Chlorine
Ammonia & Biodegradable organic matter if used without chlorine
Turbidity; Taste and odor; Protozoa; Bacteria; Biodegradable organic; Ammonia
Usage Type - centralized/ household Household Household Household Centralized Both Centralized Centralized
State of Technology Accepted; extremely rare Emerging Emerging Conventional Conventional for household scale Conventional Conventional
Relative Capital Cost - Centralized N/A N/A N/A High High High Medium
Relative Capital Cost - Household Low Medium Low N/A Medium N/A N/A
Water Source Surface water sources Surface water sources Surface water sources Surface water sources Surface water sources Surface water sources
GW with Fe; Mn of NH3
Surface water sources
Raw Water Quality Range Needs very high water quality Needs high water quality N/A Can treat wide range of water quality Needs very high water quality Raw water with turbidity below ~ 10 ntu Needs very high water quality
Operator Skill Level Required Basic Basic Basic Advanced Intermediate Advanced Basic
Monitoring Requirements Low N/A N/A High Medium High Low
Relative Operating Cost - Centralized N/A N/A N/A Medium Medium Medium Low; with good raw water
Relative Operating Cost - Household Low/High; depends on cycle length Low Low N/A Medium N/A N/A
Requires Electricity No No No Yes No Yes No
to top

Membrane Processes

Electrodialysis/Electrodialysis Reversal Microfiltration Nanofiltration Reverse Osmosis Ultrafiltration
System/Process Membrane Processes Membrane Processes Membrane Processes Membrane Processes Membrane Processes
Contaminant Types Hardness (Calcium and Magnesium); Iron; Manganese; Arsenic; Selenium; Thallium; Fluoride; Radium; Uranium; Cations; Anions; Total dissolved solids; Nitrate; Ammonia Turbidity; Algae; Protozoa; Bacteria Color; Disinfection byproduct precursor; Pesticides; Hardness (calcium and magnesium); Algae; Bacteria; Protozoa; Viruses Color; Disinfection byproduct precursor; Semivolatile compounds; Pesticides; Hardness (calcium and magnesium); Arsenic; Selenium; Thallium; Fluoride; Radium; Uranium; Cations; Anions; Total dissolved solids; Nitrate; Ammonia; salinity; Algae; Bacteria; Protozoa; Viruses Turbidity; Algae; Protozoa; Bacteria; Viruses
Usage Type - centralized/ household Centralized Centralized Centralized Both Centralized
State of Technology Accepted but rare Conventional Conventional Conventional Conventional
Relative Capital Cost - Centralized Very High High Very High High High
Relative Capital Cost - Household N/A N/A N/A High N/A
Water Source All water sources Surface water sources All water sources All water sources Surface water sources
Raw Water Quality Range Requires prefiltration for surface water Needs high water quality (or pretreatment) All surface waters require pretreatment All surface waters require pretreatment Needs very high water quality (or pretreatment)
Operator Skill Level Required Very Advanced Intermediate Very Advanced Very Advanced Intermediate
Monitoring Requirements Very High High Very High Very High Very High
Relative Operating Cost - Centralized Very High Medium High Very High Medium
Relative Operating Cost - Household N/A N/A N/A High N/A
Requires Electricity Yes Yes Yes Yes Yes
to top

Chemical Disinfection/Oxidants

Chlorination ClO2 NH2Cl/Chloramines O3 Ozonation Ultraviolet radiation
System/Process Chemical Disinfection/ Oxidants Chemical Disinfection/ Oxidants Chemical Disinfection/ Oxidants Chemical Disinfection/ Oxidants Chemical Disinfection/ Oxidants
Contaminant Types Bacteria; Viruses; & Iron Protozoa; Bacteria; Viruses Bacteria Color; Taste and odor; Protozoa; Bacteria; Viruses; & Iron Protozoa; Bacteria; & Viruses
Usage Type - centralized/ household Both Centralized Centralized Both Both
State of Technology Conventional Accepted Conventional Conventional Conventional
Relative Capital Cost - Centralized Low Low Low Medium Medium
Relative Capital Cost - Household Low N/A N/A Medium Medium
Water Source All water sources
Both primary and secondary disinfection
All water sources
Both primary and secondary disinfection
All water sources
usually only secondary disinfection
All water sources
Only primary disinfection
All water sources
Only primary disinfection
Raw Water Quality Range All; but better with higher quality All; but better with very high quality All; but better with higher quality All; but better with higher quality All; but better with higher quality
Operator Skill Level Required Basic Intermediate Basic Advanced Intermediate
Monitoring Requirements Low Medium Low High Medium
Relative Operating Cost - Centralized Low Medium/Low Low Medium Low
Relative Operating Cost - Household Low N/A N/A Medium Low
Requires Electricity No Yes Yes Yes Yes
to top

Adsorption and Ion Exchange Systems

Activated Alumina Granular Activated Carbon (GAC) Ion Exchange Powdered Activated Carbon (PAC)
System/Process Adsorption and Ion Exchange Systems Adsorption and Ion Exchange Systems Adsorption and Ion Exchange Systems Adsorption and Ion Exchange Systems
Contaminant Types Arsenic; Selenium; Thallium; Fluoride Color; Disinfection byproduct precursors; Taste and odor; Protozoa; Bacteria; Viruses; Volatile organic compounds (VOCs); Semivolatile compounds; Pesticides; & Biodegradable organic matter Catoin Resins - Hardness (Calcium and Magnesium); Fluoride; Radium; Ammonia Anion Resins - Nitrate; Perchlorate; Arsenic Color; Disinfection byproduct precursors; Taste and odor; Volatile organic compounds (VOCs); Semivolatile compounds; Pesticides; Biodegradable organic matter
Usage Type - centralized/ household Both Both Both Centralized
State of Technology Accepted but rate Conventional Conventional Conventional
Relative Capital Cost - Centralized High High High Medium
Relative Capital Cost - Household Medium Medium Medium N/A
Water Source Ground water All water sources Ground water Surface Water
Raw Water Quality Range All ground waters Surface water may require prefiltration All ground waters All surface waters
Operator Skill Level Required Advanced Intermediate Intermediate Basic
Monitoring Requirements High High High Low
Relative Operating Cost - Centralized Very High High to Very High High Medium/High
Relative Operating Cost - Household High High High N/A
Requires Electricity No No Yes Yes
to top

Air Stripping Systems

Aeration: Diffused air Mechanical Aeration Packed Tower Aeration Tray Aerators
System/Process Air Stripping Systems Air Stripping Systems Air Stripping Systems Air Stripping Systems
Contaminant Types Taste and odor; Volatile organic compounds; Iron; Radon; Sulfides Taste and odor; Volatile organic compounds; Iron; Radon; Sulfides Taste and odor; Volatile organic compounds; Iron; Radon; Sulfides Taste and odor; Volatile organic compounds; Iron; Radon; Sulfides
Usage Type - centralized/ household Both Centralized Both Both
State of Technology Conventional Conventional Conventional Conventional
Relative Capital Cost - Centralized Low Low Low Low
Relative Capital Cost - Household Medium N/A Medium Medium
Water Source Ground water Ground water Ground water Ground water
Raw Water Quality Range All ground waters All ground waters All ground waters All ground waters
Operator Skill Level Required Basic Basic Intermediate Basic
Monitoring Requirements Low Low Low Low
Relative Operating Cost - Centralized Low Low Low Low
Relative Operating Cost - Household Low N/A Medium Low
Requires Electricity Yes Yes Yes No
to top

Solar Treatment

Solar Disinfection Solar Distillation
System/Process Solar Treatment Solar Treatment
Contaminant Types Viruses; Bacteria; Parasites; Protozoa Color; Disinfection; Protozoa; Bacteria; Viruses; Semivolatile compounds; Pesticides; Hardness (Calcium and Magnesium); Arsenic; Selenium; Thallium; Fluoride; Radium; Uranium; Cations; Anions; Total dissolved solids; Nitrate; Ammonia; salinity
Usage Type - centralized/ household Household Household
State of Technology Emerging Emerging
Relative Capital Cost - Centralized N/A N/A
Relative Capital Cost - Household Low Medium
Water Source All water sources All water sources
Raw Water Quality Range Needs high water quality Can treat wide range of water quality
Operator Skill Level Required Basic Basic
Monitoring Requirements N/A Low
Relative Operating Cost - Centralized N/A N/A
Relative Operating Cost - Household Low Low
Requires Electricity No No
to top

Page Options