Water reclamation
Encyclopedia
Water reclamation is a process by which wastewater
from homes and businesses is cleaned using biological and chemical treatment so that the water can be returned to the environment safely to augment the natural systems from which it came. It is used today as both an aquifer
and stream enhancement strategy.
from sensitive eco-systems which depend greatly on the flow to improve the quality of the water. Water reclamation also decreases the pollution
to bodies of water, such as oceans and rivers, by diverting the wastewater. Some of the pollutants are used for irrigation
purposes, such as nitrogen
, which would be harmful to these bodies of water. Another benefit is the enhancement of wetlands which benefits the wildlife
dependent on that eco-system. For instance, The San Jose/Santa Clara Water Pollution Control Plant instituted a recycling program to protect the San Francisco Bay
area's natural salt water marshes.
mixing, artificial lakes, and irrigation for golf courses and public parks. Most systems run a dual piping system to keep the recycled water separate from the potable water.
Indirect water reclamation (water passing through a body of water first) will result in potable water usage. While, this is not practiced in the United States
, it is in other countries such as Namibia
.
Aboard the International Space Station
, astronauts have been able to drink recycled urine
due to the introduction of the ECLSS system. The system costs $250 million and has been working since May 2009. The system recycles wastewater and urine back into potable water used for drinking, food preparation, and oxygen generation. This cuts back on the need for resupplying the space station as often.
recycles used water for irrigation and other various uses. Greywater uses the same waste as water reclamation with the exception of toilet water. Unlike water reclamation, greywater does not purify the water through a biological process, but by sand filters and soil. After passing through the soil, where it is filtered like rain water, it flows into the groundwater where it will be reused again.
is an energy-intensive process where salt and other minerals are removed from sea water to produce potable water for drinking and irrigation, typically through membrane filtration
(reverse-osmosis), and steam-distillation.
Many ships and submarines make use of this technology. The idea of desalination is a heavily researched area worldwide. Many methodologies have been developed, including nuclear-powered desalination, and solar-powered desalination.
One of two procedures are then followed according to the future disposal site:
Wastewater
Wastewater is any water that has been adversely affected in quality by anthropogenic influence. It comprises liquid waste discharged by domestic residences, commercial properties, industry, and/or agriculture and can encompass a wide range of potential contaminants and concentrations...
from homes and businesses is cleaned using biological and chemical treatment so that the water can be returned to the environment safely to augment the natural systems from which it came. It is used today as both an aquifer
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
and stream enhancement strategy.
Benefits
Water reclamation helps decrease diverging waterWater
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
from sensitive eco-systems which depend greatly on the flow to improve the quality of the water. Water reclamation also decreases the pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
to bodies of water, such as oceans and rivers, by diverting the wastewater. Some of the pollutants are used for irrigation
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
purposes, such as nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
, which would be harmful to these bodies of water. Another benefit is the enhancement of wetlands which benefits the wildlife
Wildlife
Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative....
dependent on that eco-system. For instance, The San Jose/Santa Clara Water Pollution Control Plant instituted a recycling program to protect the San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
area's natural salt water marshes.
Uses
Most of the uses of water reclamation are non potable uses such as: Washing Cars, flushing toilets, cooling water for power plants, concreteConcrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
mixing, artificial lakes, and irrigation for golf courses and public parks. Most systems run a dual piping system to keep the recycled water separate from the potable water.
Indirect water reclamation (water passing through a body of water first) will result in potable water usage. While, this is not practiced in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, it is in other countries such as Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
.
Aboard the International Space Station
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
, astronauts have been able to drink recycled urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
due to the introduction of the ECLSS system. The system costs $250 million and has been working since May 2009. The system recycles wastewater and urine back into potable water used for drinking, food preparation, and oxygen generation. This cuts back on the need for resupplying the space station as often.
Greywater
Like water reclamation, greywaterGreywater
Greywater is wastewater generated from domestic activities such as laundry, dishwashing, and bathing, which can be recycled on-site for uses such as landscape irrigation and constructed wetlands...
recycles used water for irrigation and other various uses. Greywater uses the same waste as water reclamation with the exception of toilet water. Unlike water reclamation, greywater does not purify the water through a biological process, but by sand filters and soil. After passing through the soil, where it is filtered like rain water, it flows into the groundwater where it will be reused again.
Desalination
DesalinationDesalination
Desalination, desalinization, or desalinisation refers to any of several processes that remove some amount of salt and other minerals from saline water...
is an energy-intensive process where salt and other minerals are removed from sea water to produce potable water for drinking and irrigation, typically through membrane filtration
Membrane technology
The membrane technology covers all process engineering measures for the transport of substances between two fractions with the help of permeable membranes...
(reverse-osmosis), and steam-distillation.
Many ships and submarines make use of this technology. The idea of desalination is a heavily researched area worldwide. Many methodologies have been developed, including nuclear-powered desalination, and solar-powered desalination.
Reclamation Processes
Wastewater must pass through numerous systems before being returned to the environment. Here is a partial listing from one particular plant system:- Barscreens - Barscreens remove large solids that are sent into a grinder. All solids are then dumped into a sewer pipe at a Treatment Plant.
- Primary Settling Tanks - Readily settable and floatable solids are removed from the wastewater. These solids are skimmed from the top and bottom of the tanks and sent to the Treatment Plant where it'll be turned into fertilizer.
- Biological Treatment - The wastewater is cleaned through a biological treatment method that uses microorganisms, bacteria which digest the sludge and reduce the nutrient content. Air bubbles up to keep the organisms suspended and to supply oxygen to the aerobic bacteria so they can metabolize the food, convert it to energy, CO2, and water, and reproduce more microorganisms. This helps to remove ammonia also through nitrification.
- Secondary Settling Tanks - The force of the flow slows down as sewage enters these tanks, allowing the microorganisms to settle to the bottom. As they settle, other small particles suspended in the water are picked up, leaving behind clear wastewater. Some of the microorganisms that settle to the bottom are returned to the system to be used again.
- Tertiary Treatment - Deep-bed, single-media, gravity sand filters receive water from the secondary basins and filter out the remaining solids. As this is the final process to remove solids, the water in these filters is almost completely clear.
- Chlorine Contact Tanks - Three chlorine contact tanks disinfect the water to decrease the risks associated with discharging wastewater containing human pathogens. This step protects the quality of the waters that receive the wastewater discharge.
One of two procedures are then followed according to the future disposal site:
- Reclaimed Water Pump Station - The pump station distributes reclaimed water to users around the City. This may include golf courses, agricultural uses, cooling towers, or in land fills.
- Water is passed through high level purification to be returned to the environment. Currently this means a reverse osmosisReverse osmosisReverse osmosis is a membrane technical filtration method that removes many types of large molecules and ions from solutions by applying pressure to the solution when it is on one side of a selective membrane. The result is that the solute is retained on the pressurized side of the membrane and...
system.