Stabilization pond
Encyclopedia
Stabilization pond technology - sometimes also called facultative pond
technology - is a natural method for wastewater treatment
.
, and some of the soluble element of organic matter (BOD
). During the secondary stage in the facultative pond most of the remaining BOD is removed through the coordinated activity of algae and heterotrophic bacteria. The main function of the tertiary treatment in the maturation pond is the removal of pathogens and nutrients (especially nitrogen).
Stabilization ponds, as described here, use no aerators. High-performance lagoon technology with aerators has much more in common with that of activated sludge
. Such aerated lagoon
s are common in small towns in the United States, among other places.
s, oxidation ditches and trickling filter
s. According to this study, stabilization pond technology is a cheaper option up to a land cost of US$ 7.8/m2. Above this cost, oxidation ditches become the cheapest option. However, often the main constraint against selecting this technology is not land cost but land availability. If land is available, stabilization ponds have the advantage of very low operating costs since they use no energy compared to other wastewater treatment technologies. This makes them particularly suitable to developing countries where many “conventional” wastewater treatment plants (usually using activated sludge
technology) have had to be shut down because water and sewer utilities did not generate sufficient revenue to pay the electricity bill for the plant.
, El Salvador
, Guatemala
, Honduras
, Israel
, Jordan
, Morocco
, Nicaragua
, Tunisia
and Uganda
. They are typically used in smaller towns where land availability and cost is less of a constraint. In some cities larger stabilization ponds have been replaced in the early 2000s by activated sludge
waste water treatment plants, such as in Amman (Jordan) and in Adelaide (Australia) in 2004.
, from the effluent and to satisfy the World Health Organization
microbiological guidelines for Category B irrigation with wastewater effluent. However, sludge from all ponds was heavily contaminated with helminth eggs.
Facultative lagoon
Facultative lagoons are a type of stabilization pond used for biological treatment of industrial and domestic wastewater. Sewage or organic waste from food or fiber processing may be catabolized in a system of constructed ponds where adequate space is available to provide an average waste...
technology - is a natural method for wastewater treatment
Wastewater Treatment
Wastewater treatment may refer to:* Sewage treatment* Industrial wastewater treatment...
.
Technology
Stabilization ponds consist of shallow man-made basins comprising a single or several series of anaerobic, facultative or maturation ponds. The primary treatment takes place in the anaerobic pond, which is mainly designed for removing suspended solidsSuspended solids
Suspended solids refers to small solid particles which remain in suspension in water as a colloid or due to the motion of the water. It is used as one indicator of water quality....
, and some of the soluble element of organic matter (BOD
Biochemical oxygen demand
Biochemical oxygen demand or B.O.D. is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The term also refers to a chemical procedure for...
). During the secondary stage in the facultative pond most of the remaining BOD is removed through the coordinated activity of algae and heterotrophic bacteria. The main function of the tertiary treatment in the maturation pond is the removal of pathogens and nutrients (especially nitrogen).
Application and suitability
Stabilization ponds are particularly well suited for tropical and subtropical countries because the intensity of the sunlight and temperature are key factors for the efficiency of the removal processes. It is also recommended by the WHO for the treatment of wastewater for reuse in agriculture and aquaculture, especially because of its effectiveness in removing nematodes (worms) and helminth eggs.Stabilization ponds, as described here, use no aerators. High-performance lagoon technology with aerators has much more in common with that of activated sludge
Activated sludge
Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoans.-Purpose:...
. Such aerated lagoon
Aerated lagoon
An aerated lagoon or aerated basin is a holding and/or treatment pond provided with artificial aeration to promote the biological oxidation of wastewaters. There are many other biological processes for treatment of wastewaters, for example activated sludge, trickling filters, rotating biological...
s are common in small towns in the United States, among other places.
Cost considerations
According to the IRC International Water and Sanitation Centre, stabilization pond technology is the most cost-effective wastewater treatment technology for the removal of pathogenic micro-organisms. A World Bank study carried out in Sana’a, Yemen, in 1983 makes a detailed economic comparison of waste stabilization ponds, aerated lagoonAerated lagoon
An aerated lagoon or aerated basin is a holding and/or treatment pond provided with artificial aeration to promote the biological oxidation of wastewaters. There are many other biological processes for treatment of wastewaters, for example activated sludge, trickling filters, rotating biological...
s, oxidation ditches and trickling filter
Trickling filter
A trickling filter consists of a fixed bed of rocks, lava, coke, gravel, slag, polyurethane foam, sphagnum peat moss, ceramic, or plastic media over which sewage or other wastewater flows downward and causes a layer of microbial slime to grow, covering the bed of media...
s. According to this study, stabilization pond technology is a cheaper option up to a land cost of US$ 7.8/m2. Above this cost, oxidation ditches become the cheapest option. However, often the main constraint against selecting this technology is not land cost but land availability. If land is available, stabilization ponds have the advantage of very low operating costs since they use no energy compared to other wastewater treatment technologies. This makes them particularly suitable to developing countries where many “conventional” wastewater treatment plants (usually using activated sludge
Activated sludge
Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoans.-Purpose:...
technology) have had to be shut down because water and sewer utilities did not generate sufficient revenue to pay the electricity bill for the plant.
Use
Stabilization ponds are used for municipal waste water treatment in many countries with ample sunshine, including ColombiaWater supply and sanitation in Colombia
Water supply and sanitation in Colombia has been improved in many ways over the past decades. Between 1990 and 2004, access to sanitation increased from 82% to 86%, but access to water increased only slightly from 92% to 93%.. In particular, coverage in rural areas lags behind. Furthermore, despite...
, El Salvador
Water supply and sanitation in El Salvador
Access to water supply and sanitation in El Salvador remains low, despite recent increases in coverage, which leads to negative impacts on productivity and health in particular of the rural poor. Water resources are heavily polluted and the great majority of wastewater is discharged without any...
, Guatemala
Water supply and sanitation in Guatemala
The water supply and sanitation sector in Guatemala is characterized by low and inconsistent service coverage, especially in rural areas; unclear allocation of management responsibilities; and little or no regulation and monitoring of service provision....
, Honduras
Water supply and sanitation in Honduras
Water supply and sanitation coverage in Honduras has increased significantly in the last decades. However, the sector is still characterized by poor service quality and poor efficiency in many places. Coverage gaps still remain, particularly in rural areas....
, Israel
Water supply and sanitation in Israel
Water supply and sanitation in Israel are intricately linked to the historical development of Israel. Because rain falls only in the winter, and largely in the northern part of the country, irrigation and water engineering is vital to the country's economic survival and growth...
, Jordan
Water supply and sanitation in Jordan
Water supply and sanitation in Jordan is characterized by severe water scarcity, which has been exacerbated by forced immigration as a result of the 1948 Arab–Israeli War, the Six-Day War in 1967, the Gulf War of 1990 and the Iraq War of 2003. Jordan is considered as one of the ten most water...
, Morocco
Water supply and sanitation in Morocco
Water supply and sanitation in Morocco is provided by a wide array of utilities. They range from private companies in the largest city, Casablanca, the capital, Rabat, and two other cities, to public municipal utilities in 13 other cities, as well as a national water company...
, Nicaragua
Water supply and sanitation in Nicaragua
Water supply and sanitation in Nicaragua is provided by a national public utility in urban areas and water committees in rural areas. Despite relatively high levels of investment, access to water in urban areas has barely kept up with population growth, access to urban sanitation has actually...
, Tunisia
Water supply and sanitation in Tunisia
Tunisia has achieved the highest access rates to water supply and sanitation services among the MENA countries through sound infrastructure policy. 96% of urban dwellers and 52% of the rural population already have access to improved sanitation. By the end of 2006, the access to safe drinking water...
and Uganda
Water supply and sanitation in Uganda
The Ugandan water supply and sanitation sector has made spectacular progress in urban areas since the mid-1990s, with substantial increases in coverage as well as in operational and commercial performance...
. They are typically used in smaller towns where land availability and cost is less of a constraint. In some cities larger stabilization ponds have been replaced in the early 2000s by activated sludge
Activated sludge
Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoans.-Purpose:...
waste water treatment plants, such as in Amman (Jordan) and in Adelaide (Australia) in 2004.
Removal of pathogens
A study of ten stabilization ponds in Honduras has shown that they were effective in removing helminth eggs, a pathogenPathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
, from the effluent and to satisfy the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
microbiological guidelines for Category B irrigation with wastewater effluent. However, sludge from all ponds was heavily contaminated with helminth eggs.