Changes

sys2=[[Blackwater Treatment System with Infiltration|56]]|sys3=[[Blackwater Treatment System with SewerageEffluent Transport|67]]|sys4=[[Blackwater Transport to (Semi-) Centralized Treatment System |78]]|sys5=[[Sewerage System with Urine Diversion|89]]|

Input1=Blackwater|Input2=Greywater |Input3= Brownwater | Input4= Effluent |Input5=|Output1= Faecal Sludge | Output2=Effluent | Output3= | Output4= | Output5=

'''An Aerated Pond aerated pond is a large, outdoormixed, mixed aerobic reactor. Mechanical aerators provide oxygen and keep the aerobic organisms suspended and mixed with the water to achieve a high rate of organic degradation and nutrient removal.'''

Increased mixing and aeration from the mechanical units means that the ponds can be deeper and can tolerate much higher organic loads than a maturation pond. The increased aeration allows for increased degradation and increased pathogen removal. As well, because oxygen is introduced by the mechanical units and not by light-driven photosynthesis, the ponds can function in more northern climates. Influent should be screened and pre-treated to remove garbage and coarse particles that could interfere with the aerators. Because the aeration units mix the pond, a subsequent settling tank is required to separate the effluent from the solids.

The smaller area requirement (compared ===Design Considerations=== Influent should be screened and pre-treated to remove garbage and coarse particles that could interfere with the aerators. Because the aeration units mix the pond, a maturation pond) means that it subsequent settling tank is appropriate for both rural, and peri-urban environmentsrequired to separate the effluent from the solids.

The pond should be built to a depth of 2 to 5m 5 m and should have a detention time of 3 to 20 days, depending on the treatment target. To prevent leaching, the pond should have a liner. The liner This can be made from clay, asphalt, compacted earth, or another any other impervious material. Using the fill that is excavated, a A protective berm should be built around the pond , using the fill that is excavated, to protect it from runoff and erosion.

- Good resistance against Resistant to organic and hydraulic shock loading. loads <br> - High reduction in of BOD and pathogens. <br> - Construction can provide short-term employment to local labourers. <br> - Requires large land area. <br> - Long service life. <br> - No real problems with insects or odours if designed and maintained correctly. | con=- Effluent/sludge requires secondary treatment and/or appropriate discharge. Requires a large land area <br>- High energy consumption, a constant source of electricity is required <br> - Requires expert design High capital and operating costs depending on the price of land and construction supervision. of electricity <br> - Requires full time operation and maintenance by skilled personnel. <br> - Not all parts and materials may be locally available locally. <br> - Constant source of electricity is required. Requires expert design and construction <br> - Moderate-high capital Sludge and possibly effluent require further treatment and variable operating costs depending on the price of land, electricity. /or appropriate discharge

===AdequacyAppropriateness===A mechanically aerated pond can efficiently handle concentrated influent and significantly reduce pathogen levels. It is especially important that electricity service is uninterrupted and that replacement parts are available to prevent extended downtimes that may cause the pond to turn anaerobic.

A mechanically aerated pond Aerated ponds can efficiently handle high concentration influent be used in both rural and can reduce pathogen levels significantlyperi-urban environments. It is especially important that electricity service is uninterrupted They are most appropriate for regions with large areas of inexpensive land located away from homes and that replacement parts are available to prevent extended downtimes that may cause the pond to turn anaerobicbusinesses. Aerated lagoons can function in a larger range of climates than [[Waste Stabilization Pond|WSPs]]Ponds (T. They are most appropriate for regions with large areas of inexpensive lands that are away from homes 5) and businessesthe area requirement is smaller compared to a maturation pond.

===Health Aspects/Acceptance=== The pond is a large expanse of pathogenic wastewater; care must be taken to ensure that no one comes in contact with, or goes into the water. The aeration units can be dangerous to humans and animals. Fences, signage, or other measures should be taken to prevent entry to the area. ===Maintenance=== A permanent skilled staff is required to repair and maintain aeration machinery. The pond must be desludged once every 2 to 5 years. Care should be taken to ensure that the pond is not used as a garbage dump, especially considering the damage that could be done to the aeration equipment.

* Arthur, JP. (1983). Notes on the Design and Operation of Waste Stabilization Ponds in Warm Climates of Developing Countries. The World Bank + UNDP, Washington. (Notes on applicability and effectiveness.) * Crites, R. and Tchobanoglous, G. (1998). Small and Decentralized Wastewater Management Systems. WCB and /McGraw-Hill, New York, USAUS. pp 527–558. 527-558. (Comprehensive summary chapter.)

* Tchobanoglous, G., Burton, FLF. L. and Stensel, HDH. D. (20032004). Wastewater Engineering: Treatment and Reuse, 4th Edition. Metcalf & Eddy, 4th Ed. (Internat. Ed.). McGraw-Hill, New York, US. pp 840–85. 840-854. (Detailed design and example problems.)