secondary treatment
Quick Summary
Secondary treatment in sanitation engineering is a crucial stage in wastewater purification, primarily focused on removing soluble organic matter and additional suspended solids that escape primary treatment. This process relies on biological methods where microorganisms consume organic impurities, converting them into carbon dioxide, water, and energy for their own growth.1234
Key biological methods include:
* Trickling filters: Wastewater trickles over a bed of stones, allowing bacteria on the stones to absorb organic matter.1
* Activated sludge process: Microorganisms are suspended in aeration tanks, where they consume organics. The sludge is then separated in a clarifier, with a portion recycled.3
* Oxidation ponds: Large, shallow ponds where natural biological processes occur.2
* Rotating biological contactors: Disks partially submerged in wastewater rotate, allowing a biofilm of bacteria to metabolize impurities.2
Secondary treatment aims to significantly reduce the biochemical oxygen demand (BOD) and suspended solids, typically removing over 85% of both. This stage is vital for protecting the dissolved oxygen balance in receiving water bodies.1234
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- wastewater treatmentWastewater treatment and disposal
…as a first step before secondary treatment. Secondary treatment removes more than 85 percent of both suspended solids and BOD. A minimum level of secondary treatment is usually required in the United States and other developed countries. When more than 85 percent of total solids and BOD must be removed,…
Read More…as a first step before secondary treatment. Secondary treatment removes more than 85 percent of both suspended solids and BOD. A minimum level of secondary treatment is usually required in the United States and other developed countries. When more than 85 percent of total solids and BOD must be removed,…
Read More - wastewater treatmentSecondary treatment
Secondary treatment removes the soluble organic matter that escapes primary treatment. It also removes more of the suspended solids. Removal is usually accomplished by biological processes in which microbes consume the organic impurities as food, converting them into carbon dioxide, water, and energy…
Read MoreSecondary treatment removes the soluble organic matter that escapes primary treatment. It also removes more of the suspended solids. Removal is usually accomplished by biological processes in which microbes consume the organic impurities as food, converting them into carbon dioxide, water, and energy…
Read More