Which organisms are found in the activated sludge?
Activated sludge (AS) is composed of aerobic and anaerobic microorganisms such as bacteria, archaea, fungi, and protists. It is capable of degrading organic compounds, including petroleum products, toluene, and benzopyrene (Seviour and Nielsen, 2010).
How do stalked ciliates eat?
Most stalked ciliates are heterotrophs that feed on small bacteria and other debris. Many stalked ciliate types use their cilia to filter, or sweep in, their food. The cilia then direct this food through the mouth and into the gullet where the vacuoles are then formed for the metabolism process.
Why are ciliates important for wastewater treatment and what does their presence indicate?
Ciliates feed on bacteria, not on dissolved organics. They are usually an indicator of good quality sludge and typically found in young to medium age sludge. They are important because they work with the bacteria in the activated sludge process by feeding on them and helping to clarify the effluent.
What is MCRT in wastewater?
The mean cell residence time or MCRT is the amount of time, in days, that solids or bacteria are maintained in the activated sludge process. The MCRT is known also as the solids retention time (SRT).
Which are the three ingredients in activated sludge systems?
Which are the three ingredients in activated sludge systems? Explanation: The cells need oxygen for their metabolism, air is injected from the bottom of the aerator. The water is well agitated by the rising bubbles and creates good contact between the three ingredients: cells, sewage and oxygen.
Which are the type of microorganism used in active sludge process?
Three most common metazoa found in the activated sludge treatment system. Metazoa images are below: 4. Filamentous bacteria are present when operational conditions drastically change.
What are stalked ciliates?
Stalked ciliates are a type of protozoa that can be branched or unbranched. Stalked ciliates are “inverted bell-shaped bodies mounted on a stalk which is attached to a substratum.” A key identification feature is the presence of cilia (minute hair-like projections) on the oral region of the organism.
What rotifer means?
Rotifers thrive in conditions with plenty of oxygen and are an indicator species for low Biochemical Oxygen Demand (BOD), low toxicity, and stable wastewater systems. They are the most abundant macroinvertebrates in an activated sludge system.
How do some protozoans help in sewage treatment?
Protozoa are one of the most common components in these man-made ecosystems and play an important role in wastewater purification processes. Protozoa are responsible for improving the quality of the effluent, maintaining the density of dispersed bacterial populations by predation.
Is SRT and MCRT the same?
SRT — solids retention time — is sometimes used as a synonym for MCRT. They typically mean the same thing, but they may be calculated using different pieces of data. SRT can be viewed as the total mass of the solids in the treatment system, whereas MCRT is the mass of the bacteria in the system.
How does activated sludge process work elaborate its role in treating wastewater?
The activated sludge process in the treatment of wastewater involves blowing oxygen or air into raw, unsettled sewage. This process smashes the solids. The sewage is bubbled, and sewage liquor is discharged into an activated sludge chamber.