What is the definition of activated sludge in science?
Activated sludge is a process in sewage treatment in which air or oxygen is forced into sewage liquor to develop a biological floc which reduces the organic content of the sewage.
Which are the three ingredient in activated sludge system?
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 three ingredients in activated sludge system?
What is return sludge?
The recycled sludge in a POTW that is pumped from a secondary clarifier sludge hopper to the aeration tank.
Which is used to remove sludge?
Dewatering decreases sludge liquid volume as much as 90 percent. Digested sludge is put through large centrifuges that work in the same fashion as a washing machine spin cycle. The spinning centrifuge produces a force that separates the majority of the water from the sludge solid, creating a biosolid substance.
How is activated sludge modified for low sludge production?
Implications of conventional activated sludge (CAS) process modification to a low sludge production (LSP) process have been studied for treating pulp and paper wastewaters. The activated sludge process is modified to a two-stage design to establish a microbial food chain that would result in reduced sludge production.
How are microorganisms involved in the activated sludge process?
The principle role microorganisms have in the activated sludge process is to convert dissolved and particulate organic matter, measured as biochemical oxygen demand (BOD), into cell mass. In a conventional activated sludge process, microorganisms use oxygen to break down organic matter (food) for their growth and survival.
What is sludge used for in wastewater treatment?
In the case of wastewater treatment, the sediment is called sludge. This method facilitates the clumping of particles suspended in a liquid, which generally appears as flocs that settle down towards the base of chamber or reactor.
What should the SVI be for activated sludge?
SVI is expressed as the ratio of the volume in milliliters of activated sludge settled from a 1,000-mL sample in 30 minutes divided by the concentration of mixed liquor in milligrams per liter multiplied by 1,000. A good settling sludge (textbook value) is 100, but can commonly be between 80-150.