Design One of Combined Biological & Chemical Treatment Process
This schematic design is of Combined Chemical & Biological process for Effluent Treatment Plant with conical bottom chemical batch reaction tank.
In the first step microbial treatment is done by either activated sludge model or granular activated sludge model (depending on effluent character) with the help of Micro Bubble Generator (MBG) & Aspirating Aerator in aeration.
Oil & Grease removal happens by oil skimmer for the floating components as well as by microbial digestion during this phase.
Chemical reaction in the conical bottom treatment tank is helped by a Variable Frequency Drive (VFD) driven mixer, which operates at 150 RPM during coagulation and at 20 RPM during flocculation.
For the batch treatment process calculated chemicals doses are dosed through Venturi.
Cyclonic flash mixer improves chemical process efficiency, whereas Hydrocyclone constantly removes heavy solids during the recirculation flow.
Hydrocyclone separated solids and settled solids during chemical treatment are collected and taken to sludge bed or Filter Press or Decanter Centrifuge as per need and demand of the client.
Supernatant is taken for further biological treatment and treated for at least 24 hours.
During this phase aeration is provided by the Aspirating Aerator.
Floated sludge is separated by Micro Bubble Floatation (MBF) unit and the under-drawn clarified effluent is held in an intermediate holding tank before filtration.
Pre-filtration is done before the Hollow Fiber Ultra Filtration (UF) Membrane Assembly Unit by crossflow arrangement to reduce fouling.
UF modules are selected according to the task of the particular project and are made from PVDF, PP, PVC materials.
For specific need, ceramic membranes are also used.
Submerged Membrane Bio Reactor (MBR) can be used in biological treatment chambers replacing those two phases mentioned earlier with much better efficiency, if the budget of the client so permits.
Although generally crossflow and outside to in formation for the UF membranes is selected, in specific cases tubular membranes are also used.
Treated effluent is then polished by Activated Carbon Filter.
Additional Specialty Resin Filters are used before or after the Activated Carbon Filter to remove some specific soluble pollutant when that is the demand of the project.